粪便SEPT9基因甲基化检测在结直肠癌早期诊断中的应用研究

目的 探讨粪便SEPT9(Septin9)基因甲基化检测在结直肠癌诊断中的价值.方法 从126例结直肠癌手术切除癌组织、癌旁组织及其术前粪便中提取DNA,应用多重置换扩增(MDA)结合巢式甲基化特异性PCR(nMSP)检测结直肠癌粪便SEPT9基因甲基化水平;以手术后病理诊断为标准,比较结直肠癌组织和粪便中SEPT9甲基化检测在结直肠癌诊断中的敏感性和特异性.结果 在126例结直肠癌中,癌组织SEPT9检出率为84.1%,癌旁组织检出率为7.9%,二者比较有统计学差异(P<0.01),特异性为92.1%;结直肠癌粪便SEPT9基因甲基化检测结果与组织检测结果一致;在各临床分期之间,SEPT9甲基化检出率无统计学差异(P>0.05).结论 结直肠癌组织SEPT9基因甲基化异常发生率高;粪便SEPT9甲基化异常可作为结直肠癌早期诊断的肿瘤标志物.

Study of early diagnosis of colorectal cancer by analysis of stool SEPT9 gene methylation

Objective To investigate the diagnosis of colorectal cancer by analysis of SEPT9 methylation in stool DNA.Methods The stool SEPT9 gene methylation were detected by multiple displacement amplification/nested methylation specific PCR,MDA-nMSP in 126 colorectal cancer tissues,para-cancer tissues and stool DNA.The sensitivity and specificity of SEPT9 methylation marker in colorectal cancer diagnosis were analyzed.Results Among 126 colorectal cancers,SEPT9 gene methylation was found in 84.1%(106/126)of cancer tissues and 7.9%(10/126)of para-cancer tissues respectively.The sensitivity and specificity of SEPT9 for diagnosis of colorectal cancer were 84.1% and 92.1% respectively,and the stool SEPT9 had similar sensitivity as cancer tissues in diagnosis of colorectal cancer.There were no any differences for incidence of SEPT9 methylation among different clinical stages.Conclusions The abnormal methylation of SEPT9 happen frequently in colorectal cancer;hypermethylaion of SEPT9 gene mehylation in stool DNA can be used as a candidate of tumor marker for early diagnosis of colorectal cancer.