孟岳?余中贵?黄文峰?许岸高?李丙生

【摘要】目的 評估检测大肠肿瘤患者粪便中SEPT-9和微RNA（miRNA）-34b/c基因甲基化对大肠肿瘤筛查的临床性能。方法 采用病例对照研究方法，使用甲基化敏感性高分辨率熔解曲线法检测大肠肿瘤患者（大肠癌组35例、大肠腺瘤组47例）和正常对照人群（正常对照组52名）粪便中SEPT-9和miRNA-34b/c基因是否存在甲基化，来评估其筛查大肠肿瘤的性能。结果 大肠癌组SEPT-9和miRNA-34b/c基因的甲基化阳性率分别为68.6%、71.4%，大肠腺瘤组分别为57.4%、63.8%，正常对照组分别为9.6%、11.5%。3组的SEPT-9、miRNA-34b/c基因甲基化阳性率比较差异均有统计学意义（χ2SEPT-9 = 37.185，χ2miRNA-34b/c = 40.040，P均< 0.001），利用Bonferroni法进行两两比较，大肠癌组和大肠腺瘤组的甲基化阳性率比较差异无统计学意义，两者与正常对照组比较差异均有统计学意义（P均< 0.001）。3组联合检测SEPT-9和miRNA-34b/c基因的甲基化阳性率为88.6%、76.6%、13.5%，大肠癌组和大肠腺瘤组联合检测的甲基化阳性率均高于SEPT-9单基因检测和miRNA-34b/c单基因检测（P均< 0.05）。结论 检测粪便中SEPT-9和miRNA-34b/c基因甲基化具有效好的大肠肿瘤筛查性能，或许可作为大规模人群筛查大肠肿瘤新的生物标志物组合;多基因甲基化联合检测筛查的性能优于单基因。

【关键词】大肠肿瘤;SEPT-9;miRNA-34b/c;甲基化;甲基化敏感性高分辨率熔解曲线分析

Clinical performance of detecting fecal SEPT-9 and miRNA-34b/c gene methylation for colorectal tumor screening Meng Yue， Yu Zhonggui， Huang Wenfeng， Xu Angao， Li Bingsheng. Departmengt of Gastroenterology， the First Hospital of Huizhou， Huizhou 516000， China

Corresponding author， Li Bingsheng， E-mail： 1102066844@ qq. com

【Abstract】Objective To access the clinical performance of detecting fecal SEPT-9 and miRNA-34b/c gene methylation for colorectal tumor screening in patients diagnosed with colorectal tumor. Methods In this case-control study， the fecal SEPT-9 and miRNA-34b/c gene methylation in patients diagnosed with colorectal cancer（n = 35），colorectal adenoma（n = 47） and normal controls （n = 52） was identified by by using methylation-sensitive high-resolution melting （MS-HRM） to access the clinical performance for colorectal tumor screening. Results The methylation rates of fecal SEPT-9 and miRNA-34b/c detection in the colorectal cancer group were 68.6% and 71.4%， 57.4% and 63.8% in the colorectal adenoma group， and 9.6% and 11.5% in normal control group， respectively. The methylation rates of SEPT-9 and miRNA-34b/c significantly differed among three groups （χ2SEPT-9 = 37.185， χ2miRNA-34b/c = 40.040， all P < 0.001）. According to two-group comparison by using Bonferroni correction，the methylation rates did not significantly differ between the colorectal cancer and colorectal adenoma groups （both P > 0.05）， which significantly differed from those in the normal control group （all P < 0.001）. The methylation rates of combined detection of SEPT-9 and miRNA-34b/c were 88.6% in the colorectal cancer group， 76.6% in the colorectal adenoma group and 13.5% in normal control group. Combined decection methylation rates of SEPT-9 and miRNA-34b in colorectal cancer group and colorectal adenoma group were significantly higher compared with that of either SEPT-9 or miRNA-34b/c alone （all P < 0.05）. Conclusions Detecting fecal SEPT-9 and miRNA-34b/c gene methylation yields high clinical performance for colorectal tumor screening. Methylated SEPT-9 and miRNA-34b/c genes may be a new panel of biomarkers for colorectal tumor screening in large-scale population. The performance of combined detection of multi-gene methylation detection is better compared with that of single gene.

【Key words】Colorectal cancer;SEPT-9;miRNA-34b/c;Methylation;

Methylation-sensitive high-resolution melting

大肠癌是常见的消化道肿瘤之一，我国大肠癌发病率继胃癌、肺癌、食管癌之后排第4位，且呈上升趋势[1]。和其他恶性肿瘤不同的是，大肠肿瘤早期筛查、早期诊断、早期治疗能显著降低大肠癌的发病率和病死率，改善预后，有重大社会意义。目前，尚无行之有效的大肠肿瘤大规模筛查方法。DNA甲基化是大肠肿瘤发生发展过程中的一个早期事件，研究证实通过检测粪便DNA/微RNA（miRNA）基因的甲基化可早期筛查大肠肿瘤，并且多基因联合检测的筛查性能优于单基因检测。目前有较多的粪便DNA/miRNA基因甲基化标志物被研究用于大肠肿瘤筛查，其中SEPT-9和 miRNA-34b/c基因被证实具有较好的筛查性能[2-6]。

基于此，本研究评估联合检测粪便SEPT-9和miRNA-34b/c基因甲基化对大肠肿瘤筛查的临床性能，以期寻求更好的大肠肿瘤筛查标志物组合。

对象与方法