Department of Gynecology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
J Exp Clin Cancer Res. 2021 Sep 8;40(1):284. doi: 10.1186/s13046-021-02088-1.
Chemotherapy resistance remains a barrier to improving the prognosis of epithelial ovarian cancer (EOC). ALKBH5 has recently been shown to be one of the RNA N6-methyladenosine (m6A) demethyltransferases associated with various cancers, but its role in cancer therapeutic resistance remains unclear. This study aimed to investigate the role of AlkB homolog 5 (ALKBH5) in cisplatin-resistant EOC.
Functional assays were performed both in vitro and in vivo. RNA sequencing (RNA-seq), m6A-modified RNA immunoprecipitation sequencing (MeRIP-seq), chromatin immunoprecipitation, RNA immunoprecipitation, and luciferase reporter and actinomycin-D assays were performed to investigate RNA/RNA interaction and m6A modification of the ALKBH5-HOXA10 loop.
ALKBH5 was upregulated in cisplatin-resistant EOC and promoted cancer cell cisplatin resistance both in vivo and in vitro. Notably, HOXA10 formed a loop with ALKBH5 and was found to be the upstream transcription factor of ALKBH5. HOXA10 overexpression also facilitated EOC cell chemoresistance both in vivo and in vitro. Collective results of MeRIP-seq and RNA-seq showed that JAK2 is the m6A-modified gene targeted by ALKBH5. The JAK2/STAT3 signaling pathway was activated by overexpression of the ALKBH5-HOXA10 loop, resulting in EOC chemoresistance. Cell sensitivity to cisplatin was rescued by ALKBH5 and HOXA10 knockdown or inhibition of the JAK2/STAT3 signaling pathway in EOC cells overexpressing ALKBH5-HOXA10.
The ALKBH5-HOXA10 loop jointly activates the JAK2/STAT3 signaling pathway by mediating JAK2 m6A demethylation, promoting EOC resistance to cisplatin. Thus, inhibition of the expression of the ALKBH5-HOXA10 loop may be a potential strategy to overcome cisplatin resistance in EOC.
化疗耐药仍是改善上皮性卵巢癌（EOC）预后的障碍。ALKBH5 最近被证明是与多种癌症相关的 RNA N6-甲基腺苷（m6A）去甲基转移酶之一，但它在癌症治疗耐药性中的作用尚不清楚。本研究旨在探讨 AlkB 同源物 5（ALKBH5）在上皮性卵巢癌顺铂耐药中的作用。
在体内和体外进行功能测定。进行 RNA 测序（RNA-seq）、m6A 修饰 RNA 免疫沉淀测序（MeRIP-seq）、染色质免疫沉淀、RNA 免疫沉淀、荧光素酶报告和放线菌素 D 测定，以研究 ALKBH5-HOXA10 环的 RNA/RNA 相互作用和 m6A 修饰。
ALKBH5 在顺铂耐药性 EOC 中上调，并在体内和体外均促进癌细胞对顺铂的耐药性。值得注意的是，HOXA10 与 ALKBH5 形成环，并且被发现是 ALKBH5 的上游转录因子。HOXA10 的过表达也促进了体内和体外的 EOC 细胞化疗耐药性。MeRIP-seq 和 RNA-seq 的综合结果表明，JAK2 是 ALKBH5 靶向的 m6A 修饰基因。ALKBH5-HOXA10 环的过表达激活了 JAK2/STAT3 信号通路，导致 EOC 化疗耐药性。在过表达 ALKBH5-HOXA10 的 EOC 细胞中，通过 ALKBH5 和 HOXA10 的敲低或抑制 JAK2/STAT3 信号通路，细胞对顺铂的敏感性得到挽救。
ALKBH5-HOXA10 环通过介导 JAK2 m6A 去甲基化共同激活 JAK2/STAT3 信号通路，促进 EOC 对顺铂的耐药性。因此，抑制 ALKBH5-HOXA10 环的表达可能是克服 EOC 顺铂耐药的一种潜在策略。
