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Ramos-Alvarez I, Jensen RT. The Important Role of p21-Activated Kinases in Pancreatic Exocrine Function. BIOLOGY 2025; 14:113. [PMID: 40001881 PMCID: PMC11851965 DOI: 10.3390/biology14020113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2024] [Revised: 01/10/2025] [Accepted: 01/15/2025] [Indexed: 02/27/2025]
Abstract
The p21-activated kinases (PAKs) are a conserved family of serine/threonine protein kinases, which are effectors for the Rho family GTPases, namely, Rac/Cdc42. PAKs are divided into two groups: group I (PAK1-3) and group II (PAK4-6). Both groups of PAKs have been well studied in apoptosis, protein synthesis, glucose homeostasis, growth (proliferation and survival) and cytoskeletal regulation, as well as in cell motility, proliferation and cycle control. However, little is known about the role of PAKs in the secretory tissues, including in exocrine tissue, such as the exocrine pancreas (except for islet function and pancreatic cancer growth). Recent studies have provided insights supporting the importance of PAKs in exocrine pancreas. This review summarizes the recent insights into the importance of PAKs in the exocrine pancreas by reviewing their presence and activation; the ability of GI hormones/neurotransmitters/GFs/post-receptor activators to activate them; the kinetics of their activation; the participation of exocrine-tissue PAKs in activating the main growth-signaling cascade; their roles in the stimulation of enzyme secretion; finally, their roles in pancreatitis. These insights suggest that PAKs could be more important in exocrine/secretory tissues than currently appreciated and that their roles should be explored in more detail in the future.
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Affiliation(s)
| | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20812-1804, USA;
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Khozooei S, Veerappan S, Toulany M. YB-1 activating cascades as potential targets in KRAS-mutated tumors. Strahlenther Onkol 2023; 199:1110-1127. [PMID: 37268766 DOI: 10.1007/s00066-023-02092-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/23/2023] [Indexed: 06/04/2023]
Abstract
Y‑box binding protein‑1 (YB-1) is a multifunctional protein that is highly expressed in human solid tumors of various entities. Several cellular processes, e.g. cell cycle progression, cancer stemness and DNA damage signaling that are involved in the response to chemoradiotherapy (CRT) are tightly governed by YB‑1. KRAS gene with about 30% mutations in all cancers, is considered the most commonly mutated oncogene in human cancers. Accumulating evidence indicates that oncogenic KRAS mediates CRT resistance. AKT and p90 ribosomal S6 kinase are downstream of KRAS and are the major kinases that stimulate YB‑1 phosphorylation. Thus, there is a close link between the KRAS mutation status and YB‑1 activity. In this review paper, we highlight the importance of the KRAS/YB‑1 cascade in the response of KRAS-mutated solid tumors to CRT. Likewise, the opportunities to interfere with this pathway to improve CRT outcome are discussed in light of the current literature.
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Affiliation(s)
- Shayan Khozooei
- Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, Tuebingen, Germany
| | - Soundaram Veerappan
- Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, Tuebingen, Germany
| | - Mahmoud Toulany
- Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, Tuebingen, Germany.
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3
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Kichina JV, Maslov A, Kandel ES. PAK1 and Therapy Resistance in Melanoma. Cells 2023; 12:2373. [PMID: 37830586 PMCID: PMC10572217 DOI: 10.3390/cells12192373] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/23/2023] [Accepted: 09/27/2023] [Indexed: 10/14/2023] Open
Abstract
Malignant melanoma claims more lives than any other skin malignancy. While primary melanomas are usually cured via surgical excision, the metastatic form of the disease portents a poor prognosis. Decades of intense research has yielded an extensive armamentarium of anti-melanoma therapies, ranging from genotoxic chemo- and radiotherapies to targeted interventions in specific signaling pathways and immune functions. Unfortunately, even the most up-to-date embodiments of these therapies are not curative for the majority of metastatic melanoma patients, and the need to improve their efficacy is widely recognized. Here, we review the reports that implicate p21-regulated kinase 1 (PAK1) and PAK1-related pathways in the response of melanoma to various therapeutic modalities. Ample data suggest that PAK1 may decrease cell sensitivity to programmed cell death, provide additional stimulation to growth-promoting molecular pathways, and contribute to the creation of an immunosuppressive tumor microenvironment. Accordingly, there is mounting evidence that the concomitant inhibition of PAK1 enhances the potency of various anti-melanoma regimens. Overall, the available information suggests that a safe and effective inhibition of PAK1-dependent molecular processes would enhance the potency of the currently available anti-melanoma treatments, although considerable challenges in implementing such strategies still exist.
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Affiliation(s)
- Julia V. Kichina
- Department of Immunology, Roswell Park Comprehensive Cancer Center, Elm & Carlton St., Buffalo, NY 14263, USA
| | - Alexei Maslov
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton St., Buffalo, NY 14263, USA
| | - Eugene S. Kandel
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton St., Buffalo, NY 14263, USA
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Balakrishnan R, Garcia PA, Veluthakal R, Huss JM, Hoolachan JM, Thurmond DC. Toward Ameliorating Insulin Resistance: Targeting a Novel PAK1 Signaling Pathway Required for Skeletal Muscle Mitochondrial Function. Antioxidants (Basel) 2023; 12:1658. [PMID: 37759961 PMCID: PMC10525748 DOI: 10.3390/antiox12091658] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 09/29/2023] Open
Abstract
The p21-activated kinase 1 (PAK1) is required for insulin-stimulated glucose uptake in skeletal muscle cells. However, whether PAK1 regulates skeletal muscle mitochondrial function, which is a central determinant of insulin sensitivity, is unknown. Here, the effect of modulating PAK1 levels (knockdown via siRNA, overexpression via adenoviral transduction, and/or inhibition of activation via IPA3) on mitochondrial function was assessed in normal and/or insulin-resistant rat L6.GLUT4myc and human muscle (LHCN-M2) myotubes. Human type 2 diabetes (T2D) and non-diabetic (ND) skeletal muscle samples were also used for validation of the identified signaling elements. PAK1 depletion in myotubes decreased mitochondrial copy number, respiration, altered mitochondrial structure, downregulated PGC1α (a core regulator of mitochondrial biogenesis and oxidative metabolism) and PGC1α activators, p38 mitogen-activated protein kinase (p38MAPK) and activating transcription factor 2 (ATF2). PAK1 enrichment in insulin-resistant myotubes improved mitochondrial function and rescued PGC1α expression levels. Activated PAK1 was localized to the cytoplasm, and PAK1 enrichment concurrent with p38MAPK inhibition did not increase PGC1α levels. PAK1 inhibition and enrichment also modified nuclear phosphorylated-ATF2 levels. T2D human samples showed a deficit for PGC1α, and PAK1 depletion in LHCN-M2 cells led to reduced mitochondrial respiration. Overall, the results suggest that PAK1 regulates muscle mitochondrial function upstream of the p38MAPK/ATF2/PGC1α-axis pathway.
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Affiliation(s)
- Rekha Balakrishnan
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Pablo A. Garcia
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Janice M. Huss
- School of Medicine, Washington University, 660 S Euclid Ave, St. Louis, MO 63110, USA;
| | - Joseph M. Hoolachan
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
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Somanath PR, Chernoff J, Cummings BS, Prasad SM, Homan HD. Targeting P21-Activated Kinase-1 for Metastatic Prostate Cancer. Cancers (Basel) 2023; 15:2236. [PMID: 37190165 PMCID: PMC10137274 DOI: 10.3390/cancers15082236] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/06/2023] [Accepted: 04/09/2023] [Indexed: 05/17/2023] Open
Abstract
Metastatic prostate cancer (mPCa) has limited therapeutic options and a high mortality rate. The p21-activated kinase (PAK) family of proteins is important in cell survival, proliferation, and motility in physiology, and pathologies such as infectious, inflammatory, vascular, and neurological diseases as well as cancers. Group-I PAKs (PAK1, PAK2, and PAK3) are involved in the regulation of actin dynamics and thus are integral for cell morphology, adhesion to the extracellular matrix, and cell motility. They also play prominent roles in cell survival and proliferation. These properties make group-I PAKs a potentially important target for cancer therapy. In contrast to normal prostate and prostatic epithelial cells, group-I PAKs are highly expressed in mPCA and PCa tissue. Importantly, the expression of group-I PAKs is proportional to the Gleason score of the patients. While several compounds have been identified that target group-I PAKs and these are active in cells and mice, and while some inhibitors have entered human trials, as of yet, none have been FDA-approved. Probable reasons for this lack of translation include issues related to selectivity, specificity, stability, and efficacy resulting in side effects and/or lack of efficacy. In the current review, we describe the pathophysiology and current treatment guidelines of PCa, present group-I PAKs as a potential druggable target to treat mPCa patients, and discuss the various ATP-competitive and allosteric inhibitors of PAKs. We also discuss the development and testing of a nanotechnology-based therapeutic formulation of group-I PAK inhibitors and its significant potential advantages as a novel, selective, stable, and efficacious mPCa therapeutic over other PCa therapeutics in the pipeline.
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Affiliation(s)
- Payaningal R. Somanath
- Department of Clinical & Administrative Pharmacy, College of Pharmacy, University of Georgia, Augusta, GA 30912, USA
- MetasTx LLC, Basking Ridge, NJ 07920, USA
| | - Jonathan Chernoff
- MetasTx LLC, Basking Ridge, NJ 07920, USA
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Brian S. Cummings
- MetasTx LLC, Basking Ridge, NJ 07920, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Sandip M. Prasad
- Morristown Medical Center, Atlantic Health System, Morristown, NJ 07960, USA
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Qiu X, Xu H, Wang K, Gao F, Xu X, He H. P-21 Activated Kinases in Liver Disorders. Cancers (Basel) 2023; 15:cancers15020551. [PMID: 36672500 PMCID: PMC9857091 DOI: 10.3390/cancers15020551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
The p21 Activated Kinases (PAKs) are serine threonine kinases and play important roles in many biological processes, including cell growth, survival, cytoskeletal organization, migration, and morphology. Recently, PAKs have emerged in the process of liver disorders, including liver cancer, hepatic ischemia-reperfusion injury, hepatitis, and liver fibrosis, owing to their effects in multiple signaling pathways in various cell types. Activation of PAKs promotes liver cancer growth and metastasis and contributes to the resistance of liver cancer to radiotherapy and chemotherapy, leading to poor survival of patients. PAKs also play important roles in the development and progression of hepatitis and other pathological processes of the liver such as fibrosis and ischemia-reperfusion injury. In this review, we have summarized the currently available studies about the role of PAKs in liver disorders and the mechanisms involved, and further explored the potential therapeutic application of PAK inhibitors in liver disorders, with the aim to provide a comprehensive overview on current progress and perspectives of PAKs in liver disorders.
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Affiliation(s)
- Xun Qiu
- Key Laboratory of Integrated Oncology and Intelligent Medicine of Zhejiang Province, Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
- Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Hanzhi Xu
- Key Laboratory of Integrated Oncology and Intelligent Medicine of Zhejiang Province, Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
- Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Kai Wang
- Key Laboratory of Integrated Oncology and Intelligent Medicine of Zhejiang Province, Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China
- Correspondence: (K.W.); (H.H.)
| | - Fengqiang Gao
- Key Laboratory of Integrated Oncology and Intelligent Medicine of Zhejiang Province, Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
- Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Xiao Xu
- Zhejiang University School of Medicine, Hangzhou 310058, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China
- Key Laboratory of Integrated Oncology and Intelligent Medicine of Zhejiang Province, Hangzhou 310006, China
| | - Hong He
- Department of Surgery, University of Melbourne, Austin Health, 145 Studley Rd., Heidelberg, VIC 3084, Australia
- Correspondence: (K.W.); (H.H.)
