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Zygulska AL, Furgala A, Kaszuba-Zwoińska J, Krzemieniecki K, Gil K. Changes in plasma levels of cholecystokinin, neurotensin, VIP and PYY in gastric and colorectal cancer - Preliminary results. Peptides 2019; 122:170148. [PMID: 31541684 DOI: 10.1016/j.peptides.2019.170148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 08/29/2019] [Accepted: 09/02/2019] [Indexed: 12/11/2022]
Abstract
Physiological roles of enterohormones such as secretion, absorption and digestion were supported by clinical data. Overexpression of cholecystokinin (CCK), neurotensin (NT) and vasoactive intestinal peptide (VIP) receptors occur in gastrointestinal (GI) malignancies. The aim of the paper was to compare plasma levels of CCK, peptide YY (PYY), VIP and NT in patients with gastrointestinal malignancies and healthy controls. The study included 80 patients (37 men and 43 women) with GI malignancies (20 with gastric and 60 with colorectal cancers). Median age of the patients was 62.9 years (range: 40-85 years). Control group was comprised of 30 healthy persons with median age 59.8 years (range: 40-82 years). Fasting plasma concentrations of CKK, PYY, NT, and VIP were determined at rest, using ELISA kits for automated systems. Comparative analysis of enterohormone levels in patients with various types of gastrointestinal malignancies demonstrated presence of some cancer-specific alterations. Patients with gastric cancers presented with lower plasma concentrations of CCK than healthy controls and individuals from colorectal cancers (p = 0.02). The highest plasma concentrations of neurotensin was found in colorectal cancer patients in comparison to gastric (p = 0.02). The plasma levels of VIP observed in gastric cancer group were lower than in colorectal cancer patients (p = 0.01). Patients with GI malignancies may present with tumor-specific alterations in plasma enterohormone levels.
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Affiliation(s)
- Aneta Lidia Zygulska
- Department of Oncology, Krakow University Hospital, 10 Sniadeckich St., 31-531, Krakow, Poland.
| | - Agata Furgala
- Department of Pathophysiology, Jagiellonian University Medical College, 18 Czysta St., 31-121, Krakow, Poland.
| | - Jolanta Kaszuba-Zwoińska
- Department of Pathophysiology, Jagiellonian University Medical College, 18 Czysta St., 31-121, Krakow, Poland.
| | - Krzysztof Krzemieniecki
- Department of Oncology, Krakow University Hospital, 10 Sniadeckich St., 31-531, Krakow, Poland; Department of Oncology, Jagiellonian University, 10 Sniadeckich St., 31-531, Krakow, Poland.
| | - Krzysztof Gil
- Department of Pathophysiology, Jagiellonian University Medical College, 18 Czysta St., 31-121, Krakow, Poland.
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Rees CL, White CM, Ascoli GA. Neurochemical Markers in the Mammalian Brain: Structure, Roles in Synaptic Communication, and Pharmacological Relevance. Curr Med Chem 2017; 24:3077-3103. [PMID: 28413962 PMCID: PMC5646670 DOI: 10.2174/0929867324666170414163506] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/15/2017] [Accepted: 04/10/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Knowledge of molecular marker (typically protein or mRNA) expression in neural systems can provide insight to the chemical blueprint of signal processing and transmission, assist in tracking developmental or pathological progressions, and yield key information regarding potential medicinal targets. These markers are particularly relevant in the mammalian brain in the light of its unsurpassed cellular diversity. Accordingly, molecular expression profiling is rapidly becoming a major approach to classify neuron types. Despite a profusion of research, however, the biological functions of molecular markers commonly used to distinguish neuron types remain incompletely understood. Furthermore, most molecular markers of mammalian neuron types are also present in other organs, therefore complicating considerations of their potential pharmacological interactions. OBJECTIVE Here, we survey 15 prominent neurochemical markers from five categories, namely membrane transporters, calcium-binding proteins, neuropeptides, receptors, and extracellular matrix proteins, explaining their relation and relevance to synaptic communication. METHOD For each marker, we summarize fundamental structural features, cellular functionality, distributions within and outside the brain, as well as known drug effectors and mechanisms of action. CONCLUSION This essential primer thus links together the cellular complexity of the brain, the chemical properties of key molecular players in neurotransmission, and possible biomedical opportunities.
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Affiliation(s)
- Christopher L. Rees
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Charise M. White
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Giorgio A. Ascoli
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
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Rai R, Chandra V, Tewari M, Kumar M, Shukla HS. Cholecystokinin and gastrin receptors targeting in gastrointestinal cancer. Surg Oncol 2012; 21:281-92. [PMID: 22801592 DOI: 10.1016/j.suronc.2012.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 05/16/2012] [Accepted: 06/21/2012] [Indexed: 12/12/2022]
Abstract
Cholecystokinin and Gastrin are amongst the first gastrointestinal hormone discovered. In addition to classical actions (contraction of gallbladder, growth and secretion in the stomach and pancreas), these also act as growth stimulants for gastrointestinal malignancies and cell lines. Growth of these tumours is inhibited by antagonists of the cholecystokinin and gastrin receptors. These receptors provides most promising approach in clinical oncology and several specific radiolabelled ligands have been synthesized for specific tumour targeting and therapy of tumours overexpressing these receptors. Therefore, definition of the molecular structure of the receptor involved in the autocrine/paracrine loop may contribute to novel therapies for gastrointestinal cancer. Hence, this review tries to focus on the role and distribution of these hormones and their receptors in gastrointestinal cancer with a brief talk about the clinical trial using available agonist and antagonist in gastrointestinal cancers.
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Affiliation(s)
- Rajani Rai
- Department of Surgical Oncology, Banaras Hindu University, 7 SKG Colony, Lanka, Varanasi 221005, Uttar Pradesh, India
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Ellrichmann M, Ritter PR, Schrader H, Schmidt WE, Meier JJ, Schmitz F. Gastrin stimulates the VEGF-A promotor in a human colon cancer cell line. ACTA ACUST UNITED AC 2010; 165:146-50. [PMID: 20600355 DOI: 10.1016/j.regpep.2010.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/26/2010] [Accepted: 06/22/2010] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Hypergastrinemia has been observed in patients suffering from colorectal cancer. Vascular endothelial growth factor (VEGF) is known to play a pivotal role in tumour growth. Therefore, we addressed whether gastrin-17-gly and gastrin-17-amide regulate VEGF-A-gene and protein expression. MATERIALS AND METHODS Colo-320-cells were stably transfected with a VEGF-Luciferase-reporter gene. Luciferase activity was assessed after stimulation with various gastrin concentrations. Relevant promotor elements were identified by deletion analyses. VEGF protein levels in culture supernatants were quantified by ELISA. RESULTS VEGF-A stimulation with gastrin induced a dose- and time-dependent stimulation of luciferase activity. The greatest activities were found 6h after stimulation at concentrations of 10(-)(6)mmol/l. VEGF-promotor expression resulted in significantly (p<0.05) increased VEGF-A protein secretion. These effects were restricted to gastrin-17-amide. CONCLUSION Gastrin-17-amide enhances VEGF-A gene and protein expression in Colo320 cells stably transfected with a wild-type CCK-B/gastrin receptor. The induction of VEGF-A transcription and translation may contribute to the carcinogenic effects of gastrin observed in clinical studies. Therefore, CCK-B receptor antagonists may represent a treatment strategy in patients with colorectal cancer.
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Affiliation(s)
- Mark Ellrichmann
- Department of Medicine I, St. Josef Hospital, Ruhr-University Bochum, Gudrunstrasse 56, Bochum, Germany.
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Copps J, Murphy RF, Lovas S. The production and role of gastrin-17 and gastrin-17-gly in gastrointestinal cancers. Protein Pept Lett 2010; 16:1504-18. [PMID: 20001914 DOI: 10.2174/092986609789839269] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The gastrointestinal peptide hormone gastrin is responsible for initiating the release of gastric acid in the stomach in response to the presence of food and/or humoral factors such as gastrin releasing peptide. However, it has a role in the growth and maintenance of the gastric epithelium, and has been implicated in the formation and growth of gastric cancers. Hypergastrinemia resulting from atrophic gastritis and pernicious anemia leads to hyperplasia and carcinoid formation in rats, and contributes to tumor formation in humans. Additionally, gastrin has been suspected to play a role in the formation and growth of cancers of the colon, but recent studies have instead implicated gastrin processing intermediates, such as gastrin-17-Gly, acting upon a putative, non-cholecystokinin receptor. This review summarizes the production and chemical structures of gastrin and of the processing intermediate gastrin-17-Gly, as well as their activities in the gastrointestinal tract, particularly the promotion of colon cancers.
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Affiliation(s)
- Jeffrey Copps
- Department of Biomedical Sciences, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
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Hsu SJ, Patel A, Larsen PD, Bohmann DJ, Bauer RJ, Ma JK, Masat L, Roell M, Babuka SJ, Hansen RK, White M, Haak-Frendscho M. Development of XPA067.06, a potent high affinity human anti-gastrin monoclonal antibody. Biochem Pharmacol 2008; 76:340-52. [DOI: 10.1016/j.bcp.2008.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 05/09/2008] [Accepted: 05/13/2008] [Indexed: 10/22/2022]
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Characterization of mitochondrial trifunctional protein and its inactivation study for medicine development. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:1742-9. [PMID: 18640292 DOI: 10.1016/j.bbapap.2008.06.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2008] [Revised: 06/11/2008] [Accepted: 06/23/2008] [Indexed: 11/21/2022]
Abstract
Mitochondrial trifunctional protein (MTP) catalyzes three consecutive step reactions in the beta-oxidation of long-chain fatty acids, and plays important roles in control and regulation of the beta-oxidation. We overexpressed in E. coli, and purified the MTP as a Mistic fusion protein, which was found to be an alpha(2)beta(2) protein complex and characterized with kinetic studies. Trimetazidine, used for treating chronic stable angina, has been proposed to be an inhibitor of the beta-subunit. We found that a catalytic cysteine residue C105 was labeled by trimetazidine through MS/MS analysis of a trimetazidine-labeled peptide fragment obtained from pepsin digested beta-subunit inactivated by trimetazidine. The MTP beta-subunit was then comparatively studied with monofunctional 3-ketoacyl-CoA thiolase through sequence alignment, site-directed mutagenesis, characterization of variant enzymes with kinetic studies, and homology modeling. The results indicate that the catalytic residues of the MTP beta-subunit are positioned in the active site similarly to those of monofunctional 3-ketoacyl-CoA thiolase.
