Circular RNA Cdr1as sensitizes bladder cancer to cisplatin by upregulating APAF1 expression through miR‐1270 inhibition. Issue 7 (9th June 2019)

• Record Type: Journal Article
• Authors: Yuan, Wenbo; Zhou, Rui; Wang, Jingzi; Han, Jie; Yang, Xiao; Yu, Hao; Lu, Hongcheng; Zhang, Xiaolei; Li, Pengchao; Tao, Jun; Wei, Jifu; Lu, Qiang; Yang, Haiwei; Gu, Min
• Is Part Of: Molecular oncology. Volume 13:Issue 7(2019)
• Page Start: 1559
• Page End: 1576
• Publication Date: 2019-06-09
• Subjects: APAF1 -- bladder cancer -- Cdr1as -- circular RNA -- cisplatin -- miR‐1270; Cancer -- Molecular aspects -- Periodicals; 616.994005
• DOI: 10.1002/1878-0261.12523
• Languages: English
• ISSNs: 1574-7891

Abstract

Abstract : Circular RNAs (circRNAs) have recently emerged as essential regulators in carcinogenesis and cancer progression. Previous studies have shown that Cdr1as functions as a microRNA (miRNA) sponge in various cancer types. However, the role of Cdr1as in cisplatin chemosensitivity in bladder cancer remains unclear. Here, we used real‐time PCR to examine miRNA and gene expression in bladder cancer tissues and cell lines. The abilities of Cdr1as and its downstream regulatory molecules to induce apoptosis and promote cisplatin‐induced chemosensitivity of bladder cancer cells were determined by flow cytometry and cell counting kit. Bioinformatic analysis was utilized to predict potential miRNA target sites, and biotin‐coupled miRNA capture, biotin‐coupled probe pull‐down assay, and RNA fluorescent in situ hybridization were used to study the interaction between Cdr1as and target miRNAs. Dual‐luciferase reporter assay was also used to validate the target genes of miRNAs. The expression level of apoptotic protease‐activating factor 1 (APAF1) in bladder cancer cells was identified via western blot. Finally, the sensitivity of Cdr1as to cisplatin chemotherapy in nude mice xenografts was evaluated in terms of the size, volume of tumors, and the survival of mice. We report that Cdr1as induced the apoptosis and enhanced the cisplatin chemosensitivity of bladder cancer cells both in vitro and in vivo . Silencing of APAF1 reduced the sensitivity of bladder cancer cells to cisplatin chemotherapy. Furthermore, Cdr1as could directly sponge miR‐1270 and abolish its effect on APAF1. Our study verified that Cdr1as exerts a cisplatin‐chemosensitization effect on bladder cancer cells through the Cdr1as/miR‐1270/APAF1 axis. This newly identified axis may be a potential therapeutic target for bladder cancer patients. Abstract : In this study, we explored the effect of circular RNAs Cdr1as on the cisplatin chemosensitivity of bladder cancer and revealed the underlying regulatory mechanism: the novel Cdr1as/miR‐1270/apoptotic protease‐activating factor 1 (APAF1) axis. Cdr1as can function as a molecular sponge of miR‐1270, which weakens the inhibitory effect of microRNA on the downstream target gene APAF1. Furthermore, Cdr1as enhances the expression level of APAF1 in bladder cancer, increasing cisplatin chemosensitivity and activating the apoptotic pathway.