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Chan CH, Chiou LW, Lee TY, Liu YR, Hsieh TH, Yang CY, Jeng YM. PAK and PI3K pathway activation confers resistance to KRAS G12C inhibitor sotorasib. Br J Cancer 2023; 128:148-159. [PMID: 36319849 PMCID: PMC9814377 DOI: 10.1038/s41416-022-02032-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND KRAS is a frequently mutated oncogene in human cancer. Clinical studies on the covalent inhibitors of the KRASG12C mutant have reported promising results. However, primary and acquired resistance may limit their clinical use. METHODS Sotorasib-resistant cell lines were established. We explored the signalling pathways activated in these resistant cell lines and their roles in sotorasib resistance. RESULTS The resistant cells exhibited increased cell-matrix adhesion with increased levels of stress fibres and focal adherens. p21-activated kinases (PAKs) were activated in resistant cells, which phosphorylate MEK at serine 298 of MEK and serine 338 of c-Raf to activate the mitogen-activated protein kinase pathway. The PAK inhibitors FRAX597 and FRAX486 in synergy with sotorasib reduced the viability of KRASG12C mutant cancer cells. Furthermore, the PI3K/AKT pathway was constitutively active in sotorasib-resistant cells. The overexpression of constitutively activated PI3K or the knockdown of PTEN resulted in resistance to sotorasib. PI3K inhibitor alpelisib was synergistic with sotorasib in compromising the viability of KRASG12C mutant cancer cells. Moreover, PI3K and PAK pathways formed a mutual positive regulatory loop that mediated sotorasib resistance. CONCLUSIONS Our results indicate that the cell-matrix interaction-dependent activation of PAK mediates resistance to sotorasib through the activation of MAPK and PI3K pathways.
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Affiliation(s)
- Chien-Hui Chan
- Graduate Institute of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Li-Wen Chiou
- Graduate Institute of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Tsai-Yu Lee
- Graduate Institute of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yun-Ru Liu
- Joint Biobank, Office of Human Research, Taipei Medical University, Taipei, Taiwan
| | - Tsung-Han Hsieh
- Joint Biobank, Office of Human Research, Taipei Medical University, Taipei, Taiwan
| | - Ching-Yao Yang
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
- Department of Surgery, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | - Yung-Ming Jeng
- Graduate Institute of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan.
- Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan.
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Xu H, Wang D, Ramponi C, Wang X, Zhang H. The P21-Activated Kinase 1 and 2 As Potential Therapeutic Targets for the Management of Cardiovascular Disease. INTERNATIONAL JOURNAL OF DRUG DISCOVERY AND PHARMACOLOGY 2022:5. [PMID: 39899001 PMCID: PMC7617276 DOI: 10.53941/ijddp.v1i1.179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2025]
Abstract
Group I p21-activated kinases (Paks) are members of the serine/threonine protein kinase family. Paks are encoded by three genes (Pak 1 - 3) and are involved in the regulation of various biological processes. Pak1 and Pak2 are key members, sharing 91% sequence identity in their kinase domains. Recent studies have shown that Pak1/2 protect the heart from various types of stresses. Activated Pak1/2 participate in the maintenance of cellular homeostasis and metabolism, thus enhancing the adaptation and resilience of cardiomyocytes to stress. The structure, activation and function of Pak1/2 as well as their protective roles against the occurrence of cardiovascular disease are described in this review. The values of Pak1/2 as therapeutic targets are also discussed.
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Affiliation(s)
- Honglin Xu
- Michael Smith building, Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Dingwei Wang
- Michael Smith building, Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Chiara Ramponi
- Michael Smith building, Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Xin Wang
- Michael Smith building, Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Hongyuan Zhang
- Michael Smith building, Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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Zhou S, Zhu J, Zhou PK, Gu Y. Alveolar type 2 epithelial cell senescence and radiation-induced pulmonary fibrosis. Front Cell Dev Biol 2022; 10:999600. [PMID: 36407111 PMCID: PMC9666897 DOI: 10.3389/fcell.2022.999600] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/24/2022] [Indexed: 11/24/2022] Open
Abstract
Radiation-induced pulmonary fibrosis (RIPF) is a chronic and progressive respiratory tract disease characterized by collagen deposition. The pathogenesis of RIPF is still unclear. Type 2 alveolar epithelial cells (AT2), the essential cells that maintain the structure and function of lung tissue, are crucial for developing pulmonary fibrosis. Recent studies indicate the critical role of AT2 cell senescence during the onset and progression of RIPF. In addition, clearance of senescent AT2 cells and treatment with senolytic drugs efficiently improve lung function and radiation-induced pulmonary fibrosis symptoms. These findings indicate that AT2 cell senescence has the potential to contribute significantly to the innovative treatment of fibrotic lung disorders. This review summarizes the current knowledge from basic and clinical research about the mechanism and functions of AT2 cell senescence in RIPF and points to the prospects for clinical treatment by targeting senescent AT2 cells.
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Affiliation(s)
- Shenghui Zhou
- Hengyang Medical College, University of South China, Hengyang, China,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, AMMS, Beijing, China
| | - Jiaojiao Zhu
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, AMMS, Beijing, China
| | - Ping-Kun Zhou
- Hengyang Medical College, University of South China, Hengyang, China,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, AMMS, Beijing, China,*Correspondence: Yongqing Gu, ; Ping-Kun Zhou,
| | - Yongqing Gu
- Hengyang Medical College, University of South China, Hengyang, China,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, AMMS, Beijing, China,*Correspondence: Yongqing Gu, ; Ping-Kun Zhou,
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Lakshmanan S, Rajendran R, Jayagandhi S, Rajendran R, Palanisamy T, Manimaran V, Janani Marianne A. Expression of Marker PAK1 in Sinonasal Polyposis. Indian J Otolaryngol Head Neck Surg 2022; 74:1694-1700. [PMID: 36452523 PMCID: PMC9702192 DOI: 10.1007/s12070-021-02822-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/15/2021] [Indexed: 10/20/2022] Open
Abstract
Introduction Chronic rhinosinusitis with nasal polyposis involves mucosal lining of nose and paranasal sinuses. Numerous studies studied the mechanism leading to sinonasal polyposis. We attempted study the inflammatory mechanisms responsible for the recruitment and activation of leukocytes. Aim To study and compare the expression of the immunohistochemistry marker PAK1 in sinonasal polyposis and normal nasal mucosa. Material and Methods Prospective observational study done by comparing two groups of 30 each with Group A comprises Sinonasal polyposis and Group B comprises normal nasal mucosa. The specimens were subjected to PAK1 immunohistochemical staining. Results Immunihistrochemical staining showed higher intensity stain in sinonasal polyp when compared to normal nasal mucosa. Conclusion The upregulation of PAK1 in sinonasal polyposis when compared to normal nasal mucosa may indicate an increased cellular proliferation and turnover in the background of chronic inflammation.
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Affiliation(s)
- Somu Lakshmanan
- Department of ENT and Head and Neck Surgery, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, Tamil Nadu India
| | | | - Sathishkumar Jayagandhi
- Department of ENT and Head and Neck Surgery, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, Tamil Nadu India
| | | | - Thirunavukarasu Palanisamy
- Department of ENT and Head and Neck Surgery, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, Tamil Nadu India
| | - Vinoth Manimaran
- Department of ENT and Head and Neck Surgery, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, Tamil Nadu India
| | - A. Janani Marianne
- Department of ENT and Head and Neck Surgery, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, Tamil Nadu India
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A kinase inhibitor screen reveals MEK1/2 as a novel therapeutic target to antagonize IGF1R-mediated antiestrogen resistance in ERα-positive luminal breast cancer. Biochem Pharmacol 2022; 204:115233. [PMID: 36041543 DOI: 10.1016/j.bcp.2022.115233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/23/2022]
Abstract
Antiestrogen resistance of breast cancer has been related to enhanced growth factor receptor expression and activation. We have previously shown that ectopic expression and subsequent activation of the insulin-like growth factor-1 receptor (IGF1R) or the epidermal growth factor receptor (EGFR) in MCF7 or T47D breast cancer cells results in antiestrogen resistance. In order to identify novel therapeutic targets to prevent this antiestrogen resistance, we performed kinase inhibitor screens with 273 different inhibitors in MCF7 cells overexpressing IGF1R or EGFR. Kinase inhibitors that antagonized antiestrogen resistance but are not directly involved in IGF1R or EGFR signaling were prioritized for further analyses. Various ALK (anaplastic lymphoma receptor tyrosine kinase) inhibitors inhibited cell proliferation in IGF1R expressing cells under normal and antiestrogen resistance conditions by preventing IGF1R activation and subsequent downstream signaling; the ALK inhibitors did not affect EGFR signaling. On the other hand, MEK (mitogen-activated protein kinase kinase)1/2 inhibitors, including PD0325901, selumetinib, trametinib and TAK733, selectively antagonized IGF1R signaling-mediated antiestrogen resistance but did not affect cell proliferation under normal growth conditions. RNAseq analysis revealed that MEK inhibitors PD0325901 and selumetinib drastically altered cell cycle progression and cell migration networks under IGF1R signaling-mediated antiestrogen resistance. In a group of 219 patients with metastasized ER+ breast cancer, strong pMEK staining showed a significant correlation with no clinical benefit of first-line tamoxifen treatment. We propose a critical role for MEK activation in IGF1R signaling-mediated antiestrogen resistance and anticipate that dual-targeted therapy with a MEK inhibitor and antiestrogen could improve treatment outcome.
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Saldivar-Cerón HI, Villamar-Cruz O, Wells CM, Oguz I, Spaggiari F, Chernoff J, Patiño-López G, Huerta-Yepez S, Montecillo-Aguado M, Rivera-Pazos CM, Loza-Mejía MA, Vivar-Sierra A, Briseño-Díaz P, Zentella-Dehesa A, Leon-Del-Rio A, López-Saavedra A, Padierna-Mota L, Ibarra-Sánchez MDJ, Esparza-López J, Hernández-Rivas R, Arias-Romero LE. p21-Activated Kinase 1 Promotes Breast Tumorigenesis via Phosphorylation and Activation of the Calcium/Calmodulin-Dependent Protein Kinase II. Front Cell Dev Biol 2022; 9:759259. [PMID: 35111748 PMCID: PMC8802317 DOI: 10.3389/fcell.2021.759259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 12/07/2021] [Indexed: 12/22/2022] Open
Abstract
p21-Activated kinase-1 (Pak1) is frequently overexpressed and/or amplified in human breast cancer and is necessary for transformation of mammary epithelial cells. Here, we show that Pak1 interacts with and phosphorylates the Calcium/Calmodulin-dependent Protein Kinase II (CaMKII), and that pharmacological inhibition or depletion of Pak1 leads to diminished activity of CaMKII. We found a strong correlation between Pak1 and CaMKII expression in human breast cancer samples, and combined inhibition of Pak1 and CaMKII with small-molecule inhibitors was synergistic and induced apoptosis more potently in Her2 positive and triple negative breast cancer (TNBC) cells. Co-adminstration of Pak and CaMKII small-molecule inhibitors resulted in a dramatic reduction of proliferation and an increase in apoptosis in a 3D cell culture setting, as well as an impairment in migration and invasion of TNBC cells. Finally, mice bearing xenografts of TNBC cells showed a significant delay in tumor growth when treated with small-molecule inhibitors of Pak and CaMKII. These data delineate a signaling pathway from Pak1 to CaMKII that is required for efficient proliferation, migration and invasion of mammary epithelial cells, and suggest new therapeutic strategies in breast cancer.
