人参皂苷活性单体20(S)-Rg3拮抗卵巢癌细胞有氧糖酵解的机制研究

Ovarian cancer is the most lethal gynecologic malignancies. The prognosis of patients with ovarian cancer has remained poor mainly because of aggressive cancer progression. Since aerobic glycolysis is crucial for cancer progression, targeting aerobic glycolysis with more efficacious and less toxic compounds to inhibit cancer cell growth and metastasis is of great therapeutic value for the treatment of ovarian cancer. We have reported that the ginsenoside 20(S)-Rg3, a pharmacologically active component of the traditional Chinese herb Panax ginseng, potently downregulates HIF1α，and blocks aerobic glycolysis of ovarian cancer cells in vitro and in vivo. Recently, we have found 20(S)-Rg3 downregulates DNMT3A and HIF1α-responsive long non-coding RNA H19. And we identify 20(S)-Rg3-stimulated aerobic glycolysis-inhibitory microRNA-324-5p/519a-5p/603 that are negatively regulated by DNMT3A and H19. We therefore propose that 20(S)-Rg3 promotes aerobic glycolysis-inhibitory microRNAs via inhibiting DNMT3A-mediated DNA methylation and HIF1α-H19 axis to antagonize aerobic glycolysis in ovarian cancer cells. This proposal aims to, by using a set of biological methods, elucidate the molecular basis of inhibition of 20(S)-Rg3 on aerobic glycolysis in ovarian cancer cells, including the pathway that 20(S)-Rg3 reduces the methylation regulation of DNMT3A on the promoter regions in microRNA-324-5p/519a-5p/603 precursor genes, the regulatory mechanism of HIF1α-H19 axis on microRNA-324-5p, and the direct targets of these microRNAs. The overall goal is to further the understanding the mechanisms of aerobic glycolysis via establishing molecular pathways mediating 20(S)-Rg3 inhibition on aerobic glycolysis, thus provide essential data toward clinical translation of 20(S)-Rg3 in ovarian cancer treatment.

针对卵巢癌细胞代谢特点研发抑制癌细胞特异能量代谢的药物将有助于改善卵巢癌疗效。我们发现人参皂苷20(S)-Rg3下调HIF1α、拮抗卵巢癌细胞有氧糖酵解、阻止卵巢癌进展，并下调DNA甲基转移酶DNMT3A和HIF1α反应性lncRNA H19而诱导有氧糖酵解抑制性miR-324-5p/519a-5p/603表达。推测20(S)-Rg3可能通过抑制DNMT3A和HIF1α-H19轴而增强上述miR对有氧糖酵解关键酶HK2和PKM2的抑制。现拟利用细胞分子生物学和实验动物学技术，从卵巢癌细胞、组织和动物水平分析20(S)-Rg3对DNMT3A甲基化调控miR-324-5p/519-5p/603及HIF1α-H19轴负调控miR-324-5p进而削弱miR抑制HK2和PKM2活性的影响，探讨20(S)-Rg3抗有氧糖酵解的分子通路，为明确其抑制卵巢癌进展的机制并将其转化于临床提供必要的研究资料。

有氧糖酵解是肿瘤细胞能量代谢异常的重要特征之一。人参皂苷活性单体20（S）-Rg3具有拮抗卵巢癌细胞有氧糖酵解的活性。本项目从卵巢癌细胞、组织和动物水平研究20(S)-Rg3通过分别下调DNMT3A和H19而增强相关microRNA抑制有氧糖酵解关键酶HK2和PKM2的分子机制。研究结果显示，20(S)-Rg3通过抑制H19作为内源竞争性RNA负调控miR-324-5p的活性以及抑制DNMT3A介导的miR-519a-5p/532-3p/603前体基因启动子区甲基化，增强了miR-324-5p靶向抑制PKM2、miR-519a-5p靶向抑制HIF-1α、miR-532-3p/603靶向抑制HK2的活性，最终抑制了卵巢癌细胞的增殖、迁移和侵袭能力。此外，项目对20（S）-Rg3调控的microRNA表达谱数据进行了挖掘，拓展研究了20（S）-Rg3通过下调miR-4425而促进FDFT1表达、进而抑制卵巢癌细胞增殖和迁移侵袭的相关机制，这是在卵巢癌中首次发现miR-4425的促癌作用和FDFT1的抑癌作用。以上结果首次揭示了以microRNA为调控分子的20(S)-Rg3拮抗卵巢癌细胞有氧糖酵解的关键分子通路，为明确20(S)-Rg3抑制卵巢癌进展的机制提供了必要的研究资料，同时获得了新的卵巢癌相关microRNA及其靶分子调控卵巢癌细胞恶性表型的新数据，为阐明卵巢癌进展机理提供了重要信息。