高危型人乳头瘤病毒（HPV）持续性感染及转归的机制研究

Cervical cancer is one of the serious diseases threatening the life and health of Chinese women. High-risk human papillomavirus (HPV) has been demonstrated to be a risk factor of cervical cancer. The mutation of host core genetic susceptibility loci is a critical internal cause, and high-risk HPV persistent infection is the key factor and necessary condition of the disease. Our preliminary studies showed that there are mutated genetic susceptibility loci in cervical cancer patients, in cervical carcinogenesis high-risk HPV oncogene homologous integrate into the genome of susceptible hosts, inducing molecular events such as genomic instability in cervical cells, which is the basis of cervical cancer carcinogenesis and development. On the basis of reliable preliminary studies, the change of HPV four-dimensional space and superfine conformation will be analyzed in this project, and the specific molecular structure characteristics of high-risk HPV will be explored. On the other hand, high-risk HPV nonhomologous integration mode-mediated fusion gene specific structural variation will be illuminated through fine mapping and functional analysis of genetic susceptibility gene, the specific expressed fusion gene profiles will be filtrated and verified for the further analysis the mechanism of host oncogene/anti-oncogene imbalance. The foundation will be laid at illuminating cervical cancer pathogenesis deeply and systematically and establishing precise targeted intervention and early prevention and treatment strategy focusing on high-risk HPV persistent infection and prognosis.

宫颈癌是严重威胁我国妇女生命健康的重大疾病之一。已证实高危型人乳头瘤病毒（Human Papillomavirus，HPV）是宫颈癌的致病因素。宿主核心遗传易感位点变异是关键内在因素，而高危型HPV持续性感染是发病的关键因素和必然条件。我们前期研究证实宫颈癌宿主存在遗传易感变异位点，在宫颈癌演变过程中高危型HPV致癌基因整合到易感宿主DNA，引导宫颈细胞产生基因组不稳定性等分子事件是宫颈癌发生发展的基础。本项目在前期笃实的研究基础上，分析HPV四维空间和超微构象改变，探索高危型HPV特有分子结构性状；另一方面，通过对遗传易感致病基因的精细定位及功能分析，阐明高危型HPV非同源整合模式介导的融合基因特异性结构变异，筛选验证特异表达的融合基因谱，进一步解析宿主癌基因/抑癌基因失衡机制，为深入系统地明确宫颈癌发病机制、建立针对高危型HPV持续性感染及转归的精准靶向干预及早期防治的新策略奠定基础。

本项目从宿主本身遗传易感变异调控网络、高危性HPV非同源整合模式介导融合基因特异表达、宫颈恶性转归过程中关键步骤等多方面阐明宫颈高危型HPV持续性感染的交联机制，探索与宫颈癌发病紧密关联的重要分子事件，项目从以下四方面开展了深入系列的研究：（1）基于HPV16人类基因组染色体整合的基因组三维结构研究：项目通过三维测序技术分析宿主基因组整合位点附近三维基因组特征性变化，结合ChIP-seq、RNA-seq分析表观重编程和基因表达情况，明确了HPV16整合13q22引起的宿主细胞恶性变化的三维分子机制，筛选出整合特异性的分子靶标，并在持续性感染和癌前病变的临床标本中得到验证。（2）用宫颈癌家族深化宫颈癌后GWAS分析，研究宫颈癌遗传易感性：选取家系样品23个进行全基因组WGS技术深度测序，筛选宫颈癌家族易感致病基因，最后利用GWAS数据在大样本人群中验证突变及功能，筛选到AHN、MUC、CPA、ERA、UNC、MHC6个候选基因。（3）宫颈癌HPV持续性感染影响的关键致癌基因研究：HPV在宫颈癌细胞中和全基因组和整合染色体的交互作用，通过转录因子SP1介导染色体的开放状态和激活型组蛋白的重编程状态实现，其抑制剂Plicamycin抑制SP1能够逆转组蛋白激活状态，抑制癌基因的异常表达，介导免疫抗原提呈和PD-L1/PD-L2的表达，提高了宫颈癌免疫治疗的应答率；（4）宫颈癌高危HPV非同源整合模式介导融合基因特异表达：项目总结了在宫颈癌中表达频率高于10%的融合基因的基因谱，对融合基因的融合模式和信号通路进行了研究，同时对宫颈癌中特异表达高频率的融合基因，在不同宫颈癌细胞系和临床标本内进行了验证。项目经过近五年的系统深入的研究，完成了项目计划的全部内容，并在此基础上，强化和拓展了研究目标一和研究目标三的相关内容，对HPV整合感染和机制做了进一步深入的研究。