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Affiliation(s)
- Héctor I Saldivar-Cerón
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Mexico.,Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
| | - Olga Villamar-Cruz
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Mexico
| | - Claire M Wells
- Division of Cancer Studies, New Hunts House, Guy's Campus, King's College London, London, United Kingdom
| | - Ibrahim Oguz
- Division of Cancer Studies, New Hunts House, Guy's Campus, King's College London, London, United Kingdom
| | - Federica Spaggiari
- Division of Cancer Studies, New Hunts House, Guy's Campus, King's College London, London, United Kingdom
| | - Jonathan Chernoff
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Genaro Patiño-López
- Laboratorio de Investigación en Inmunología y Proteómica, Hospital Infantil de México, Mexico City, Mexico
| | - Sara Huerta-Yepez
- Unidad de Investigación en Enfermedades Hemato-Oncológicas, Hospital Infantil de México Federico Gómez, Mexico City, Mexico
| | - Mayra Montecillo-Aguado
- Unidad de Investigación en Enfermedades Hemato-Oncológicas, Hospital Infantil de México Federico Gómez, Mexico City, Mexico
| | - Clara M Rivera-Pazos
- Unidad de Investigación en Enfermedades Hemato-Oncológicas, Hospital Infantil de México Federico Gómez, Mexico City, Mexico
| | - Marco A Loza-Mejía
- Facultad de Ciencias Químicas, Universidad La Salle-México, Mexico City, Mexico
| | - Alonso Vivar-Sierra
- Facultad de Ciencias Químicas, Universidad La Salle-México, Mexico City, Mexico
| | - Paola Briseño-Díaz
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
| | - Alejandro Zentella-Dehesa
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, UNAM, Mexico City, Mexico.,Unidad de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), Mexico City, Mexico
| | - Alfonso Leon-Del-Rio
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, UNAM, Mexico City, Mexico
| | - Alejandro López-Saavedra
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, UNAM, Mexico City, Mexico
| | - Laura Padierna-Mota
- UNe Aplicaciones Biológicas, Laboratorios de Especialidades Inmunologicas, Mexico City, Mexico
| | - María de Jesús Ibarra-Sánchez
- Unidad de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), Mexico City, Mexico
| | - José Esparza-López
- Unidad de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), Mexico City, Mexico
| | - Rosaura Hernández-Rivas
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
| | - Luis E Arias-Romero
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Mexico
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13
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p21-Activated kinase 1 (PAK1) in aging and longevity: An overview. Ageing Res Rev 2021; 71:101443. [PMID: 34390849 DOI: 10.1016/j.arr.2021.101443] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/26/2021] [Accepted: 08/10/2021] [Indexed: 02/08/2023]
Abstract
The p21-activated kinases (PAKs) belong to serine/threonine kinases family, regulated by ∼21 kDa small signaling G proteins RAC1 and CDC42. The mammalian PAK family comprises six members (PAK1-6) that are classified into two groups (I and II) based on their domain architecture and regulatory mechanisms. PAKs are implicated in a wide range of cellular functions. PAK1 has recently attracted increasing attention owing to its involvement in oncogenesis, tumor progression, and metastasis as well as several life-limiting diseases and pathological conditions. In Caenorhabditis elegans, PAK1 functions limit the lifespan under basal conditions by inhibiting forkhead transcription factor DAF-16. Interestingly, PAK depletion extended longevity and attenuated the onset of age-related phenotypes in a premature-aging mouse model and delayed senescence in mammalian fibroblasts. These observations implicate PAKs as not only oncogenic but also aging kinases. Therefore, PAK-targeting genetic and/or pharmacological interventions, particularly PAK1-targeting, could be a viable strategy for developing cancer therapies with relatively no side effects and promoting healthy longevity. This review describes PAK family proteins, their biological functions, and their role in regulating aging and longevity using C. elegans. Moreover, we discuss the effect of small-molecule PAK1 inhibitors on the lifespan and healthspan of C. elegans.
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14
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Hawley E, Gehlhausen J, Karchugina S, Chow HY, Araiza-Olivera D, Radu M, Smith A, Burks C, Jiang L, Li X, Bessler W, Masters A, Edwards D, Burgin C, Jones D, Yates C, Clapp DW, Chernoff J, Park SJ. PAK1 inhibition reduces tumor size and extends the lifespan of mice in a genetically engineered mouse model of Neurofibromatosis Type 2 (NF2). Hum Mol Genet 2021; 30:1607-1617. [PMID: 34075397 DOI: 10.1093/hmg/ddab106] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
Neurofibromatosis Type II (NF2) is an autosomal dominant cancer predisposition syndrome in which germline haploinsufficiency at the NF2 gene confers a greatly increased propensity for tumor development arising from tissues of neural crest derived origin. NF2 encodes the tumor suppressor, Merlin, and its biochemical function is incompletely understood. One well established function of Merlin is as a negative regulator of group A serine/threonine p21 activated kinases (PAKs). In these studies we explore the role of PAK1 and its closely related paralog, PAK2, both pharmacologically and genetically, in Merlin deficient Schwann cells and in a genetically engineered mouse model (GEMM) that develops spontaneous vestibular and spinal schwannomas. We demonstrate that PAK1 and PAK2 are both hyper activated in Merlin deficient murine schwannomas. In preclinical trials, a pan Group A PAK inhibitor, FRAX-1036, transiently reduced PAK1 and PAK2 phosphorylation in vitro, but had insignificant efficacy in vivo. NVS-PAK1-1, a PAK1 selective inhibitor, had a greater but still minimal effect on our GEMM phenotype. However, genetic ablation of Pak1 but not Pak2 reduced tumor formation in our NF2 GEMM. Moreover, germline genetic deletion of Pak1 was well tolerated while conditional deletion of Pak2 in Schwann cells resulted in significant morbidity and mortality. These data support the further development of PAK1-specific small molecule inhibitors and the therapeutic targeting of PAK1 in vestibular schwannomas and argue against PAK1 and PAK2 existing as functionally redundant protein isoforms in Schwann cells.
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Affiliation(s)
- Eric Hawley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jeffrey Gehlhausen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Sofiia Karchugina
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Hoi-Yee Chow
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | | | - Maria Radu
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Abbi Smith
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ciersten Burks
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Li Jiang
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Xiaohong Li
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Waylan Bessler
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Andrea Masters
- Clinical Pharmacology Analytical Core, Indiana University School of Medicine, Indianapolis, Indiana
| | - Donna Edwards
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Callie Burgin
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - David Jones
- Clinical Pharmacology Analytical Core, Indiana University School of Medicine, Indianapolis, Indiana
| | - Charles Yates
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana
| | - D Wade Clapp
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jonathan Chernoff
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Su-Jung Park
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
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15
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Bautista L, Knippler CM, Ringel MD. p21-Activated Kinases in Thyroid Cancer. Endocrinology 2020; 161:bqaa105. [PMID: 32609833 PMCID: PMC7417880 DOI: 10.1210/endocr/bqaa105] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/24/2020] [Indexed: 02/07/2023]
Abstract
The family of p21-activated kinases (PAKs) are oncogenic proteins that regulate critical cellular functions. PAKs play central signaling roles in the integrin/CDC42/Rho, ERK/MAPK, PI3K/AKT, NF-κB, and Wnt/β-catenin pathways, functioning both as kinases and scaffolds to regulate cell motility, mitosis and proliferation, cytoskeletal rearrangement, and other cellular activities. PAKs have been implicated in both the development and progression of a wide range of cancers, including breast cancer, pancreatic melanoma, thyroid cancer, and others. Here we will discuss the current knowledge on the structure and biological functions of both group I and group II PAKs, as well as the roles that PAKs play in oncogenesis and progression, with a focus on thyroid cancer and emerging data regarding BRAF/PAK signaling.
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Affiliation(s)
- Luis Bautista
- Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, and Cancer Biology Program, The Ohio State University College of Medicine and Arthur G. James Comprehensive Cancer Center, Columbus, Ohio
| | - Christina M Knippler
- Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, and Cancer Biology Program, The Ohio State University College of Medicine and Arthur G. James Comprehensive Cancer Center, Columbus, Ohio
- Department of Hematology and Medical Oncology, Emory University and Winship Cancer Institute, Atlanta, Georgia
| | - Matthew D Ringel
- Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, and Cancer Biology Program, The Ohio State University College of Medicine and Arthur G. James Comprehensive Cancer Center, Columbus, Ohio
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16
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Kanumuri R, Saravanan R, Pavithra V, Sundaram S, Rayala SK, Venkatraman G. Current trends and opportunities in targeting p21 activated kinase-1(PAK1) for therapeutic management of breast cancers. Gene 2020; 760:144991. [PMID: 32717309 DOI: 10.1016/j.gene.2020.144991] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/18/2020] [Accepted: 07/21/2020] [Indexed: 12/24/2022]
Abstract
Breast cancer is the most frequently diagnosed cancer in women worldwide. Identifying reliable biomarkers and druggable molecular targets pose to be a significant quest in breast cancer research. p21-activated kinase 1 (PAK1) is a serine/threonine kinase that direct cell motility, cytoskeletal remodelling, and has been shown to function as a downstream regulator for various cancer signalling cascades that promote cell proliferation, apoptosis deregulation and hasten mitotic abnormalities, resulting in tumor formation and progression. The heterogeneity and acquired drug resistance are important factors that challenge the treatment of breast cancer. p21-activated kinase 1 signalling is crucial for activation of the Ras/RAF/MEK/ERK, PI3K/Akt/mTOR and Wnt signalling cascades which regulate cell survival, cell cycle progression, differentiation, and proliferation. A study involving proteogenomics analysis on breast cancer tissues showed the PAK1 as outlier kinase. In addition to this, few outlier molecules were identified specific to subtypes of breast cancer. A few substrates of PAK1 in breast cancer are already known. In this paper, we have discussed a similar approach called Kinase Interacting Substrate Screening (KISS) for the identification of novel oncogenic substrates of p21-activated kinase specific to subtypes of breast cancer. Such high throughput approaches are expected to accelerate the process of identifying novel drug targets and biomarkers.
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Affiliation(s)
- Rahul Kanumuri
- Department of Human Genetics, Sri Ramachandra Faculty of Biomedical Sciences & Technology, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Porur, Chennai, Tamilnadu, India; Department of Biotechnology, Indian Institute of Technology Madras, Chennai, Tamilnadu, India
| | - Roshni Saravanan
- Department of Human Genetics, Sri Ramachandra Faculty of Biomedical Sciences & Technology, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Porur, Chennai, Tamilnadu, India
| | - V Pavithra
- Department of Pathology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Porur, Chennai, Tamilnadu, India
| | - Sandhya Sundaram
- Department of Pathology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Porur, Chennai, Tamilnadu, India
| | - Suresh K Rayala
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, Tamilnadu, India.
| | - Ganesh Venkatraman
- Department of Human Genetics, Sri Ramachandra Faculty of Biomedical Sciences & Technology, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Porur, Chennai, Tamilnadu, India.
