ADAR1 Prevents R-loop Accumulation-Driven ATR Pathway Activation in Ovarian Cancer

作者：Hanwei Cui, Qian Yi, Min Tian, Hai Yang, Yuteng Liang, Jie Huang, Qi Zeng, Weichao Sun, Jian Han, Jianxin Guo, Zhiying Yu, Wenlan Liu, Xiufeng Ye · 发表于：Journal of Cancer · 年份：2022 · DOI：10.7150/jca.72108 · 被引用次数：19 · 研究领域：RNA regulation and disease、Herpesvirus Infections and Treatments、RNA Research and Splicing

Adenosine (A)-to-inosine (I) RNA editing is the most prevalent RNA editing mechanism, in which adenosine deaminase acting on RNA 1 (ADAR1) is a major adenosine deaminase. Increasing evidence suggests that editing dysregulation of ADAR1 plays an important role in human tumorigenesis, while the underlying mechanism remains elusive. Here, we demonstrated that ADAR1 was highly expressed in ovarian cancer tissues and negatively correlated with progression free survival of ovarian cancer patients. Importantly, silence of ADAR1 repressed ovarian cancer cell growth and colony formation in vitro and inhibited ovarian cancer cell tumorigenesis in vivo. Further cell cycle and transcriptome profile analysis revealed that silence of ADAR1 in ovarian cancer cells induced cell cycle arrest at G1/G0 stage. Mechanistically, loss of ADAR1 caused R-loop abnormal accumulation, thereby contributing to single stand DNA break and ATR pathway activation. Additionally, ADAR1 interacted with DHX9 to regulate R-loop complex formation, and A-to-I editing of nascent RNA repressed R-loop formation during co-transcriptional process. Together, our results identify a novel ADAR1/R-loop/ATR axis critical for ovarian cancer progression and a potential target for ovarian cancer therapy.