肝癌血浆游离DNA甲基化谱检测及临床意义

摘要

Objective:This study aimed to detect the special methylation profile in peripheral blood for hepatocellular carcinoma (HCC). Methods:The methylation status of 12 tumor suppressor genes (TSGs) in the plasma of 55 HCCs and 54 chronic liver diseases (CLDs) was tested by methylation-specific PCR (MSP). Results:In HCC, the methylation frequencies were 78.18%in APC, 63.64%in cyclin D2, 58.18% in TFPI2, 49.09% in DKK3, 49.09% in GSTP1, 47.27% in p16, 40.00% in Sigma 14-3-3, 18.18% in SFRP2, 16.36% in ppENK, 9.09% in DKK2, 7.27% in NPTX2, and 5.45% in LHX1. In CLD, the methylation frequencies were 27.78% in APC, 22.22%in cyclin D2, 7.41%in TFPI2, 3.70%in DKK3, 16.67%in GSTP1, 37.04%in p16, 37.04%in Sigma 14-3-3, 11.11%in SFRP2, 20.37%in ppENK, 7.41%in DKK2, 7.41%in NPTX2, and 9.26%in LHX1. The methylation frequencies of APC, cyclin D2, TFPI2, DKK3, and GSTP1 were higher in HCC than in CLD (P<0.01). The methylation index (MI) of the five-gene methylation profile was statistically higher in HCC (median, 0.6;IQR, 0.4-0.8) than CLD (median, 0.2;IQR, 0-0.2) (P<0.01). In HCC, MI was statistically related to the patient's age. Older patients with HCC had a higher MI. No significant correlation was observed between MI and other clinicopathological data. Moreover, MI was not related to the disease free survival and the overall survival in HCC. Conclusion:This five-gene methylation profile may be a promising biomarker for the assistant diagnosis of HCC.%目的：在外周血游离DNA中筛选肝癌特异的甲基化谱。方法：收集55例肝癌和54例慢性肝病患者血浆标本，应用甲基化特异性PCR方法检测血浆游离DNA的12个抑癌基因甲基化状态。结果：在肝癌组中，APC、p16、GSTP1、Cyclin D2、LHX1、TFPI2、DKK2、DKK3、SFRP2、14-3-3 sigma、ppENK、NPTX2基因的甲基化频率分别为78.18%、63.64%、58.18%、49.09%、49.09%、47.27%、40.00%、18.18%、16.36%、9.09%、7.27%和5.45%，而在慢性肝病组中，各基因的甲基化频率分别为27.78%、22.22%、7.41%、3.70%、16.67%、37.04%、37.04%、11.11%、20.37%、7.41%、7.41%和9.26%。APC、Cyclin D2、TFPI2、DKK3和GSTP1基因在肝癌组中的甲基化频率高于慢性肝病组（P<0.01）。将它们组成5基因甲基化谱，肝癌组甲基化指数（中位值为0.6，IQR 0.4～0.8）显著高于慢性肝病组（中位值为0.2，IQR 0～0.2）。在肝癌组中，甲基化指数与患者年龄具有相关性，年龄大者甲基化指数较高，而甲基化指数与其它临床病理参数未见相关性。甲基化指数与肝癌患者的无瘤生存期及总体生存期均未见相关性。结论：该甲基化谱可能成为肝癌辅助诊断的核酸标志物。