Lung adenocarcinoma (LUAD) remains associated with limited effective pharmacological treatment options. This study aimed to identify potential therapeutic targets for LUAD through the integration and analysis of multi-omics datasets.

A meta-analysis was conducted using two extensive proteomics datasets, the UK Biobank Proteomics Project (UKB-PPP) and the Fenland study, to identify disease-associated targets for LUAD through the Summary-Data-Based Mendelian Randomization method. Sensitivity analysis, including heterogeneity tests for dependent instruments, were conducted to validate the findings. The prognostic relevance of the identified candidate targets was assessed using transcriptomic data. Functional interactions were explored via protein-protein interaction network analysis, while single-cell analyses were employed to determine cell-specific expression patterns and differentiation trajectories. Potential side effects and therapeutic indications of these targets were evaluated using phenome-wide association studies and pharmacological data mining.

Following meta-analysis, a primary significant target, intercellular adhesion molecule 5 (ICAM5), along with potential targets FUT8 and KLK13, were identified as therapeutic candidates for LUAD. FUT8 demonstrated a positive association with LUAD risk (OR = 1.02, p = 0.049), while ICAM5 (OR = 0.88, p = 0.002) and KLK13 (OR = 0.85, p = 0.021) exhibited negative associations. ICAM5 was further identified as an independent prognostic factor for patient survival (HR: 0.788, 95% CI: 0.663-0.936, p = 0.007) and revealed significant diagnostic and prognostic utility in LUAD. ICAM5 expression correlated with various immune infiltration patterns, suggesting potential modulation of the tumor immune microenvironment. Single-cell analysis revealed that ICAM5 did not directly impact LUAD cell differentiation, though its downstream target, MUC1, may contribute to differentiation processes, particularly in KRAS-mutated LUAD. Furthermore, phenome-wide association studies did not reveal substantial evidence of adverse phenotypes linked to ICAM5, supporting its safety profile for drug development.

ICAM5 emerges as a promising biological marker with significant prognostic and therapeutic potential in LUAD.

The prolyl-isomerase Pin1 is a unique enzyme that catalyzes cis-trans isomerization of phosphorylated Ser/Thr-Pro motifs. These motifs are present in many proteins, where isomerization of the typically rigid prolyl-peptide bond can lead to conformational changes, and subsequently regulate activity, stability, or localization. The specificity of Pin1 for phosphorylated motifs allows it to serve as a master regulator of proteins after phosphorylation, adding an additional layer of regulation to intricately control cellular signaling. As such, Pin1 plays an expansive role in numerous cancer and age-related signaling pathways, and is recognized as a major driver of cancer and promising therapeutic target. In this review, we discuss the role of Pin1 in regulation of age-related cancer signaling pathways, and we highlight the early development and current landscape of Pin1 inhibitors, and the prospect of Pin1 inhibition for cancer therapy.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers demanding better and more effective therapies. BARD1 or BRCA1-Associated -Ring Domain-1 plays a pivotal role in homologous recombination repair (HRR). However, its function and the underlying molecular mechanisms in PDAC are still not fully elucidated. Here, we demonstrate that BARD1 is overexpressed in PDAC and its genetic inhibition suppresses c-Myc and disrupts c-Myc dependent transcriptional program. Mechanistically, BARD1 stabilizes c-Myc through ubiquitin-proteasome system by regulating FBXW7. Importantly, targeting BARD1 using either siRNAs or CRISPR/Cas9 deletion blocks PDAC growth in vitro and in vivo, without any signs of toxicity to mice. Using a focused drug library of 477 DNA damage response compounds, we also found that BARD1 inhibition enhances therapeutic efficacy of several clinically relevant agents (fold changes ≥4), including PARPi, in HRR proficient PDAC cells. These data uncover BARD1 as an attractive therapeutic target for HRR proficient PDAC.

Protein phosphatase 2A (PP2A) is a ubiquitously expressed serine/threonine phosphatase with a diverse and integral role in cellular signalling pathways. Consequently, its dysfunction is frequently observed in disease states such as cancer, inflammation and Alzheimer's disease. A growing understanding of both PP2A and its endogenous regulatory proteins has presented numerous targets for therapeutic intervention. This provides important context for the dynamic control and dysregulation of PP2A function in disease states. Understanding the intricate regulation of PP2A signalling in disease has resulted in the development of novel pharmacological agents aimed at restoring cellular homeostasis. Herein we review the structure and function of PP2A together with pharmacological modulators, both endogenous (proteins) and exogenous (small molecules and peptides), with relevance to targeting PP2A as a future pharmacotherapeutic strategy.

High c-Myc protein accumulation contributes to the proliferation, invasion, and drug resistance in multiple cancer cells, but the underlying mechanism about c-Myc accumulation remains not to be elucidated. Here, we demonstrate that TTC36 promotes c-Myc protein accumulation in hepatocellular carcinoma cells, thereby driving the proliferation and sorafenib resistance in hepatocellular carcinoma cells. Ttc36 depletion disrupts the interaction between SET and PPP2R1A, consequently activating PP2A. Activated PP2A directly dephosphorylates p-c-MycS62 and activates GSK3β, relying on AKT, leading increased phosphorylation of p-c-MycT58, finally promotes FBXW7-mediated polyubiquitination and degradation of c-Myc. Inhibitors targeting GSK3β and PP2A effectively reverse the sorafenib resistance promoted by TTC36. These findings highlight the crucial role of TTC36 in c-Myc accumulation-caused proliferation and sorafenib resistance in HCC, providing a promising combination strategy for treating patients with c-Myc protein accumulation in advanced HCC.

Neuroblastoma (NB), a malignant extracranial solid tumor originating from the sympathetic nervous system, exhibits poor prognosis in high-risk cases, with a 5-year overall survival rate below 50%. Glycolysis has been implicated in NB pathogenesis, and targeting glycolysis-related pathways shows therapeutic potential. This study investigates the role of the glycolysis-associated gene ALDOC in NB pathogenesis and its impact on chemotherapy sensitivity.

