Kim Jo-Heon, Choi Yoo Duk, Lee Ji Shin, Lee Jae Hyuk, Nam Jong Hee, Choi Chan
Department of Pathology, Chonnam National University Medical School and Research Institute of Medical Sciences, Gwangju 501-746, Republic of Korea.
Gynecol Oncol. 2010 Jan;116(1):99-104. doi: 10.1016/j.ygyno.2009.09.032.
DNA methylation is an early event in carcinogenesis. Testing for DNA methylation has potential in cancer screening. The aim of this study was to investigate the feasibility of methylated DNA detection as a screening tool for squamous cell carcinomas (SCC) and squamous intraepithelial lesions (SIL) in cervical scrapings.
A multiplex, nested, methylation-specific polymerase chain reaction approach was used to examine promoter methylation of 12 genes (CDH1, DAPK, GSTP1, HIC-1, HIN-1, hMLH1, MGMT, p16, RAR-beta, RASSF1A, SHP-1, and Twist) in biopsy-proven SCC (n=69), high-grade SIL (HSIL, n=67), low-grade SIL (LSIL, n=32), and negative (n=41) liquid-based cytology samples.
The methylation frequency in normal, LSIL, HSIL, and SCC was significantly different (p<0.01) for eight genes (DAPK, HIC-1, HIN-1, MGMT, RAR-beta, RASSF1A, SHP-1, and Twist). There was a trend toward increasing methylation of HIN-1, MGMT, RAR-beta, RASSF1A, and SHP-1 with increasing severity of cervical squamous lesions. The number of methylated genes increased with the severity of cervical squamous lesions (p<0.001). In receiver-operating characteristic analysis, the three-gene combination (RAR-beta/Twist/MGMT) showed the best performance to distinguish HSIL/SCC from LCIS/negative samples. The estimated specificity of this three-gene panel for detecting HSIL/SCC was 82.2%, and its sensitivity was 78.7%.
Although aberrant DNA methylation has the potential to function as a molecular biomarker of HSIL and SCC in liquid-based cytology tests, additional genes that are selectively methylated in HSIL and SCC are needed to improve clinical performance.
DNA甲基化是癌症发生的早期事件。检测DNA甲基化在癌症筛查中具有潜力。本研究的目的是探讨甲基化DNA检测作为宫颈刮片中鳞状细胞癌（SCC）和鳞状上皮内病变（SIL）筛查工具的可行性。
采用多重、巢式、甲基化特异性聚合酶链反应方法检测经活检证实的SCC（n = 69）、高级别SIL（HSIL，n = 67）、低级别SIL（LSIL，n = 32）和阴性（n = 41）液基细胞学样本中12个基因（CDH1、DAPK、GSTP1、HIC-1、HIN-1、hMLH1、MGMT、p16、RAR-β、RASSF1A、SHP-1和Twist）的启动子甲基化情况。
8个基因（DAPK、HIC-1、HIN-1、MGMT、RAR-β、RASSF1A、SHP-1和Twist）在正常、LSIL、HSIL和SCC中的甲基化频率有显著差异（p<0.01）。随着宫颈鳞状病变严重程度的增加，HIN-1、MGMT、RAR-β、RASSF1A和SHP-1的甲基化有增加趋势。甲基化基因的数量随着宫颈鳞状病变的严重程度增加而增加（p<0.001）。在受试者工作特征分析中，三基因组合（RAR-β/Twist/MGMT）在区分HSIL/SCC与LCIS/阴性样本方面表现最佳。该三基因检测组合检测HSIL/SCC的估计特异性为82.2%，敏感性为78.7%。
虽然异常DNA甲基化有可能在液基细胞学检测中作为HSIL和SCC的分子生物标志物，但需要在HSIL和SCC中选择性甲基化的其他基因来提高临床性能。