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17
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Aguilar BJ, Zhao Y, Zhou H, Huo S, Chen YH, Lu Q. Inhibition of Cdc42-intersectin interaction by small molecule ZCL367 impedes cancer cell cycle progression, proliferation, migration, and tumor growth. Cancer Biol Ther 2019; 20:740-749. [PMID: 30849276 PMCID: PMC6606017 DOI: 10.1080/15384047.2018.1564559] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/19/2018] [Accepted: 12/25/2018] [Indexed: 10/27/2022] Open
Abstract
Cdc42 is a member of the Rho family of small GTPases that are at the crossroads of major oncogenic signaling pathways involved in both lung and prostate cancers. However, the therapeutic potential of Cdc42 regulation is still unclear due to the lack of pharmacological tools. Herein, we report that ZCL367 is a bona fide Cdc42 inhibitor that suppressed cancer development and ZCL278 can act as a partial Cdc42 agonist. In lung cancer cell lines with varying EGFR and Ras mutations as well as both androgen-independent and androgen-dependent prostate cancer cell lines, ZCL367 impeded cell cycle progression, reduced proliferation, and suppressed migration. ZCL367 decreased Cdc42-intersectin interactions and reduced Cdc42-mediated filopodia formation. ZCL367 showed increased potency and selectivity for Cdc42 when compared to Rac1 and RhoA. ZCL367 reduced A549 tumorigenesis in a xenograft mouse model. Altogether, ZCL367 is a selective Cdc42 inhibitor and an excellent candidate for lead compound optimization for further anticancer studies.
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Affiliation(s)
- Byron J. Aguilar
- Department of Anatomy & Cell Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Yaxue Zhao
- State Key Laboratory of Microbial Metabolism, School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Huchen Zhou
- State Key Laboratory of Microbial Metabolism, School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Shouquan Huo
- Department of Chemistry, Harriot College of Arts and Sciences, East Carolina University, Greenville, NC, USA
| | - Yan-Hua Chen
- Department of Anatomy & Cell Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Qun Lu
- Department of Anatomy & Cell Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, USA
- The Harriet and John Wooten Laboratory for Alzheimer’s and Neurodegenerative Diseases Research, The Brody School of Medicine, East Carolina University, Greenville, NC, USA
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18
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Ramos-Alvarez I, Lee L, Jensen RT. Cyclic AMP-dependent protein kinase A and EPAC mediate VIP and secretin stimulation of PAK4 and activation of Na +,K +-ATPase in pancreatic acinar cells. Am J Physiol Gastrointest Liver Physiol 2019; 316:G263-G277. [PMID: 30520694 PMCID: PMC6397337 DOI: 10.1152/ajpgi.00275.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rat pancreatic acinar cells possess only the p21-activated kinase (PAKs), PAK4 of the group II PAK, and it is activated by gastrointestinal hormones/neurotransmitters stimulating PLC and by a number of growth factors. However, little is known generally of cAMP agents causing PAK4 activation, and there are no studies with gastrointestinal hormones/neurotransmitters activating cAMP cascades. In the present study, we examined the ability of VIP and secretin, which stimulate cAMP generation in pancreatic acini, to stimulate PAK4 activation, the signaling cascades involved, and their possible role in activating sodium-potassium adenosine triphosphatase (Na+,K+-ATPase). PAK4 activation was compared with activation of the well-established cAMP target, cyclic AMP response element binding protein (CREB). Secretin-stimulated PAK4 activation was inhibited by KT-5720 and PKA Type II inhibitor (PKI), protein kinase A (PKA) inhibitors, whereas VIP activation was inhibited by ESI-09 and HJC0197, exchange protein directly activated by cAMP (EPAC) inhibitors. In contrast, both VIP/secretin-stimulated phosphorylation of CREB (pCREB) via EPAC activation; however, it was inhibited by the p44/42 inhibitor PD98059 and the p38 inhibitor SB202190. The specific EPAC agonist 8-CPT-2- O-Me-cAMP as well 8-Br-cAMP and forskolin stimulated PAK4 activation. Secretin/VIP activation of Na+,K+-ATPase, was inhibited by PAK4 inhibitors (PF-3758309, LCH-7749944). These results demonstrate PAK4 is activated in pancreatic acini by stimulation of both VIP-/secretin-preferring receptors, as is CREB. However, they differ in their signaling cascades. Furthermore, PAK4 activation is needed for Na+,K+ATPase activation, which mediates pancreatic fluid secretion. These results, coupled with recent studies reporting PAKs are involved in both pancreatitis/pancreatic cancer growth/enzyme secretion, show that PAK4, similar to PAK2, likely plays an important role in both pancreatic physiological/pathological responses. NEW & NOTEWORTHY Pancreatic acini possess only the group II p21-activated kinase, PAK4, which is activated by PLC-stimulating agents/growth factors and is important in enzyme-secretion/growth/pancreatitis. Little information exists on cAMP-activating agents stimulating group II PAKs. We studied ability/effect of cyclic AMP-stimulating agents [vasoactive intestinal polypeptide (VIP), secretin] on PAK4 activity in rat pancreatic-acini. Both VIP/secretin activated PAK4/CREB, but the cAMP signaling cascades differed for EPAC, MAPK, and PKA pathways. Both hormones require PAK4 activation to stimulate sodium-potassium adenosine triphosphatase activity. This study shows PAK4 plays an important role in VIP-/secretin-stimulated pancreatic fluid secretion and suggests it plays important roles in pancreatic acinar physiological/pathophysiological responses mediated by cAMP-activating agents.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - R. T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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19
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Molosh AI, Shekhar A. Neurofibromatosis type 1 as a model system to study molecular mechanisms of autism spectrum disorder symptoms. PROGRESS IN BRAIN RESEARCH 2018; 241:37-62. [PMID: 30447756 DOI: 10.1016/bs.pbr.2018.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Neurofibromatosis type 1 (NF1) is monogenic neurodevelopmental disorder caused by mutation of NF1 gene, which leads to increased susceptibility to various tumors formations. Additionally, majority of patients with NF1 are experience high incidence of cognitive deficits. Particularly, we review the growing number of reports demonstrated a higher incidence of autism spectrum disorder (ASD) in individuals with NF1. In this review we also discuss face validity of preclinical Nf1 mouse models. Then we describe discoveries from these animal models that have uncovered the deficiencies in the regulation of Ras and other intracellular pathways as critical mechanisms underlying the Nf1 cognitive problems. We also summarize and interpret recent preclinical and clinical studies that point toward potential pharmacological therapies for NF1 patients.
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Affiliation(s)
- Andrei I Molosh
- Department of Psychiatry, Institute of Psychiatric Research, IU School of Medicine, Indianapolis, IN, United States; Stark Neurosciences Research Institute, IU School of Medicine, Indianapolis, IN, United States.
| | - Anantha Shekhar
- Department of Psychiatry, Institute of Psychiatric Research, IU School of Medicine, Indianapolis, IN, United States; Stark Neurosciences Research Institute, IU School of Medicine, Indianapolis, IN, United States; Department of Pharmacology & Toxicology, IU School of Medicine, Indianapolis, IN, United States; Indiana Clinical and Translational Institute, IU School of Medicine, Indianapolis, IN, United States
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20
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Wang K, Baldwin GS, Nikfarjam M, He H. p21-activated kinase signalling in pancreatic cancer: New insights into tumour biology and immune modulation. World J Gastroenterol 2018; 24:3709-3723. [PMID: 30197477 PMCID: PMC6127653 DOI: 10.3748/wjg.v24.i33.3709] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/22/2018] [Accepted: 06/27/2018] [Indexed: 02/06/2023] Open
Abstract
Pancreatic cancer is one of the most aggressive and lethal malignancies worldwide, with a very poor prognosis and a five-year survival rate less than 8%. This dismal outcome is largely due to delayed diagnosis, early distant dissemination and resistance to conventional chemo-therapies. Kras mutation is a well-defined hallmark of pancreatic cancer, with over 95% of cases harbouring Kras mutations that give rise to constitutively active forms of Kras. As important down-stream effectors of Kras, p21-activated kinases (PAKs) are involved in regulating cell proliferation, apoptosis, invasion/migration and chemo-resistance. Immunotherapy is now emerging as a promising treatment modality in the era of personalized anti-cancer therapeutics. In this review, basic knowledge of PAK structure and regulation is briefly summarised and the pivotal role of PAKs in Kras-driven pancreatic cancer is highlighted in terms of tumour biology and chemo-resistance. Finally, the involvement of PAKs in immune modulation in the tumour microenvironment is discussed and the potential advantages of targeting PAKs are explored.
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Affiliation(s)
- Kai Wang
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
| | - Graham S Baldwin
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
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21
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Zhang N, Li X, Liu X, Cao Y, Chen D, Liu X, Wang Q, Du J, Weng J, Ma W. p21-activated kinase 1 activity is required for histone H3 Ser 10 phosphorylation and chromatin condensation in mouse oocyte meiosis. Reprod Fertil Dev 2018; 29:1287-1296. [PMID: 27166635 DOI: 10.1071/rd16026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/06/2016] [Indexed: 01/04/2023] Open
Abstract
p21-activated kinase 1 (Pak1) is essential for a variety of cellular events, including gene transcription, cytoskeletal organisation, cell proliferation and apoptosis. Pak1 is activated upon autophosphorylation on many amino residues; in particular, phosphorylation on Thr423 maintains maximal Pak1 activation. In the present study we investigated the protein expression, subcellular localisation and function of Pak1 phosphorylated on Thr423 (pPak1Thr423) in mouse oocytes. pPak1Thr423 was detected upon meiotic resumption and localised on the condensing chromatin. Thr423 phosphorylation was markedly suppressed by the Pak1 ATP-competitive inhibitor PF-3758309, but not by the allosteric inhibitors IPA-3 (2.5 μM and 10μM) (1, 1'-dithiobis-2-naphthalenol) and TAT-PAK18 (10 μM), which prevent the binding of Pak1 to its upstream activators GTPase Cdc42/Rac and Pak-interacting exchange factor (PIX), respectively, implying that Pak1 activation may be independent of GTPase and PIX in oocyte meiosis. Inhibition of Pak1 activation concomitantly restrained histone H3 phosphorylation on Ser10 and consequently inhibited chromatin condensation; however, this phenotype was reversed by concomitant administration of the Pak1 activator FTY720. The changes in the pattern of expression of phosphorylated extracellular signal-regulated kinase 1/2 in response to PF-3758309 or FTY720 were the same as seen for pPak1Thr423. These results show that activated Pak1 regulates chromatin condensation by promoting H3 Ser10 phosphorylation in oocytes after the resumption of meiotic progression.
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Affiliation(s)
- Nana Zhang
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Xiuhong Li
- Biospecimen and Clinical Data Repository, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Xiaoyun Liu
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Yan Cao
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Dandan Chen
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Xiaoyu Liu
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Qian Wang
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Juan Du
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Jing Weng
- Experimental Center for Basic Medical Teaching, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Wei Ma
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
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22
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IGF1R signaling drives antiestrogen resistance through PAK2/PIX activation in luminal breast cancer. Oncogene 2018; 37:1869-1884. [PMID: 29353882 DOI: 10.1038/s41388-017-0027-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 08/31/2017] [Accepted: 09/24/2017] [Indexed: 02/07/2023]
Abstract
Antiestrogen resistance in estrogen receptor positive (ER+) breast cancer is associated with increased expression and activity of insulin-like growth factor 1 receptor (IGF1R). Here, a kinome siRNA screen has identified 10 regulators of IGF1R-mediated antiestrogen with clinical significance. These include the tamoxifen resistance suppressors BMPR1B, CDK10, CDK5, EIF2AK1, and MAP2K5, and the tamoxifen resistance inducers CHEK1, PAK2, RPS6KC1, TTK, and TXK. The p21-activated kinase 2, PAK2, is the strongest resistance inducer. Silencing of the tamoxifen resistance inducing genes, particularly PAK2, attenuates IGF1R-mediated resistance to tamoxifen and fulvestrant. High expression of PAK2 in ER+ metastatic breast cancer patients is correlated with unfavorable outcome after first-line tamoxifen monotherapy. Phospho-proteomics has defined PAK2 and the PAK-interacting exchange factors PIXα/β as downstream targets of IGF1R signaling, which are independent from PI3K/ATK and MAPK/ERK pathways. PAK2 and PIXα/β modulate IGF1R signaling-driven cell scattering. Targeting PIXα/β entirely mimics the effect of PAK2 silencing on antiestrogen re-sensitization. These data indicate PAK2/PIX as an effector pathway in IGF1R-mediated antiestrogen resistance.
