人粪便SFRP2基因甲基化分析对结直肠癌的诊断价值

目的探讨人粪便中分泌型卷曲相关蛋白2(SFRP2)基因甲基化分析用于结直肠癌(CRC)早期诊断的可行性。方法从87例结直肠癌或良性病变的患者及24例正常对照者的粪便中分别提取DNA,采用甲基化特异性PCR(MSP)技术分析其SFRP2基因甲基化状态。结果CRC、腺瘤、增生性息肉和溃疡性结肠炎患者的SFRP2基因甲基化阳性率分别为94.2%(49/52)、52.4%(11/21)、37.5%(3/8)和16.7%(1/6)。1例正常对照SFRP2基因甲基化检测阳性。检测SFRP2基因甲基化诊断CRC及癌前病变的敏感性和特异性分别为90.5%和85.4%。结论SFRP2基因甲基化是CRC进展过程中的早期事件。粪便SFRP2基因甲基化分析可望成为CRC早期无创诊断或CRC高风险人群筛查的新途径。

Value of SFRP2 methylation analysis in stool in early diagnosis of colorectal cancer

[Objective] To evaluate the possibility of methylation analysis of secreted frizzled-related protein gene 2(SFRP2)in feces for screening early colorectal cancer (CRC). [Methods] DNA was isolated from fecal samples from 87 patients with malignant or benign colorectal diseases (52 with cancer,21 with adenomas,8 with hyperplastic polyp and 6 with ulcerative colitis) and 24 normal volunteer, and the methylation status of SFRP2 was analyzed with methylation-specific polymerase chain reaction(MSP).[Results] Methylated SFRP2 occurred in 94.2%(49/52),52.4%(11/21),37.5%(3/8)and 16.7%(1/6) of patients with CRC, adenomas, hyperplstic polyps and ulcerative colitis, respectively. One normal control also revealed SFRP2 methylation. The sensitivity and specificity of SFRP2 methylation assay for CRC and precancerous lesions was 90.5% and 85.4%, respectively. [Conclusions] Hypermethylation of SFRP2 is an event that occurs early in disease progression of CRC. Analysis of fecal SFRP2 methylation is expected to serve as a new early detection way for CRC or a new screening tool for individuals at high-risk of developing colorectal neoplasm.