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9
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Tietze L, Panknin O, Major F, Krewer B. Synthesis of a Novel Pentagastrin-Drug Conjugate for a Targeted Tumor Therapy. Chemistry 2008; 14:2811-8. [DOI: 10.1002/chem.200701521] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Prognostic significance of gastrin expression in patients undergoing R0 gastrectomy for adenocarcinoma. Gastric Cancer 2008; 10:159-66. [PMID: 17922093 DOI: 10.1007/s10120-007-0429-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Accepted: 05/19/2007] [Indexed: 02/07/2023]
Abstract
BACKGROUND Gastrointestinal (GI) hormones regulate several GI functions, including the proliferation and repair of normal mucosa, and hormone receptors may therefore be implicated in the growth, invasion, and metastasis of cancers of the GI tract. The aim of this study was to determine the cellular distribution of gastrin in intestinal-type gastric cancers, and to determine its relationship to outcomes after R0 gastrectomy. METHODS Eighty-six consecutive patients undergoing R0 gastrectomy for adenocarcinoma were studied. Normal gastric mucosa and tumor were stained for gastrin and their specific cellular distribution was determined. RESULTS The duration of survival of patients whose tumors exhibited well-differentiated gastrin-positive tumor (GPT) cells (n = 12) was significantly poorer than that of patients whose tumors were GPT-negative (5-year survival, 30% vs 54%; P = 0.037). Patients with GPT-positive intestinal-type gastric cancer (5 of 47 patients) had the poorest survival of all (median, 14 months; 5-year survival, 0%; P = 0.006). In a multivariate analysis, only lymph node metastases (hazard ratio [HR], 2.13; 95% confidence interval [CI], 1.2 to 3.79; P = 0.01) and the presence of GPT cells (HR, 6.61; 95% CI, 1.74 to 25.09; P = 0.01) were independently and significantly associated with durations of survival in patients with intestinal-type gastric cancer. CONCLUSION The presence of GPT cells in patients with gastric adenocarcinoma is a significant and independent prognostic indicator.
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Singh M, Dhindsa G, Friedland S, Triadafilopoulos G. Long-term use of proton pump inhibitors does not affect the frequency, growth, or histologic characteristics of colon adenomas. Aliment Pharmacol Ther 2007; 26:1051-61. [PMID: 17877512 DOI: 10.1111/j.1365-2036.2007.03450.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The clinical significance of the trophic effects of long-term proton pump inhibitors (PPI)-related hypergastrinemia on colon polyps remains unknown. AIM To study the frequency, growth, and histology of colon polyps in patients on chronic PPI therapy (cases), compared to those not receiving acid suppression (controls). METHODS Medical records of 2868 consecutive patients who underwent two or more colonoscopies, performed 3 or more months apart were reviewed. Cases (116) that used PPIs between the two colonoscopies were then compared to controls (194). RESULTS Demographics and risk factors for colon cancer were comparable between the two groups. At baseline the mean frequency and size of adenomatous polyps were similar in cases and controls (P > 0.05) and at follow-up, these were 0.89 and 1.18 (P > 0.05; 95% CI of -0.08 to 0.66) and 4.09 mm and 4.00 mm (P > 0.05; 95% CI -2.29 to 2.11), respectively with no significant change. However, control group had a higher mean frequency and size of hyperplastic polyps at baseline as well as at follow-up colonoscopy (P < 0.05). CONCLUSIONS The long-term use of PPI does not influence the frequency, growth, or histology of adenomatous polyps, but is associated with a reduction in both baseline and interval development of hyperplastic polyps.
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Affiliation(s)
- M Singh
- Gastroenterology Section, Veterans Affairs Health Care System, Palo Alto, CA, USA
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Sebens Müerköster S, Rausch AV, Isberner A, Minkenberg J, Blaszczuk E, Witt M, Fölsch UR, Schmitz F, Schäfer H, Arlt A. The apoptosis-inducing effect of gastrin on colorectal cancer cells relates to an increased IEX-1 expression mediating NF-κB inhibition. Oncogene 2007; 27:1122-34. [PMID: 17704804 DOI: 10.1038/sj.onc.1210728] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Addressing the puzzling role of amidated gastrin(17) (G17) and the gastrin/CCKB/CCK2 receptor in colorectal carcinogenesis, we analysed potential candidate genes involved in G17-dependent NF-kappaB inhibition and apoptosis. The colorectal carcinoma cell line Colo320 overexpressing the wild-type CCK2 receptor (Colo320wt) underwent G17-induced apoptosis along with suppressed NF-kappaB activation and decreased expression of the antiapoptotic NF-kappaB target genes cIAP1 and cIAP2, whereas G17 was without effect on Colo320 cells expressing a CCK2 receptor bearing a loss of function mutation (Colo320mut). Gene microarray analysis revealed an elevated expression of the stress response gene IEX-1 in G17-treated Colo320wt but not Colo320mut cells. Quantitative real-time PCR and conventional RT-PCR confirmed this G17-dependent increase of IEX-1 expression in Colo320wt cells. If these cells were subjected to IEX-1 knockdown by small interfering RNA transfection, the apoptosis-inducing effect of G17 was abolished. Moreover, tumor necrosis factor alpha (TNFalpha)- or 5-FU-induced apoptosis that is greatly enhanced by G17 treatment in Colo320wt cells was prevented if IEX-1 expression was repressed. Under these conditions of blocked IEX-1 expression, the NF-kappaB activity remained unaffected by G17, in particular in Colo320wt cells co-treated with TNFalpha and also the suppressive effect of G17 on cIAP1 and cIAP2 expression was not observed anymore if IEX-1 expression was blocked. Conversely, IEX-1 overexpression in Colo320mut cells caused an increase of basal and TNFalpha- or 5-FU-induced apoptosis, an effect not further triggered by G17 treatment. Using a xenograft tumor model in severe combined immune deficiency mice, we could show that experimental systemic hypergastrinemia induced by the administration of omeprazole led to enhanced apoptosis as well as to a marked increase of IEX-1 expression in Colo320wt tumors, but not in Colo320mut tumors. These observations indicate that the proapoptotic effect of G17 on human colon cancer cells expressing the wild-type CCK2 receptor is mediated by IEX-1, which modulates NF-kappaB-dependent antiapoptotic protection and thereby exerts tumor-suppressive potential.
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Affiliation(s)
- S Sebens Müerköster
- Laboratory of Molecular Gastroenterology and Hepatology, 1st Department of Medicine, University Hospital of Schleswig-Holstein, Kiel, Germany
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Jiang CP, Kong C, Ding YT. Expression of gastrin receptor in tumors and its application as a molecular target for cancer diagnosis and therapy. Shijie Huaren Xiaohua Zazhi 2007; 15:980-985. [DOI: 10.11569/wcjd.v15.i9.980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Gastrin is widely distributed in gastrointestinal tract and pancreatic tissues, and it plays important roles in the modulation of physiological functions and pathogenic mechanism of some diseases. Recent studies showed that gastrin might promote the pathogenesis and growth of tumors, especially digestive tumors such as gastric cancer and colorectal cancer. The biological effect of gastrin is mainly mediated by cholecystokinin (CCK) receptors. Gastrin mRNA has been found in CCK-receptor positive small-cell lung carcinoma, breast cancer, ovarian cancer and cancer stem cells of various origins and it may serve as the indicator of self-secretive regulation. The tumors with over-expressed gastin receptor can be diagnosed and treated by radiolabelling or linking to the cytotoxic agents with gastin peptide and analogs, and scintigraphy was used to visualize the image in vivo.
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Smith KA, Patel O, Lachal S, Jennings I, Kemp B, Burgess J, Baldwin GS, Shulkes A. Production, secretion, and biological activity of the C-terminal flanking peptide of human progastrin. Gastroenterology 2006; 131:1463-74. [PMID: 17101322 DOI: 10.1053/j.gastro.2006.08.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 07/12/2006] [Indexed: 01/12/2023]
Abstract
BACKGROUND & AIMS Processing of progastrin, the 80-amino acid precursor of the hormone gastrin, generates a variety of peptides with distinct distributions and biological activities. However, little is known regarding the expression, secretion, and biological activity of the 6-amino acid C-terminal flanking peptide (CTFP) of progastrin. The objectives were to determine the concentration of CTFP in normal subjects and patients with gastrointestinal diseases and to investigate the biological activity of CTFP. METHODS CTFP, gastrin-amide (Gamide), glycine-extended gastrin (Ggly), and progastrin were measured using region-specific radioimmunoassay (RIA) in antral extracts and resected colorectal cancers (CRC) and in plasma from normal subjects (fasting and meal stimulated) and from patients with CRC, multiple endocrine neoplasia type 1 (MEN-1), or pernicious anemia. The effect of CTFP on proliferation, migration, and activation of the mitogen-activated protein kinase (MAPK) pathway in several types of gastrointestinal cell lines was determined. RESULTS CTFP is by far the predominant progastrin-derived peptide found in the antrum (4-fold higher than Gamide), resected CRC, and circulation (60-fold higher than Gamide) and is released after meal stimulation. The hypergastrinemic patients (MEN-1, pernicious anemia) had elevated plasma Gamide but unaltered CTFP demonstrating differential secretion of these 2 progastrin-derived peptides. Finally, CTFP stimulated proliferation and migration and activated MAPK of cells in culture. CONCLUSIONS The high and regulated expression of CTFP in healthy and diseased subjects combined with the evidence for biological activity of CTFP demonstrates that CTFP is not an inactive metabolite of progastrin processing but is a bioactive peptide with potential roles in the normal and diseased gastrointestinal tract.
