胃癌发生过程中DNA修复蛋白表达的意义

Significance of DNA repair protein in gastric carcinoma

[目的]探讨错配修复蛋白hMSH2、损伤直接逆转蛋白MGMT、同源重组修复蛋白XRCC2和XRCC3蛋白表达在胃癌诊断中的意义及用于胃癌预警的可能性。[方法]免疫组织化学(SP)法检测56例胃癌患者的癌组织(癌组)、癌旁黏膜上皮(癌旁组)与30例非肿瘤患者(正常组)胃黏膜上皮hMSH2、MGMT、XRCC2及XRCC3蛋白表达情况。[结果]胃癌、癌旁与正常组hMSH2蛋白阳性表达率为76.8%(43/56)、33.9%(19/56)与33.3%(10/30),胃癌组明显高于癌旁和正常组(P<0.05)。MGMT蛋白阳性表达率分别为26.8%(15/56)、32.1%(18/56)与73.3%(22/30),胃癌组和癌旁组明显低于正常组(P<0.05);XRCC2蛋白阳性表达率分别为32.1%(18/56)、3.6%(2/56)与0%(0/30),胃癌组明显高于癌旁和正常组(P<0.05);XRCC3蛋白阳性表达率分别为76.8%(43/56)、35.7%(20/56)与36.7%(11/30),胃癌组明显高于癌旁和正常组(P<0.05)。粘液癌、低分化与高中分化癌组hMSH2蛋白阳性表达率分别为62.5%(10/16)、76.9%(20/26)与85.7%(12/14);MGMT分别为12.5%(2/16)、34.6%(9/26)与28.6%(4/14);XRCC2分别为18.8%(3/16)、42.3%(11/26)与28.5%(4/14);XRCC3分别为56.3%(9/16)、84.6%(22/26)与85.7%(12/14),这些蛋白表达在各组间差异无显著性意义(P>0.05)。胃癌组织中hMSH2阳性组和阴性组MGMT蛋白阳性表达率分别为34.9%(15/43)和0%(0/13),两种蛋白表达明显正相关(r=0.333,P<0.05)。[结论]hMSH2、MGMT、XRCC2及XRCC3蛋白的异常表达说明胃癌中存在多种形式的DNA损伤。检测它们的表达会有助于诊断和预警胃癌。

[Objective] To study the possibility of hMSH2,MGMT,XRCC2 and XRCC3 protein as a marker to predict and diagnose gastric carcinoma.[Methods] The expressions of these proteins were detected by immunohistochemistry SP method.[Results] In carcinoma,surrounding epithelia and non carcinoma gastric mucosa（normal） groups,the positive expression rates of hMSH2 were 76.8%,33.9% and 33.3%（P0.05）;of MGMT were 26.8%,32.1% and NCGM 73.3%（P0.05）;of XRCC2 were 32.1%,3.6% and 0%（P0.05）;of XRCC3 were 76.8%,35.7% and 36.7%（P0.05）.In low,moderate and high differentiate gastric carcinoma groups of mucinous carcinoma,there was no significant difference on the expression rates of hMSH2,MGMT,XRCC2 and XRCC3,respectively（P0.05）.In gastric carcinoma,the expression of hMSH2 and MGMT were positively related（P0.05）.[Conclusions] The abnormal expressions of hMSH2,MGMT,XRCC2 and XRCC3 protein in gastric carcinoma indicate that there are many forms of DNA damage repair.Detection of these proteins may be helpful to diagnose and predict gastric carcinoma.