[Effect of NMBzA on the oncogene and multiple tumor suppressor genes in monkey esophageal epithelium].
Mutations of ras oncogene and multiple tumor suppressor genes p53, Rb and APC in esophageal epithelium of rhesus monkey fed with one dose of N-methyl-N-benzylnitrosamine (NMBzA 30mg/kg), which was found in high incidence areas of esophageal cancer in China, were analysed by PCR and direct sequencing. Mutation at codon 12 of Ha-ras gene was not found in esophageal epithelium of monkey fed with NMBzA. Some mutations of p53 gene were found in esophageal epithelium of monkey after being fed with NMBzA for 24-48 hours. Some mutation of Rb and APC were found in esophageal epithelium of monkey after being fed with NMBzA for 48 hours. The mutation fingerprints of these genes disappeared in esophageal epithelium of monkey after being fed with NMBzA for 5 days. The results demonstrated that chemical carcinogen NMBzA can induce mutations of multiple tumor suppressor genes in monkey (in vivo) and indicated that the alteration of tumor suppressor genes in the initial stage of carcinogenesis needs many hits by chemical carcinogen. These alterations of p53, Rb, APC genes were similar to the changes of these genes in some reported previously primary esophageal cancer.
Li
H
H
Cancer Institute, CAMS and PUMC, Beijing.
Lu
S
S
Feng
L
L
D000818:Animals; D001483:Base Sequence; D002273:Carcinogens / Q000633:toxicity; D004128:Dimethylnitrosamine / Q000031:analogs & derivatives* / Q000633:toxicity; D004848:Epithelium / Q000187:drug effects; D004947:Esophagus / Q000187:drug effects*; D017491:Genes, APC; D016161:Genes, Retinoblastoma; D016147:Genes, Tumor Suppressor; D016158:Genes, p53; D011905:Genes, ras; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D017354:Point Mutation
D002273:Carcinogens; C014707:nitrosobenzylmethylamine; D004128:Dimethylnitrosamine