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Affiliation(s)
- Kelly A Smith
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
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Goswami RS, Minoo P, Baker K, Chong G, Foulkes WD, Jass JR. Hyperplastic polyposis and cancer of the colon with gastrinoma of the duodenum. ACTA ACUST UNITED AC 2006; 3:281-4; quiz 285. [PMID: 16683006 DOI: 10.1038/ncponc0482] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Accepted: 02/07/2006] [Indexed: 12/15/2022]
Abstract
BACKGROUND A 64-year-old woman presented to the emergency room with a 3-month history of intermittent abdominal cramps, accompanied by nausea, vomiting, anorexia, and decreased bowel movements consistent with a partial intestinal obstruction. She had a 12-year history of peptic ulcers, which had been treated with histamine-2 blockers. INVESTIGATIONS Physical examination, abdominal X-ray, abdominal CT scan, colonoscopy and assessment of gastrin levels. DIAGNOSIS Duodenal neuroendocrine neoplasm showing gastrin expression and stage III (T3N2M0), poorly differentiated adenocarcinoma of the cecum arising from hyperplastic polyposis. MANAGEMENT Right-sided hemicolectomy with ileocolonic anastomosis, duodenal resection, leucovorin and 5-fluorouracil chemotherapy, annual colonoscopic surveillance, and polypectomy.
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Beales ILP, Ogunwobi O. Glycine-extended gastrin inhibits apoptosis in colon cancer cells via separate activation of Akt and JNK pathways. Mol Cell Endocrinol 2006; 247:140-149. [PMID: 16442704 DOI: 10.1016/j.mce.2005.12.050] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 12/07/2005] [Accepted: 12/20/2005] [Indexed: 01/12/2023]
Abstract
Glycine-extended gastrin (G-Gly) is produced by colon cancers and has growth promoting and anti-apoptotic effects in the colonic epithelium. We have examined the anti-apoptotic effects of G-Gly and the signal transduction pathways involved. G-Gly stimulated HT-29 cell proliferation in a concentration dependent manner and inhibited serum-starvation and celecoxib-induced apoptosis. Inhibition of signalling via c-Jun NH2-terminal kinase (JNK) with SP600125 or PI3-kinase/Akt with LY294002 abolished the effects of G-Gly. G-Gly significantly increased phosphorylation of both JNK and Akt. The JAK2 inhibitor AG490 abolished the anti-apoptotic effect of G-Gly and inhibited phosphorylation of Akt but not of JNK. G-Gly stimulated tyrosine phosphorylation of JAK2. G-Gly-increased activation of AP-1 was JNK-dependant and activation of STAT3 was JAK2-dependant. We conclude that G-Gly promotes growth and inhibits apoptosis in colon cancer cells. These effects are mediated via the JAK2, PI3-kinase/Akt and JNK pathways. Activation of JAK2 is upstream of Akt but not of JNK.
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Affiliation(s)
- Ian L P Beales
- Gastroenterology Unit, Norfolk and Norwich University Hospital, Norwich NR4 7UZ, United Kingdom.
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Jensen RT. Consequences of long-term proton pump blockade: insights from studies of patients with gastrinomas. Basic Clin Pharmacol Toxicol 2006; 98:4-19. [PMID: 16433886 DOI: 10.1111/j.1742-7843.2006.pto_378.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Proton pump inhibitors are being increasingly used and for longer periods of time, especially in patients with gastroesophageal reflux disease. Each of these trends has led to numerous studies and reviews of the potential risk-benefit ratio of the long-term use of proton pump inhibitors. Both long-term effects of hypergastrinaemia due to the profound acid suppression caused by proton pump inhibitors as well as the effects of hypo-/achlorhydria per se have been raised and studied. Potential areas of concern that have been raised in the long-term use of proton pump inhibitors, which could alter this risk-benefit ratio include: gastric carcinoid formation; the development of rebound acid hypersecretion when proton pump inhibitor treatment is stopped; the development of tolerance; increased oxyntic gastritis in H. pylori patients and the possibility of increasing the risk of gastric cancer; the possible stimulation of growth of non-gastric tumours due to hypergastrinaemia; and the possible effect of the hypo/achlorhydria on nutrient absorption, particularly iron and vitamin B12. Because few patients with idiopathic gastro-oesophageal reflux disease/peptic ulcer disease have been treated long-term (i.e., >10 years), there is little known to address the above areas of potential concern. Most patients with gastrinomas with Zollinger-Ellison syndrome have life-long hypergastrinaemia, require continuous proton pump inhibitors treatment and a number of studies report results of >5-10 years of tratment and follow-up. Therefore, an analysis of Zollinger-Ellison syndrome patients can provide important insights into some of the safety concerns raised above. In this paper, results from studies of Zollinger-Ellison syndrome patients and other recent studies dealing with the safety concerns above, are briefly reviewed.
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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, Maryland 20892-1804, USA.
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Houli N, Loh SW, Giraud AS, Baldwin GS, Shulkes A. Mitogenic effects of both amidated and glycine-extended gastrin-releasing peptide in defunctioned and azoxymethane-treated rat colon in vivo. ACTA ACUST UNITED AC 2005; 134:9-16. [PMID: 16297463 DOI: 10.1016/j.regpep.2005.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 10/08/2005] [Accepted: 10/13/2005] [Indexed: 12/16/2022]
Abstract
Although there is abundant evidence that gastrin-releasing peptide acts as a mitogen in various carcinoma cell lines, the effect of administration of gastrin-releasing peptide on the colorectal mucosa in vivo has not been reported. The aims of this study were to determine whether continuous infusion of gastrin-releasing peptide stimulated proliferation or accelerated carcinogenesis in the rat gastrointestinal tract and other organs. The possible requirement for C-terminal amidation for mitogenic activity in vivo was also investigated. Proliferation was measured in the colon by metaphase index and by immunostaining for the proliferation marker Ki-67, and in other tissues by immunostaining alone. Acceleration of colorectal carcinogenesis was assessed by counting aberrant crypt foci after treatment with the carcinogen azoxymethane. Defunctioning of the rectum reduced both the proliferative index and the crypt height of the rectal mucosa of untreated rats. Treatment with amidated or glycine-extended gastrin-releasing peptide for 4 weeks using implanted mini-osmotic pumps resulted in a two- to three-fold increase in proliferation, and an increase in crypt height, in the defunctioned rectal mucosa (p<0.001), with smaller but significant increases in the caecum and distal colon. No changes in proliferation were detected in lung, pancreas or gastric mucosa. The numbers of aberrant crypt foci in the mid-colon, distal colon and rectum following treatment with azoxymethane were also significantly increased by infusion with amidated or glycine-extended gastrin-releasing peptide. We conclude that administration of gastrin-releasing peptide to mature rats stimulates proliferation and accelerates carcinogenesis in the colorectal mucosa, and that C-terminal amidation is not essential for either effect. Gastrin-releasing peptides could thus potentially act as promoters of colorectal carcinogenesis.
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Affiliation(s)
- Nezor Houli
- University of Melbourne Departments of Surgery, Austin Health, Studley Rd., Heidelberg, Victoria 3084, Australia
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19
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Müerköster S, Isberner A, Arlt A, Witt M, Reimann B, Blaszczuk E, Werbing V, Fölsch UR, Schmitz F, Schäfer H. Gastrin suppresses growth of CCK2 receptor expressing colon cancer cells by inducing apoptosis in vitro and in vivo. Gastroenterology 2005; 129:952-68. [PMID: 16143134 DOI: 10.1053/j.gastro.2005.06.059] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Accepted: 05/26/2005] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS The role of amidated gastrin17 (G17) and the gastrin/CCKB/CCK2 receptor in colorectal carcinogenesis is still a controversial issue. Here, we investigated the effect of G17 on proliferation and apoptosis of CCK2 receptor-expressing human colon cancer cell lines in vitro and in vivo. METHODS Proliferation was determined by cell counting and cell cycle analysis. Apoptosis was analyzed by annexin V staining, TUNEL staining, caspase-3/7 assay, and JC1 (delta psi) assay. Signal-transduction pathways were analyzed by Western blotting and gel-shift and luciferase assays. An in vivo tumor model with subcutaneously inoculated colon cancer cells in SCID mice was used, and systemic hypergastrinemia was induced by omeprazole. RESULTS In Colo320 cells stably transfected with the wild-type CCK2 receptor (Colo320wt) or in Lovo cells endogenously expressing CCK2 receptors, G17 treatment inhibited proliferation along with a G2/M cell cycle arrest. Furthermore, the administration of G17 significantly augmented apoptosis of CCK2 receptor-expressing cells. In contrast, G17 had no effect on proliferation and apoptosis in Colo320 cells stably transfected with a tumor-derived CCK2 receptor mutant (Colo320mut) or in cells lacking CCK2 receptor expression. Systemic hypergastrinemia in severe combined immunodeficiency (SCID) mice suppressed the growth of Colo320wt tumors accompanied by enhanced apoptosis as compared with untreated tumors. In contrast, omeprazole did not affect Colo320mut tumors reflecting a loss-of-function state of the CCK2(mut) receptor. This is supported by the observation that, in Colo320wt cells, but not in Colo320mut cells, G17 treatment induced the MAPK/ERK/AP-1 pathway and inhibited the activity of NF-kappaB. CONCLUSIONS G17 exerts an antiproliferative and proapoptotic effect on human colon cancer cells expressing the wild-type CCK2 receptor. This supports the view that amidated gastrin prevents rather than promotes colorectal carcinogenesis.
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Affiliation(s)
- Susanne Müerköster
- Division of Molecular Gastroenterology and Hepatology, First Department of Medicine, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel, Germany
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20
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Song DH, Kaufman JC, Borodyansky L, Albanese C, Pestell RG, Wolfe MM. Gastrin stabilises beta-catenin protein in mouse colorectal cancer cells. Br J Cancer 2005; 92:1581-7. [PMID: 15798764 PMCID: PMC2362014 DOI: 10.1038/sj.bjc.6602509] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
As gastrin may play a role in the pathophysiology of gastrointestinal (GI) malignancies, the elucidation of the mechanisms governing gastrin-induced proliferation has recently gained considerable interest. Several studies have reported that a large percentage of colorectal tumours overexpress or stabilise the β-catenin oncoprotein. We thus sought to determine whether gastrin might regulate β-catenin expression in colorectal tumour cells. Amidated gastrin-17 (G-17), one of the major circulating forms of gastrin, not only enhanced β-catenin protein expression, but also one of its target genes, cyclin D1. Furthermore, activation of β-catenin-dependent transcription by gastrin was confirmed by an increase in LEF-1 reporter activity, as well as enhanced cyclin D1 promoter activity. Finally, G-17 prolonged the τ1/2 of β-catenin protein, demonstrating that gastrin appears to exert its mitogenic effects on colorectal tumour cells, at least in part, by stabilising β-catenin.
