Mxi1 is a potential cellular target of carcinogens and frequently mutated in experimental rat tumors and tumor cell lines

摘要: Mxi1, a member of the Myc family transcription factors, negatively regulates oncoprotein activity and thus may be tumor suppressor gene. It is mutated in few human prostate cancers. Rat Mxi1 was isolated as selective overexpressive message rat esophageal cancer induced by N-nitrososarcosine ethyl ester using differential display polymerase chain reaction cloning. Reverse transcription, single-strand conformation polymorphism analysis subsequent DNA sequencing were used to screen mutations for coding region including functional domains, Sin3-interacting, helix-loop-helix leucine zipper samples from 24 tissues various cell lines. Seven revealed exist six tumors (including two breast cancer), three lines: Leydig tumor, osteogenic sarcoma, pituitary tumor. No changes detected 34 sporadic gastric adenocarcinoma. A silent base substitution (GAG GAA) at codon 131 also identified well one cancer. Our results indicate that often experimental but are rare The gene cellular target strong carcinogens. Considering frequency chemical carcinogen-induced tumors, searches mutation should directed toward patients with specific epidemiological background.