Transcriptomic data from NB patients were analyzed to identify ALDOC as an independent risk factor for high-risk NB. Protein expression levels of ALDOC were assessed in NB cells versus normal cells using immunoblotting. Functional experiments, including proliferation and migration assays, were conducted in ALDOC-interfered NB cell lines. Glycolytic activity was evaluated by measuring glucose uptake, lactate production, and ATP generation. Additionally, the sensitivity of ALDOC-downregulated NB cells to cisplatin and cyclophosphamide was tested to explore its role in chemotherapy response.

ALDOC was identified as a high-risk prognostic marker in NB, with elevated protein expression in NB cells compared to normal controls. Silencing ALDOC significantly inhibited NB cell proliferation and migration. Glycolytic activity was markedly reduced in ALDOC-downregulated cells, evidenced by decreased glucose uptake, lactate production, and ATP levels. Furthermore, ALDOC suppression enhanced NB cell sensitivity to cisplatin and cyclophosphamide, suggesting a glycolysis-dependent mechanism underlying chemotherapy resistance.

Our findings highlight ALDOC as a critical driver of NB progression through glycolysis acceleration, with implications for therapeutic targeting. The observed increase in chemotherapy sensitivity upon ALDOC inhibition underscores its potential as a biomarker for treatment optimization. However, the complexity of glycolysis regulation, involving multiple genes and pathways, necessitates further mechanistic studies to clarify ALDOC's specific role. Despite this limitation, our work emphasizes the importance of aerobic glycolysis in NB pathogenesis and provides a foundation for developing novel therapeutic strategies targeting ALDOC or associated pathways. Future research should explore interactions between ALDOC and other glycolytic regulators to refine combinatorial treatment approaches.

High Myc phenotypes are extensively documented in the hyperproliferative cell cycle of cancer cells, as well as non-proliferative endoreplication cycles engaged during normal development and stress response. Notably, endoreplication in cancer produces chemotherapy resistant polyploid cells, necessitating a clearer understanding of altered cell cycle regulation that uncouples DNA replication and mitotic cell division. The c-Myc oncogene is a well-established transcriptional regulator of cell cycle progression and has been extensively published as an essential driver of the G1/S transition. Beyond S phase, Myc transcriptionally activates the proteins that drive mitotic entry. Sustained activation of Myc through the cell cycle transcriptionally couples DNA replication and mitotic cell division. Based on the literature in this field, we propose a new model of temporal regulation of Myc activity that serves to either couple or uncouple these two processes, determining cell cycle fate - proliferation or polyploidy. The mitotic cell cycle requires two pulses of Myc activity - the first driving the G1/S transition and the second driving the G2/M transition. During mitosis, Myc activity must be silenced to achieve high-fidelity division. Absence of the second activity pulse during G2 results in the downregulation of the proteins essential for mitotic entry and permits premature activation of APC/C, inducing mitotic bypass. A subsequent rise of Myc activity following mitotic bypass permits genome re-replication, driving polyploid phenotypes. This model serves to provide a new level of understanding to the global regulation of S phase-mitosis coupling, as well as a new lens to view low Myc phenotypes.

Upon encountering antigens, B cells may undergo multiple differentiation paths, including becoming plasma cells and memory B cells. Although it is well-known that transcription factors govern gene expression programs underpinning these fate decisions in transcriptional level, the role of post-transcriptional regulators, with a focus on RNA-binding proteins, in the fate determination are lesser known. Here we find by RNA interactome capture-coupled CRISPR/Cas9 functional screening that the Csde1-Strap complex plays an important role in plasma cell differentiation. Mechanistically, the Csde1-Strap complex establishes the expression kinetics of Bach2, a key regulator of plasma cell differentiation. Bach2 expression is rapidly induced to promote B cell expansion and then decreased to initiate plasma cell differentiation. The Csde1-Strap interaction is critical for their binding to Bach2 mRNA to couple its decay with translation to restrain the magnitude and duration of Bach2 protein expression. In the absence of Csde1 or Strap, Bach2 translation is de-coupled from mRNA decay, leading to elevated and prolonged expression of Bach2 protein and impaired plasma cell differentiation. This study thus establishes the functional RBP landscape in B cells and illustrates the fundamental importance of controlling protein expression kinetics in cell fate determination.

Genomic instability is a hallmark of cancer, driving oncogenic mutations that enhance tumor aggressiveness and drug resistance. MYC, a master transcription factor that is deregulated in nearly all human tumors, paradoxically induces replication stress and associated DNA damage while also increasing expression of DNA repair factors and mediating resistance to DNA-damaging therapies. Emerging evidence supports a non-transcriptional role for MYC in preserving genomic integrity at sites of active transcription and protecting stalled replication forks under stress. Understanding how MYC's genotoxic and genoprotective functions diverge may reveal new therapeutic strategies for MYC-driven cancers. Here, we identify a non-canonical role of MYC in DNA damage response (DDR) through its direct association with DNA breaks. We show that phosphorylation at serine 62 (pS62-MYC) is crucial for the efficient recruitment of MYC to damage sites, its interaction with repair factors BRCA1 and RAD51, and effective DNA repair to support cell survival under stress. Mass spectrometry analysis with MYC-BioID2 during replication stress reveals a shift in MYC's interactome, maintaining DDR associations while losing transcriptional regulators. These findings establish pS62-MYC as a key regulator of genomic stability and a potential therapeutic target in cancers.

This study provides deeper insights into the regulatory role of the phospho-dependent prolyl isomerase PIN1 in bladder cancer. The identification of the link between PIN1 and SREBP2-mediated transcription and cholesterol biosynthesis offers the potential for developing novel therapeutic strategies for bladder cancer.