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Affiliation(s)
- D H Song
- Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Boston, MA 02118, USA
| | - J C Kaufman
- Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Boston, MA 02118, USA
| | - L Borodyansky
- Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Boston, MA 02118, USA
| | - C Albanese
- Department of Oncology and the Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, USA
| | - R G Pestell
- Department of Oncology and the Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, USA
| | - M Michael Wolfe
- Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Boston, MA 02118, USA
- Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Boston, MA 02118, USA. E-mail:
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21
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Ottewell PD, Varro A, Dockray GJ, Kirton CM, Watson AJM, Wang TC, Dimaline R, Pritchard DM. COOH-terminal 26-amino acid residues of progastrin are sufficient for stimulation of mitosis in murine colonic epithelium in vivo. Am J Physiol Gastrointest Liver Physiol 2005; 288:G541-9. [PMID: 15486344 DOI: 10.1152/ajpgi.00268.2004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Transgenic mice (hGAS) that overexpress human progastrin are more susceptible than wild-type mice (FVB/N) to the induction of colonic aberrant crypt foci (ACF) and adenomas by the chemical carcinogen azoxymethane. We have previously shown significantly increased levels of colonic mitosis in hGAS compared with FVB/N mice after gamma-radiation. To investigate whether the effects of progastrin observed in hGAS colon require the presence of other forms of circulating gastrin, we have crossed hGAS (hg(+/+)) with gastrin knockout (G(-/-)) mice to generate mice that express progastrin and no murine gastrin (G(-/-)hg(+/+)). After azoxymethane, G(-/-)hg(+/+) mice developed significantly more ACF than control G(-/-)hg(-/-) mice (which do not express any forms of gastrin). G(-/-)hg(+/+) mice also exhibited significantly increased colonic mitosis both before and after exposure to 8 Gray Gy gamma-radiation or 50 mg/kg azoxymethane compared with G(-/-)hg(-/-). Treatment of G(-/-)hg(-/-) mice with synthetic progastrin (residues 21-101 of human preprogastrin) or G17 extended at its COOH terminus corresponding to the COOH-terminal 26-amino-acid residues of human preprogastrin (residues 76-101, G17-CFP) resulted in continued colonic epithelial mitosis after gamma-radiation, whereas glycine-extended gastrin-17 and the COOH-terminal tryptic fragment of progastrin [human preprogastrin-(96-101)] had no effect. Immunoneutralization with an antibody against G17-CFP before gamma-radiation significantly decreased colonic mitosis in G(-/-)hg(+/+) mice to levels similar to G(-/-)hg(-/-). We conclude that progastrin does not require the presence of other forms of gastrin to exert proliferative effects on colonic epithelia and that the portion of the peptide responsible for these effects is contained within amino acid residues 76-101 of human preprogastrin.
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Affiliation(s)
- P D Ottewell
- Deptartment of Medicine, 5th Fl. UCD Bldg., Daulby St., Liverpool L69 3BX, UK
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22
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Moore TC, Jepeal LI, Boylan MO, Singh SK, Boyd N, Beer DG, Chang AJ, Wolfe MM. Gastrin stimulates receptor-mediated proliferation of human esophageal adenocarcinoma cells. ACTA ACUST UNITED AC 2005; 120:195-203. [PMID: 15177938 DOI: 10.1016/j.regpep.2004.03.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Revised: 03/01/2004] [Accepted: 03/15/2004] [Indexed: 01/12/2023]
Abstract
The prevalence of esophageal adenocarcinoma in the setting of Barrett's metaplasia continues to increase in Western nations at a rate greater than any other cancer. The trophic properties of gastrin have been documented in gastric, pancreatic and colon cancer cell lines, suggesting a potential role for this regulatory peptide in the growth of these malignancies. The aims of these studies were to identify and characterize the presence of functional cholecystokinin type-2 (gastrin) receptors on the membranes of human esophageal adenocarcinoma cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated the presence of cholecystokinin type-2 receptor transcripts in human esophageal adenocarcinoma cell lines. Competitive binding assays revealed specific binding of gastrin in SEG-1 cells (IC50 of 2.4 x 10(-8) M). This finding was confirmed by laser scanning confocal microscopy through internalization of rhodamine green labeled gastrin heptapeptide in SEG-1 cells. Gastrin caused a dose-dependent increase in proliferation of SEG-1 cells when compared to controls. This effect was abolished by co-incubation with L365,260, a CCK-2-specific receptor antagonist. Gastrin-induced phosphorylation of the p44 and p42 mitogen-activated protein kinases was demonstrated by Western blot analysis. In conclusion, the studied human esophageal adenocarcinoma cell lines possess cholecystokinin type-2 (gastrin) receptors. Receptors bind gastrin, resulting in increased proliferation in SEG-1 cells.
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Affiliation(s)
- T Carlton Moore
- Section of Gastroenterology, Boston University School of Medicine and Boston Medical Center, 650 Albany Street, EBRC Fifth Floor, MA 02118, USA
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23
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Lachal S, Ford J, Shulkes A, Baldwin GS. PPARalpha agonists stimulate progastrin production in human colorectal carcinoma cells. ACTA ACUST UNITED AC 2005; 120:243-51. [PMID: 15177943 DOI: 10.1016/j.regpep.2004.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2003] [Revised: 03/15/2004] [Accepted: 03/26/2004] [Indexed: 02/08/2023]
Abstract
The three subtypes of peroxisome proliferator activated-receptors (PPARalpha, delta and gamma) control the storage and metabolism of fatty acids. Treatment of rats with the PPARalpha ligand ciprofibrate increases serum gastrin concentrations, and several lines of evidence suggest that non-amidated gastrins act as growth factors for the colonic mucosa. The aim of the present study was to investigate the expression of PPARs and the effect of PPAR ligands on gastrin production and cell proliferation in human colorectal carcinoma (CRC) cell lines. mRNAs for all three PPAR subtypes were detected by PCR in all CRC cell lines tested. The concentrations of progastrin, but not of glycine-extended or amidated gastrin, measured by radioimmunoassay in LIM 1899 conditioned media and cell extracts were significantly increased by treatment with the PPARalpha ligand clofibrate. Similar increases in progastrin were seen following treatment with the PPARalpha ligands ciprofibrate and fenofibrate, but not with bezafibrate, gemfibrozil or Wy 14643. The PPARgamma agonist rosiglitazone had no significant effect on progastrin production. The PPARalpha ligand clofibrate also stimulated proliferation of the LIM 1899 cell line. We conclude that some PPARalpha ligands increase progastrin production by the human CRC cell line LIM 1899, and that clofibrate increases proliferation of LIM 1899 cells. These studies have revealed a relationship between PPARs and gastrin, two regulatory molecules implicated in the pathogenesis of CRC.
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Affiliation(s)
- Shamilah Lachal
- Department of Surgery ARMC, University of Melbourne, Department of Surgery, Austin Health, Heidelberg, Victoria 3084, Australia
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24
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Abstract
The gastric hormone gastrin stimulates gastric acid secretion and epithelial cell proliferation. Multiple active products are generated from the precursor, preprogastrin, including the well-characterized amidated gastrins acting at the cholecystokinin-2 (CCK-2, or gastrin-CCK(B)) receptor, and others that may be growth factors in a range of cancers. Plasma concentrations of the amidated gastrins are elevated as a consequence of gastrin-secreting tumours (gastrinomas) and in conditions in which the normal inhibition of the antral G-cell by acid is depressed, for example chronic atrophic gastritis and prolonged treatment with proton pump inhibitors. There may also be increased gastrin release in Helicobacter pylori infection. Provocative tests for the diagnosis of gastrinoma include the secretin and calcium infusion tests. Hypergastrinaemia is associated with enterochromaffin-like (ECL) cell proliferation; the factors that determine progression to ECL cell dysplasia and gastric ECL cell carcinoid tumours are discussed. Several strategies for inhibiting the effects of gastrin are under evaluation, and their potential application is discussed.
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Affiliation(s)
- Graham J Dockray
- Physiological Laboratory, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
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25
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Abstract
Binding of ferric ions to the hormone glycine-extended gastrin17 is essential for biological activity (Pannequin, J., et al. (2002). J. Biol. Chem. 277: 48602-48609). The aims of the current study were to determine the properties of the complex between recombinant human progastrin6-80 and ferric ions. The stoichiometry and affinity of ferric ion binding were determined by fluorescence spectroscopy. The selectivity of metal ion binding and the stability of the 59Fe(III) progastrin6-80 complex were determined by equilibrium dialysis. The stoichiometry of 2.5 +/- 0.1 moles Fe/mole progastrin, and the apparent dissociation constant of 2.2 +/- 0.1 microM, were similar to the values previously determined for glycine-extended gastrin17 at pH 4.0. Of the four trivalent and seven divalent metal ions tested, only ferrous and ferric ions bound to progastrin6-80. The ferric ion-progastrin complex was extremely stable, with a half-life of 117 +/- 8 days at pH 7.6 and 25 degrees C. We conclude that recombinant human progastrin6-80 selectively binds ferrous and ferric ions with high affinity in a stable 2:1 complex.
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Affiliation(s)
- Graham S Baldwin
- University of Melbourne, Department of Surgery, Austin Campus, Austin, Australia.
