散发性结直肠癌微卫星不稳定性与Mt-p53及bcl-2蛋白表达的研究

目的 探讨散发性结直肠癌微卫星不稳定性民Mt-p53及bcl-2蛋白表达的关系。方法 应用聚合酶链式反应（PCR）技术检测了48例散发性结白肠癌中四个位点的微卫星不稳定性,同时应用免疫组织化学技术对癌基因bcl-2、抑癌基因Mt-p53蛋白的表达。结果 ①48例散发性结直肠癌中四个微卫星位点D2S123、BAT-26、D17S261、D16S799的微卫垦不稳定性检出率分别为12.5％、18.8％、10.4％、8.3％;②Mt-p53蛋白和bcl-2蛋白阳性个分别为66.7％和77.1％;③微卫星不稳定性与mt-p53和bcl-2蛋白的表达均相差个显著（P>0.05）。结论 微卫星不稳定性引起散发性结直肠癌的RER途径是不同于由抑癌基因p53失活及癌基因bcl-2的激活引起的LOH途径的新致癌机制。

A study on microsatellite instability and expression of the mt- p53 and bcl - 2 in the sporadic colorectal cancer

Objective To investigate the relation between mierosatellite instability (MSI) and expression of the mt-p53 and bcl-2. Methods MSI at the loci D2S123. BAT-26, D2S261, D2S799 and expression of mt -p53, bcl-2 protein were studied in 48 surgical specimens of sporadic colorectal cancer (SRC) with radioactive poly-inerase chain reaction (PCR) and immunohisloehemistry. Results (1)MSI at loci D2S123, BAT-26, D17S261, D17S799 occurred in 12.5%, 18.8%, 10.4%, 8.3% of the SRC respectively; (2)The expression of p53, bcl - 2 protein was positive in 66.7%, , 77. 1 % of the SRC respectively; (3)There was no correlation of MSI to the expression of mt - p53 and bcl - 2 protein. Conclusions MSI exerts effects through a different mechanism from LOH caused by oncogene bcl - 2 and anti - oncogene p53 in the development of sporadic colorectal cancer.