A deep understanding of the biological mechanisms driving the pathogenesis of myelodysplastic neoplasms (MDS) is essential to develop comprehensive therapeutic approaches that will benefit patient's disease management and quality of life. In this review, we focus on MDS harboring mutations in the splicing factor SF3B1. Clones harboring this mutation arise from the most primitive hematopoietic compartment and expand throughout the entire myeloid lineage, exerting distinct effects at various stages of differentiation. Supportive care, particularly managing anemia, remains essential in SF3B1-mutated MDS. While SF3B1 mutations are frequently linked with ring sideroblasts and iron overload due to impaired erythropoiesis, the current therapeutic landscape fails to adequately address the underlying disease biology, particularly in transfusion-dependent patients, where further iron overload contributes to increased morbidity and mortality. Novel agents such as Luspatercept and Imetelstat have shown promise, but their availability remains restricted and their long-term efficacy is to be investigated. Spliceosome modulators have failed to deliver and inhibitors of inflammatory pathways, including TLR and NF-κB inhibitors, are still under investigation. This scarcity of effective and disease-modifying therapies highlights the unmet need for new approaches tailored to the molecular and genetic abnormalities in SF3B1-mutated MDS. Emerging strategies targeting metabolic mis-splicing (e.g., COASY) with vitamin B5, pyruvate kinase activators, and inhibitors of oncogenic pathways like MYC and BCL-2 represent potential future avenues for treatment, but their clinical utility remains to be fully explored. The current limitations in treatment underscore the urgency of developing novel, more effective therapies for patients with SF3B1-mutated MDS.

Decorin (DCN) is primarily found in the connective tissues of various parts of the body, including the lungs, kidneys, bone tissue, aorta, and tendons. It is an important component of the extracellular matrix (ECM) and belongs to the class I small leucine-rich proteoglycans family. DCN is increasingly attracting attention due to its significant role in tumors, fibrotic diseases, and the regulation of vascular formation. Moreover, its anti-tumor properties have positioned it as a promising biomarker in the fight against cancer. Numerous studies have confirmed that DCN can exert inhibitory effects in various solid tumors, particularly in oral squamous cell carcinoma (OSCC), by activating its downstream pathways through binding with the epidermal growth factor receptor (EGFR) and mesenchymal-epithelial transition (MET) receptor, or by stabilizing and enhancing the expression of the tumor suppressor gene p53 to mediate apoptosis in cancer cells that have undergone mutation. The occurrence of OSCC is a continuous and dynamic process, encompassing the transition from normal mucosa to oral potentially malignant disorders (OPMDs), and further progressing from OPMDs to the malignant transformation into OSCC. We have found that DCN may exhibit a bidirectional effect in the progression of oral mucosal carcinogenesis, showing a trend of initial elevation followed by a decline, which decreases with the differentiation of OSCC. In OPMDs, DCN exhibits high expression and may be associated with malignant transformation, possibly linked to the increased expression of P53 in OPMDs. In OSCC, the expression of DCN is reduced, which can impact OSCC angiogenesis, and inhibit tumor cell proliferation, migration, and invasion capabilities, serving as a potential marker for predicting adverse prognosis in OSCC patients. This article reviews the current research status of DCN, covering its molecular structure, properties, and involvement in the onset and progression of oral mucosal carcinogenesis. It elucidates DCN's role in this process and aims to offer insights for future investigations into its mechanism of action in oral mucosal carcinogenesis and its potential application in the early diagnosis and treatment of OSCC.

Although natural killer (NK) cell responses to tumor and viral infection have been studied, the mechanisms underlying NK cell homeostasis in vivo remain unclear. In this study, we demonstrate the pharmacological action of cytostatin, a protein phosphatase 2A (PP2A) specific inhibitor (PP2Ai), on NK cells in regulating NK cell homeostasis in the peripheral tissues. We found that PP2Ai treatment decreased NK cell percentages in the bone marrow and secondary lymphoid tissues while increasing NK cell percentages in peripheral tissues such as the lung and liver. In the peripheral tissues of PP2Ai-treated mice, Ki-67 expression and BrdU uptake in NK cells were upregulated, and an initial increase in the pre-mature CD11bhiCD27hi NK subset was observed, followed by an increase in the terminally differentiated mature CD11bhiCD27lo NK subset. In addition, bone marrow Ki-67+ NK cells predominantly expressed CX3CR1 in the PP2Ai-treated mice and were further mobilized to the peripheral tissues. Among various target molecules of PP2A, we found that the upregulation of c-Myc pathway and its phosphorylation, along with its downstream cyclin E expression and G1/S cell cycle transition in PP2Ai-treated mice NK cells. Our results suggest that PP2Ai modulates NK cell proliferation through c-Myc and cyclin E, leading to their maturation and trafficking from the bone marrow to the peripheral tissues.

Bladder cancer (BLCA) is a common malignancy characterized by dysregulated transcription and a lack of effective therapeutic targets. In this study, we aimed to identify and evaluate novel targets with clinical potential essential for tumor growth in BLCA.

CRISPR-Cas9 screening was used to identify transcription factors essential for bladder cancer cell viability. The biological functions of KLF16 in bladder cancer were investigated both in vitro and in vivo. The regulatory mechanism between KLF16 and MYC was elucidated through a series of analyses, including RNA sequencing, quantitative polymerase chain reaction (qPCR), RNA immunoprecipitation, Western blotting, Mass spectrometry, Dual-luciferase reporter assays, Cleavage Under Targets and Tagmentation (CUT&Tag) sequencing, OptoDroplets assays, and RNA stability assay. The clinical relevance of KLF16 and MYC in bladder cancer was evaluated through analyses of public databases and immunohistochemistry.

