以MED29为靶向抗上皮性卵巢癌的分子机制研究

Ovarian cancer is a gynecological malignancy with the highest mortality。It is still lacking of effective targeted therapy for now. Recently, genomics screening for ovarian cancer found that there were a mass of SCNVs (somatic copy number variations), which were highly correlated with the prognosis of tumors. SCNVs are identified to alter the expression of effect genes and lead to promote tumor progression. However, the effect genes and their functions of most SCNVs remain unclear. In our previous study, we conducted genomics screening targeting a common SCNVs (19q13.2 AMP) and discovered its effect gene (MED29), which was a crucial subunit of Mediator complex exerting important role in transcriptional regulation in eukaryotes process. Accordingly, we will elucidate the effect and molecular mechanism to tumor of MED29 in proliferation, apoptosis and migration in cancer cells and screen the target functional genes with the transcriptional regulation net. Further, the antitumor effect of MED29 and its target genes will be assessed in cells and animal model, and the potential role as a therapeutic target in ovarian cancer will be evaluated though clinical resources. Our study will disclose the molecular mechanism for Mediator as a therapeutic target for ovarian cancer and provide clues for the newly therapeutic strategy.

卵巢癌是死亡率居首位的妇科恶性肿瘤，尚缺乏有效的靶向治疗方案。近期的组学筛查发现卵巢癌基因组中存在大量SCNVs（体细胞拷贝数变异），且与肿瘤的预后高度相关。SCNVs可改变效应基因的表达，促进肿瘤发展，但多数SCNVs的效应基因及其功能影响尚待研究。我们前期针对常见SCNVs（19q13.2 AMP）的组学筛查发现了效应基因（MED29），其作为中介体复合物（Mediator）的核心亚基，在真核生物的转录调控过程中发挥重要作用。据此，本项目拟利用细胞模型阐释MED29对肿瘤生长、凋亡及迁移的影响及分子机制，基于转录调控网络筛查其功能相关靶基因；采用细胞及动物模型评价MED29及靶基因的抗癌作用；通过临床资源评价以MED29为靶向抗上皮性卵巢癌潜力。本课题的开展将解析Mediator作为上皮性卵巢癌治疗靶点的分子机制，为新的靶向治疗策略的提供线索。

卵巢癌是死亡率居首位的妇科恶性肿瘤，尚缺乏有效的靶向治疗方案。组学筛查发现卵巢癌基因组中存在大量SCNVs（体细胞拷贝数变异），且与肿瘤的预后高度相关。据此，我们前期针对常见SCNVs（19q13.2 AMP）的组学筛查发现潜在的效应基因（MED29）的基础上，推测MED29可能在卵巢癌发生、进展中起重要作用。通过本项目的实验研究，获得了以下结果：（1）针对19q13.2 AMP区域全基因组学筛查，确定MED29为关键效应基因，其在卵巢癌组织中异常高表达，而在正常组织中相对低表达；（2）构建抑制MED29表达的细胞模型，转录组测序筛查出细胞周期为MED29潜在的下游调控通路；（3）利用特异性敲低MED29表达的两种卵巢癌细胞系（OVCAR3和A2780），运用CCK8、克隆形成、EdU、Transwell侵袭迁移、耐药IC50、流式细胞周期分析等细胞功能性实验，同时进行细胞周期及EMT相关蛋白western blot检测，阐释了MED29可通过细胞周期通路促进卵巢癌增殖，MED29通过调控EMT过程促进卵巢癌转移，且MED29可促进卵巢癌铂类耐药；（4）临床样本免疫组化分析证实卵巢癌样本中MED29表达量明显高于癌旁组织，且MED29表达量越高，卵巢癌患者临床分期越晚，病理分级越差，其总体生存及无病生存时间越短；（5）慢病毒转染建立稳定抑制MED29的OVCAR3细胞系，通过裸鼠异体移植瘤实验证实MED29可在体内环境促进肿瘤组织的生长。基于本课题的研究，我们首次阐明了MED29在卵巢癌中的作用及其分子机制，进一步拓展了对卵巢癌发生机制的理解，为今后以MED29为靶向抗上皮性卵巢癌提供有益的线索。