RESUMO
Objective To study the effect of imbalance of proliferation and apoptosis in the development of colorectal carcinoma(CRC),and the molecular mechanism of the dynamic change.Methods ORC was(induced) with dimethylhydrazine(DMH) in male mice of Kimming strain.The mice were killed in batches in the 12th,18th and 24th weeks of carcinoma induction.The distribution and extent of proliferation and(apoptosis) of the colorectal mucosa,at various intervals,were dynamically observed.Three genes,p21waf1,Bax and Gadd45 were analyzed by RT-PCR,immunohistochemistry and Western blot.Results During the course of carcinoma induction,the mucosas of the model mice showed sequential changes of atypital(hyperplasia),adenoma,and carcinoma.Compared with control group,the PCNA expression of the model group mice was significantly higher(P