Krüppel-like factor 16 (KLF16) was essential for BLCA cell viability. Elevated expression of KLF16 was observed in bladder cancer tissues, and higher expression levels of KLF16 were correlated with poor progression-free survival (PFS) and cancer-specific survival (CSS) probabilities in BLCA patients. Mechanistically, KLF16 mRNA competed with the mRNA of dual-specificity phosphatase 16 (DUSP16) for binding to the RNA-binding protein, WW domain binding protein 11 (WBP11), resulting in destabilization of the DUSP16 mRNA. This, in turn, led to activation of ERK1/2, which stabilized the MYC protein. Furthermore, KLF16 interacted with MYC to form nuclear condensates, thereby enhancing MYC's transcriptional activity. Additionally, MYC transcriptionally upregulated KLF16, creating a positive feedback loop between KLF16 and MYC that amplified their oncogenic functions. Targeting this loop with bromodomain inhibitors, such as OTX015 and ABBV-744, suppressed the transcription of both KLF16 and MYC, resulting in reduced BLCA cell viability and tumor growth, as well as increased sensitivity to chemotherapy.

Our study revealed the crucial role of the KLF16/MYC regulatory axis in modulating tumor growth and chemotherapy sensitivity in BLCA, suggesting that combining bromodomain inhibitors, such as OTX015 or ABBV-744, with DDP or gemcitabine could be a promising therapeutic intervention for BLCA patients.

Myc proteins are transcription factors crucial for cell proliferation. They have a C-terminal domain that mediates Max and DNA binding, and an N-terminal disordered region culminating in the transactivation domain (TAD). The TAD participates in many protein-protein interactions, notably with kinases that promote stability (Aurora-A) or degradation (ERK1, GSK3) via the ubiquitin-proteasome system. We probed the structure, dynamics and interactions of N-myc TAD using nuclear magnetic resonance (NMR) spectroscopy following its complete backbone assignment. Chemical shift analysis revealed that N-myc has two regions with clear helical propensity: Trp77-Glu86 and Ala122-Glu132. These regions also have more restricted ps-ns motions than the rest of the TAD, and, along with the phosphodegron, have comparatively high transverse (R2) 15N relaxation rates, indicative of slower timescale dynamics and/or chemical exchange. Collectively these features suggest differential propensities for structure and interaction, either internal or with binding partners, across the TAD. Solution studies on the interaction between N-myc and Aurora-A revealed a previously uncharacterised binding site. The specificity and kinetics of sequential phosphorylation of N-myc by ERK1 and GSK3 were characterised using NMR and resulted in no significant structural changes outside the phosphodegron. When the phosphodegron was doubly phosphorylated, N-myc formed a robust interaction with the Fbxw7-Skp1 complex, but mapping the interaction by NMR suggests a more extensive interface. Our study provides foundational insights into N-myc TAD dynamics and a backbone assignment that will underpin future work on the structure, dynamics, interactions and regulatory post-translational modifications of this key oncoprotein.

The serine/threonine with-no-lysine (WNK) kinase family function in blood pressure control, electrolyte homeostasis, and cellular osmoregulation. These kinases and their downstream effectors are considered promising therapeutic targets in hypertension and stroke. However, the role of WNK kinases in immune cells remains poorly understood.

Using the small-molecule WNK kinase inhibitors WNK463 and WNK-IN-11, we investigated how WNK kinase inhibition affects natural killer (NK) cell physiology.

WNK kinase inhibition with WNK463 or WNK-IN-11 significantly decreased IL-2-activated NK cell volume, motility, and cytolytic activity. Treatment of NK cells with these inhibitors induced autophagy by activating AMPK and inhibiting mTOR signaling. Moreover, WNK kinase inhibition increased phosphorylation of Akt and c-Myc by misaligning activity of activating kinases and inhibitory phosphatases. Treatment of tumor-bearing mice with WNK463 impaired tumor metastasis control by adoptively transferred NK cells.

The catalytic activity of WNK kinases has a critical role of multiple aspects of NK cell physiology and their pharmacologic inhibition negatively impacts NK cell function.

RAS and MYC rank amongst the most commonly altered oncogenes in cancer, with RAS being the most frequently mutated and MYC the most amplified. The cooperative interplay between RAS and MYC constitutes a complex and multifaceted phenomenon, profoundly influencing tumor development. Together and individually, these two oncogenes regulate most, if not all, hallmarks of cancer, including cell death escape, replicative immortality, tumor-associated angiogenesis, cell invasion and metastasis, metabolic adaptation, and immune evasion. Due to their frequent alteration and role in tumorigenesis, MYC and RAS emerge as highly appealing targets in cancer therapy. However, due to their complex nature, both oncogenes have been long considered "undruggable" and, until recently, no drugs directly targeting them had reached the clinic. This review aims to shed light on their complex partnership, with special attention to their active collaboration in fostering an immunosuppressive milieu and driving immunotherapeutic resistance in cancer. Within this review, we also present an update on the different inhibitors targeting RAS and MYC currently undergoing clinical trials, along with their clinical outcomes and the different combination strategies being explored to overcome drug resistance. This recent clinical development suggests a paradigm shift in the long-standing belief of RAS and MYC "undruggability", hinting at a new era in their therapeutic targeting.

Precursor T-cell neoplasms (T-ALL/LBL) are aggressive hematological malignancies that arise from the malignant transformation of immature thymocytes. Despite the JAK/STAT pathway is recurrently altered in these neoplasms, there are not pharmacological inhibitors officially approved for the treatment of T-ALL/LBL patients that present oncogenic JAK/STAT pathway mutations. In the effort to identify potential therapeutic targets for those patients, we followed an alternative approach and focused on their transcriptional profile. We combined the analysis of molecular data from T-ALL/LBL patients with the generation of hematopoietic cellular models to reveal that JAK/STAT pathway mutations are associated with an aberrant transcriptional profile. Specifically, we demonstrate that JAK/STAT pathway mutations induce the overexpression of the PIM1 gene. Moreover, we show that the pan-PIM inhibitor, PIM447, significantly reduces the leukemogenesis, as well as the aberrant activation of c-MYC and mTOR pathways in cells expressing different JAK/STAT pathway mutations, becoming a potential therapeutic opportunity for a relevant subset of T-ALL/LBL patients.

