摘要:
目的 研究DNA错配修复基因hMLH1和hMSH2在结直肠癌合并慢性血吸虫肠病患者与散发型结直肠癌患者的肿瘤组织中的表达差异.方法 回顾性分析浙江省肿瘤医院2008年1月至2010年12月收治的338例结直肠癌患者的临床病理资料, 根据术前患者病史和肿瘤标本病理检查结果,将患者分为慢性血吸虫肠病组(80例)和散发型结直肠癌组(258例).应用免疫组织化学法检测hMLH1和hMSH2蛋白在两组患者肿瘤组织中的差异性表达, 并分析其与患者临床病理特征的关系.结果 与散发型结直肠癌组患者相比,慢性血吸虫病组患者的年龄更高[(62.2 ± 9.6)岁比(57.2 ± 11.7)岁,P=0.000],术前血小板与白细胞水平更低[(197.0 ± 59.6)×109/L比(217.0 ± 84.3) × 109/L, (5.9 ± 1.9) × 109/L比(6.6 ± 2.8) × 109/L,均P=0.020]. 两组患者的低分化和未分化肿瘤的比例分别为44.2%(34/77)和4.9%(12/247),差异具有统计学意义(P=0.001). 慢性血吸虫病组中hMLH1和hMSH2的表达水平均低于散发型结直肠癌组 [77.5%(62/80) 比98.1%(253/258),75.0%(60/80)比95.3%(246/258), 均P=0.000]. 合并慢性血吸虫病是hMLH1和hMSH2表达缺失的危险因素之一(RR:0.913, 95%CI:0.836~0.997, P=0.043),但非独立危险因素(RR:0.951,95%CI:0.867~1.043, P=0.286).结论 慢性血吸虫肠病的结直肠癌组织中hMLH1和hMSH2蛋白的表达水平低于散发型结直肠癌,提示慢性血吸虫肠病诱发结直肠癌的机制可能与hMLH1和hMSH2基因的缺失有关.%Objective To investigate the expression difference of DNA mismatch repair gene hMLH1 and hMSH2 between schistosomiasis-associated colorectal cancer and sporadic colorectal cancer. Method Clinical and pathological data of colorectal cancer patients receiving operations in Zhejiang Cancer Hospital between January 2008 and December 2010 were retrospectively analyzed. Patients were divided into schistosomiasis group (n=80) and sporadic group (n=258) according to the preoperative history and pathologic results. Pathological specimens were collected and tissue chips were made to analyze the expression of hMLH1 and hMSH2 by immunohistochemistr. Results Compared with sporadic group, older age [(62.2 ± 9.6) year vs. (57.2 ± 11.7) year, P = 0.000)], lower platelet level [(197.0 ± 59.6) × 109/L vs. (217.0 ± 84.3) × 109/L, P = 0.02] and lower WBC level [(5.9 ± 1.9) ×109/L vs. (6.6 ± 2.8) ×109/L, P = 0.02] were found in schistosomiasis group. Ratio of low differentiation-undifferentiation tumor was significantly higher in schistosomiasis group [44.2% (34/77) vs. 4.9% (12/247), P<0.05]. Lower positive rate of hMLH1 expression [77.5% (62/80) vs. 98.1%(253/258), P = 0.000] and hMSH2 expression [75.0% (60/80) vs. 95.3% (246/258), P = 0.000] was found in schistosomiasis group compared with sporadic group. Concurrent schistosomiasis was one of the risk factors of hMLH1/hMSH2 deficiency (RR:0.913, 95%CI:0.836-0.997, P=0.043), but not an independent factor (RR:0.951, 95%CI:0.867-1.043, P=0.286). Conclusion Schistosomiasis is associated with lower positive expression of hMLH1 and hMSH2 , which indicates that hMLH1/hMSH2 deficiency may be a potential mechanism of schistosomiasis inducing carcinogenesis of colorectal cancer.