Department of Geriatrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Department of Anesthesiology, The Second Clinical College of North Sichuan Medical College, Nanchong Central Hospital, Nanchong, Sichuan, China.
Cell Biol Int. 2020 Dec;44(12):2416-2426. doi: 10.1002/cbin.11449. Epub 2020 Aug 31.
Multifactor and multistep processes were elucidated to participate in the progression of non-small-cell lung cancer (NSCLC). Circular RNA 0031250 (circ-PRMT5) was a vital factor in NSCLC. However, the role of circ-PRMT5 in cisplatin (DDP)-resistance needed to be further highlighted. Expression profiles of circ-PRMT5, microRNA (miR)-4458, and EV3-like DNA-directed polymerase ζ catalytic subunit (REV3L) were detected using quantitative real-time polymerase chain reaction. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and transwell assays were performed to determine the half-maximal inhibitory concentration of DDP, cell viability, apoptosis, and invasion in vitro. Besides, the protein levels of REV3L and indicated proteins were examined by adopting western blot. Dual-luciferase reporter assay was performed to analyze the interaction between miR-4458 and circ-PRMT5 or REV3L. The functional role of circ-PRMT5 was explored using a xenograft tumor model. Levels of circ-PRMT5 and REV3L were markedly increased, while miR-4458 was downregulated in resistant tissues and cells. Knockdown of circ-PRMT5 enhanced cell apoptosis, DDP-sensitivity, and declined metastasis in NSCLC with DDP resistance. Besides, miR-4458 inhibition or REV3L upregulation could revert circ-PRMT5 absence-mediated effect on DDP-sensitivity in vitro. Mechanically, circ-PRMT5 was a sponge of miR-4458 to regulate REV3L. Importantly, circ-PRMT5 silencing could interact with DDP treatment expedite the decrease of tumor growth in vivo. Circ-PRMT5 promoted DDP resistance via REV3L by sponging miR-4458 in NSCLC, thus providing a novel therapeutic strategy for patients with NSCLC.
多因素和多步骤的过程被阐明参与非小细胞肺癌（NSCLC）的进展。环状 RNA 0031250（circ-PRMT5）是 NSCLC 的一个重要因素。然而，circ-PRMT5 在顺铂（DDP）耐药中的作用需要进一步强调。采用实时定量聚合酶链反应检测circ-PRMT5、microRNA（miR）-4458和 EV3 样 DNA 指导聚合酶 ζ 催化亚基（REV3L）的表达谱。通过 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐、流式细胞术和transwell 测定法测定体外 DDP 的半最大抑制浓度、细胞活力、凋亡和侵袭。此外，采用蛋白质印迹法检测 REV3L 和指示蛋白的蛋白水平。采用双荧光素酶报告基因检测分析 miR-4458 与 circ-PRMT5 或 REV3L 的相互作用。采用异种移植肿瘤模型探讨 circ-PRMT5 的功能作用。在耐药组织和细胞中，circ-PRMT5 和 REV3L 的水平明显升高，而 miR-4458 下调。在 DDP 耐药的 NSCLC 中，circ-PRMT5 的敲低增强了细胞凋亡、DDP 敏感性，并降低了转移。此外，miR-4458 抑制或 REV3L 上调可逆转体外 circ-PRMT5 缺失对 DDP 敏感性的影响。机制上，circ-PRMT5 是 miR-4458 的海绵体，可调节 REV3L。重要的是，circ-PRMT5 沉默与 DDP 治疗相互作用可促进体内肿瘤生长的减少。circ-PRMT5 通过海绵吸附 miR-4458 促进 NSCLC 中的 DDP 耐药，从而为 NSCLC 患者提供了一种新的治疗策略。
