环状RNA circ-0007444调控卵巢癌恶性进展的作用与机制研究

By high-throughput sequencing，we disclosed a novel and function-unknown circular RNA, circ-0007444, which is remarkably downregulated in epithelial ovarian cancer tissues and cell lines. Our previous studies have found that circ-0007444 was negatively associated with lymph node metastasis, while positively related with overall survival of ovarian cancer patients. Knock-down of circ-0007444 could promote proliferation, migration, invasion and inhibit apoptosis of ovarian cancer cells. Besides, we also found that circ-0007444 could sponge miR-103a-3p/miR-107 to modulate the expression of DICER by bioinformatics analysis and luciferase reporter assay, while DICER has been reported to regulate cancer progression in several human tumors. In this study, we firstly aimed to validate the expression of circ-0007444 in more human samples and verify the prognosis prediction value of circ-0007444. And then we intended to examine the role of circ-0007444 in ovarian cancer progression in vivo and in vitro. Finally, the mechanism of circ-0007444 sponging miR-103a-3p/miR-107 to regulate the expression of DICER will be investigated by using RIP and rescue experiments. If successful, this study may provide a new method for prognosis prediction and the clinical treatments of ovarian cancer.

circ-0007444是我们通过高通量测序筛选获得的，在上皮性卵巢癌组织及细胞株中均显著下调的一条功能未知的环状RNA。前期研究发现circ-0007444与卵巢癌淋巴结转移负相关，与总体生存率正相关；敲降该环状RNA可促进卵巢癌细胞的增殖、迁移、侵袭，抑制其凋亡；生物信息学分析及荧光素酶报告基因实验等初步发现circ-0007444可结合miR-103a-3p/miR-107调控下游靶基因DICER的表达，而DICER可以抑制多种肿瘤的进展。本研究拟进一步扩大样本评估circ-0007444的表达规律及预后预测价值；通过体外及在体实验验证其调控卵巢癌恶性进展的功能；结合RIP，挽救实验等深入研究circ-0007444通过吸附miR-103a-3p/miR-107，上调DICER来抑制卵巢癌恶性进展的作用机制。如获资助，有望为卵巢癌的预后预测及临床治疗提供新的手段。

卵巢癌是女性生殖系统常见的一种恶性肿瘤，恶性程度高，病死率一直高居妇科肿瘤之首。环状RNA是一类参与癌症发生和进展的非编码RNA分子。先前的研究表明hsa_circ_0007444在卵巢癌组织中低表达。本课题拟阐明hsa_circ_0007444在卵巢癌进展中的功能及机制。采用qRT-PCR技术定量hsa_circ_0007444的表达量，利用CCK-8实验、transwell实验及流式细胞分析技术分别研究卵巢癌细胞的增殖、侵袭和迁移及凋亡功能。构建Balb/c裸鼠的皮下成瘤及尾静脉注射模型，在体研究hsa_circ_0007444在肿瘤生长和转移中的作用。Hsa_circ_0007444在卵巢癌细胞系中显著低表达。过表达和干扰研究表明hsa_circ_0007444抑制了细胞增殖、侵袭和迁移，促进了细胞凋亡，抑制了肿瘤的生长和肺转移。生物信息学分析、RNA结合蛋白免疫沉淀实验、荧光素酶报告基因实验及挽救实验等分析了hsa_circ_0007444的作用机制，表明hsa_circ_0007444通过海绵样结合miR-23a-3p上调基因DICER1的表达，从而发挥抑制肿瘤的作用。Hsa_circ_0007444 通过调节hsa_circ_0007444/miR-23a-3p/DICER1轴的作用发挥抑癌作用，为肿瘤的治疗提供了新的靶点。