hMLH1、hMSH2、COX-2蛋白在散发性大肠癌的表达及意义

目的：探讨错配修复基因hMLH1、hMSH2及COX-2蛋白在散发性大肠癌（sporadic colorectal carcinoma，SCC）中的表达及意义。方法：应用免疫组化SP法对60例SCC标本中的癌组织hMLH1、hMSH2和COX-2蛋白的表达进行检测。结果：（1）hMLH1、hMSH2在60例SCC组织中的阳性率为76．7％、51．7％，均较正常组有显著性差异（P〈0．05）；hMLH1、hMSH2左半结肠癌阳性率为92．0％、68．0％，右半结肠癌阳性率为65．7％、40．0％，两者比较均有显著性差异（P〈0．05）；淋巴结转移组中hMLH1和hMSH2蛋白阳性率分别为53．3％和26．7％，较无淋巴结转移组84．4％和60．0％均有显著性差异（P〈0．05）。（2）COX-2蛋白在60例SCC组织中的阳性率为73．3％，较正常组阳性率（25．0％）有显著性差异（P〈0．05）；COX-2蛋白淋巴结转移组中阳性率（93．3％）明显高于无淋巴结转移组66．7％，两组比较有显著性差异（P〈0．05）；浸润黏膜层及肌层阳性率（55．0％）低于浆膜层表达率82．5％，两组比较有显著性差异（P〈0．05）。（3）COX-2低表达的病例中hMLH1和hMSH2表达缺失。结论：hMLH1、hMSH2与COX-2蛋白通过不同的途径参与SCC的发生、发展。

Expression and Significance of hMLHI,hMSH2 and COX-2 in Sporadic Colorectal Carcinoma

Objective..To study the Significane and expression of hMLHI,hMSH2 and COX-2 in the development of sporadic colorectal carcinoma. Methods： Expression of hMLH1, hMSH2 and COX-2 was evaluated by immunohistochemistry in 60 SCCs. Results= （1）The positive expression rate of hMLH1 ,hMSH2 in SCCs was 76. 7% and 51. 7% ,respectively. Furthermore,they are significantly lower than that in normal colorectal tissues（ P 〈0. 05）. The protein expression of hMLH1 and hMLH2 in tumor tissues with lymph node metastasis was 53. 3% and 26. 7% ,significantly higher than that（84. 4% and 60. 0%） in tumors without lymph node metastasis（ P〈0. 05） ;the positive rate of hMLH1 and hMSH2 protein expression in the left colon was 92. 0% and 68. 0% ,significantly higher than that in the right colon（65. 7%, 40. 0%）. （2）The expression rate of COX-2 in SCCs was 73. 3%, significantly higher than that in normal colorectal tissues（ P 〈0. 05）;The positive rate of COX-2 protein expression in tumor tissues with lymph node metastasis was 93. 3%, higher than that（66. 7%） in tumor without lymph node metastasis. The positive rate of COX-2 protein expression in tumor tissues with mucous and muscular layer infiltration was 55. 0% lower than that（82. 5%） in those with serosal layer infiltration. The expression rate of COX-2 was significantly associated with lymph node metastasis（ P~0. 05） and with depth of infiltration（ P 〈0.05）. （3）In the tumor tissue with negative COX-2 expression, hMLHland hMSH2 have a tendency of absent expression. Conclusion：hMLH1 ,hMSH2 and COX-2 are involved in genesis and development of sporadic eolorectal carcinoma with defferent approach.