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26
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Paterson AC, Lockhart SM, Baker J, Neumann G, Baldwin GS, Shulkes A. Identity and regulation of stored and secreted progastrin-derived peptides in sheep. Endocrinology 2004; 145:5129-40. [PMID: 15308616 DOI: 10.1210/en.2004-0912] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Amidated and nonamidated progastrin-derived peptides have distinct biological activities that are mediated by a range of receptor subtypes. The objective was to determine the nature of the stored and secreted progastrin-derived peptides and to investigate whether progastrin release is regulated by gastric acidity. Using an antiserum directed to the C terminus of progastrin for identification and to monitor purification, C-terminal flanking peptides (CTFP) of progastrin (prog(76-83), prog(77-83), and prog(78-83) in approximately equivalent amounts) were isolated and identified from extracts of sheep antrum using ion exchange, HPLC, and mass spectrometry. Only trace amounts of full-length progastrin were present. Progastrin CTFP was the predominant progastrin-derived peptide in the antrum [progastrin CTFP/gastrin amide (Gamide) = 3]. Similarly, progastrin CTFP was the major circulating form in the antral (CTFP, 710 +/- 62 pmol/liter; Gamide, 211 +/- 35 pmol/liter) and jugular (CTFP, 308 +/- 16 pmol/liter; gastrin amide, 32 +/- 3 pmol/liter) veins. Alteration of gastric acidity in sheep by iv infusion of a H/K-adenosine triphosphatase inhibitor or somatostatin or by intragastric infusion of HCl demonstrated that the CTFP concentrations changed, although to a lesser extent than the changes in circulating gastrin amide. We conclude that the CTFP of progastrin is the major stored and circulating species of the gastrin gene, and that it is secreted in a regulated fashion rather than constitutively. Because full-length progastrin is bioactive, but is only a minor antral and secreted form, determination of the biological activity of the C-terminal flanking peptides will be important for a complete understanding of gastrin endocrinology.
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Affiliation(s)
- Adrienne C Paterson
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
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27
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Aly A, Shulkes A, Baldwin GS. Gastrins, cholecystokinins and gastrointestinal cancer. Biochim Biophys Acta Rev Cancer 2004; 1704:1-10. [PMID: 15238241 DOI: 10.1016/j.bbcan.2004.01.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2003] [Revised: 01/15/2004] [Accepted: 01/21/2004] [Indexed: 12/11/2022]
Abstract
The gastrointestinal peptide hormones gastrin and cholecystokinin (CCK) are well known for their ability to stimulate gastric acid secretion and pancreatic enzyme secretion, respectively. The suggestion that gastrin and CCK might also promote the development of cancers of the gastrointestinal tract has been controversial, but an increasing body of evidence now supports the view that the amidated and non-amidated forms of gastrin act as growth factors via different receptors in different regions of the gut. For example, animal experiments indicate that amidated gastrins are involved in cellular differentiation and repair in the gastric mucosa, and synergize with Helicobacter pylori infection in the development of gastric carcinoma. In contrast, non-amidated gastrins stimulate colonic mucosal growth, accelerate the early steps in colorectal carcinoma formation, and are elevated in the tumour and circulation of patients with colorectal cancer. Although human pancreatic carcinomas express CCK-1 and CCK-2 receptors, the role of gastrins and CCK in pancreatic carcinogenesis is yet to be established. Further investigation of the possible role of the CCK-2 receptor in gastric and pancreatic neoplasia, and of the hypothesis that gastrin precursors act as autocrine growth factors in colorectal carcinoma, is warranted. However, therapies aimed at the gastrins must be targeted to the relevant gastrin/gastrin receptor combination.
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Affiliation(s)
- Ahmad Aly
- Department of Surgery, University of Melbourne, Austin Campus, A and RMC, Studley Road, Heidelberg, Melbourne, Victoria 3084, Australia
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28
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Zhou JJ, Chen ML, Zhang QZ, Hu JK, Wang WL. Coexpression of cholecystokinin-B/gastrin receptor and gastrin gene in human gastric tissues and gastric cancer cell line. World J Gastroenterol 2004; 10:791-4. [PMID: 15040018 PMCID: PMC4727015 DOI: 10.3748/wjg.v10.i6.791] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To compare the expression patterns of cholecystokinin-B (CCK-B)/gastrin receptor genes in matched human gastric carcinoma and adjacent non-neoplastic mucosa of patients with gastric cancer, inflammatory gastric mucosa from patients with gastritis, normal stomachs from 2 autopsied patients and a gastric carcinoma cell line (SGC-7901), and to explore their relationship with progression to malignancy of human gastric carcinomas.
METHODS: RT-PCR and sequencing were employed to detect the mRNA expression levels of CCK-B receptor and gastrin gene in specimens from 30 patients with gastric carcinoma and healthy bordering non-cancerous mucosa, 10 gastritis patients and normal stomachs from 2 autopsied patients as well as SGC-7901. The results were semi-quantified by normalizing it to the mRNA level of β-actin gene using Lab Image software. The sequences were analyzed by BLAST program.
RESULTS: CCK-B receptor transcripts were detected in all of human gastric tissues in this study, including normal, inflammatory and malignant tissues and SGC-7901. However, the expression levels of CCK-B receptor in normal gastric tissues were higher than those in other groups (P < 0.05), and its expressions did not correlate with the differentiation and metastasis of gastric cancer (P > 0.05). On the other hand, gastrin mRNA was detected in SGC-7901 and in specimens obtained from gastric cancer patients (22/30) but not in other gastric tissues, and its expression was highly correlated with the metastases of gastric cancer (P < 0.05).
CONCLUSION: Human gastric carcinomas and gastric cancer cell line SGC-7901 cells coexpress CCK-B receptor and gastrin mRNA. Gastrin/CCK-B receptor autocrine or paracrine pathway may possibly play an important role in the progression of gastric cancer.
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Affiliation(s)
- Jian-Jiang Zhou
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, West China Medical Center, Sichuan University, Chengdu, Sichuan Province, China.
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29
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Slice LW, Hodikian R, Zhukova E. Gastrin and EGF synergistically induce cyclooxygenase-2 expression in Swiss 3T3 fibroblasts that express the CCK2 receptor. J Cell Physiol 2003; 196:454-63. [PMID: 12891702 DOI: 10.1002/jcp.10304] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Over-expression of cyclooxygenase-2 (COX-2) has been demonstrated to be tumorigenic in transgenic mice. Chronic treatment with NSAIDs is chemoprotective for colorectal cancer. Gastrin is a growth factor for gastric mucosa and has been shown to promote proliferation of colorectal cells. Recent studies suggest that COX-2 expression levels could mediate the growth effects of gastrin. Here, we report that gastrin increased PGE2 secretion in Swiss 3T3 cells expressing the CCK2 receptor. Gastrin dose dependently induced COX-2 protein levels in a time dependent manner. COX-2 mRNA levels were rapidly induced by a dose dependent increase in gastrin. Prior treatment of the cells with the CCK2 receptor specific antagonist, L365,260, inhibited gastrin-induced COX-2 protein and mRNA expression. Pretreatment with L364,714, the CCK1 receptor specific antagonist did not block COX-2 induction by gastrin. Inhibition of de novo protein synthesis by cycloheximide did not block COX-2 mRNA induction by gastrin. Also, gastrin-dependent COX-2 expression did not require PKC activity, activation of ERK, or transactivation of EGFR. However, co-stimulation with EGF and gastrin synergistically induced COX-2 protein and mRNA expression and PGE2 secretion. Measurements of COX-2 mRNA stability and COX-2 gene transcription reveal that EGF significantly increased the half-life of COX-2 mRNA with only a slight increase in the COX-2 transcription rate. Conversely, gastrin significantly increased COX-2 gene transcription rates but did not enhance COX-2 mRNA stability.
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Affiliation(s)
- Lee W Slice
- Division of Digestive Diseases, Department of Medicine, CURE: Digestive Diseases Research Center, Greater Los Angeles VA Medical Center, University of California, Los Angeles, California, USA.
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30
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Abstract
During the past decade, proof of the principle that peptide receptors can be used successfully for in vivo targeting of human cancers has been provided. The molecular basis for targeting rests on the in vitro observation that peptide receptors can be expressed in large quantities in certain tumors. The clinical impact is at the diagnostic level: in vivo receptor scintigraphy uses radiolabeled peptides for the localization of tumors and their metastases. It is also at the therapeutic level: peptide receptor radiotherapy of tumors emerges as a serious treatment option. Peptides linked to cytotoxic agents are also considered for therapeutic applications. The use of nonradiolabeled, noncytotoxic peptide analogs for long-term antiproliferative treatment of tumors appears promising for only a few tumor types, whereas the symptomatic treatment of neuroendocrine tumors by somatostatin analogs is clearly successful. The present review summarizes and critically evaluates the in vitro data on peptide and peptide receptor expression in human cancers. These data are considered to be the molecular basis for peptide receptor targeting of tumors. The paradigmatic peptide somatostatin and its receptors are extensively reviewed in the light of in vivo targeting of neuroendocrine tumors. The role of the more recently described targeting peptides vasoactive intestinal peptide, gastrin-releasing peptide, and cholecystokinin/gastrin is discussed. Other emerging and promising peptides and their respective receptors, including neurotensin, substance P, and neuropeptide Y, are introduced. This information relates to established and potential clinical applications in oncology.
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Affiliation(s)
- Jean Claude Reubi
- Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, CH-3010 Berne, Switzerland
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31
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Song DH, Rana B, Wolfe JR, Crimmins G, Choi C, Albanese C, Wang TC, Pestell RG, Wolfe MM. Gastrin-induced gastric adenocarcinoma growth is mediated through cyclin D1. Am J Physiol Gastrointest Liver Physiol 2003; 285:G217-22. [PMID: 12606305 DOI: 10.1152/ajpgi.00516.2002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastrin is a gastrointestinal (GI) peptide that possesses potent trophic effects on most of the normal and neoplastic mucosa of the GI tract. Despite abundant evidence for these properties, the mechanisms governing gastrin-induced proliferation are still largely unknown. To elucidate the mechanisms by which gastrin might influence mitogenesis in gastric adenocarcinoma, we analyzed its effects on the human cell line AGS-B. Amidated gastrin (G-17), one of the major circulating forms of gastrin, induced a concentration-dependent increase in [3H]thymidine incorporation of cells in culture, with the maximum effective concentration occurring with 20 nM G-17. This effect was significantly attenuated by the gastrin-specific receptor antagonist L-365260. In addition, we found that G-17 induced a significant increase in the levels of cyclin D1 transcripts, protein, and promoter activity. The results of these studies indicate that gastrin appears to exert its mitogenic effects on gastric adenocarcinoma, at least in part, through changes in cyclin D1 expression.
