Li Yi-Jung, Chen Yu-Hsuan, Wang Jiun-Wen, Wu Hsin-Hsu, Hsu Hsiang-Hao, Ho Dong-Ru, Yang Chih-Wei, Tian Ya-Chung
Kidney Research Center and Department of Nephrology, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; Department of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
Kidney Research Center and Department of Nephrology, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
Biomed Pharmacother. 2025 May;186:118032. doi: 10.1016/j.biopha.2025.118032. Epub 2025 Apr 11.
Recent evidence links BK polyomavirus (BKPyV) infection to an increased risk of bladder cancer. This study investigates the role of BKPyV and its microRNA, miR-B1, in cisplatin-induced apoptosis. PCR analysis detected BKPyV DNA in 3 of 22 urothelial carcinoma (UC) samples from a non-transplant population. Bladder cancer cells infected with BKPyV showed increased proliferation and miR-B1-3p and -5p expression. Bioinformatics analysis identified a miR-B1-5p target site in the 3'-UTR of activating transcription factor 3 (ATF3), confirmed by a luciferase assay. The inhibitory effect was further validated by reduced ATF3 mRNA levels following overexpression of miR-B1 vectors or 5p mimics. Cisplatin treatment upregulated ATF3 expression, as shown by qPCR and immunoblotting. Overexpression of ATF3 mitigated the cisplatin-induced reduction in cell viability and elevated apoptotic markers, including cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). BKPyV infection or large T antigen (TAg) overexpression suppressed cisplatin-induced ATF3 expression, reducing its cytotoxicity and apoptotic marker expression. However, overexpression of ATF3 in BKPyV-infected bladder cancer cells attenuated BKPyV's inhibitory effects, restoring cisplatin-induced cytotoxicity and apoptotic marker expression, suggesting BKPyV infection promotes resistance to cisplatin cytotoxicity. Transfection with miR-B1 vectors or miR-B1-5p mimics decreased cisplatin-induced annexin V-positive cells, caspase-3 activity, and apoptotic marker expression, indicating that miR-B1 suppresses cisplatin-induced apoptosis. In conclusion, this study demonstrates that BKPyV promotes bladder cancer cell growth and impairs cisplatin-induced apoptosis, with miR-B1 targeting ATF3 as a key mechanism. Targeting BKPyV replication or regulating miR-B1 expression could offer potential therapeutic strategies for managing BKPyV-positive and cisplatin-resistant urothelial carcinoma.
近期证据表明，BK多瘤病毒（BKPyV）感染会增加患膀胱癌的风险。本研究调查了BKPyV及其微小RNA（miR-B1）在顺铂诱导的细胞凋亡中的作用。PCR分析在来自非移植人群的22例尿路上皮癌（UC）样本中的3例中检测到BKPyV DNA。感染BKPyV的膀胱癌细胞显示出增殖增加以及miR-B1-3p和-5p表达升高。生物信息学分析在激活转录因子3（ATF3）的3'-非翻译区（3'-UTR）中鉴定出一个miR-B1-5p靶位点，荧光素酶测定证实了这一点。在miR-B1载体或5p模拟物过表达后，ATF3 mRNA水平降低进一步验证了这种抑制作用。如qPCR和免疫印迹所示，顺铂处理上调了ATF3表达。ATF3的过表达减轻了顺铂诱导的细胞活力降低，并提高了凋亡标志物的表达，包括裂解的半胱天冬酶-3和裂解的聚（ADP-核糖）聚合酶（PARP）。BKPyV感染或大T抗原（TAg）过表达抑制了顺铂诱导的ATF3表达，降低了其细胞毒性和凋亡标志物表达。然而，在感染BKPyV的膀胱癌细胞中过表达ATF3减弱了BKPyV的抑制作用，恢复了顺铂诱导的细胞毒性和凋亡标志物表达，表明BKPyV感染促进了对顺铂细胞毒性的抗性。用miR-B1载体或miR-B1-5p模拟物转染可减少顺铂诱导的膜联蛋白V阳性细胞、半胱天冬酶-3活性和凋亡标志物表达，表明miR-B1抑制顺铂诱导的细胞凋亡。总之，本研究表明BKPyV促进膀胱癌细胞生长并损害顺铂诱导的细胞凋亡，miR-B1靶向ATF3是关键机制。靶向BKPyV复制或调节miR-B1表达可为治疗BKPyV阳性和顺铂耐药的尿路上皮癌提供潜在的治疗策略。