The eyes absent (Eya) proteins were first identified as co-activators of the six homeobox family of transcription factors and are critical in embryonic development. These proteins are also re-expressed in cancers after development is complete, where they drive tumor progression. We have previously shown that the Eya3 N-terminal domain (NTD) contains Ser/Thr phosphatase activity through an interaction with the protein phosphatase 2A (PP2A)-B55α holoenzyme and that this interaction increases the half-life of Myc through pT58 dephosphorylation. Here, we showed that Eya3 directly interacted with the NTD of Myc, recruiting PP2A-B55α to Myc. We also showed that Eya3 increased the Ser/Thr phosphatase activity of PP2A-B55α but not PP2A-B56α. Furthermore, we demonstrated that the NTD (∼250 amino acids) of Eya3 was completely disordered, and it used a 38-residue segment to interact with B55α. In addition, knockdown and phosphoproteomic analyses demonstrated that Eya3 and B55α affected highly similar phosphosite motifs with a preference for Ser/Thr followed by Pro, consistent with Eya3's apparent Ser/Thr phosphatase activity being mediated through its interaction with PP2A-B55α. Intriguingly, mutating this Pro to other amino acids in a Myc peptide dramatically increased dephosphorylation by PP2A. Not surprisingly, MycP59A, a naturally occurring mutation hotspot in several cancers, enhanced Eya3-PP2A-B55α-mediated dephosphorylation of pT58 on Myc, leading to increased Myc stability and cell proliferation, underscoring the critical role of this phosphosite in regulating Myc stability.

Protein phosphorylation is one of the most common mechanisms regulating cellular signaling pathways, and many kinases and phosphatases are proven drug targets. Upon phosphorylation, protein functions can be further regulated by the distinct isomerase Pin1 through cis-trans isomerization. Numerous protein targets and many important roles have now been elucidated for Pin1. However, no tools are available to detect or target cis and trans conformation events in cells. The development of Pin1 inhibitors and stereo- and phospho-specific antibodies has revealed that cis and trans conformations have distinct and often opposing cellular functions. Aberrant conformational changes due to the dysregulation of Pin1 can drive pathogenesis but can be effectively targeted in age-related diseases, including cancers and neurodegenerative disorders. Here, we review advances in understanding the roles of Pin1 signaling in health and disease and highlight conformational regulation as a distinct signal transduction checkpoint in disease development and treatment.

Members of the MYC family of proteins are a major target for cancer drug discovery, but the development of drugs that block MYC-driven cancers has not yet been successful. Approaches to achieve success may include the development of combination therapies or dual-acting drugs that target MYC at multiple nodes. Such treatments hold the possibility of additive or synergistic activity, potentially reducing side effect profiles and the emergence of resistance. In this review, we examine the prominent MYC-related targets and highlight those that have been targeted in combination and/or dual-target approaches. Finally, we explore the challenges of combination and dual-target approaches from a drug development perspective.

In vertical inhibition treatment strategies, multiple components of an intracellular pathway are simultaneously inhibited. Vertical inhibition of the BRAFV600E-MEK-ERK signalling pathway is a standard of care for treating BRAFV600E-mutated melanoma where two targeted cancer drugs, a BRAFV600E-inhibitor, and a MEK inhibitor, are administered in combination. Targeted therapies have been linked to early onsets of drug resistance, and thus treatment strategies of higher complexities and lower doses have been proposed as alternatives to current clinical strategies. However, finding optimal complex, low-dose treatment strategies is a challenge, as it is possible to design more treatment strategies than are feasibly testable in experimental settings. To quantitatively address this challenge, we develop a mathematical model of BRAFV600E-MEK-ERK signalling dynamics in response to combinations of the BRAFV600E-inhibitor dabrafenib (DBF), the MEK inhibitor trametinib (TMT), and the ERK-inhibitor SCH772984 (SCH). From a model of the BRAFV600E-MEK-ERK pathway, and a set of molecular-level drug-protein interactions, we extract a system of chemical reactions that is parameterised by in vitro data and converted to a system of ordinary differential equations (ODEs) using the law of mass action. The ODEs are solved numerically to produce simulations of how pathway-component concentrations change over time in response to different treatment strategies, i.e., inhibitor combinations and doses. The model can thus be used to limit the search space for effective treatment strategies that target the BRAFV600E-MEK-ERK pathway and warrant further experimental investigation. The results demonstrate that DBF and DBF-TMT-SCH therapies show marked sensitivity to BRAFV600E concentrations in silico, whilst TMT and SCH monotherapies do not.

This review examines the complex role of Pin1 in the development and treatment of cancer. Pin1 is the only peptidyl-prolyl isomerase (PPIase) that can recognize and isomerize phosphorylated Ser/Thr-Pro peptide bonds. Pin1 catalyzes a structural change in phosphorylated Ser/Thr-Pro motifs that can modulate protein function and thereby impact cell cycle regulation and tumorigenesis. The molecular mechanisms by which Pin1 contributes to oncogenesis are reviewed, including Pin1 overexpression and its correlation with poor cancer prognosis, and the contribution of Pin1 to aggressive tumor phenotypes involved in therapeutic resistance is discussed, with an emphasis on cancer stem cells, the epithelial-to-mesenchymal transition (EMT), and immunosuppression. The therapeutic potential of Pin1 inhibition in cancer is discussed, along with the promise and the difficulties in identifying potent, drug-like, small-molecule Pin1 inhibitors. The available evidence supports the efficacy of targeting Pin1 as a novel cancer therapeutic by analyzing the role of Pin1 in a complex network of cancer-driving pathways and illustrating the potential of synergistic drug combinations with Pin1 inhibitors for treating aggressive and drug-resistant tumors.

