m6A去甲基化酶ALKBH5调节lncRNA THRIL—PTBP1信号轴介导细胞自噬促进卵巢癌顺铂耐药的机制研究

以顺铂为基础的联合化疗是卵巢癌的主要治疗方法之一，而顺铂耐药是临床上亟待解决的重要问题。近年来m6A修饰被报道与多种肿瘤化疗耐药相关，但其在卵巢癌顺铂耐药中的作用尚不清楚。我们前期研究发现：m6A去甲基化酶ALKBH5在卵巢癌顺铂耐药细胞和组织中均高表达，而敲低ALKBH5抑制细胞顺铂耐药和自噬。ALKBH5降低长链非编码RNA THRIL的m6A水平增强THRIL稳定性，同时增加THRIL结合蛋白PTBP1的稳定性，导致ATG5水平升高。据此我们提出假说：ALKBH5通过降低lncRNA THRIL的m6A水平，抑制PTBP1蛋白泛素化增强其蛋白稳定性，进而增加ATG5水平，诱导细胞自噬，促进卵巢癌顺铂耐药。本项目拟从细胞自噬的角度，深入探讨ALKBH5-THRIL-PTBP1-ATG5信号轴在卵巢癌顺铂耐药中的作用，将为卵巢癌化疗增敏靶分子的探寻提供新的理论和实验依据。

Cisplatin is widely used in combination chemotherapy for ovarian cancer. However, cisplatin resistance largely limits its clinical application. Recently, m6A modification has been reported to confer chemotherapy resistance in various tumors, but its role in cisplatin mediated resistance in ovarian cancer remains unclear. Our preliminary results showed that m6A demethylase ALKBH5 was highly expressed in cisplatin resistant ovarian cancer cells and tissues, while knockdown of ALKBH5 diminished the cisplatin resistance and autophagy. Notably, ALKBH5 decreased the m6A level of lncRNA THRIL and reinforced THRIL stability, while enhanced the stability of THRIL binding protein PTBP1, which resulted in an increase in ATG5 level. Hence, we hypothesized that ALKBH5 attenuated the m6A modification of THRIL and stabilized PTBP1 protein by inhibiting its ubiquitination, and further induced autophagy by elevating ATG5 level, which ultimately lead to cisplatin resistance of ovarian cancer. This project highlights the role of autophagy regulated by ALKBH5-THRIL-PTBP1-ATG5 axis in cisplatin mediated resistance and provides a new theoretical and experimental basis for exploring targeted molecules of chemotherapy sensitization in ovarian cancer.