title: Infrequent detectable somatic mutations of the RET and glial cell line-derived neurotrophic factor (GDNF) genes in human pituitary adenomas.
abstract: RET is a receptor tyrosine kinase expressed in neuroendocrine cells and tumors. RET is activated by a ligand complex comprising glial cell line-derived neurotrophic factor (GDNF) and GDNF receptor-alpha (GDNFR-alpha). Activating mutations of the RET proto-oncogene were found in multiple endocrine neoplasia (MEN) 2 and in sporadic medullary thyroid carcinoma and pheochromocytoma of neuroendocrine origin. Mutations of the RET proto-oncogene and the glial cell line-derived neurotrophic factor (GDNF) gene were examined in human pituitary tumors. No mutations of the RET proto-oncogene including the cysteine-rich region or codon 768 and 918 in the tyrosine kinase domain were detected in 172 human pituitary adenomas either by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) or by PCR-restriction fragment length polymorphism (RFLP). Further, somatic mutations of the GDNF gene in 33 human pituitary adenomas were not detected by PCR-SSCP. One polymorphism of the GDNF gene at codon 145 of TGC or TGT was observed in a prolactinoma. The RET proto-oncogene message was detected in a normal human pituitary gland or 4 of 4 human pituitary adenomas with reverse transcription (RT)-PCR, and in rodent pituitary tumor cell lines with Western blotting. The expression of GDNF gene was detected in 1 of 4 human somatotroph adenomas, 1 of 2 corticotroph adenomas, and 2 of 6 rodent pituitary tumor cell lines with RT-PCR. Based on these, it is concluded that somatic mutations of the RET proto-oncogene or the GDNF gene do not appear to play a major role in the pituitary tumorigenesis in examined tumors.
authors.affiliation: Otsuka Department of Clinical and Molecular Nutrition, The University of Tokushima, Tokushima-city, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoshimoto
authors.forename: C
authors.initials: C
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Moritani
authors.forename: E
authors.initials: E
authors.lastname: Shimizu
authors.forename: T
authors.initials: T
authors.lastname: Yamaoka
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Sano
authors.forename: M
authors.initials: M
authors.lastname: Itakura
mesh_terms: D000236:Adenoma / Q000235:genetics*; D000818:Animals; D004252:DNA Mutational Analysis; D029721:Drosophila Proteins; D015870:Gene Expression; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006801:Humans; D051379:Mice; D009154:Mutation; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010911:Pituitary Neoplasms / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D012334:RNA, Neoplasm / Q000032:analysis; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D029721:Drosophila Proteins; C495039:GDNF protein, human; C495040:Gdnf protein, mouse; C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; C000715470:MAS1 protein, human; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D012334:RNA, Neoplasm; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C494999:Ret protein, mouse; C495001:Ret protein, rat