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Semenova G, Stepanova DS, Dubyk C, Handorf E, Deyev SM, Lazar AJ, Chernoff J. Targeting group I p21-activated kinases to control malignant peripheral nerve sheath tumor growth and metastasis. Oncogene 2017; 36:5421-5431. [PMID: 28534510 PMCID: PMC5608634 DOI: 10.1038/onc.2017.143] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 02/28/2017] [Accepted: 03/18/2017] [Indexed: 12/15/2022]
Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are devastating sarcomas for which no effective medical therapies are available. Over 50% of MPSNTs are associated with mutations in NF1 tumor suppressor gene, resulting in activation of Ras and its effectors, including the Raf/Mek/Erk and PI3K/Akt/mTORC1 signaling cascades, and also the WNT/β-catenin pathway. As Group I p21-activated kinases (Group I Paks, PAK1/2/3) have been shown to modulate Ras-driven oncogenesis, we asked if these enzymes might regulate signaling in MPNSTs. In this study we found a strong positive correlation between the activity of PAK1/2/3 and the stage of human MPNSTs. We determined that reducing Group I Pak activity diminished MPNST cell proliferation and motility, and that these effects were not accompanied by significant blockade of the Raf/Mek/Erk pathway, but rather by reductions in Akt and β-catenin activity. Using the small molecule PAK1/2/3 inhibitor Frax1036 and the MEK1/2 inhibitor PD0325901, we showed that the combination of these two agents synergistically inhibited MPNST cell growth in vitro and dramatically decreased local and metastatic MPNST growth in animal models. Taken together, these data provide new insights into MPNST signaling deregulation and suggest that co-targeting of PAK1/2/3 and MEK1/2 may be effective in the treatment of patients with MPNSTs.
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Affiliation(s)
- Galina Semenova
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Dina S. Stepanova
- Russian National Research Medical University, Moscow, Russia
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Cara Dubyk
- Biosample Repository, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Elizabeth Handorf
- Biostatistics and Bioinformatics, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Sergey M. Deyev
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- National Research Tomsk Polytechnic University, Tomsk, Russia
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Babagana M, Johnson S, Slabodkin H, Bshara W, Morrison C, Kandel ES. P21-activated kinase 1 regulates resistance to BRAF inhibition in human cancer cells. Mol Carcinog 2017; 56:1515-1525. [PMID: 28052407 DOI: 10.1002/mc.22611] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/16/2016] [Accepted: 12/31/2016] [Indexed: 12/13/2022]
Abstract
BRAF is a commonly mutated oncogene in various human malignancies and a target of a new class of anti-cancer agents, BRAF-inhibitors (BRAFi). The initial enthusiasm for these agents, based on the early successes in the management of metastatic melanoma, is now challenged by the mounting evidence of intrinsic BRAFi-insensitivity in many BRAF-mutated tumors, by the scarcity of complete responses, and by the inevitable emergence of drug resistance in initially responsive cases. These setbacks put an emphasis on discovering the means to increase the efficacy of BRAFi and to prevent or overcome BRAFi-resistance. We explored the role of p21-activated kinases (PAKs), in particular PAK1, in BRAFi response. BRAFi lowered the levels of active PAK1 in treated cells. An activated form of PAK1 conferred BRAFi-resistance on otherwise sensitive cells, while genetic or pharmacologic suppression of PAK1 had a sensitizing effect. While activation of AKT1 and RAC1 proto-oncogenes increased BRAFi-tolerance, the protective effect was negated in the presence of PAK inhibitors. Furthermore, combining otherwise ineffective doses of PAK- and BRAF-inhibitors synergistically affected intrinsically BRAFi-resistant cells. Considering the high incidence of PAK1 activation in cancers, our findings suggests PAK inhibition as a strategy to augment BRAFi therapy and overcome some of the well-known resistance mechanisms.
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Affiliation(s)
- Mahamat Babagana
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York
| | - Sydney Johnson
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York
| | - Hannah Slabodkin
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York
| | - Wiam Bshara
- Department of Pathology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York
| | - Carl Morrison
- Department of Pathology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York
| | - Eugene S Kandel
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York
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Group I Paks Promote Skeletal Myoblast Differentiation In Vivo and In Vitro. Mol Cell Biol 2017; 37:MCB.00222-16. [PMID: 27920252 DOI: 10.1128/mcb.00222-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 11/26/2016] [Indexed: 12/15/2022] Open
Abstract
Skeletal myogenesis is regulated by signal transduction, but the factors and mechanisms involved are not well understood. The group I Paks Pak1 and Pak2 are related protein kinases and direct effectors of Cdc42 and Rac1. Group I Paks are ubiquitously expressed and specifically required for myoblast fusion in Drosophila We report that both Pak1 and Pak2 are activated during mammalian myoblast differentiation. One pathway of activation is initiated by N-cadherin ligation and involves the cadherin coreceptor Cdo with its downstream effector, Cdc42. Individual genetic deletion of Pak1 and Pak2 in mice has no overt effect on skeletal muscle development or regeneration. However, combined muscle-specific deletion of Pak1 and Pak2 results in reduced muscle mass and a higher proportion of myofibers with a smaller cross-sectional area. This phenotype is exacerbated after repair to acute injury. Furthermore, primary myoblasts lacking Pak1 and Pak2 display delayed expression of myogenic differentiation markers and myotube formation. These results identify Pak1 and Pak2 as redundant regulators of myoblast differentiation in vitro and in vivo and as components of the promyogenic Ncad/Cdo/Cdc42 signaling pathway.
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Hertecant J, Komara M, Nagi A, Al-Zaabi O, Fathallah W, Cui H, Yang Y, Eng CM, Al Sorkhy M, Ghattas MA, Al-Gazali L, Ali BR. A de novo mutation in the X-linked PAK3 gene is the underlying cause of intellectual disability and macrocephaly in monozygotic twins. Eur J Med Genet 2017; 60:212-216. [PMID: 28126652 DOI: 10.1016/j.ejmg.2017.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 02/08/2023]
Abstract
Pathogenic variants in theP21 protein (Cdc42/Rac)-activated kinase 3gene (PAK3) lead to a rare non syndromic X-linked intellectual disability. The protein encoded by this gene forms an activated complex with GTP-bound RAS-like (P21), CDC2 and RAC1 proteins which then mediates a variety of cellular processes. So far, mutations in PAK3 gene have been reported in few families affected with intellectual disability associated with neurological manifestations such as speech defect, behavioral problem, brain structural abnormalities, microcephaly and cerebral palsy. In this study whole exome sequencing revealed a de novo likely pathogenic variant in PAK3 gene in monozygotic twins presented with intellectual disability, speech delay, behavioral problems and macrocephaly. Macrocephaly was noticed in our patients from birth at 35 weeks of gestation. This aspect of the phenotype has not been previously reported in other documented cases with pathogenic mutations in PAK3 gene. Our findings extend the phenotype of this disorder to include macrocephaly and offers further clues to the importance of the serine/threonine-protein kinase 3 (PAK3) protein in brain development and function.
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Affiliation(s)
- Jozef Hertecant
- Department of Paediatrics, Tawam Hospital, Al-Ain, United Arab Emirates; Department of Paediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Makanko Komara
- Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Aslam Nagi
- Department of Paediatrics, Tawam Hospital, Al-Ain, United Arab Emirates
| | | | | | - Hong Cui
- Department of Molecular and Human Genetics, Baylor College of Medicine, Baylor Miraca Genetics Laboratories, Houston, TX 77030, USA
| | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Baylor Miraca Genetics Laboratories, Houston, TX 77030, USA
| | - Christine M Eng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Baylor Miraca Genetics Laboratories, Houston, TX 77030, USA
| | - Mohammad Al Sorkhy
- College of Pharmacy, Al Ain University of Science and Technology, Al-Ain, United Arab Emirates
| | - Mohammad A Ghattas
- College of Pharmacy, Al Ain University of Science and Technology, Al-Ain, United Arab Emirates
| | - Lihadh Al-Gazali
- Department of Paediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Bassam R Ali
- Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
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Nekova TS, Kneitz S, Einsele H, Bargou R, Stuhler G. Silencing of CDK2, but not CDK1, separates mitogenic from anti-apoptotic signaling, sensitizing p53 defective cells for synthetic lethality. Cell Cycle 2016; 15:3203-3209. [PMID: 27831832 DOI: 10.1080/15384101.2016.1241915] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Small molecule inhibitors targeting CDK1/CDK2 have been clinically proven effective against a variety of tumors, albeit at the cost of profound off target toxicities. To separate potential therapeutic from toxic effects, we selectively knocked down CDK1 or CDK2 in p53 mutated HACAT cells by siRNA silencing. Using dynamic, cell cycle wide proteome arrays, we observed minor changes in overall abundance of proteins critically involved in cell cycle transition despite profound G2/M or G1/S arrest, respectively. Employing phospho site specific analyses, we identified uncoupled mitogenic, yet pro-apoptotic signaling from counter balancing anti-apoptotic activity in CDK2 disrupted cells. Moreover, a crucial role of CDK2 activity in early serum response was observed, extending well-established roles of CDKs outside their cell cycle regulating functions. In contrast, disruption of CDK1 only marginally affected phosphorylation events of crucial signaling nodes prior to G2/S transition. The data presented here suggest that the temporal separation of pro- and anti-apoptotic pathways by selective inhibition of CDK2 disrupts coherent signaling modules and may synergize with anti-proliferative drugs, averting toxic side effects from CDK1 inhibition.
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Affiliation(s)
- Tatyana S Nekova
- a Department of Internal Medicine II , Julius-Maximilians University , Wuerzburg , Germany
| | - Susanne Kneitz
- b Physiological Chemistry I, Biocenter, Julius-Maximilians University , Wuerzburg , Germany
| | - Hermann Einsele
- a Department of Internal Medicine II , Julius-Maximilians University , Wuerzburg , Germany
| | - Ralf Bargou
- c Cancer Comprehensive Center Mainfranken, Julius-Maximilians University , Wuerzburg , Germany
| | - Gernot Stuhler
- a Department of Internal Medicine II , Julius-Maximilians University , Wuerzburg , Germany.,d DKD Helios Klinik Wiesbaden , Wiesbaden , Germany
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Yellapu NK, Pulaganti M, Pakala SB. Bioinformatics exploration of PAK1 (P21-activated kinase-1) revealed potential network gene elements in breast invasive carcinoma. J Biomol Struct Dyn 2016; 35:2269-2279. [DOI: 10.1080/07391102.2016.1216894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Nanda Kumar Yellapu
- Biomedical Informatics Centre, Vector Control Research Centre (VCRC)-ICMR, Pondicherry 605006, India
| | - Madhusudana Pulaganti
- Multi-Disciplinary Research Unit, Sri Venkateswara Medical College, Tirupati 517501, India
| | - Suresh Babu Pakala
- Biology Division, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India
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Kumar R, Janjanam J, Singh NK, Rao GN. A new role for cofilin in retinal neovascularization. J Cell Sci 2016; 129:1234-49. [PMID: 26857814 DOI: 10.1242/jcs.179382] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 02/02/2016] [Indexed: 12/17/2022] Open
Abstract
Pak1 plays an important role in several cellular processes, including cell migration, but its role in pathological angiogenesis is not known. Here, we have determined its role in pathological retinal angiogenesis using an oxygen-induced retinopathy (OIR) model. VEGFA induced phosphorylation of Pak1 and its effector cofilin in a manner that was dependent on time as well as p38MAPKβ (also known as MAPK11) in human retinal microvascular endothelial cells (HRMVECs). Depletion of the levels of any of these molecules inhibited VEGFA-induced HRMVEC F-actin stress fiber formation, migration, proliferation, sprouting and tube formation. In accordance with these observations, hypoxia induced Pak1 and cofilin phosphorylation with p38MAPKβ being downstream to Pak1 and upstream to cofilin in mouse retina. Furthermore, Pak1 deficiency abolished hypoxia-induced p38MAPKβ and cofilin phosphorylation and abrogated retinal endothelial cell proliferation, tip cell formation and neovascularization. In addition, small interfering RNA (siRNA)-mediated downregulation of p38MAPKβ or cofilin levels in the wild-type mouse retina also diminished endothelial cell proliferation, tip cell formation and neovascularization. Taken together, these observations suggest that, although the p38MAPKβ-Pak1-cofilin axis is required for HRMVEC migration, proliferation, sprouting and tubulogenesis, Pak1-p38MAPKβ-cofilin signaling is also essential for hypoxia-induced mouse retinal endothelial cell proliferation, tip cell formation and neovascularization.