Breast cancer has become the most prevalent malignancy worldwide; however, therapeutic efficacy is far from satisfactory. To alleviate the burden of this disease, it is imperative to discover novel mechanisms and treatment strategies. Protein phosphatase 2 A (PP2A) comprises a family of mammalian serine/threonine phosphatases that regulate many cellular processes. PP2A is dysregulated in several human diseases, including oncological pathologies, and plays a pivotal role in the initiation and progression of tumours. The role of PP2A as a tumour suppressor has been extensively studied, and its regulation can serve as a target for anticancer therapy. Recent studies have shown that PP2A is a tumour promotor. PP2A-mediated anticancer therapy may involve two opposing mechanisms: activation and inhibition. In general, the contradictory roles of PP2A should not be overlooked, and more work is needed to determine the molecular mechanism by which PP2A affects in tumours. In this review, the literature on the role of PP2A in tumours, especially in breast cancer, was analysed. This review describes relevant targets of breast cancer, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may lead to effective therapeutic strategies or influence drug development in breast cancer.

Background: Anaplastic thyroid cancer (ATC) is highly aggressive and has very limited treatment options. Recent studies suggest that cancer stem cell (CSC) activity in ATC could underlie this recurrence and resistance to treatment. The recent approval by the U.S. Food and Drug Administration of the combined treatment of BRAF and MEK inhibitors for ATC patients has shown some efficacy in patients harboring the BRAFV600E mutation. However, it was unknown whether the combined treatment could affect the CSC activity. This study explores the effects of the BRAF and MEK inhibitors on CSC activity in human ATC cells. Methods: Using three human ATC cells, THJ-11T, THJ-16T, and 8505C cells, we evaluated the effects of dabrafenib (a BRAF kinase inhibitor), trametinib (an MEK inhibitor), or a combined treatment of the two drugs on the CSC activity by tumorsphere formation, Aldefluor assays, expression profiles of key CSC markers, immunohistochemistry, and in vivo xenograft mouse models. Furthermore, we also used confocal imaging to directly visualize the effects on drugs on CSCs by the SORE6-mCherry reporter in cultured cells and xenograft tumor cells. Results: The BRAF inhibitor, dabrafenib, had weak efficacy, while the MEK inhibitor, trametinib, showed strong efficacy in attenuating the CSC activity, as evidenced by suppression of CSC marker expression, tumorsphere formation, and Aldefluor assays. Using ATC cells expressing a fluorescent CSC SORE6 reporter, we showed reduction of CSC activity in the rank order of combined > trametinib > dabrafenib through in vitro and in vivo xenograft models. Molecular analyses showed that suppression of CSC activity by these drugs was, in part, mediated by attenuation of the transcription by dampening the RNA polymerase II activity. Conclusions: Our analyses demonstrated the presence of CSCs in ATC cells. The inhibition of CSC activity by the MEK signaling could partially account for the efficacy of the combined treatment shown in ATC patients. However, our studies also showed that not all CSC activity was totally abolished, which may account for the recurrence observed in ATC patients. Our findings have provided new insights into the molecular basis of efficacy and limitations of these drugs in ATC patients.

Various diseases, including cancers, age-associated disorders, and acute liver failure, have been linked to the oncogene, MYC. Animal testing and clinical trials have shown that sustained tumor volume reduction can be achieved when MYC is inactivated, and different combinations of therapeutic agents including MYC inhibitors are currently being developed. In this review, we first provide a summary of the multiple biological functions of the MYC oncoprotein in cancer treatment, highlighting that the equilibrium points of the MYC/MAX, MIZ1/MYC/MAX, and MAD (MNT)/MAX complexes have further potential in cancer treatment that could be used to restrain MYC oncogene expression and its functions in tumorigenesis. We also discuss the multifunctional capacity of MYC in various cellular cancer processes, including its influences on immune response, metabolism, cell cycle, apoptosis, autophagy, pyroptosis, metastasis, angiogenesis, multidrug resistance, and intestinal flora. Moreover, we summarize the MYC therapy patent landscape and emphasize the potential of MYC as a druggable target, using herbal medicine modulators. Finally, we describe pending challenges and future perspectives in biomedical research, involving the development of therapeutic approaches to modulate MYC or its targeted genes. Patients with cancers driven by MYC signaling may benefit from therapies targeting these pathways, which could delay cancerous growth and recover antitumor immune responses.

Chordomas are clinically aggressive tumors with a high rate of disease progression despite maximal therapy. Given the limited therapeutic options available, there remains an urgent need for the development of novel therapies to improve clinical outcomes. Cell surface proteins are attractive therapeutic targets yet are challenging to profile with common methods. Four chordoma cell lines were analyzed by quantitative proteomics using a differential ultracentrifugation organellar fractionation approach. A subtractive proteomics strategy was applied to select proteins that are plasma membrane enriched. Systematic data integration prioritized PLA2R1 (secretory phospholipase A2 receptor-PLA2R1) as a chordoma-enriched surface protein. The expression profile of PLA2R1 was validated across chordoma cell lines, patient surgical tissue samples, and normal tissue lysates via immunoblotting. PLA2R1 expression was further validated by immunohistochemical analysis in a richly annotated cohort of 25-patient tissues. Immunohistochemistry analysis revealed that elevated expression of PLA2R1 is correlated with poor prognosis. Using siRNA- and CRISPR/Cas9-mediated knockdown of PLA2R1, we demonstrated significant inhibition of 2D, 3D and in vivo chordoma growth. PLA2R1 depletion resulted in cell cycle defects and metabolic rewiring via the MAPK signaling pathway, suggesting that PLA2R1 plays an essential role in chordoma biology. We have characterized the proteome of four chordoma cell lines and uncovered PLA2R1 as a novel cell-surface protein required for chordoma cell survival and association with patient outcome.

