RAD51AP1-PARG参与浆液性卵巢癌PARP抑制剂耐药分子机制研究

癌症基因组图谱计划（TCGA）分析发现50%以上高级别浆液性卵巢癌样本中存在同源重组修复通路异常，但其高表达机制及生物学意义尚未系统阐明。课题组前期发现RAD51AP1在HGSOC组织中高表达并与患者不良预后相关，RAD51AP1促进卵巢癌细胞的增殖、侵袭，免疫共沉淀(Co-IP)和RNA-seq发现RAD51AP1与PARG相互作用调控RRM2表达。课题组提出假说：HGSOC中MYC转录激活RAD51AP1，进而募集PARG转录调控RRM2表达，促进HGSOC恶性行为。本课题拟利用体内外实验明确RAD51AP1在HGSOC中的生物学功能；利用Co-IP、GST pull-down等方法明确RAD51AP1与PARG相互作用，阐明其激活RRM2表达的分子机制。利用免疫组化分析RAD51AP1及其相关DNA修复网络的表达，为HGSOC分子分型、耐药机制和个体化治疗提供新的分子靶标。

Abnormal homologous recombinational repair (HRR) pathway was found in above 50% of HGSOC cases according to the analysis of the Cancer Genome Atlas (TCGA), but the mechanism of high expression and biological significance have not been systematically elucidated. RAD51AP1 was found to be overexpressed and related to poor clinical prognosis of HGSOC in our preliminary study. RAD51AP1 could promote the proliferation and invasion of ovarian cancer cells, besides, Co-immunoprecipitation (Co-IP) and RNA-seq demonstrated that RAD51AP1 interacted with PARG and regulated the expression of RRM2. We proposed a hypothesis that MYC activated the expression of RAD51AP1 and RAD51AP1 recruited PARG to transcriptional regulate RRM2 expression and promoted the malignant behavior of HGSOC. We will elucidate the biological function of RAD51AP1 both in vitro and in vivo. We will demonstrate the interaction between RAD51AP1 and PARG and illuminate the molecular mechanism of its activation of RRM2 expression by immunoprecipitation, GST pull-down assay and other methods. We will characterize the expression of RAD51AP1 and related DNA damage and repair network of HGSOC by immunohistochemistry staining analysis. This study will provide new molecular targets for HGSOC molecular typing, drug resistance mechanism and individualized therapy.