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Affiliation(s)
- Diane H Song
- Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Boston, MA 02118, USA
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32
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Ottewell PD, Watson AJM, Wang TC, Varro A, Dockray GJ, Pritchard DM. Progastrin stimulates murine colonic epithelial mitosis after DNA damage. Gastroenterology 2003; 124:1348-57. [PMID: 12730875 DOI: 10.1016/s0016-5085(03)00288-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Transgenic mice that overexpress progastrin are more susceptible than either wild-type mice or mice that overexpress amidated gastrin to chemical carcinogen-induced colonic adenomas. We have investigated whether alterations in the regulation of apoptosis or mitosis after DNA damage contribute to the effects of progastrin on murine colonic epithelium. METHODS Apoptosis and mitosis were assessed on a cell positional basis in murine intestinal epithelium after gamma-irradiation. Mice analyzed were progastrin overexpressing, gastrin overexpressing, gastrin knockout, and their wild-type counterparts. The expression of cell cycle regulators was analyzed by gene array and Western blotting. RESULTS Apoptosis was induced to similar levels in the small intestinal and colonic crypts of all mice 4.5 hours after 8 Gy gamma-radiation. Colonic mitosis was inhibited to almost undetectable levels by 8Gy gamma-radiation in wild-type, gastrin-knockout, and gastrin-overexpressing mice. However, significant colonic mitosis persisted in progastrin-overexpressing mice up to 24 hours after 8Gy gamma-radiation. Increased levels of cdk4 and cyclin D1 proteins were found in the colonic epithelium of progastrin-overexpressing mice relative to wild-type animals after gamma-radiation. CONCLUSIONS After DNA damage by gamma-radiation, mice with elevated progastrin exhibit significantly higher levels of colonic mitosis than wild-type or gastrin-overexpressing mice. Persistently elevated cdk4 and cyclin D1 in progastrin overexpressing mice accounts for the capacity of colon cells to continue with the cell cycle after DNA damage.
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Jensen RT. Involvement of cholecystokinin/gastrin-related peptides and their receptors in clinical gastrointestinal disorders. PHARMACOLOGY & TOXICOLOGY 2002; 91:333-350. [PMID: 12688377 DOI: 10.1034/j.1600-0773.2002.910611.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this paper the possible roles of cholecystokinin (CCK), gastrin, or gastrin-related peptides and their receptors in human gastrointestinal diseases are reviewed. For CCK/CCK(A) receptors (CCK(A)-R), the evidence for their proposed involvement in diseases caused by impaired CCK release or CCK(A)-R mutations, pancreatic disorders (acute/chronic pancreatitis), gastrointestinal motility disorders (gallbladder disease, irritable bowel syndrome), pancreatic tumor growth and satiety disorders, is briefly reviewed. The evidence that has established the involvement of gastrin/CCK(B)-R in mediating the action of hypergastrinaemic disorders, mediating hypergastrinaemic effects on the gastric mucosa (ECL hyperplasia, carcinoids, parietal cell mass), and acid-peptic diseases, is reviewed. The evidence for their possible involvement in mediating growth of gastric and pancreatic tumours and possible involvement of gastrin-related peptides in colon cancers, is reviewed briefly.
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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, Maryland 20892-1804, USA.
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McQueen K, Kovac S, Ho PK, Rorison K, Pannequin J, Neumann G, Shulkes A, Baldwin GS. Preparation of biologically active recombinant human progastrin(1-80). JOURNAL OF PROTEIN CHEMISTRY 2002; 21:465-71. [PMID: 12523650 DOI: 10.1023/a:1021399003934] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The bacterial expression of human progastrin(6-80) has been reported previously [Baldwin, G.S. et al. (2001) J. Biol. Chem. 276: 7791-7796]. The aims of the present study were to prepare full-length recombinant human progastrin(1-80) and to compare its biological activity with that of progastrin(6-80) in vitro, to determine whether or not the N-terminal five amino acids contributed to activity. A fusion protein of glutathione-S-transferase and human progastrin(1-80) was expressed in Escherichia coli, collected on glutathione-agarose beads, and cleaved with enterokinase. Progastrin(1-80) was purified by reversed-phase and anion exchange HPLC and characterized by radioimmunoassay, amino acid sequencing, and mass spectrometry. No differences were detected in the extent of stimulation by progastrin(1-80) and progastrin(6-80) in proliferation and migration assays with the mouse gastric cell line IMGE-5. We conclude that residues 1-5 of progastrin(1-80) are not essential for biological activity.
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Affiliation(s)
- Kim McQueen
- University of Melbourne Department of Surgery, Austin and Repatriation Medical Centre, Melbourne, Victoria, Australia
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Abstract
Precursor forms of peptide hormones may be biologically active with effects distinct from the mature end product. Nonamidated progastrin-derived peptides stimulate growth of colonic epithelium and are elevated in the circulation of patients with colorectal carcinomas, whereas the amidated end product is the major regulator of gastric acidity. Using region-specific radioimmunoassays, we here compared the in vitro and in vivo metabolism of recombinant human progastrin-(6-80) and two other nonamidated gastrins, gastrin-17-Gly and Tyr(70)-progastrin-(71-80). Although progastrin-(6-80) was very stable in vitro, both progastrin-(6-80) and gastrin-17-Gly were degraded in vivo. The in vivo data were best fitted by a double-exponential decay curve, and the half-lives for progastrin-(6-80) (t1/2alpha = 5.1 +/- 1.1, t(1/2)beta = 42 +/- 11 min) were significantly (P < 0.05) longer than for gastrin-17-Gly (t(1/2)alpha = 2.2 +/- 0.6, t(1/2)beta = 13 +/- 1 min). Tyr(70)-progastrin-(71-80) was degraded more rapidly. Comparison with amidated gastrins suggests that peptide length, rather than sequence, is the critical determinant of clearance. Progastrin has the clearance characteristics to be considered a circulating hormone.
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Affiliation(s)
- Adrienne C Paterson
- Department of Surgery, University of Melbourne, Austin, and Repatriation Medical Centre, Melbourne, Victoria 3084, Australia
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36
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Yao M, Song DH, Rana B, Wolfe MM. COX-2 selective inhibition reverses the trophic properties of gastrin in colorectal cancer. Br J Cancer 2002; 87:574-9. [PMID: 12189559 PMCID: PMC2376154 DOI: 10.1038/sj.bjc.6600495] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2002] [Revised: 05/16/2002] [Accepted: 05/16/2002] [Indexed: 12/29/2022] Open
Abstract
Gastrin is a gastrointestinal peptide that possesses potent trophic properties on both normal and neoplastic cells of gastrointestinal origin. Previous studies have indicated that chronic hypergastrinaemia increases the risk of colorectal cancer and cancer growth and that interruption of the effects of gastrin could be a potential target in the treatment of colorectal cancer. Here we demonstrate that gastrin leads to a dose-dependent increase in colon cancer cell proliferation and tumour growth in vitro and in vivo, and that this increment is progressively reversed by pretreatment with the cyclo-oxygenase-2 inhibitor NS-398. Gastrin was able to induce cyclo-oxygenase-2 protein expression, as well as the synthesis of prostaglandin E2, the major product of cyclo-oxygenase. Moreover, gastrin leads to approximately a two-fold induction of cyclo-oxygenase-2 promoter activity in transiently transfected cells. The results of these studies demonstrate that cyclo-oxygenase-2 appears to represent one of the downstream targets of gastrin and that selective cyclo-oxygenase-2 inhibition is capable of reversing the trophic properties of gastrin and presumably might prevent the growth of colorectal cancer induced by hypergastrinaemia.
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Affiliation(s)
- M Yao
- Section of Gastroenterology, Boston University School of Medicine and Boston Medical Center, 605 Albany Street, Room 504, Boston, Massachusetts, MA 02118, USA
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Abstract
Neuropeptides are molecular messengers that regulate multiple functions in the central nervous system and in the periphery via G-protein-coupled receptors. These signaling peptides have also been identified as potent cellular growth factors for normal cells and they participate in autocrine/paracrine stimulation of tumor cell proliferation and migration. Recent studies on the signaling pathways activated by mitogenic neuropeptides revealed previously unsuspected connections and complexities, including the realization that these receptors not only stimulate the synthesis of conventional second messengers but also induce tyrosine phosphorylation cascades. A major task for the future will be to identify all the contributing molecules, define their functional importance and elucidate the spatiotemporal relationships of this complicated signaling network. As our understanding of the role of neuropeptides in cancer increases, novel possibilities for translational research are emerging for improving the diagnosis and treatment of the disease.
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Affiliation(s)
- Enrique Rozengurt
- Department Medicine, School of Medicine and Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.
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The expression of receptors for vasoactive intestinal peptide and secretin in colon neoplasms. Chin J Cancer Res 2001. [DOI: 10.1007/s11670-001-0048-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Zhukova E, Sinnett-Smith J, Wong H, Chiu T, Rozengurt E. CCK(B)/gastrin receptor mediates synergistic stimulation of DNA synthesis and cyclin D1, D3, and E expression in Swiss 3T3 cells. J Cell Physiol 2001; 189:291-305. [PMID: 11748587 DOI: 10.1002/jcp.10018] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In order to develop a model system for identifying signaling pathways and cell cycle events involved in gastrin-mediated mitogenesis, we have used high efficiency retroviral-mediated transfection of cholecystokinin (CCK)(B)/gastrin receptor into Swiss 3T3 cells. The retrovirally-transfected CCK(B)/gastrin receptor binds 125I-CCK-8 with high affinity (Kd = 1.1 nM) and is functionally coupled to intracellular signaling pathways including rapid and transient increase in Ca2+ fluxes, protein kinase C-dependent protein kinase D activation, and MEK-dependent ERK1/2 activation. In the presence of insulin, CCK-8 or gastrin induced a 66.5 +/- 8.8-fold (mean +/- SEM, n = 24 in eight independent experiments) increase in cellular DNA synthesis, reaching a level similar to that achieved by stimulation with a saturating concentration of fresh serum, and much greater than the response to each agonist added alone. CCK-8 also induced a striking increase in the expression of cyclins D1, D3, and E and hyperphosphorylation of Rb acting synergistically with insulin. Similar effects were observed when CCK(B)/gastrin receptor was activated in the presence of EGF or bombesin. Our results demonstrate that activation of CCK(B)/gastrin receptor retrovirally-transfected into Swiss 3T3 induces a potent synergistic effect on DNA synthesis, accumulation of cyclins D1, D3, and E and hyperphosphorylation of Rb in combination with insulin, EGF, or bombesin. Thus, the CCK(B)/gastrin receptor transfected into Swiss 3T3 cells provides a novel model system to elucidate mitogenic signal transduction pathways and cell cycle events activated via this receptor.
