人粪便中MALL基因甲基化检测在结直肠癌早期诊断中的作用

摘要

Objective To explore the potential application of MALL gene methylation of stool DNA in early clinic diagnosis of colorectal cancers. Methods From January 2013 to December 2014 , morning stool specimens were collected from 89 patients with colorectal cancer and 33 healthy people in our hospital , then DNA was extracted,methylation-specie PCR was carried out for methylation analysis of MALL in DNA samples.The sensitivity of MALL gene methylation of stool DNA to the diagnosis of colorectal cancer was compared with fecal occult blood test(FOBT) and CEA. Results The positive rate of of MALL gene methyhtion was 78.7%(70/89)in colorectal cancer patients, significantly higher than 3.0%(1/33) in healthy people (P<0.01). The sensitivity of MALL gene methyhtion to the diagnosis of colorectal cancer was 78.7%, significantly higher than FOBT examination (30.3%) and CEA (29.2%) (all P<0.01). No significant correlations were found between MALL gene methylation and clinical characteristics including sex,age,tumor location,lymph node metastasis and TNM stage (all P>0.05). Conclusions The sensitivity of stool DNA MALL methylation to the diagnosis is high in colorectal cancer , which may be used as an optional noninvasive method for the diagnosis of colorectal tumor.%目的：探讨粪便中MALL 基因甲基化检测在结直肠癌诊断中的价值。方法收集2013年1月至2014年12月在本院确诊的89例结直肠癌患者及33例正常人清晨粪便标本，提取其DNA 经处理后采用甲基化特异性 PCR 技术分析 MALL 甲基化状态，比较粪便 MALL 基因甲基化状态与粪便潜血（FOBT）、CEA 诊断结直肠癌的价值。结果结直肠癌患者粪便 DNA 中 MALL 基因启动子甲基化率为78．7％（70／89），显著高于正常人3．0％（1／33）（P＜0．01）。粪便 MALL 基因甲基化诊断结直肠癌的敏感度（78．7％）显著高于粪便潜血（30．3％）、CEA（29．2％）（均 P＜0．01）。 MALL 基因甲基化状态与结直肠癌患者的性别、年龄、肿瘤部位、淋巴结转移及TNM分期均无关（均P＞0．05）。结论粪便MALL基因异常甲基化对于诊断结直肠癌具有较高的敏感性，可作为诊断结直肠癌的无创性初筛方法。