环状RNA circ_0047020通过miR-200a-3p/KLF9信号轴调控子宫内膜癌转移的机制研究

Endometrial cancer is a serious threat to women's health, its mechanism underlying metastasis is not clear. By using high-throughput microarray chips and bioinformatics analysis, we found that down-regulation of circular RNA circ_0047020 was associated with the metastasis of endometrial cancer. Down-regulation of circ_0047020 expression promoted the migration and invasion of endometrial cancer cells, increased the expression of miR-200a-3p and decreased the expression of tumor-associated gene Kruppel-like factor 9 (KLF9). Therefore, we propose a hypothesis: circ_0047020 regulates the expression of KLF9 by competitively binding miR-200a-3p and affects the metastasis of endometrial cancer. We intend to perform luciferase reporter system, circRIP, FISH and cellular functional experiments on endometrial cancer cell lines to investigate whether circ_0047020 could reduce the targeted suppressing effect of miR-200a-3p on KLF9 by competitively binding miR-200a-3p, inhibiting the migration and invasion of endometrial cancer cells consequently. This hypothesis would be further verified by animal experiments and clinical specimens as well. Our study will elucidate the new mechanism by which circular RNA circ_0047020 regulates endometrial cancer metastasis, enriching the theory of endometrial cancer metastasis and providing new ideas for the development of anti-tumor therapy.

子宫内膜癌严重威胁女性健康，其转移机制尚不明确。本课题前期通过高通量芯片及生物信息学分析发现环状RNA circ_0047020表达下调可能与内膜癌转移有关。下调circ_0047020表达可促进内膜癌细胞迁移和侵袭、上调miR-200a-3p及下调肿瘤相关基因Kruppel样转录因子9（KLF9）的表达。故提出假说：circ_0047020通过竞争性结合miR-200a-3p调控KLF9表达，影响内膜癌转移。本研究拟进一步在内膜癌细胞系中通过荧光素酶报告系统、circRIP、FISH及相关功能学实验等探讨circ_0047020是否通过竞争性结合miR-200a-3p，减少miR-200a-3p对KLF9的靶向抑制，从而抑制内膜癌细胞迁移和侵袭。并进一步通过动物实验及临床样本验证该假说。阐明circ_0047020调控内膜癌转移的新机制，将丰富内膜癌转移理论，为开发抗肿瘤治疗提供新思路。

子宫内膜癌是女性最常见的恶性肿瘤之一，约20-30%的病人在确诊时已伴有局部浸润或远处转移，这类患者对目前常见的手术或放化疗治疗反应欠佳，死亡率高，故寻求内膜癌治疗的新靶点至关重要。本课题通过高通量芯片筛选发现在内膜癌中环状RNA circ_0047020表达下降，circ_0047020可能通过miR-200a-3p/KLF9调控子宫内膜癌转移。此外进一步生信分析发现，HIF高表达导致内膜癌对谷氨酰胺利用和对铁死亡敏感性增加，联合铁死亡诱导剂RSL3和谷氨酰胺酶抑制剂CB-839可有效在体内外协同抑制内膜癌生长，诱导细胞凋亡和铁死亡。进一步利用RNA-SEQ筛选发现细胞色素P450酶家族的CYP1A1基因，可能是调控以上协同致死作用的关键基因。该研究为阐明内膜癌转移、寻找抗肿瘤药物提供了新的靶点和思路。