Wnt拮抗因子SFRP1在结直肠癌发病机制中的作用  

Effect of Wnt Antagonist SFRP1 in the Pathogenesy of Colorectal Cancer

作　　者：王巍[1] 张冰[2] 阎雪晶[3] 王舰[4] 张宁[1] 赵成海[1] 

机构地区：[1]中国医科大学基础医学院病理生理教研室,沈阳110001 [2]中国医科大学基础医学院机能实验中心,沈阳110001 [3]中国医科大学第95期临床医学七年制,沈阳110001 [4]中国医科大学基础医学院病原生物学教研室,沈阳110001

出　　处：《中国医科大学学报》2012年第5期440-443,共4页Journal of China Medical University

基　　金：辽宁省自然科学基金资助项目(20092125);辽宁省教育厅高校科研计划(2009A751;2008799)

摘　　要：目的检测结直肠癌中Wnt拮抗因子分泌型卷曲相关蛋白1(SFRP1)基因的甲基化及表达状态,探讨SFRP1在结直肠癌发病中的作用。方法选自中国医科大学盛京医院的结直肠癌组织标本及相应的癌旁组织标本各35例,利用逆转录聚合酶链反应(RT-PCR)和即时定量聚合酶链反应(real-time PCR)技术检测在结直肠癌组织和相应的癌旁组织中SFRP1的表达状态。利用甲基化特异性聚合酶链反应(MSP-PCR)技术检测结直肠癌组织和相应的癌旁组织中SFRP1的甲基化状态。利用RT-PCR和Western blot技术检测结直肠癌细胞中SFRP1的表达状态。结果 SFRP1 mRNA的表达水平在结直肠癌组织中明显低于癌旁组织(P<0.01)。SFRP1的甲基化频率结直肠癌组织(68.6%)明显高于癌旁组织(11.4%)(χ2=21.49,P<0.01)。在结肠癌细胞HCT116、SW480和SW620中SFRP1未见表达,SFRP1存在甲基化,而在HT-29中SFRP1有表达,SFRP1无甲基化。对HCT116、SW480和SW620使用去甲基化试剂5-氮杂-2'-脱氧胞苷(DAC)处理后,SFRP1出现表达。结论 SFRP1甲基化是引起SFRP1在结直肠癌中表达下调的重要原因之一。SFRP1甲基化及其所致表达下调可能在部分结直肠癌的发病过程中起重要作用。Objective To determine the methylation and the expression status of Wnt antagonist Secreted Frizzled-Related Protein 1（SFRP1） in colorectal cancer and explore the effect of SFRP1 in colorectal carcinogenesis.Methods Reverse-transcription PCR（RT-PCR） and Real-time PCR were used to determine the SFRP1 expression in colorectal cancer tissues and its adjacent tissues.Methylation-specific PCR（MSP） was used to detect the methylation of SFRP1.SFRP1 expression in colorectal cancer cell lines was detected by RT-RCR and Western blot.Results The level of SFRP1 expression was remarkably lower in colorectal cancer tissues than that in corresponding cancer adjacent tissues（P 〈 0.01）.The frequency of methylation of SFRP1 was significantly higher in colorectal cancer tissues（68.6%） than that in matched cancer adjacent tissues（11.4%）（χ2=21.49,P 〈 0.01）.SFRP1 was methylated and not expressed in colorectal cancer line HCT116,SW480 and SW620.And SFRP1 was expressed and not methylated in colorectal cancer line HT-29.After HCT116,SW480 and SW620 were treated with demethylating agent 5-aza-2′-deoxycytidine（DAC）,SFRP1 expression was restored in HCT116,SW480 and SW620.Conclusion Methylation is one of the major factors causing aberrant expression of SFRP1,which are common in colorectal cancer and play an important role in colorectal carcinogenesis.

关 键 词：结直肠癌 分泌型卷曲相关蛋白1 甲基化 

分 类 号：R730.2[医药卫生—肿瘤]