雌激素受体α介导的C1orf132逆转卵巢癌细胞化疗耐药的机制研究

Epithelial ovarian cancer is the most lethal gynecologic malignancy in China. Chemoresistance is a main obstacle constraining clinical prognosis of epithelial ovarian cancer patients. It has been suggested that tumor stem cells are the root of chemotherapeutic resistance, and endocrine therapy targeting estrogen receptor alpha (ERα) plays an important role in reversing chemotherapeutic resistance in epithelial ovarian cancer. However, little is known about which gene is regulated by ERα in ovarian cancer cells and its effect on chemoresistance. In our previous study, we have found that C1orf132 was mediated by ERα and closely related to chemoresistance by high-throughput sequencing and screening. Besides, the expression level of C1orf132 was significantly correlated with chemoresistance and clinical prognosis. It was concluded that C1orf132 was a key molecule mediated by ERαwhich inducing chemoresistance.Bioinformatics analysis and in vitro experiments suggested that DNA damage repair signaling pathway was regulated by C1orf132. Based on our previous work, this project intends to further explore the mechanism of ERα-mediated C1orf132 affecting chemotherapy resistance of ovarian cancer cells by means of chromatin immunoprecipitation, RNA immunoprecipitation, cell biology and bioinformatics. The results of this study are helpful to provide effective biomarkers for the application of endocrine therapy in patients with chemo-resistant ovarian cancer, and to explore new therapeutic strategies for reversing chemotherapy resistance of ovarian cancer.

上皮性卵巢癌是我国致死率最高的妇科恶性肿瘤，化疗耐药是限制患者临床预后的重要障碍。有研究认为肿瘤干细胞是化疗耐药的根源所在，靶向雌激素受体α（ERα）的内分泌治疗对逆转化疗耐药有重要作用。然而，目前ERα在卵巢癌细胞中调控的基因及其对卵巢癌干细胞化疗耐药的影响所知甚少。我们前期通过高通量测序和筛选发现ERα介导的C1orf132与卵巢癌化疗耐药关系密切，且其表达量与患者临床无进展生存期和总生存期显著正相关，这提示C1orf132是ERα介导的影响化疗耐药的关键分子；生物信息学分析及体外实验提示DNA损伤修复信号受C1orf132调控。本课题拟在前期工作的基础上，采用分子生物学、细胞生物学、生物信息学等手段进一步研究ERα介导C1orf132影响卵巢癌干细胞化疗耐药的机制。研究结果可以为促进内分泌治疗在耐药复发卵巢癌患者中应用提供有效的分子筛选标记物，为逆临床转卵巢癌化疗耐药探索新的治疗策。

上皮性卵巢癌是我国致死率最高的妇科恶性肿瘤，化疗耐药是限制患者临床预后的重要障碍。研究认为肿瘤干细胞是在肿瘤内部存在一部分能够自我更新、异性分化并且能够耐受化疗药物的杀伤作用的细胞，它们是肿瘤化疗耐药的根源所在。60%-80%的卵巢癌组织雌激素受体ɑ表达阳性，抑制雌激素受体ɑ（ERɑ）被视为逆转卵巢癌化疗耐药的一个重要途径。近年来NCCN指南也将内分泌治疗列为铂耐药性卵巢癌的治疗方案之一。然而目前ERα在卵巢癌细胞中调控的基因及其对卵巢癌干细胞化疗耐药的影响所知甚少。本项目通过使用染色质免疫共沉淀测序(ChIP-seq)对卵巢癌、乳腺癌、子宫内膜癌细胞中ERɑ在全基因组中的结合位点进行系统性的分析和研究，详细的描绘了ERα在卵巢癌等女性恶性肿瘤中的调控位点。通过对使用多浓度梯度、多时间点的雌激素处理的ER+肿瘤细胞基因表达谱数据进行分析发现ERα对基因表达的时间和浓度依赖特性。项目在高通量测序和筛选的基础上发现ERα介导的长链非编码RNA C1orf132，其表达水平在铂耐药性卵巢癌组织中表达显著下调，且其表达量与患者临床无进展生存期和总生存期显著正相关。结合生物信息学分析及体外实验我们证实了C1orf132可以作为miR29b2和miR29c的前体RNA，通过抑制DNA损伤修复因子FOXO3逆转卵巢癌细胞的化疗耐药。此外，项目还采用单细胞RNA测序和空间单细胞RNA测序技术对卵巢癌干细胞表面标记物的分布状态及肿瘤微环境内不同细胞信号转导进行探索。项目研究发现EPCAM,CD24,PROM1可以有效筛选和富集出卵巢癌干细胞；肿瘤微环境中肿瘤成纤维细胞及单核细胞对肿瘤细胞的生存干性维持提供TGF-β，IL6等炎性信号分子。项目的研究成果为进一步研究内分泌治疗在铂耐药性卵巢癌中的治疗提供有理论依据，为后续进一步发现靶向肿瘤微环境的治疗方案提供重要线索。