title: C-cell hyperplasia, pheochromocytoma and sympathoadrenal malformation in a mouse model of multiple endocrine neoplasia type 2B.
abstract: Dominantly inherited multiple endocrine neoplasia type 2B (MEN2B) is characterized by tumors of the thyroid C-cells and adrenal chromaffin cells, together with ganglioneuromas of the gastrointestinal tract and other developmental abnormalities. Most cases are caused by substitution of threonine for Met918 in the RET receptor tyrosine kinase, which is believed to convert the RET gene to an oncogene by altering the enzyme's substrate specificity. We report the production of a mouse model of MEN2B by introduction of the corresponding mutation into the ret gene. Mutant mice displayed C-cell hyperplasia and chromaffin cell hyperplasia progressing to pheochromocytoma. Homozygotes did not develop gastrointestinal ganglioneuromas, but displayed ganglioneuromas of the adrenal medulla, enlargement of the associated sympathetic ganglia and a male reproductive defect. Surprisingly, homozygotes did not display any developmental defects attributable to a loss-of-function mutation. Thus, while our results support the conclusion that the Met918Thr substitution is responsible for MEN2B, they suggest that the substrate specificity of the RET kinase does not interfere with its normal role in the development of the kidneys and enteric nervous system.
authors.affiliation: Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 W. 168th Street, New York, NY 10032, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Smith-Hicks
authors.forename: K C
authors.initials: KC
authors.lastname: Sizer
authors.forename: J F
authors.initials: JF
authors.lastname: Powers
authors.forename: A S
authors.initials: AS
authors.lastname: Tischler
authors.forename: F
authors.initials: F
authors.lastname: Costantini
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000235:genetics* / Q000473:pathology; D000311:Adrenal Glands / Q000002:abnormalities*; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004195:Disease Models, Animal; D029721:Drosophila Proteins; D005260:Female; D005728:Ganglia, Sympathetic / Q000002:abnormalities*; D005729:Ganglioneuroma / Q000235:genetics / Q000473:pathology; D018095:Germ-Line Mutation; D006801:Humans; D006965:Hyperplasia; D007248:Infertility, Male / Q000235:genetics; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D018813:Multiple Endocrine Neoplasia Type 2a / Q000235:genetics*; D010641:Phenotype; D010673:Pheochromocytoma / Q000235:genetics* / Q000473:pathology; D017354:Point Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D013961:Thyroid Gland / Q000473:pathology*
chemical_list: D017931:DNA Primers; D029721:Drosophila Proteins; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C494999:Ret protein, mouse