Zhao Tong, Li Kai, Zhang Yetao, Dong Yuxiang, Li Yongshan, Pang Mingyang, Wei Yong, Yao Bing, Zhu Qingyi
Department of Urology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Department of Urology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Life Sci. 2025 Jul 1;372:123646. doi: 10.1016/j.lfs.2025.123646. Epub 2025 Apr 17.
Docetaxel (DTX) is used in the first-line chemotherapy for advanced castration-resistant prostate cancer (CRPC), but resistance remains a major clinical challenge. Circular RNAs (circRNAs) play critical roles in DTX resistance. This study aimed to investigate the mechanism of a novel circRNA, circQKI, in DTX resistance and its regulatory network in CRPC.
DTX-resistant cell lines (PC3/DR and 22RV1/DR) were established, and circQKI's circular structure was validated by Sanger sequencing. CircQKI expression was modulated via siRNA knockdown and overexpression plasmids. Cell viability, apoptosis, and colony formation were assessed by CCK-8, flow cytometry, and clonogenic assays. The interaction between circQKI and miR-188-3p was verified by dual-luciferase reporter, RIP, and RNA pull-down. Autophagy activation was analyzed via Western blot and TEM. Subcutaneous xenograft models evaluated in vivo drug resistance. M6A modification was investigated through m6A RIP-PCR, METTL3/IGF2BP2 knockdown, and stability assays.
CircQKI was significantly upregulated in resistant cells and promoted DTX resistance by sponging miR-188-3p, thereby enhancing Beclin-1 expression and autophagy activation. Inhibiting Beclin-1 or co-treatment with chloroquine (CQ) partially restored DTX sensitivity. Mechanistically, METTL3-mediated m6A modification stabilized circQKI via IGF2BP2 recognition, leading to its accumulation in resistant cells. In vivo studies confirmed that circQKI overexpression reduced tumor sensitivity to DTX by enhancing autophagy.
circQKI drives DTX resistance via the miR-188-3p/Beclin-1 axis and autophagy activation, with its expression regulated by METTL3-dependent m6A modification and IGF2BP2. Targeting circQKI or autophagy pathways may offer novel therapeutic strategies to overcome DTX resistance in prostate cancer.
多西他赛（DTX）用于晚期去势抵抗性前列腺癌（CRPC）的一线化疗，但耐药性仍然是一个主要的临床挑战。环状RNA（circRNAs）在DTX耐药中起关键作用。本研究旨在探讨一种新型环状RNA circQKI在DTX耐药中的机制及其在CRPC中的调控网络。
建立DTX耐药细胞系（PC3/DR和22RV1/DR），通过Sanger测序验证circQKI的环状结构。通过siRNA敲低和过表达质粒调节circQKI表达。通过CCK-8、流式细胞术和克隆形成试验评估细胞活力、凋亡和集落形成。通过双荧光素酶报告基因、RIP和RNA下拉实验验证circQKI与miR-188-3p之间的相互作用。通过蛋白质免疫印迹法和透射电子显微镜分析自噬激活情况。皮下异种移植模型评估体内耐药性。通过m6A RIP-PCR、METTL3/IGF2BP2敲低和稳定性试验研究m6A修饰。
circQKI在耐药细胞中显著上调，通过海绵吸附miR-188-3p促进DTX耐药，从而增强Beclin-1表达和自噬激活。抑制Beclin-1或与氯喹（CQ）联合治疗部分恢复了DTX敏感性。机制上，METTL3介导的m6A修饰通过IGF2BP2识别使circQKI稳定，导致其在耐药细胞中积累。体内研究证实，circQKI过表达通过增强自噬降低肿瘤对DTX的敏感性。
circQKI通过miR-188-3p/Beclin-1轴和自噬激活驱动DTX耐药，其表达受METTL3依赖性m6A修饰和IGF2BP2调控。靶向circQKI或自噬途径可能为克服前列腺癌DTX耐药提供新的治疗策略。