Acute myeloid leukemia (AML) with fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) has poor outcomes. FLT3-ITD drives constitutive and aberrant FLT3 signaling, activating STAT5 and upregulating the downstream oncogenic serine/threonine kinase Pim-1. FLT3 inhibitors are in clinical use, but with limited and transient efficacy. We previously showed that concurrent treatment with Pim and FLT3 inhibitors increases apoptosis induction in FLT3-ITD-expressing cells through posttranslational downregulation of Mcl-1. Here we further elucidate the mechanism of action of this dual targeting strategy. Cytotoxicity, apoptosis and protein expression and turnover were measured in FLT3-ITD-expressing cell lines and AML patient blasts treated with the FLT3 inhibitor gilteritinib and/or the Pim inhibitors AZD1208 or TP-3654. Pim inhibitor and gilteritinib cotreatment increased apoptosis induction, produced synergistic cytotoxicity, downregulated c-Myc protein expression, earlier than Mcl-1, increased turnover of both proteins, which was rescued by proteasome inhibition, and increased efficacy and prolonged survival in an in vivo model. Gilteritinib and Pim inhibitor cotreatment of Ba/F3-ITD cells infected with T58A c-Myc or S159A Mcl-1 plasmids, preventing phosphorylation at these sites, did not downregulate these proteins, increase their turnover or increase apoptosis induction. Moreover, concurrent treatment with gilteritinib and Pim inhibitors dephosphorylated (activated) the serine/threonine kinase glycogen synthase kinase-3β (GSK-3β), and GSK-3β inhibition prevented c-Myc and Mcl-1 downregulation and decreased apoptosis induction. The data are consistent with c-Myc T58 and Mcl-1 S159 phosphorylation by activated GSK-3β as the mechanism of action of gilteritinib and Pim inhibitor combination treatment, further supporting GSK-3β activation as a therapeutic strategy in FLT3-ITD AML.

FLT3-ITD is present in 25% of in AML, with continued poor outcomes. Combining Pim kinase inhibitors with the FDA-approved FLT3 inhibitor gilteritinib increases cytotoxicity in vitro and in vivo through activation of GSK-3β, which phosphorylates and posttranslationally downregulates c-Myc and Mcl-1. The data support efficacy of GSK-3β activation in FLT3-ITD AML, and also support development of a clinical trial combining the Pim inhibitor TP-3654 with gilteritinib.

PIM3 (provirus-integrating Moloney site 3) is a serine/threonine kinase and belongs to the PIM family (PIM1, PIM2, and PIM3). PIM3 is a proto-oncogene that is frequently overexpressed in cancers originating from endoderm-derived tissues, such as the liver, pancreas, colon, stomach, prostate, and breast cancer. PIM3 plays a critical role in activating multiple oncogenic signaling pathways promoting cancer cell proliferation, survival, invasion, tumor growth, metastasis, and progression, as well as chemo- and radiation therapy resistance and immunosuppressive microenvironment. Genetic inhibition of PIM3 expression suppresses in vitro cell proliferation and in vivo tumor growth and metastasis in mice with solid cancers, indicating that PIM3 is a potential therapeutic target. Although several pan-PIM inhibitors entered phase I clinical trials in hematological cancers, there are currently no FDA-approved inhibitors for the treatment of patients. This review provides an overview of recent developments and insights into the role of PIM3 in various cancers and its potential as a novel molecular target for cancer therapy. We also discuss the current status of PIM-targeted therapies in clinical trials.

Medulloblastoma is the most common pediatric brain malignancy. Patients with the Group 3 subtype of medulloblastoma (MB) often exhibit MYC amplification and/or overexpression and have the poorest prognosis. While Group 3 MB is known to be highly dependent on MYC, direct targeting of MYC remains elusive.

Patient gene expression data were used to identify highly expressed EYA2 in Group 3 MB samples, assess the correlation between EYA2 and MYC, and examine patient survival. Genetic and pharmacological studies were performed on EYA2 in Group 3 derived MB cell models to assess MYC regulation and viability in vitro and in vivo.

EYA2 is more highly expressed in Group 3 MB than other MB subgroups and is essential for Group 3 MB growth in vitro and in vivo. EYA2 regulates MYC expression and protein stability in Group 3 MB, resulting in global alterations of MYC transcription. Inhibition of EYA2 tyrosine phosphatase activity, using a novel small molecule inhibitor (NCGC00249987, or 9987), significantly decreases Group 3 MB MYC expression in both flank and intracranial growth in vivo. Human MB RNA-seq data show that EYA2 and MYC are significantly positively correlated, high EYA2 expression is significantly associated with a MYC transcriptional signature, and patients with high EYA2 and MYC expression have worse prognoses than those that do not express both genes at high levels.

Our data demonstrate that EYA2 is a critical regulator of MYC in Group 3 MB and suggest a novel therapeutic avenue to target this highly lethal disease.

KMT2A-rearranged (KMT2A-R) is an aggressive and chemo-refractory acute leukemia which mostly affects children. Transcriptomics-based characterization and chemical interrogation identified kinases as key drivers of survival and drug resistance in KMT2A-R leukemia. In contrast, the contribution and regulation of phosphatases is unknown. In this study we uncover the essential role and underlying mechanisms of SET, the endogenous inhibitor of Ser/Thr phosphatase PP2A, in KMT2A-R-leukemia. Investigation of SET expression in acute myeloid leukemia (AML) samples demonstrated that SET is overexpressed, and elevated expression of SET is correlated with poor prognosis and with the expression of MEIS and HOXA genes in AML patients. Silencing SET specifically abolished the clonogenic ability of KMT2A-R leukemic cells and the transcription of KMT2A targets genes HOXA9 and HOXA10. Subsequent mechanistic investigations showed that SET interacts with both KMT2A wild type and fusion proteins, and it is recruited to the HOXA10 promoter. Pharmacological inhibition of SET by FTY720 disrupted SET-PP2A interaction leading to cell cycle arrest and increased sensitivity to chemotherapy in KMT2A-R-leukemic models. Phospho-proteomic analyses revealed that FTY720 reduced the activity of kinases regulated by PP2A, including ERK1, GSK3β, AURB and PLK1 and led to suppression of MYC, supporting the hypothesis of a feedback loop among PP2A, AURB, PLK1, MYC, and SET. Our findings illustrate that SET is a novel player in KMT2A-R leukemia and they provide evidence that SET antagonism could serve as a novel strategy to treat this aggressive leukemia.

