title: Molecular heterogeneity of RET loss of function in Hirschsprung's disease.
abstract: The RET proto-oncogene encodes a receptor with tyrosine kinase activity (RET) that is involved in several neoplastic and non-neoplastic diseases. Oncogenic activation of RET, achieved by different mechanisms, is detected in a sizeable fraction of human thyroid tumors, as well as in multiple endocrine neoplasia types 2A and 2B (MEN2A and MEN2B) and familial medullary thyroid carcinoma tumoral syndromes. Germline mutations of RET have also been associated with a non-neoplastic disease, the congenital colonic aganglionosis, i.e. Hirschsprung's disease (HSCR). To analyse the impact of HSCR mutations on RET function, we have introduced into wild-type RET and activated RET(MEN2A) and RET(MEN2B) alleles three missense mutations associated with HSCR. Here we show that the three mutations caused a loss of function of RET when assayed in two model cell systems, NIH 3T3 and PC12 cells. The effect of different HSCR mutations was due to different molecular mechanisms. The HSCR972 (Arg972-->Gly) mutation, mapping in the intracytoplasmic region of RET, impaired its tyrosine kinase activity, while two extracellular mutations, HSCR32 (Ser32-->Leu) and HSCR393 (Phe393-->Leu), inhibited the biological activity of RET by impairing the correct maturation of the RET protein and its transport to the cell surface.
authors.affiliation: Centro di Endocrinologia ed Oncologia Sperimentale del CNR, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Carlomagno
authors.forename: G
authors.initials: G
authors.lastname: De Vita
authors.forename: M T
authors.initials: MT
authors.lastname: Berlingieri
authors.forename: V
authors.initials: V
authors.lastname: de Franciscis
authors.forename: R M
authors.initials: RM
authors.lastname: Melillo
authors.forename: V
authors.initials: V
authors.lastname: Colantuoni
authors.forename: M H
authors.initials: MH
authors.lastname: Kraus
authors.forename: P P
authors.initials: PP
authors.lastname: Di Fiore
authors.forename: A
authors.initials: A
authors.lastname: Fusco
authors.forename: M
authors.initials: M
authors.lastname: Santoro
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins; D051766:Early Growth Response Protein 1; D015972:Gene Expression Regulation, Neoplastic; D006627:Hirschsprung Disease / Q000235:genetics*; D006801:Humans; D017874:Immediate-Early Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors; D009479:Neuropeptides; D016716:PC12 Cells; D017354:Point Mutation; D011506:Proteins / Q000235:genetics; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000235:genetics
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; C000715470:MAS1 protein, human; D009414:Nerve Growth Factors; D009479:Neuropeptides; D011506:Proteins; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C512697:Vgf protein, mouse; C062040:Vgf protein, rat; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C494999:Ret protein, mouse; C495001:Ret protein, rat