hMLH1、hMSH2、c-Myc、PTEN在残胃癌中的表达和意义

Expressions of hMLH1,hMSH2,c-Myc,and PTEN in Gastric Remnant Cancer and Their Significance

目的:比较正常胃黏膜、残胃炎、胃癌、残胃癌中hMLH1、hMSH2、c-Myc及PTEN蛋白表达情况,探讨上述蛋白在残胃癌发生、发展中的作用。方法:用免疫组化SP法检测hMLH1、hMSH2、c-Myc、PTEN蛋白在20例正常胃黏膜、20例残胃炎、38例胃癌、18例残胃癌组织中hMLH1、hMSH2、c-Myc、PTEN蛋白的表达情况。结果:在残胃癌中hMLH1、hMSH2蛋白的阳性率分别为50.0%,44.4%,分别低于正常胃黏膜组织100.0%,100.0%(P<0.01)。胃癌中hMLH1、hMSH2的表达阳性率为68.4%,63.2%,与残胃癌相比无显著差异(P>0.05)。c-Myc蛋白在残胃炎黏膜组织的表达阳性率(45.0%)要高于正常胃黏膜(0.0%)(P<0.05),而残胃癌中的表达阳性率(61.1%)与胃癌中的表达(55.3%)差异无显著性(P>0.05)。PTEN蛋白在残胃癌(44.4%)和胃癌(47.4%)中的表达均下调,两组之间差异无统计学意义(P>0.05)。结论:残胃癌的发生可能与错配修复系统失活有关,癌基因c-myc激活和抑癌基因PTEN的失活也参与了残胃癌的发生、发展。

Objective： To compare the expression of hMLH1, hMSH2, c-Myc and PTEN in normal gastric mucosa, gastric remnant mucosa, gastric remnant cancer （GRC） and gastric cancer（GC）, and to investigate their roles in carcinogenesis and development of gastric remnant cancer. Methods： The SP immunohistochemical method was applied to detect the expression rate of hMLH1, hMSH2, c-myc and PTEN gene in normal gastric mucosa, gastric remnant mucosa, gastric remnant cancer and gastric cancer. Results. The expression rate of hMLHI（50.0%） and hMSH2 （44. 4%） was significantly decreased in GRC, compared with that in normal gastric mucosa （100.0% and 100.0% respectively） （P〈0.01）, while was not different from that in GC（68.4% and 63.2%, respectively）. The positive expression of c-Myc in gastric remnant mucosa（45.0%） was higher than in normal gastric mucosa（0.0%） （P〈0.05）. There was no difference in positive expression rate of c-Myc protein between GRC （61.1%） and GC（55.3%）. The positive expression rate of PTEN was observed and was downregulated in GRC（44.4%） and GC（47.4%）, but no significant differences were observed between the two groups. Conclusion： GRC might be associated with the inactivation of mismatch repair gene. Increased expression of c Myc protein and reduced expression of PTEN protein might be important in the tumorigenesis and progression of GRC.