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Affiliation(s)
- Raj Kumar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jagadeesh Janjanam
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Nikhlesh K Singh
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Gadiparthi N Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Epidermal Growth Factor Receptor Signaling to the Mitogen Activated Protein Kinase Pathway Bypasses Ras in Pancreatic Cancer Cells. Pancreas 2016; 45:286-92. [PMID: 26262587 PMCID: PMC5891223 DOI: 10.1097/mpa.0000000000000379] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Epidermal growth factor (EGF) receptor (EGFR/HER1) is overexpressed in human pancreatic cancers. However, anti-EGFR therapy does not exhibit significant therapeutic activity with oncogenic K-ras mutation. We sought to assess the signaling relationship between EGFR and mutant K-ras, which is commonly detected in pancreatic cancer. METHODS Pancreatic cancer cells harboring mutated K-ras were treated with EGF to assess signaling from EGFR to mitogen-activated protein kinase (MAPK) pathway. The role of Ras family of proteins in transducing EGFR signals was assessed using short interfering RNA. Other components of MAPK and PI3K (phosphoinositide 3-kinase) pathways were examined for their roles in EGFR signaling. RESULTS First, EGF signaling in pancreatic cancer cells occurs selectively through HER1. Second, knockdown of all Ras isoforms failed to block EGF-mediated phosphorylation of extracellular signal-regulated kinase (ERK). Inhibition of Raf was observed to partially abrogate ERK phosphorylation, whereas MEK inhibition resulted in complete attenuation of EGF-mediated ERK phosphorylation. Finally, inhibition of phosphoinositide 3-kinase/AKT and CDC42/PAK pathways did not block EGFR signaling. CONCLUSIONS Our study results demonstrate that EGFR-mediated signaling in mutant K-ras pancreatic cancer cells does not follow canonical MAPK signaling. Our novel findings suggest the existence of alternate signaling pathways to downstream MAPK in the presence of mutant K-ras.
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Group I Paks as therapeutic targets in NF2-deficient meningioma. Oncotarget 2015; 6:1981-94. [PMID: 25596744 PMCID: PMC4385830 DOI: 10.18632/oncotarget.2810] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/24/2014] [Indexed: 11/25/2022] Open
Abstract
Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by the development of multiple tumors in the central nervous system, most notably schwannomas and meningiomas. Mutational inactivation of NF2 is found in 40-60% of sporadic meningiomas, but the molecular mechanisms underlying malignant changes of meningioma cells remain unclear. Because group I p21-activated kinases (Paks) bind to and are inhibited by the NF2-encoded protein Merlin, we assessed the signaling and anti-tumor effects of three group-I specific Pak inhibitors - Frax597, 716 and 1036 - in NF2-/- meningiomas in vitro and in an orthotopic mouse model. We found that these Pak inhibitors suppressed the proliferation and motility of both benign (Ben-Men1) and malignant (KT21-MG1) meningiomas cells. In addition, we found a strong reduction in phosphorylation of Mek and S6, and decreased cyclin D1 expression in both cell lines after treatment with Pak inhibitors. Using intracranial xenografts of luciferase-expressing KT21-MG1 cells, we found that treated mice showed significant tumor suppression for all three Pak inhibitors. Similar effects were observed in Ben-Men1 cells. Tumors dissected from treated animals exhibited an increase in apoptosis without notable change in proliferation. Collectively, these results suggest that Pak inhibitors might be useful agents in treating NF2-deficient meningiomas.
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Tanaka T, Iino M. Sec8 regulates cytokeratin8 phosphorylation and cell migration by controlling the ERK and p38 MAPK signalling pathways. Cell Signal 2015; 27:1110-9. [DOI: 10.1016/j.cellsig.2015.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/02/2015] [Accepted: 02/16/2015] [Indexed: 12/15/2022]
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Gastrointestinal hormones/neurotransmitters and growth factors can activate P21 activated kinase 2 in pancreatic acinar cells by novel mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2371-82. [PMID: 25979836 DOI: 10.1016/j.bbamcr.2015.05.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 04/28/2015] [Accepted: 05/07/2015] [Indexed: 12/15/2022]
Abstract
P-21-activated kinases (PAKs) are serine/threonine kinases comprising six isoforms divided in two groups, group-I (PAK1-3)/group-II (PAK4-6) which play important roles in cell cytoskeletal dynamics, survival, secretion and proliferation and are activated by diverse stimuli. However, little is known about PAKs ability to be activated by gastrointestinal (GI) hormones/neurotransmitters/growth-factors. We used rat pancreatic acini to explore the ability of GI-hormones/neurotransmitters/growth-factors to activate Group-I-PAKs and the signaling cascades involved. Only PAK2 was present in acini. PAK2 was activated by some pancreatic growth-factors [EGF, PDGF, bFGF], by secretagogues activating phospholipase-C (PLC) [CCK, carbachol, bombesin] and by post-receptor stimulants activating PKC [TPA], but not agents only mobilizing cellular calcium or increasing cyclic AMP. CCK-activation of PAK2 required both high- and low-affinity-CCK1-receptor-state activation. It was partially reduced by PKC- or Src-inhibition, but not with PI3K-inhibitors (wortmannin, LY294002) or thapsigargin. IPA-3, which prevents PAK2 binding to small-GTPases partially inhibited PAK2-activation, as well as reduced CCK-induced ERK1/2 activation and amylase release induced by CCK or bombesin. This study demonstrates pancreatic acini, possess only one Group-I-PAK, PAK2. CCK and other GI-hormones/neurotransmitters/growth-factors activate PAK2 via small GTPases (CDC42/Rac1), PKC and SFK but not cytosolic calcium or PI3K. CCK-activation of PAK2 showed several novel features being dependent on both receptor-activation states, having PLC- and PKC-dependent/independent components and small-GTPase-dependent/independent components. These results show that PAK2 is important in signaling cascades activated by numerous pancreatic stimuli which mediate their various physiological/pathophysiological responses and thus could be a promising target for the development of therapies in some pancreatic disorders such as pancreatitis.
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p21-activated kinase 1 determines stem-like phenotype and sunitinib resistance via NF-κB/IL-6 activation in renal cell carcinoma. Cell Death Dis 2015; 6:e1637. [PMID: 25675297 PMCID: PMC4669810 DOI: 10.1038/cddis.2015.2] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 12/22/2014] [Accepted: 01/02/2015] [Indexed: 12/29/2022]
Abstract
The p21-activated kinase 1 (PAK1), a serine/threonine kinase that orchestrates cytoskeletal remodeling and cell motility, has been shown to function as downstream node for various oncogenic signaling pathways to promote cell proliferation, regulate apoptosis and accelerate mitotic abnormalities, resulting in tumor formation and invasiveness. Although alterations in PAK1 expression and activity have been detected in various human malignancies, its potential biological and clinical significance in renal cell carcinoma (RCC) remains obscure. In this study, we found increased PAK1 and phosphorylated PAK1 levels in tumor tissues according to TNM stage progression. Elevated phosphorylated PAK1 levels associated with progressive features and indicated unfavorable overall survival (OS) as an independent adverse prognosticator for patients with RCC. Moreover, PAK1 kinase activation with constitutive active PAK1 mutant T423E promoted growth, colony formation, migration, invasion and stem-like phenotype of RCC cells, and vice versa, in PAK1 inhibition by PAK1 kinase inactivation with specific PAK1 shRNA, dead kinase PAK1 mutant K299R or allosteric inhibitor IPA3. Stem-like phenotype due to sunitinib administration via increased PAK1 kinase activation could be ameliorated by PAK1 shRNA, PAK1 mutant K299R and IPA3. Furthermore, nuclear factor-κB (NF-κB)/interleukin-6 (IL-6) activation was found to be responsible for PAK1-mediated stem-like phenotype following sunitinib treatment. Both IL-6 neutralizing antibody and IPA3 administration enhanced tumor growth inhibition effect of sunitinib treatment on RCC cells in vitro and in vivo. Our results unraveled that oncogenic activation of PAK1 defines an important mechanism for maintaining stem-like phenotype and sunitinib resistance through NF-κB/IL-6 activation in RCC, lending PAK1-mediated NF-κB/IL-6 activation considerable appeal as novel pharmacological therapeutic targets against sunitinib resistance.
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Elsherif L, Ozler M, Zayed MA, Shen JH, Chernoff J, Faber JE, Parise LV. Potential compensation among group I PAK members in hindlimb ischemia and wound healing. PLoS One 2014; 9:e112239. [PMID: 25379771 PMCID: PMC4224450 DOI: 10.1371/journal.pone.0112239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/14/2014] [Indexed: 12/04/2022] Open
Abstract
PAKs are serine/threonine kinases that regulate cytoskeletal dynamics and cell migration. PAK1 is activated by binding to the small EF hand protein, CIB1, or to the Rho GTPases Rac1 or Cdc42. The role of PAK1 in angiogenesis was established based only on in vitro studies and its role in angiogenesis in vivo has never been examined. Here we tested the hypothesis that PAK1 is an essential regulator of ischemic neovascularization (arteriogenesis and angiogenesis) and wound healing using a global PAK1 knockout mouse. Neovascularization was assessed using unilateral hindlimb ischemia. We found that plantar perfusion, limb use and appearance were not significantly different between 6-8 week old PAK1-/- and PAK1+/+ mice throughout the 21-day period following hindlimb ischemia; however a slightly delayed healing was observed in 16 week old PAK1-/- mice. In addition, the wound healing rate, as assessed with an ear punch assay, was unchanged in PAK1-/- mice. Surprisingly, however, we observed a notable increase in PAK2 expression and phosphorylation in ischemic gastrocnemius tissue from PAK1-/- but not PAK1+/+ mice. Furthermore, we observed higher levels of activated ERK2, but not AKT, in ischemic and non-ischemic muscle of PAK1-/- mice upon hindlimb ischemic injury. A group I PAK inhibitor, IPA3, significantly inhibited endothelial cell sprouting from aortic rings in both PAK1-/- and PAK1+/+ mice, implying that PAK2 is a potential contributor to this process. Taken together, our data indicate that while PAK1 has the potential to contribute to neovascularization and wound healing, PAK2 may functionally compensate when PAK1 is deficient.
