Xu Jun, Xu Ling, Yang Baohua, Wang Lifeng, Lin Xiao, Tu Hong
Department of Gynaecology and Obstetrics, Shanghai Minhang District Center Hospital 170 Xinsong Road, Shanghai 201199, China.
State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine 2200-25 Xietu Road, Shanghai 20032, China.
Int J Clin Exp Pathol. 2015 Feb 1;8(2):1674-81. eCollection 2015.
Previous studies have demonstrated that levels of hypermethylation of paired boxed gene 1 in cervical tissues are associated with the grades of severities of cervical neoplasia in women, which suggests that testing for DNA methylation has a potential role in neoplasma screening. In this study, by testing methylation levels of PAX1 genes in cervical scrapings and cervical tissues of different lesion levels, aims to evaluate the diagnostic value of DNA methylation testing as a biomarker for early detecting cancerous changes in cervical tissues and to compare the efficacy between PAX1 methylation test and HPV test in detecting of cervical cancer.
A total of 121 cervical scrapings were analyzed, including normal (n = 28), cervical intraepithelial neoplasm 1 (CIN1; n = 32), CIN2/3 (n = 34), and invasive cancer (n = 27), which were all diagnosed by pathologic examination.
The values of PAX1 methylation reference in invasive cancer (mean [SE], 26.3 [3.5]) was significantly higher than CIN2/3 (13. 2 [2.2]) and the CIN1 (4.5 [0.45]; P < 0.001). The PAX1 promoter was hypermethylated in 100% of invasive cancer tissue compared with 0% of normal tissue, 9% of CIN1, 44% of CIN2/3 (P < 0.01). Methylation levels of cervical scrapings and cervical tissues represent strong consistency within each group. In contrast, the HPV test result was positive in 17% of normal tissue, 81% of CIN1, 91% of CIN2/CIN3, and 92% of invasive cancer. Based on receiver operating characteristic (ROC) analysis, hypermethylation of PAX1 was a significant candidate in segregating cervical cancer from normal/cervical neoplasia cases (P < 0.001). At an optimal cutoff value, sensitivity and specificity between 80% and 93% were obtained. In conclusion, the current results indicated that the methylation density of PAX1 by pyrosequencing in cervical scrapings held a great promise for cervical cancer screening.
既往研究表明，宫颈组织中配对盒基因1的高甲基化水平与女性宫颈肿瘤的严重程度相关，这表明DNA甲基化检测在肿瘤筛查中具有潜在作用。在本研究中，通过检测不同病变程度宫颈刮片和宫颈组织中PAX1基因的甲基化水平，旨在评估DNA甲基化检测作为早期检测宫颈组织癌变生物标志物的诊断价值，并比较PAX1甲基化检测与HPV检测在宫颈癌检测中的效果。
共分析121份宫颈刮片，包括正常组（n = 28）、宫颈上皮内瘤变1级（CIN1；n = 32）、CIN2/3级（n = 34）和浸润癌组（n = 27），所有病例均经病理检查确诊。
浸润癌中PAX1甲基化参考值（均值[标准误]，26.3[3.5]）显著高于CIN2/3级（13.2[2.2]）和CIN1级（4.5[0.45]；P < 0.001）。与0%的正常组织、9%的CIN1、44%的CIN2/3相比，100%的浸润癌组织中PAX1启动子发生高甲基化（P < 0.01）。宫颈刮片和宫颈组织的甲基化水平在每组内表现出高度一致性。相比之下，HPV检测结果在17%的正常组织、81%的CIN1、91%的CIN2/CIN3和92%的浸润癌中呈阳性。基于受试者工作特征（ROC）分析，PAX1的高甲基化是区分宫颈癌与正常/宫颈肿瘤病例的重要指标（P < 0.001）。在最佳临界值时，敏感性和特异性在80%至93%之间。总之，目前的结果表明，通过焦磷酸测序检测宫颈刮片中PAX1的甲基化密度对宫颈癌筛查具有很大的前景。
