Colon Cancer In A Multi-stage Process Of Cancer Genetic Research

It is believed that cancer is the result of a series of genetic alterations which lead to a progressivedisturbance of cell growth control mechanism. The development of colonic carcinoma is thought to be a multistep process. The colonic tumors provide an excellent opportunity to study this progression since most colon carcinomas appeared to be arisen from adenomas, and tumor tissues at different stages of development are available for analysis.Studies on different stages of colonic tumors for comparision of the frequency of tumor suppressor genes and oncogenes altered in adenomas and carcinomas may shed light on the genetic process involved in tumor development and progression.In this study,different types of colonic tumors were studied, including both fresh tissues from 5 cases of and paraffin embedded tissues from 41 cases of surgically resected colonic specimenes respectively in which all specimenes contained separable normal mucosa .adenoma, and adenocarcinoma; 10 cases of endoscopically excised paraffin-embedded colonic adenomas and 4 human colonic carcinoma cell lines. Expression of 8 oncogenes (c- myc,c-myb,Ki-ras, H-ras, N-ras,p53,Rb,and c-fos) in these cell lines and fresh tissues was studied by Northern blot hybridization. Amplification of three oncogenes (c- myc, c-myb,and Ki-ras) and Ki- ras codon 12/61 mutations in...