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Affiliation(s)
- Laila Elsherif
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Mehmet Ozler
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Mohamed A. Zayed
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Jessica H. Shen
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Jonathan Chernoff
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, United States of America
| | - James E. Faber
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Leslie V. Parise
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
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Arias-Romero LE, Chernoff J. p21-activated kinases in Erbb2-positive breast cancer: A new therapeutic target? Small GTPases 2014; 1:124-128. [PMID: 21686266 DOI: 10.4161/sgtp.1.2.14109] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 10/27/2010] [Accepted: 10/29/2010] [Indexed: 02/03/2023] Open
Abstract
The activation of receptor tyrosine kinases, particularly ErbB2, has been linked to the genesis and progression of breast cancer. Two of the central signaling pathways activated by ErbB2 are the Ras/Raf-1/Mek/Erk pathway, which plays an important role in tumor cell growth and migration, and the PI3K/Akt pathway, which plays an important role in cell survival. Recently, we and others have shown that signaling through the Ras-Erk pathway can be influenced by p21-activated kinase 1 (Pak1), an effector of the Rho family GTP ases Rac and Cdc42. Expression of activated forms of Rac promotes activation of Erk through mechanisms involving Pak1 phosphorylation of Raf-1 and Mek1. In addition, Pak1 has also been implicated in the activation of Akt. However, our understanding regarding the degree to which Rho GTPases, and their effectors such as Pak1, contribute to ErbB2-mediated signaling is very limited.Recent results from our laboratory indicate that ErbB2 expression correlates with Pak activation in estrogen receptor negative human breast tumor samples. Using a three-dimensional (3D) culture of human MCF-10A mammary epithelial cells, we found that activation of Rac-Pak pathway by ErbB2 induces growth factor independent proliferation and promotes disruption of acini-like structures through the activation of the Erk and Akt pathways. We also observed that blocking Pak1 activity by small molecule inhibitors impeded the ability of activated ErbB2 to transform these cells and to activate its associated downstream signaling targets. In addition, we found that suppressing Pak activity in ErbB2-amplified breast cancer cells delayed tumor formation and downregulated Erk and Akt signaling in vivo. These results support a model in which Pak, by activating Erk and Akt, cooperates with ErbB2 in transforming mammary epithelial cells.
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Abstract
Transformation of a normal cell to a cancer cell is caused by mutations in genes that regulate proliferation, apoptosis, and invasion. Small GTPases such as Ras, Rho, Rac and Cdc42 orchestrate many of the signals that are required for malignant transformation. The p21-activated kinases (PAKs) are effectors of Rac and Cdc42. PAKs are a family of serine/threonine protein kinases comprised of six isoforms (PAK1–6), and they play important roles in cytoskeletal dynamics, cell survival and proliferation. They act as key signal transducers in several cancer signaling pathways, including Ras, Raf, NFκB, Akt, Bad and p53. Although PAKs are not mutated in cancers, they are overexpressed, hyperactivated or amplified in several human tumors and their role in cell transformation make them attractive therapeutic targets. This review discusses the evidence that PAK is important for cell transformation and some key signaling pathways it regulates. This review primarily discusses Group I PAKs (PAK1, PAK2 and PAK3) as Group II PAKs (PAK4, PAK5 and PAK6) are discussed elsewhere in this issue (by Minden).
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Affiliation(s)
- Diana Zi Ye
- Department of Pharmacology; Perelman School of Medicine; University of Pennsylvania; Philadelphia, PA USA
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Zhao ZS, Manser E. PAK family kinases: Physiological roles and regulation. CELLULAR LOGISTICS 2014; 2:59-68. [PMID: 23162738 PMCID: PMC3490964 DOI: 10.4161/cl.21912] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The p21-activated kinases (PAKs) are a family of Ser/Thr protein kinases that are represented by six genes in humans (PAK 1-6), and are found in all eukaryotes sequenced to date. Genetic and knockdown experiments in frogs, fish and mice indicate group I PAKs are widely expressed, required for multiple tissue development, and particularly important for immune and nervous system function in the adult. The group II PAKs (human PAKs 4-6) are more enigmatic, but their restriction to metazoans and presence at cell-cell junctions suggests these kinases emerged to regulate junctional signaling. Studies of protozoa and fungal PAKs show that they regulate cell shape and polarity through phosphorylation of multiple cytoskeletal proteins, including microtubule binding proteins, myosins and septins. This chapter discusses what we know about the regulation of PAKs and their physiological role in different model organisms, based primarily on gene knockout studies.
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Affiliation(s)
- Zhuo-Shen Zhao
- sGSK Group; Astar Neuroscience Research Partnership; Singapore
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Abstract
INTRODUCTION Overexpression of p21-activated kinase 5 (PAK5) is discovered in many tumors, probably due to its regulation in cytoskeleton, antiapoptosis and proliferation. A better understanding of the modulation mechanisms of PAK5 is needed for the development of tumor treatment where current therapeutics is inadequate. AREAS COVERED This review discusses the current understanding of PAK5 functions as an oncogenic kinase in tumor cellular regulation. Mechanisms of action and molecular pathways involved in cytoskeleton regulation, antiapoptosis and proliferation of tumors are discussed. EXPERT OPINION PAKs are serine/threonine kinases and downstream effectors for Cdc42 and Rac, the subfamilies of Rho small GTPases. PAK5 shares sequence identities in p21-GTPase-binding domain and kinase domain and is completely different in other regions compared with other PAKs. Overexpression of PAK5 has been found in several tumors, probably due to its contribution to proliferation, cytoskeleton and anti-apoptosis. Additional regulation mechanisms which are independent of Rho GTPases also indicate that PAK5 functions as a special signal molecule in cellular signaling pathways of tumor progression.
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Affiliation(s)
- Yi-Yang Wen
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College , 84 West Huai-hai Road, Xuzhou, Jiangsu , China +86 0516 85582513 ; ;
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Abstract
p21-Activated protein kinases (PAKs) are centrally involved in a plethora of cellular processes and functions. Their function as effectors of small GTPases Rac1 and Cdc42 has been extensively studied during the past two decades, particularly in the realms of cell proliferation, apoptosis, and hence tumorigenesis, as well as cytoskeletal remodeling and related cellular events in health and disease. In recent years, a large number of studies have shed light onto the fundamental role of group I PAKs, most notably PAK1, in metabolic homeostasis. In skeletal muscle, PAK1 was shown to mediate the function of insulin on stimulating GLUT4 translocation and glucose uptake, while in pancreatic β-cells, PAK1 participates in insulin granule localization and vesicle release. Furthermore, we demonstrated that PAK1 mediates the cross talk between insulin and Wnt/β-catenin signaling pathways and hence regulates gut proglucagon gene expression and the production of the incretin hormone glucagon-like peptide-1 (GLP-1). The utilization of chemical inhibitors of PAK and the characterization of Pak1(-/-) mice enabled us to gain mechanistic insights as well as to assess the overall contribution of PAKs in metabolic homeostasis. This review summarizes our current understanding of PAKs, with an emphasis on the emerging roles of PAK1 in glucose homeostasis.
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Magini P, Pippucci T, Tsai IC, Coppola S, Stellacci E, Bartoletti-Stella A, Turchetti D, Graziano C, Cenacchi G, Neri I, Cordelli DM, Marchiani V, Bergamaschi R, Gasparre G, Neri G, Mazzanti L, Patrizi A, Franzoni E, Romeo G, Bordo D, Tartaglia M, Katsanis N, Seri M. A mutation in PAK3 with a dual molecular effect deregulates the RAS/MAPK pathway and drives an X-linked syndromic phenotype. Hum Mol Genet 2014; 23:3607-17. [PMID: 24556213 DOI: 10.1093/hmg/ddu070] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Loss-of-function mutations in PAK3 contribute to non-syndromic X-linked intellectual disability (NS-XLID) by affecting dendritic spine density and morphology. Linkage analysis in a three-generation family with affected males showing ID, agenesis of corpus callosum, cerebellar hypoplasia, microcephaly and ichthyosis, revealed a candidate disease locus in Xq21.33q24 encompassing over 280 genes. Subsequent to sequencing all coding exons of the X chromosome, we identified a single novel variant within the linkage region, affecting a conserved codon of PAK3. Biochemical studies showed that, similar to previous NS-XLID-associated lesions, the predicted amino acid substitution (Lys389Asn) abolished the kinase activity of PAK3. In addition, the introduced residue conferred a dominant-negative function to the protein that drives the syndromic phenotype. Using a combination of in vitro and in vivo studies in zebrafish embryos, we show that PAK3(N389) escapes its physiologic degradation and is able to perturb MAPK signaling via an uncontrolled kinase-independent function, which in turn leads to alterations of cerebral and craniofacial structures in vivo. Our data expand the spectrum of phenotypes associated with PAK3 mutations, characterize a novel mechanism resulting in a dual molecular effect of the same mutation with a complex PAK3 functional deregulation and provide evidence for a direct functional impact of aberrant PAK3 function on MAPK signaling.
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Affiliation(s)
- Pamela Magini
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC)
| | - Tommaso Pippucci
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC)
| | - I-Chun Tsai
- Center for Human Disease Modeling, Duke University Medical Center, Durham 27710, USA
| | - Simona Coppola
- Centro Nazionale per le Malattie Rare, Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Roma 00161, Italy
| | - Emilia Stellacci
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Roma 00161, Italy
| | - Anna Bartoletti-Stella
- Laboratorio di Neuropatologia, Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM)
| | - Daniela Turchetti
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC)
| | - Claudio Graziano
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC)
| | - Giovanna Cenacchi
- U.O. Anatomia e Istologia Patologica, Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM)
| | - Iria Neri
- U.O. Dermatologia, Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale (DIMES)
| | - Duccio Maria Cordelli
- U.O. Neuropsichiatria Infantile, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC) and
| | - Valentina Marchiani
- U.O. Neuropsichiatria Infantile, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC) and
| | - Rosalba Bergamaschi
- Pediatria d'Urgenza, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), Università di Bologna, Bologna 40138, Italy
| | - Giuseppe Gasparre
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC)
| | - Giovanni Neri
- Istituto di Genetica Medica, Università Cattolica del Sacro Cuore, Roma 00168, Italy
| | - Laura Mazzanti
- S.S. Malattie Rare e Sindromologia, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), Università di Bologna, Policlinico S.Orsola-Malpighi, Bologna 40138, Italy
| | - Annalisa Patrizi
- U.O. Dermatologia, Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale (DIMES)
| | - Emilio Franzoni
- U.O. Neuropsichiatria Infantile, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC) and
| | - Giovanni Romeo
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC)
| | - Domenico Bordo
- IRCCS AOU S. Martino - IST, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
| | - Marco Tartaglia
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Roma 00161, Italy
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham 27710, USA
| | - Marco Seri
- U.O. Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche (DIMEC),
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Role of p-21-activated kinases in cancer progression. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 309:347-87. [PMID: 24529727 DOI: 10.1016/b978-0-12-800255-1.00007-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The p-21-activated kinases (PAKs) are downstream effectors of Rho GTPases Rac and Cdc42. The PAK family consists of six members which are segregated into two subgroups (Group I and Group II) based on sequence homology. Group I PAKs (PAK1-3) are the most extensively studied but there is increasing interest in the functionality of Group II PAKs (PAK4-6). The PAK family proteins are thought to play an important role in many different cellular processes, some of which have particular significance in the context of cancer progression. This review explores established and more recent data, linking the PAK family kinases to cancer progression including expression profiles, evasion of apoptosis, promotion of cell survival, and regulation of cell invasion. Finally, we discuss attempts to therapeutically target the PAK family and outline the major obstacles that still need to be overcome.