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Affiliation(s)
- E Zhukova
- Department of Medicine, School of Medicine and Molecular Biology Institute, University of California, Los Angeles, CA 90095-1786, USA
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Yang CH, Ford J, Karelina Y, Shulkes A, Xiao SD, Baldwin GS. Identification of a 70-kDa gastrin-binding protein on DLD-1 human colorectal carcinoma cells. Int J Biochem Cell Biol 2001; 33:1071-9. [PMID: 11551823 DOI: 10.1016/s1357-2725(01)00077-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Gastrin17gly acts as a growth factor for the colonic mucosa. Studies of the receptor involved have generally been restricted to its binding properties, and no investigation of the structure of gastrin17gly receptors on human colorectal carcinoma cell lines has yet been reported. The aim of this study was to optimise the conditions for binding of gastrin17gly to the human colorectal carcinoma cell line DLD-1, and to investigate the structure of the receptor responsible. Binding of 125I[Met15]gastrin17gly to DLD-1 cells was measured in competition experiments with increasing concentrations of either gastrin17gly or gastrin17, or with single concentrations of gastrin receptor antagonists. The molecular weights of the gastrin17gly binding proteins were determined by gel electrophoresis and autoradiography after covalent cross-linking of 125I[Nle15]gastrin2,17gly to cells or membranes with disuccinimidyl suberate. The IC50 value for binding of gastrin17gly to DLD-1 cells was 2.1+/-0.4 microM. Binding was inhibited by the non-selective gastrin/cholecystokinin receptor antagonists proglumide and benzotript, but not by the cholecystokinin-A receptor antagonist L364,718, or the gastrin/cholecystokinin-B receptor antagonist L365,260. The molecular weight of the major gastrin binding protein on DLD-1 cells or membranes was 70,000. We conclude that the major gastrin17gly binding site on the human colorectal carcinoma cell line DLD-1 is clearly distinct from the cholecystokinin-A and gastrin/cholecystokinin-B receptors, but is similar in some respects to the gastrin/cholecystokinin-C receptor.
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Affiliation(s)
- C H Yang
- Shanghai Institute of Digestive Disease, Shanghai Second Medical University, Shanghai, People's Republic of China
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41
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Aly A, Shulkes A, Baldwin GS. Short term infusion of glycine-extended gastrin(17) stimulates both proliferation and formation of aberrant crypt foci in rat colonic mucosa. Int J Cancer 2001; 94:307-13. [PMID: 11745407 DOI: 10.1002/ijc.1483] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Evidence is accumulating that gastrin precursors may act as growth factors for the colonic mucosa in vivo and for colorectal carcinoma cell lines in vitro. The effect of short term administration of synthetic gastrins on the colonic mucosa in vivo, however, has not been reported. The aim of our study was to determine whether continuous systemic infusion of glycine-extended gastrin(17) stimulated proliferation and accelerated carcinogenesis in the colorectal mucosa. A significant increase in colonic mucosal proliferation as assessed by metaphase index was seen in the caecum (23%, p < 0.02) and distal colon (27%, p < 0.001), but not the rectum, after treatment of intact rats with glycine-extended gastrin(17) for 1 week using implanted miniosmotic pumps. Defunctioning of the rectum reduced both the proliferative index and crypt height of the rectal mucosa of untreated rats. Treatment of rectally defunctioned animals with glycine-extended gastrin(17) for either 1 or 4 weeks resulted in a significant increase in both the proliferative index (40% and 93%, respectively) and crypt height (11% and 19%, respectively) of the rectal mucosa. The total number of aberrant crypt foci in intact rats treated with the procarcinogen azoxymethane plus glycine-extended gastrin(17) was increased by 48% compared to the value in controls treated with azoxymethane only (p = 0.01). We conclude that short term administration of glycine-extended gastrin(17) to mature rats not only has a proliferative effect upon colonic mucosa, but also increases the number of aberrant crypt foci formed in the colorectal mucosa after treatment with azoxymethane. Glycine-extended gastrin(17) could thus potentially act as a promoter of carcinogenesis.
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Affiliation(s)
- A Aly
- University of Melbourne Department of Surgery, Austin Campus, A&RMC, Melbourne, Victoria, Australia
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42
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Rooman I, Lardon J, Flamez D, Schuit F, Bouwens L. Mitogenic effect of gastrin and expression of gastrin receptors in duct-like cells of rat pancreas. Gastroenterology 2001; 121:940-9. [PMID: 11606507 DOI: 10.1053/gast.2001.27998] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND & AIMS Ductular metaplastic cells are observed during pancreas injury. Growth control by gastrin and expression of gastrin/cholecystokinin (CCK) B receptors were evaluated in these cells. METHODS Acinoductal transdifferentiation was induced in vitro by culturing of acinar cells, and ductular metaplasia was obtained in vivo by ligation of the pancreatic ducts. Mitogenic effects of gastrin I on ductal complexes in vivo and of tetragastrin, pentagastrin, and gastrin I and II, with or without the CCK-B receptor antagonist L-365,260, on duct-like cells in vitro were analyzed by 5-bromo-2'-deoxyuridine labeling. Immunocytochemistry, Western blotting, and reverse-transcription polymerase chain reaction were applied for detection of the CCK-B receptor. RESULTS Gastrin analogues induced a mitogenic stimulus in the duct-like cells in vitro and in ductal complexes in duct-ligated rat pancreas. Immunocytochemistry showed expression of CCK-B receptors in these models and in fetal but not normal adult exocrine pancreas. Additionally, up-regulation of CCK-B receptors during ductular metaplasia was shown by Western blotting and reverse-transcription polymerase chain reaction. CONCLUSIONS Duct-like pancreatic epithelial cells in vitro and ductal complexes in vivo express gastrin/CCK-B receptors and proliferate in response to gastrin.
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Affiliation(s)
- I Rooman
- Cell Differentiation Unit, Diabetes Research Center, Free University Brussel, Brussels, Belgium
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Abstract
Tumor markers used in the diagnosis and follow-up of patients with neuroendocrine tumors are in most instances not specific for a given tumor and circulate under normal conditions in the serum, making their use as an early diagnostic tool difficult (low sensitivity). By combining hormone measurements with tissue responsiveness, demonstrations of inappropriate secretions of PTH, insulin, and gastrin during hypercalcemia, hypoglycemia, and hyperacidity, respectively, become highly sensitive and specific diagnostic tests. The application of polyclonal antibodies in RIAs of hormones, such as ACTH, insulin, and gastrin, increase the diagnostic level of hormone measurements in patients with neuroendocrine tumors. Other markers, such as chromogranin A, neuron-specific enolase, and alpha-subunit, as well as peptide receptor visualization, are of increasing importance in the diagnosis and follow-up of neuroendocrine and non-neuroendocrine tumors.
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Affiliation(s)
- S W Lamberts
- Department of Medicine, University Hospital Dijkzigt, Erasmus University, 40 Dr. Molewaterplein, 3015 GD Rotterdam, The Netherlands.
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Schmitz F, Schrader H, Otte J, Schmitz H, Stüber E, Herzig K, Schmidt WE. Identification of CCK-B/gastrin receptor splice variants in human peripheral blood mononuclear cells. REGULATORY PEPTIDES 2001; 101:25-33. [PMID: 11495676 DOI: 10.1016/s0167-0115(01)00281-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There is increasing evidence for a direct interaction of the enteric nervous and immune system. Receptors for neuropeptides such as VIP, somatostatin, and substance P have been characterised in human immuno-haematopoietic cells but little is known about the functional significance and expression of receptors for cholecystokinin (CCK) on cells of the immune system. There are only few studies that describe the expression of CCK receptors on human leukaemia-derived cell lines but the receptor structure and function in normal leukocytes have not been clearly established. We therefore sought to determine CCK receptor expression, structure, and function in nontransformed human peripheral blood mononuclear cells.Full-length cDNA clones encoding the human CCK-A and CCK-B/gastrin receptor are expressed in peripheral blood mononuclear cells from healthy volunteers without haematopoietic malignancy. In addition to wild-type CCK-B/gastrin receptor cDNAs, we isolated a splice variant with an in frame insertion of 69 amino acids within its putative third intracellular receptor loop. Dideoxy sequence analysis revealed that the cDNA of this splice variant comprises exons 1-4 but retains intron 4 (207 bp) in the absence of mutations within the splice donor sites. Transient expression of this splice variant in COS-7 cells reveals wild-type affinity for CCK-8, Gastrin-17, and antagonist L-365,260. Affinity for glycine-extended gastrin-17 was not increased when compared to the wild-type CCK-B/gastrin receptor. In vitro, gastrin decreased 3H-thymidine labelling in phytohaemagglutinin-pretreated mononuclear cells at a half-maximally effective concentration of 1.5 nM. We also isolated a cDNA encoding another splice variant of the CCK-B/gastrin receptor with a 158 bp deletion of the entire exon 4 sequence. We conclude that wild-type transcripts of both CCK receptor subtypes and splice variants of the CCK-B/gastrin receptor are expressed in nontransformed human mononuclear cells and that gastrin exhibits antiproliferative effects.
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Affiliation(s)
- F Schmitz
- Laboratory for Experimental Gastroenterology, Department of Medicine I at St. Josef-Hospital, Ruhr-University Bochum, Gudrunstr. 56, D-44791, Bochum, Germany.
