Gynecology Clinic, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College Huazhong University of Science &Technology.
Hubei Integrated Traditional Chinese and Western Medicine Hospital, Wuhan City, Hubei, China.
Anticancer Drugs. 2023 Aug 1;34(7):816-826. doi: 10.1097/CAD.0000000000001479. Epub 2022 Dec 23.
Circular RNA (circRNA) plays a significant role in cisplatin (DDP) resistance. The purpose of this study was to explore the role of circ_0005667 in DDP resistance of endometrial carcinoma (EC) cells.
The expression of circular RNA circ_0005667, microRNA-145-5p (miR-145-5p) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in DDP-sensitive and DDP-resistant EC tissues and EC cells was determined by quantitative real-time PCR (qRT-PCR). The expression of apoptosis-related proteins, drug resistance-related proteins and IGF2BP1 proteins were detected by western blot. The half-maximal inhibitory concentration (IC 50 ) of DDP was determined using a cell counting kit-8 (CCK-8) assay. For functional assays, cell proliferation, migration, invasion and cell apoptosis were determined using 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing assay, transwell assay and flow cytometry assay, respectively. The binding relationship between miR-145-5p and circ_0005667 or IGF2BP1 was verified by dual-luciferase reporter assay. A xenograft experiment was applied to clarify the functional role of circ_0005667 in vivo .
Levels of circ_0005667 and IGF2BP1 were markedly increased, whereas miR-145-5p was downregulated in DDP-resistant EC tissues and cells. The circ_0005667 deficiency could enhance DDP sensitivity, inhibit cell proliferation, migration and invasion and promote cell apoptosis in DDP-resistant EC cells in vitro . Mechanistically, circ_0005667 modulated IGF2BP1 expression through sponging miR-145-5p. In addition, miR-145-5p depletion attenuated circ_0005667 silencing-induced effects in EC cells. The regulation of miR-145-5p in DDP resistance involved low IGF2BP1 expression. In vivo experiments revealed that circ_0005667 silencing could improve the sensitivity of the tumor to DDP.
Circ_0005667 enhanced DDP resistance in EC by elevating IGF2BP1 through sponging miR-145-5p.
环状 RNA（circRNA）在顺铂（DDP）耐药中发挥重要作用。本研究旨在探讨环状 RNA circ_0005667 在子宫内膜癌（EC）细胞 DDP 耐药中的作用。
采用实时定量 PCR（qRT-PCR）检测 DDP 敏感和耐药的 EC 组织和 EC 细胞中 circ_0005667、微小 RNA-145-5p（miR-145-5p）和胰岛素样生长因子 2 mRNA 结合蛋白 1（IGF2BP1）的表达。采用 Western blot 检测凋亡相关蛋白、耐药相关蛋白和 IGF2BP1 蛋白的表达。采用细胞计数试剂盒-8（CCK-8）法测定 DDP 的半抑制浓度（IC50）。通过 5-乙炔基-2'-脱氧尿苷（EdU）测定、划痕愈合测定、Transwell 测定和流式细胞术测定，分别检测细胞增殖、迁移、侵袭和细胞凋亡等功能试验。采用双荧光素酶报告实验验证 miR-145-5p 与 circ_0005667 或 IGF2BP1 的结合关系。应用异种移植实验阐明 circ_0005667 在体内的功能作用。
DDP 耐药的 EC 组织和细胞中 circ_0005667 和 IGF2BP1 水平显著升高，miR-145-5p 水平下调。在体外，circ_0005667 缺失可增强 DDP 耐药 EC 细胞的 DDP 敏感性，抑制细胞增殖、迁移和侵袭，促进细胞凋亡。机制上，circ_0005667 通过海绵吸附 miR-145-5p 来调节 IGF2BP1 的表达。此外，miR-145-5p 耗竭可减弱 EC 细胞中 circ_0005667 沉默引起的作用。miR-145-5p 在 DDP 耐药中的调节作用涉及 IGF2BP1 表达降低。体内实验表明，circ_0005667 沉默可提高肿瘤对 DDP 的敏感性。
circ_0005667 通过海绵吸附 miR-145-5p 升高 IGF2BP1 水平，从而增强 EC 中的 DDP 耐药性。
