Genetic analysis in dysplasia and carcinoma accompanied with longstanding ulcerative colitis

点击翻译按钮获取中文摘要

Vogelstein et a1. proposed a multistep carcinogenesis model of colorectal cancer in 1988, and a number of genetic abnormalities associated with colorectal cancer have been noted in many institutes. On the other hand, with the increase in patients contracting ulcerative colitis (UC) for a long period, mutation of the K-ras and p53 genes in colorectal cancer with a complication of UC,has been investigated, although this issue now will be controversial. we investigated the ras gene mutations, overexpression of p53 protein and DCC polymorphism in codon 201 in cancer complicated with longstanding ulcerative colitis to elucidate the diagnosis of dysplasia and found that in dysplasia of colitis which are difficult to judge whether to be regenerative, p53 immunostaining was positive at a high rate if complicated with cancer but in DCC and ras abnormalities, no differences between dysplasia and regenerative epithelia were detected. Mutaions of ras gene were extremely low.In conclusion, our studies suggested that p53 positive patients found in surveillance colonoscopy are likely to have complication of cancer although the detection of DCC polymorphism and point mutation of ras genes was not useful for the diagnosis of dysplasia accompanied with longstanding ulcerative colitis.