外周血中SFRP2基因超甲基化改变与大肠癌关系的初步研究

Preliminary study on relation of hypermethylation of secreted frizzled-related protein(SFRP2) gene in peripheral blood with colorectal cancer

目的 :探讨外周血分泌型卷曲相关蛋白2(SFRP2)基因超甲基化改变与大肠癌发生、发展的关系。方法:利用甲基化特异性PCR(MSP)技术分析117例大肠癌患者术前的外周血中SFRP2基因启动子区异常甲基化改变情况,其中直肠癌69例,结肠癌48例。以50例大肠良性疾病患者和30例健康志愿者的外周血标本作为对照。结果:外周血中SFRP2基因超甲基化在直肠癌、结肠癌和大肠良性病变中的发生率分别为60.8%(42/69)、56.2%(27/48)和4%(2/50),在30例健康志愿者的血液标本中没有检测到SFRP2基因甲基化。此外,SFRP2基因超甲基化与肿瘤分期、分化及淋巴结转移呈正相关性,而与患者的年龄、性别及肿瘤的大小、位置等临床病理学特征无统计学相关性。结论:外周血中SFRP2基因甲基化与大肠癌的发生、发展呈一定相关性,其可成为检测早期CRC较为敏感的DNA单碱基标志物。

Objective： To investigate the promoter hypermethylation of secreted frizzled-relat-ed protein 2（SFRP2） gene in peripheral blood of colorectal cancer. Methods： Methylation-specific PCR （MSP） was performed to analyze promoter methylation status of secreted frizzled-related pro- tein 2（SFRP2） in peripheral blood from 117 colorectal cancer patients, including 69 patients with rectal cancer, 48 patients with colon carcinoma. 50 patients with benign intestinal disease and 30 blood samples of healthy volunteer as normal controls. Results： Hypermethylated SFRP2 was found in 60.8% （42/69）,56.2（27/48）,4% （2/50） of blood samples from rectal carcinoma, colon carcinoma, benign intestinal diseasperipheral ,respectively. In contrast, no hypermethylated SFRP2 was detected in blood of normal controls. Moreover, it is found that SFRP2 methylation has positive relation with tu- mor stage, differentiation and lymph node metastasis. But no significant associations were observed between hypermethylated SFRP2 and clinicopathological features including sex, age, tumor stage and location. Conclusion： Hypermethylation of SFRP2 gene in peripheral blood has some associations with CRC, and might be a high potential biomarker for the early screening of CRC.