title: The G691S RET polymorphism increases glial cell line-derived neurotrophic factor-induced pancreatic cancer cell invasion by amplifying mitogen-activated protein kinase signaling.
abstract: Mutations of the RET proto-oncogene are responsible for several inherited human diseases and may function as genetic modifiers of the disease. However, the role of RET mutations in pancreatic cancer has not been studied. Expression of the glial cell line-derived neurotrophic factor (GDNF) receptors RET and GDNF family receptor alpha1 (GFRalpha1) in human pancreatic cancer cells was determined by Western blot, immunofluorescence, and flow cytometry. The effect of GDNF on cell proliferation and invasion was assessed. Small interfering RNA and antibodies were used to evaluate the involvement of RET. The G691S RET polymorphism was analyzed by sequencing and restriction analysis. The modifying effect of G691S RET on GDNF-induced invasion and mitogen-activated protein kinase (MAPK) signaling was evaluated. Transfection studies with wild-type and mutated RET determined the functional role of the G691S polymorphism. Pancreatic cancer specimens and matched tissues were analyzed for the presence of the G691S RET polymorphism. GDNF receptors were found on all cell lines. GDNF increased pancreatic cancer cell proliferation and invasion, which was mediated by RET. The effect of GDNF was more profound in cells with the G691S RET polymorphism (P < 0.01). G691S RET correlated with an enhanced activation of the downstream extracellular signal-regulated kinase pathway. Overexpression of G691S RET increased pancreatic cancer cell invasion. The G691S RET polymorphism was also detected in human pancreatic tumors and represented a somatic mutation in some patients. These findings indicate that the G691S RET single nucleotide polymorphism may directly correlate with the aggressive growth of pancreatic cancers and may function as a genetic modifier or even low-penetrance gene.
authors.affiliation: Hirshberg Laboratories for Pancreatic Cancer Research, Department of Surgery, David Geffen School of Medicine, University of California at Los Angeles, 90095, USA.
authors.forename: Hirozumi
authors.initials: H
authors.lastname: Sawai
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okada
authors.forename: Kevork
authors.initials: K
authors.lastname: Kazanjian
authors.forename: Joseph
authors.initials: J
authors.lastname: Kim
authors.forename: Sascha
authors.initials: S
authors.lastname: Hasan
authors.forename: Oscar J
authors.initials: OJ
authors.lastname: Hines
authors.forename: Howard A
authors.initials: HA
authors.lastname: Reber
authors.forename: Dave S B
authors.initials: DS
authors.lastname: Hoon
authors.forename: Guido
authors.initials: G
authors.lastname: Eibl
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D049109:Cell Proliferation; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000473:pathology*; D010179:Pancreas / Q000378:metabolism / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D051096:Proto-Oncogene Proteins c-ret / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: C494987:GFRA1 protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D034741:RNA, Small Interfering; D051096:Proto-Oncogene Proteins c-ret; D020928:Mitogen-Activated Protein Kinases