Department of Radiology, Yantai Shan Hospital, Yantai, China.
Anticancer Drugs. 2023 Feb 1;34(2):214-226. doi: 10.1097/CAD.0000000000001406. Epub 2022 Nov 15.
Cisplatin (DDP)-based chemotherapy is the main chemotherapeutic agent for ovarian cancer (OC) treatment. Circular RNA PIP5K1A (circ-PIP5K1A) was found to promote OC tumorigenesis. However, whether circ-PIP5K1A was involved in DDP resistance in OC remains unclear. Levels of circ-PIP5K1A, microRNA (miR)-942-5p, and nuclear factor I B (NFIB) were detected using quantitative real-time PCR and Western blot assays. In-vitro experiments were conducted by using cell counting kit-8, cell colony formation, 5-ethynyl-2'-deoxyuridine, flow cytometry, and transwell assays, respectively. In-vivo assay was performed using murine xenograft model. The binding interaction between miR-942-5p and circ-PIP5K1A or NFIB was confirmed using dual-luciferase reporter assay. Exosomes were obtained from culture media by the use of commercial kits and qualified by transmission electron microscopy and Western blot. Circ-PIP5K1A was highly expressed in DDP-resistant OC tissues and cells. Circ-PIP5K1A knockdown could constrain the proliferation, migration, and invasion, as well as increase apoptosis and sensitivity to DDP in DDP-resistant OC cells. Mechanistically, circ-PIP5K1A acted as a sponge for miR-942-5p to positively regulate NFIB expression. Moreover, rescue experiments demonstrated that the anticancer and DDP sensitization effects caused by circ-PIP5K1A silencing in DDP-resistant OC cells were achieved through the miR-942-5p/NFIB axis. Importantly, circ-PIP5K1A silencing enhanced DDP efficacy and impeded tumor growth in OC in vivo . Additionally, we also found that circ-PIP5K1A was packaged into exosomes and could be internalized by surrounding cells. Circ-PIP5K1A knockdown reduced the resistance to DDP in OC via regulating miR-942-5p/NFIB axis. Besides that, circ-PIP5K1A was packaged into exosomes and exosomal circ-SKA3 could mediate intercellular communication between OC cells. These findings provided a promising therapeutic target for OC.
顺铂（DDP）为基础的化疗是卵巢癌（OC）治疗的主要化疗药物。环状 RNA PIP5K1A（circ-PIP5K1A）被发现促进 OC 肿瘤发生。然而，circ-PIP5K1A 是否参与 OC 中的 DDP 耐药仍不清楚。使用实时定量 PCR 和 Western blot 检测 circ-PIP5K1A、微小 RNA（miR）-942-5p 和核因子 I B（NFIB）的水平。通过细胞计数试剂盒-8、细胞集落形成、5-乙炔基-2'-脱氧尿苷、流式细胞术和 Transwell 测定分别进行体外实验。通过使用小鼠异种移植模型进行体内实验。通过双荧光素酶报告实验证实 miR-942-5p 与 circ-PIP5K1A 或 NFIB 的结合相互作用。通过商业试剂盒从培养物中获得外泌体，并通过透射电子显微镜和 Western blot 进行鉴定。circ-PIP5K1A 在 DDP 耐药 OC 组织和细胞中高表达。circ-PIP5K1A 敲低可抑制 DDP 耐药 OC 细胞的增殖、迁移和侵袭，增加细胞凋亡并提高对 DDP 的敏感性。在机制上，circ-PIP5K1A 作为 miR-942-5p 的海绵正向调节 NFIB 表达。此外，挽救实验表明，circ-PIP5K1A 沉默在 DDP 耐药 OC 细胞中引起的抗癌和 DDP 增敏作用是通过 miR-942-5p/NFIB 轴实现的。重要的是，circ-PIP5K1A 沉默增强了 OC 体内的 DDP 疗效并抑制了肿瘤生长。此外，我们还发现 circ-PIP5K1A 被包裹在 exosomes 中，并可被周围细胞内化。circ-PIP5K1A 敲低通过调节 miR-942-5p/NFIB 轴降低 OC 对 DDP 的耐药性。除此之外，circ-PIP5K1A 被包裹在 exosomes 中，exosomal SKA3 可以介导 OC 细胞之间的细胞间通讯。这些发现为 OC 提供了一个有前途的治疗靶点。