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Schmitz F, Otte JM, Stechele HU, Reimann B, Banasiewicz T, Fölsch UR, Schmidt WE, Herzig KH. CCK-B/gastrin receptors in human colorectal cancer. Eur J Clin Invest 2001; 31:812-20. [PMID: 11589724 DOI: 10.1046/j.1365-2362.2001.00870.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Mature amidated gastrin (G17 amide) mediates its effects in the gastrointestinal tract by activating G protein-coupled CCK-B/gastrin receptors. Although trophic actions of gastrin on the gastric mucosa have been well-established, the effect of G17 amide, progastrin and intermediates to colon neoplasia in humans is controversial. While epidemiological evidence from patients with elevated serum gastrin levels related to pernicious anaemia does not support an increased risk for colon cancer, a recent study suggests that prolonged hypergastrinaemia is associated with an increased risk for colon cancer. The extent to which trophic actions of gastrin in colorectal cancer are mediated by functional gastrin receptors remains to be defined. The aim of the present study was to determine CCK-B/gastrin receptor expression, structure, and function in 79 patients with colon cancer. MATERIALS AND METHODS CCK-B/gastrin receptor cDNAs were isolated from 79 human colorectal cancer specimens and 15 control tissues, subcloned into the eukaryotic expression vector pCR3.1 and subjected to DNA sequence analysis. Wild-type and mutant cDNAs were transiently expressed in COS-7 cells to determine ligand affinities by 125I-labelled CCK-8S competition binding. Activation of the MAP kinase signalling cascade by G17 amide was determined in transfected Colo 320 cells expressing the wild-type or mutant CCK-B/gastrin receptors. Clonal expansion of single cells was quantified in transfected Colo 320 cells. RESULTS Gastrin mRNA is expressed in 44% of colorectal cancers and in 13% of control tissues. CCK-B/gastrin receptor mRNA is expressed in 38% of colorectal cancers and 13% of normal colonic tissue. Co-expression of gastrin and CCK-B/gastrin receptor message is significantly increased in colorectal cancer specimens (32% vs. 0%). There is no correlation between CCK-B/gastrin receptor expression and disease stage or histological grading. DNA sequence analysis revealed one spontaneous CCK-B/gastrin receptor mutation within the third intracellular loop with an exchange of valine-287 for phenylalanine. Pharmacological characterisation of the 287V --> F CCK-B/gastrin receptor reveals wild-type affinities for G17 amide, glycine-extended gastrin, CCK-8S and L-365,260. Mutation 287V --> F is associated with a loss of gastrin-induced MAPK p44/p42 signalling in Colo 320 cells while clonal expansion from single cells is increased by 53.1 +/- 15.9% when compared to Colo 320 cells expressing wild-type CCK-B/gastrin receptors. CONCLUSIONS Structural alterations of CCK-B/gastrin receptors may account for increased growth-promoting effects of amidated gastrins in colorectal cancer.
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Affiliation(s)
- F Schmitz
- Department of Medicine, Christian-Albrechts-University Kiel, Germany.
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Abstract
Gastrin, produced by G cells in the gastric antrum, has been identified as the circulating hormone responsible for stimulation of acid secretion from the parietal cell. Gastrin also acts as a potent cell-growth factor that has been implicated in a variety of normal and abnormal biological processes including maintenance of the gastric mucosa, proliferation of enterochromaffin-like cells, and neoplastic transformation. Here, we review the models used to study the effects of gastrin on cell proliferation in vivo and in vitro with respect to mechanisms by which this hormone might influence normal and cancerous cell growth. Specifically, human and animal models of hypergastrinemia and hypogastrinemia have been described in vivo, and several cells that express cholecystokinin (CCK)B/gastrin receptors have been used for analysis of intracellular signaling pathways initiated by biologically active amidated gastrins. The binding of gastrin or CCK to their common cognate receptor triggers the activation of multiple signal transduction pathways that relay the mitogenic signal to the nucleus and promote cell proliferation. A rapid increase in the synthesis of lipid-derived second messengers with subsequent activation of protein phosphorylation cascades, including mitogen-activated protein kinase, is an important early response to these signaling peptides. Gastrin and CCK also induce rapid Rho-dependent actin remodeling and coordinate tyrosine phosphorylation of cellular proteins including the non-receptor tyrosine kinases p125fak and Src and the adaptor proteins p130cas and paxillin. This article reviews recent advances in defining the role of gastrin and CCK in the control of cell proliferation in normal and cancer cells and in dissecting the signal transduction pathways that mediate the proliferative responses induced by these hormonal GI peptides in a variety of normal and cancer cell model systems.
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Affiliation(s)
- E Rozengurt
- Department of Medicine, School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California 90095, USA.
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Abstract
Gastric epithelial organization and function are controlled and maintained by a variety of endocrine and paracrine mediators. Peptides encoded by the gastrin gene are an important part of this system because targeted deletion of the gene, or of the gastrin-CCKB receptor gene, leads to decreased numbers of parietal cells and decreased gastric acid secretion. Recent studies indicate that the gastrin precursor, preprogastrin, gives rise to a variety of products, each with a distinctive spectrum of biological activity. The conversion of progastrin to smaller peptides is regulated by multiple mechanisms including prohormone phosphorylation and secretory vesicle pH. Progastrin itself stimulates colonic epithelial proliferation; biosynthetic intermediates (Gly-gastrins) stimulate colonic epithelial proliferation and gastric epithelial differentiation; and C-terminally amidated gastrins stimulate colonic proliferation, gastric epithelial proliferation and differentiation, and acid secretion. The effects of progastrin-derived peptides on gastric epithelial function are mediated in part by release of paracrine factors that include histamine, epidermal growth factor (EGF)-receptor ligands, and Reg. The importance of the appropriate regulation of this system is shown by the observation that prolonged moderate hypergastrinemia in transgenic mice leads to remodelling of the gastric epithelium, and in the presence of Helicobacter, to gastric cancer.
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Affiliation(s)
- G J Dockray
- Physiological Laboratory, University of Liverpool, Liverpool, L69 3BX, United Kingdom.
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48
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Abstract
Autocrine and paracrine signaling leading to stimulation of tumor cell growth is a common theme in human cancers. In addition to polypeptide growth factors such as EGF family members which signal through receptor tyrosine kinases, accumulating evidence supports the autocrine and paracrine involvement of specific neuropeptides with defined physiologic actions as neurotransmitters and gut hormones in lung, gastric, colorectal, pancreatic and prostatic cancers. These neuropeptides, including gastrin-releasing peptide, neuromedin B, neurotensin, gastrin, cholecystokinin and arginine vasopressin bind seven transmembrane-spanning receptors that couple to heterotrimeric G proteins. Studies with human small cell lung cancer (SCLC) cells support a requirement for balanced signaling through G(q) and G(12/13) proteins leading to intracellular Ca2+ mobilization, PKC activation and regulation of the ERK and JNK MAP kinase pathways. While specific neuropeptide antagonists offer promise for interrupting the single neuropeptide autocrine systems operating in pancreatic and prostatic cancers, SCLC is exemplified by multiple, redundant neuropeptide autocrine systems such that tumor growth cannot be inhibited with a single specific antagonist. However, a novel class of neuropeptide derivatives based on the substance P sequence have been defined that exhibit broad specificity for neuropeptide receptors and induce apoptosis in SCLC by functioning as biased agonists that stimulate discordant signal transduction. Thus, interruption of autocrine and paracrine neuropeptide signaling with specific antagonists or broad-spectrum biased agonists offer promising new therapeutic approaches to the treatment of human cancers.
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Affiliation(s)
- L E Heasley
- Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado, CO 80262, USA
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Baldwin GS, Hollande F, Yang Z, Karelina Y, Paterson A, Strang R, Fourmy D, Neumann G, Shulkes A. Biologically active recombinant human progastrin(6-80) contains a tightly bound calcium ion. J Biol Chem 2001; 276:7791-6. [PMID: 11113148 DOI: 10.1074/jbc.m009985200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Evidence is accumulating that gastrin precursors may act as growth factors for the colonic mucosa in vivo. The aims of this study were to prepare recombinant human progastrin(6-80) and to investigate its structure and biological activities in vitro. Human progastrin(6-80) was expressed in Escherichia coli as a glutathione S-transferase fusion protein. After thrombin cleavage progastrin(6-80) was purified by reverse phase high pressure liquid chromatography and characterized by radioimmunoassay, amino acid sequencing, and mass spectrometry. Assays for metal ions by atomic emission spectroscopy revealed the presence of a single tightly bound calcium ion. Progastrin(6-80) at concentrations in the pm to nm range stimulated proliferation of the conditionally transformed mouse colon cell line YAMC. The observations that progastrin(6-80) did not bind to either the cholecystokinin (CCK)-A or the gastrin/CCK-B receptor expressed in COS cells and that antagonists selective for either receptor did not reverse the proliferative effects of progastrin(6-80) suggested that progastrin(6-80) stimulated proliferation independently of either the CCK-A or the gastrin/CCK-B receptor. We conclude that recombinant human progastrin(6-80) is biologically active and contains a single calcium ion. With the exception of the well known zinc-dependent polymerization of insulin and proinsulin, this is the first report of selective, high affinity binding of metal ions to a prohormone.
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Affiliation(s)
- G S Baldwin
- University Department of Surgery, Austin Hospital, Heidelberg, Victoria 3084, Australia.
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Abstract
BACKGROUND AND AIMS Gastrin17gly acts as a growth factor for the colonic mucosa. Studies on the binding properties of the receptor involved in transducing the proliferative effects have generally been confined to colorectal carcinoma cell lines, and no investigation of gastrin17gly receptors on normal colonocytes has yet been reported. The aim of this study was to investigate the binding of 125I-[Met15]-gastrin17gly to normal colonic crypts. METHODS Crypts were released from normal rat and rabbit colonic mucosa by treatment with EDTA and isolated by centrifugation. The binding of 125I-[Met15]-gastrin17gly was measured in displacement experiments with increasing concentrations of either gastrin17gly, gastrin17 or gastrin receptor antagonists. The concentrations required for 50% inhibition were determined by the use of curve fitting. RESULTS 125I-[Met15]-Gastrin17gly bound to both rat and rabbit crypts, and displacement experiments with unlabeled gastrin17gly revealed that the IC50 values were 1.0 +/- 0.6 and 0.6 +/- 0.2 micromol/L, respectively. Binding was also competed by gastrin17, with IC50 values of 2.4 +/- 1.7 and 2.4 +/- 0.7 micromol/L, respectively. Binding was inhibited by the non-selective gastrin/CCK receptor antagonists proglumide and benzotript, but not by the cholecystokinin (CCK)-A receptor antagonist L364 718, or the gastrin/CCK-B receptor antagonist L365 260. CONCLUSION We conclude that the gastrin17gly binding site on normal colonic crypts has properties consistent with the gastrin/CCK-C receptor.
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Affiliation(s)
- Y Karelina
- University Department of Surgery, Austin Hospital, Austin and Repatriation Medical Centre, Melbourne, Victoria, Australia
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