宫颈脱落细胞circRNA预测高危型HPV阳性妇女成癌风险的分子流行病学研究

High-risk Human Papillomavirus (HR-HPV) has been widely applied for cervical cancer screening. However, only a small proportion of HR-HPV positive women will finally develop invasive cancer. An efficient triage is necessary for the HR-HPV positivity．circRNAs, a kind of circular RNA with 200-800 bp, have been recently reported to regulate gene expression, and involve in carcinogenesis. Due to their cell enrichment and stable properties, circRNAs have great potential application value in minimally invasive and easy screening of cervical cancer by using exfoliated cells. The present study will at first screen cervical cancer-specific circRNAs spectrum in cervical cancer and adjacent noncancerous tissues, with further validation in exfoliated cells to determine circRNAs biomarkers. A case-control study using multi-stage cervical exfoliated cell samples (HR-HPV positive normal vs. HR-HPV positive CIN1 vs. HR-HPV positive CIN2-3 vs. HR-HPV positive cancer) will be designed to identify circRNAs as biomarkers for the estimation of cervical cancer risk for the HR-HPV positivity. The prediction model of cervical cancer risk after HR-HPV acquisition will be established by combining the circRNAs expression and HR-HPV genotypes/ variants, and then be validated in a prospective cohort study. The biological mechanism of circRNAs will be explored by functional experiments. Our findings will provide scientific evidence for the identification of high-risk population of cervical cancer after HR-HPV acquisition and benefit the individualized intervention.

高危型人乳头状瘤病毒(HR-HPV)检测是宫颈癌筛查主要手段，但HR-HPV阳性者癌变比例很低。探索有效方法，预测HR-HPV阳性者成癌风险意义重大。circRNA是200-800bp环状RNA，可调控基因表达，最新报道与多种肿瘤相关。因其在细胞中富集且性质稳定，在提倡微创易行、以脱落细胞检测为主导的宫颈癌筛查中，极具潜在应用价值。本课题拟首先在组织中构建宫颈癌特异性circRNA表达谱，并在脱落细胞中验证；其次行多组病例-对照研究 (正常 vs. CIN1 vs. CIN2-3 vs. 癌)，鉴定可作为HR-HPV阳性者成癌风险早期预测的circRNA，并联合HR-HPV亚型/变异体，构建HR-HPV阳性者成癌风险预测模型；最后在已建立的前瞻性队列中评价模型预警效果，功能实验探索circRNA作用机制。本课题的顺利实施将为识别HR-HPV感染后易于癌变的高危个体，实施个体化干预提供依据。

本研究应用以人群和医院为基础相结合的大样本病例-对照研究，首先在20对宫颈癌和健康对照的宫颈脱落细胞中开展转录组测序和生物信息学分析，构建了宫颈癌特异性circRNA表达谱，选择表达差异最显著的22个circRNA，在二阶段病例对照研究（818例新发宫颈癌患者和292例宫颈正常者，均为HPV 阳性）进行扩大验证，证实hsa_circ_0004649（Circ-AKT3）、hsa_circ_0084591(Circ-CHD7)、hsa_circ_0084004（Circ-FGFR1）、hsa_circ_0073817（Circ-ADAMTS19）、hsa_circ_0031989（Circ-SAMD4A）、hsa_circ_0033142（Circ-VRK1）及hsa_circ_0067724（Circ-RNF13）共7个circRNA的表达水平与第一阶段的差异结果一致。ROC分析发现这7个circRNA能够较好的区分宫颈癌患者和对照（AUC=0.89）。前瞻性队列研究证实Circ-AKT3低表达与宫颈癌早期病变的发生风险增加有关（HR for Q4 vs Q1=1.42, 95% CI: 1.04-2.02）。已有证据支持Circ-AKT3能够抑制肿瘤的发生和侵袭转移，具有潜在抑癌作用。本研究为识别HR-HPV感染后易于癌变的高危个体，实施个体化干预提供了新的科学依据和线索。该研究结果不仅具有基础科学研究意义，更具有一定的公共卫生人群应用价值。