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Ke Y, Lei M, Wang X, Solaro RJ. Unique catalytic activities and scaffolding of p21 activated kinase-1 in cardiovascular signaling. Front Pharmacol 2013; 4:116. [PMID: 24098283 PMCID: PMC3784770 DOI: 10.3389/fphar.2013.00116] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 08/28/2013] [Indexed: 01/16/2023] Open
Abstract
P21 activated kinase-1 (Pak1) has diverse functions in mammalian cells. Although a large number of phosphoproteins have been designated as Pak1 substrates from in vitro studies, emerging evidence has indicated that Pak1 may function as a signaling molecule through a unique molecular mechanism – scaffolding. By scaffolding, Pak1 delivers signals through an auto-phosphorylation-induced conformational change without transfer of a phosphate group to its immediate downstream effector(s). Here we review evidence for this regulatory mechanism based on structural and functional studies of Pak1 in different cell types and research models as well as in vitro biochemical assays. We also discuss the implications of Pak1 scaffolding in disease-related signaling processes and the potential in cardiovascular drug development.
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Affiliation(s)
- Yunbo Ke
- Department of Physiology and Biophysics, University of Illinois at Chicago Chicago, IL, USA ; Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago Chicago, IL, USA
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Miller ML, Molinelli EJ, Nair JS, Sheikh T, Samy R, Jing X, He Q, Korkut A, Crago AM, Singer S, Schwartz GK, Sander C. Drug synergy screen and network modeling in dedifferentiated liposarcoma identifies CDK4 and IGF1R as synergistic drug targets. Sci Signal 2013; 6:ra85. [PMID: 24065146 DOI: 10.1126/scisignal.2004014] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Dedifferentiated liposarcoma (DDLS) is a rare but aggressive cancer with high recurrence and low response rates to targeted therapies. Increasing treatment efficacy may require combinations of targeted agents that counteract the effects of multiple abnormalities. To identify a possible multicomponent therapy, we performed a combinatorial drug screen in a DDLS-derived cell line and identified cyclin-dependent kinase 4 (CDK4) and insulin-like growth factor 1 receptor (IGF1R) as synergistic drug targets. We measured the phosphorylation of multiple proteins and cell viability in response to systematic drug combinations and derived computational models of the signaling network. These models predict that the observed synergy in reducing cell viability with CDK4 and IGF1R inhibitors depends on the activity of the AKT pathway. Experiments confirmed that combined inhibition of CDK4 and IGF1R cooperatively suppresses the activation of proteins within the AKT pathway. Consistent with these findings, synergistic reductions in cell viability were also found when combining CDK4 inhibition with inhibition of either AKT or epidermal growth factor receptor (EGFR), another receptor similar to IGF1R that activates AKT. Thus, network models derived from context-specific proteomic measurements of systematically perturbed cancer cells may reveal cancer-specific signaling mechanisms and aid in the design of effective combination therapies.
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Affiliation(s)
- Martin L Miller
- 1Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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Abstract
INTRODUCTION The Rho GTPases are a family of proteins that control fundamental cellular processes in response to extracellular stimuli and internal programs. Rho GTPases function as molecular switches in which the GTP-bound proteins are active and GDP-bound proteins are inactive. This article will focus on one Rho family member, Cdc42, which is overexpressed in a number of human cancers, and which might provide new therapeutic targets in malignancies. AREAS COVERED In this article, the key regulators and effectors of Cdc42 and their molecular alterations are described. The complex interactions between the signaling cascades regulated by Cdc42 are also analyzed. EXPERT OPINION While mutations in Cdc42 have not been reported in human cancer, aberrant expression of Cdc42 has been reported in a variety of tumor types and in some instances has been correlated with poor prognosis. Recently, it has been shown that Cdc42 activation by oncogenic Ras is crucial for Ras-mediated tumorigenesis, suggesting that targeting Cdc42 or its effectors might be useful in tumors harboring activating Ras mutations.
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Affiliation(s)
- Luis E Arias-Romero
- Cancer Biology Program, Fox Chase Cancer Center , Philadelphia, PA , USA +1 215 728 5319 ; +1 215 728 3616 ;
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Wang Z, Fu M, Wang L, Liu J, Li Y, Brakebusch C, Mei Q. p21-activated kinase 1 (PAK1) can promote ERK activation in a kinase-independent manner. J Biol Chem 2013; 288:20093-9. [PMID: 23653349 PMCID: PMC3707706 DOI: 10.1074/jbc.m112.426023] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 04/24/2013] [Indexed: 11/06/2022] Open
Abstract
PAK1 plays an important role in proliferation and tumorigenesis, at least partially by promoting ERK phosphorylation of C-RAF (Ser-338) or MEK1 (Ser-298). We observed how that overexpression of a kinase-dead mutant form of PAK1 increased phosphorylation of MEK1/2 (Ser-217/Ser-221) and ERK (Thr-202/Tyr-204), although phosphorylation of B-RAF (Ser-445) and C-RAF (Ser-338) remained unchanged. Furthermore, increased activation of the PAK1 activator Rac1 induced the formation of a triple complex of Rac1, PAK1, and MEK1 independent of the kinase activity of PAK1. These data suggest that PAK1 can stimulate MEK activity in a kinase-independent manner, probably by serving as a scaffold to facilitate interaction of C-RAF.
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Affiliation(s)
- Zhipeng Wang
- From the Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China 710032
- the Department of Biochemistry and Molecular Biology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China 710032, and
| | - Meng Fu
- the Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China 710032
| | - Lifeng Wang
- the Department of Biochemistry and Molecular Biology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China 710032, and
| | - Juanjuan Liu
- From the Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China 710032
| | - Yuhua Li
- From the Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China 710032
| | - Cord Brakebusch
- the Biomedical Institute, Biotech Research and Innovation Centre (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark
| | - Qibing Mei
- From the Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China 710032
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HÖLTERS SEBASTIAN, ANACKER JELENA, JANSEN LARS, BEER-GRONDKE KATRIN, DÜRST MATTHIAS, RUBIO IGNACIO. Tetraspanin 1 promotes invasiveness of cervical cancer cells. Int J Oncol 2013; 43:503-12. [DOI: 10.3892/ijo.2013.1980] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 04/22/2013] [Indexed: 11/06/2022] Open
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Dart AE, Wells CM. P21-activated kinase 4--not just one of the PAK. Eur J Cell Biol 2013; 92:129-38. [PMID: 23642861 DOI: 10.1016/j.ejcb.2013.03.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/24/2013] [Accepted: 03/25/2013] [Indexed: 12/18/2022] Open
Abstract
P21-activated kinase 4 (PAK4) is a member of the p21-activated kinase (PAK) family. Historically much of the attention has been directed towards founding family member PAK1 but the focus is now shifting towards PAK4. It is a pluripotent serine/threonine kinase traditionally recognised as a downstream effector of the Rho-family GTPases. However, emerging research over the last few years has revealed that this kinase is much more than that. New findings have shed light on the molecular mechanism of PAK4 activation and how this kinase is critical for early development. Moreover, the number of PAK4 substrates and binding partners is rapidly expanding highlighting the increasing amount of cellular functions controlled by PAK4. We propose that PAK4 should be considered a signalling integrator regulating numerous fundamental cellular processes, including actin cytoskeletal dynamics, cell morphology and motility, cell survival, embryonic development, immune defence and oncogenic transformation. This review will outline our current understanding of PAK4 biology.
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Affiliation(s)
- Anna E Dart
- Division of Cancer Studies, New Hunts House, Guy's Campus, King's College London, London SE1 1UL, UK
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Ong CC, Jubb AM, Jakubiak D, Zhou W, Rudolph J, Haverty PM, Kowanetz M, Yan Y, Tremayne J, Lisle R, Harris AL, Friedman LS, Belvin M, Middleton MR, Blackwood EM, Koeppen H, Hoeflich KP. P21-activated kinase 1 (PAK1) as a therapeutic target in BRAF wild-type melanoma. J Natl Cancer Inst 2013; 105:606-7. [PMID: 23535073 DOI: 10.1093/jnci/djt054] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Although remarkable clinical response rates in melanoma have been observed using vemurafenib or dabrafenib in patients with tumors carrying oncogenic mutations in BRAF, a substantial unmet medical need remains for the subset of patients with wild-type BRAF tumors. METHODS To investigate the role of p21-activated kinases (PAKs) in melanoma, we determined PAK1 genomic copy number and protein expression for a panel of human melanoma tissues. PAK1 was inhibited in vitro and in vivo using RNA interference or PF-3758309 inhibitor treatment in a panel of melanoma cell lines with known BRAF and RAS (rat sarcoma) genotype to better understand its role in melanoma cell proliferation and migration. Tumorigenesis was assessed in vivo in female NCR nude mice and analyzed with cubic spline regression and area under the curve analyses. All statistical tests were two-sided. RESULTS Strong cytoplasmic PAK1 protein expression was prevalent in melanomas (27%) and negatively associated with activating mutation of the BRAF oncogene (P < .001). Focal copy number gain of PAK1 at 11q13 was also observed in 9% of melanomas (n = 87; copy number ≥ 2.5) and was mutually exclusive with BRAF mutation (P < .005). Selective PAK1 inhibition attenuated signaling through mitogen-activated protein kinase (MAPK) as well as cytoskeleton-regulating pathways to modulate the proliferation and migration of BRAF wild-type melanoma cells. Treatment of BRAF wild-type melanomas with PF-3758309 PAK inhibitor decreased tumor growth for SK-MEL23 and 537MEL xenografts (91% and 63% inhibition, respectively; P < .001) and MAPK pathway activation in vivo. CONCLUSIONS Taken together, our results provide evidence for a functional role of PAK1 in BRAF wild-type melanoma and therapeutic use of PAK inhibitors in this indication.
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Affiliation(s)
- Christy C Ong
- Department of Translational Oncology Genentech, MS 50, 1 DNA Way, South San Francisco, CA 94080, USA
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Singhal R, Kandel ES. The response to PAK1 inhibitor IPA3 distinguishes between cancer cells with mutations in BRAF and Ras oncogenes. Oncotarget 2013; 3:700-8. [PMID: 22869096 PMCID: PMC3443253 DOI: 10.18632/oncotarget.587] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
While new drugs aimed at BRAF-mutated cancers are entering clinical practice, cells and tumors with activating Ras mutations are relatively resistant to those and quite a few other anti-cancer agents. This inspires the effort to reverse this resistance or to uncover new vulnerabilities in such resistant cancers. IPA3 has been originally identified as a small molecule inhibitor of p21-activated protein kinase 1 (PAK1), a candidate therapeutic target in human malignancies. We have tested a battery of melanoma and colon carcinoma cell lines that carry mutations in BRAF, NRAS and KRAS genes and have observed that those with NRAS and KRAS mutations are more sensitive to killing by IPA3. Genetic manipulations suggest that the differential response depends not just on these oncogenes, but also on additional events that were co-selected during tumor evolution. Furthermore, sublethal doses of IPA3 or ectopic expression of dominant-negative PAK1 sensitized Ras-mutated cells to GDC-0897 and AZD6244, which otherwise have reduced efficiency against cells with activated Ras. Dominant-negative PAK1 also reduced the growth of NRAS-mutated cells in confluent cultures, but, unlike IPA3, caused no significant toxicity. Although it remains to be proven that all the effects of IPA3 are exclusively due to inhibition of PAK1, our findings point to the existence of selective vulnerabilities, which are associated with Ras mutations and could be useful for better understanding and treatment of a large subset of tumors.
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Affiliation(s)
- Ruchi Singhal
- Roswell Park Cancer Institute, Department of Cell Stress Biology, Elm and Carlton St., Buffalo, NY 142263, USA
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