Testicular germ cell tumors (TGCTs) frequently affect adolescent and young adult males. Although TGCT is more responsive to cisplatin-based chemotherapy than other solid tumors, some patients are nonresponders, and following treatment, many patients continue to experience acute and long-term cytotoxic effects from cisplatin-based chemotherapy. Consequently, it is imperative to develop new therapeutic modalities for treatment-resistant TGCTs. Peptidyl-prolyl isomerase (Pin1) regulates the activity and stability of many cancer-associated target proteins. Prior findings suggest that Pin1 contributes to the pathogenesis of multiple human cancers. However, the specific function of Pin1 in TGCTs has not yet been elucidated. TGCT cell proliferation and viability were examined using cell cycle analysis and apoptosis assays following treatment with KPT6566, a potent, selective Pin1 inhibitor that covalently binds to the catalytic domain of Pin1. A xenograft mouse model was used to assess the effect of KPT6566 on tumor growth in vivo. KPT6566 effectively suppressed cell proliferation, colony formation, and ATP production in P19 and NCCIT cells. Further, KPT6566 induced apoptotic cell death by generating cellular reactive oxygen species and downregulating the embryonic transcription factors Oct-4 and Sox2. Finally, KPT6566 treatment significantly reduced tumor volume and mass in P19 cell xenografts. The Pin1 inhibitor KPT6566 has significant antiproliferative and antitumor effects in TGCT cells. These findings suggest that Pin1 inhibitors could be considered as a potential therapeutic approach for TGCTs.

Cell cycle errors can lead to mutations, chromosomal instability, or death; thus, the precise control of cell cycle progression is essential for viability. The nutrient-sensing posttranslational modification, O-GlcNAc, regulates the cell cycle allowing one central control point directing progression of the cell cycle. O-GlcNAc is a single N-acetylglucosamine sugar modification to intracellular proteins that is dynamically added and removed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. These enzymes act as a rheostat to fine-tune protein function in response to a plethora of stimuli from nutrients to hormones. O-GlcNAc modulates mitogenic growth signaling, senses nutrient flux through the hexosamine biosynthetic pathway, and coordinates with other nutrient-sensing enzymes to progress cells through Gap phase 1 (G1). At the G1/S transition, O-GlcNAc modulates checkpoint control, while in S Phase, O-GlcNAcylation coordinates the replication fork. DNA replication errors activate O-GlcNAcylation to control the function of the tumor-suppressor p53 at Gap Phase 2 (G2). Finally, in mitosis (M phase), O-GlcNAc controls M phase progression and the organization of the mitotic spindle and midbody. Critical for M phase control is the interplay between OGT and OGA with mitotic kinases. Importantly, disruptions in OGT and OGA activity induce M phase defects and aneuploidy. These data point to an essential role for the O-GlcNAc rheostat in regulating cell division. In this review, we highlight O-GlcNAc nutrient sensing regulating G1, O-GlcNAc control of DNA replication and repair, and finally, O-GlcNAc organization of mitotic progression and spindle dynamics.

Due to the enhanced glycolytic rate, cancer cells generate lactate copiously, subsequently promoting the lactylation of histones. While previous studies have explored the impact of histone lactylation in modulating gene expression, the precise role of this epigenetic modification in regulating oncogenes is largely unchartered. In this study, using breast cancer cell lines and their mutants exhibiting lactate-deficient metabolome, we have identified that an enhanced rate of aerobic glycolysis supports c-Myc expression via promoter-level histone lactylation. Interestingly, c-Myc further transcriptionally upregulates serine/arginine splicing factor 10 (SRSF10) to drive alternative splicing of MDM4 and Bcl-x in breast cancer cells. Moreover, our results reveal that restricting the activity of critical glycolytic enzymes affects the c-Myc-SRSF10 axis to subside the proliferation of breast cancer cells. Our findings provide novel insights into the mechanisms by which aerobic glycolysis influences alternative splicing processes that collectively contribute to breast tumorigenesis. Furthermore, we also envisage that chemotherapeutic interventions attenuating glycolytic rate can restrict breast cancer progression by impeding the c-Myc-SRSF10 axis.

Hepatocellular carcinoma (HCC) is the third deadliest and sixth most common cancer in the world. Histone-lysine N-methyltransferase EHMT2 (also known as G9a) is a histone methyltransferase frequently overexpressed in many cancer types, including HCC. We showed that Myc-driven liver tumours have a unique H3K9 methylation pattern with corresponding G9a overexpression. This phenomenon of increased G9a was further observed in our c-Myc-positive HCC patient-derived xenografts. More importantly, we showed that HCC patients with higher c-Myc and G9a expression levels portend a poorer survival with lower median survival months. We demonstrated that c-Myc interacts with G9a in HCC and cooperates to regulate c-Myc-dependent gene repression. In addition, G9a stabilises c-Myc to promote cancer development, contributing to the growth and invasive capacity in HCC. Furthermore, combination therapy between G9a and synthetic-lethal target of c-Myc, CDK9, demonstrates strong efficacy in patient-derived avatars of Myc-driven HCC. Our work suggests that targeting G9a could prove to be a potential therapeutic avenue for Myc-driven liver cancer. This will increase our understanding of the underlying epigenetic mechanisms of aggressive tumour initiation and lead to improved therapeutic and diagnostic options for Myc-driven hepatic tumours.

MYC, a key member of the Myc-proto-oncogene family, is a universal transcription amplifier that regulates almost every physiological process in a cell including cell cycle, proliferation, metabolism, differentiation, and apoptosis. MYC interacts with several cofactors, chromatin modifiers, and regulators to direct gene expression. MYC levels are tightly regulated, and deregulation of MYC has been associated with numerous diseases including cancer. Understanding the comprehensive biology of MYC under physiological conditions is an utmost necessity to demark biological functions of MYC from its pathological functions. Here we review the recent advances in biological mechanisms, functions, and regulation of MYC. We also emphasize the role of MYC as a global transcription amplifier.