title: Mutations of the p53 gene and other genes involving in human colorectal carcinogenesis.
abstract: In this study, structural changes of the p53 gene in primary specimens of human colorectal carcinomas were analyzed by polymerase chain reaction mediated-DNA sequencing method. Point mutations of p53 gene, including an intronic mutation case, were detected in 8 of 14 carcinomas (57%). Point mutations of the gene were also observed in 2 of 2 adenomas, suggesting that mutations occur prior to the carcinoma stage. These results support that p53 gene plays an important role in the development of colorectal cancer. The frequency of Ki-ras oncogene mutations was also studied by polymerase chain reaction-single strand conformation polymorphism analysis (PCR-SSCP). This resulted in the rate of 42% (10/24), a quite similar value obtained by other methods. As PCR-SSCP analysis is a convenient method to detect point mutation, we have now examined 24 colorectal cancers for the p53 gene by this method, and detected the mutations. Furthermore, expression of the DCC gene, a candidate of tumor suppressor gene involved in colorectal carcinogenesis, was examined by reverse transcriptase-mediated PCR (RT-PCR) assay, resulting in significant reduction on the DCC expression in 8 of 14 carcinoma cases (57%).
authors.affiliation: Department of Clinical Cancer Chemotherapy, Tohoku University, Sendai, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Kanamaru
authors.forename: C
authors.initials: C
authors.lastname: Ishioka
mesh_terms: D000236:Adenoma / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015179:Colorectal Neoplasms / Q000235:genetics*; D016158:Genes, p53; D011905:Genes, ras; D006801:Humans; D008969:Molecular Sequence Data; D017354:Point Mutation