Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.
Department of Biological Repositories, Human Genetic Resources Preservation Center of Hubei Province, Hubei Key Laboratory of Urological Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China.
Cell Death Dis. 2024 Jan 13;15(1):44. doi: 10.1038/s41419-024-06446-7.
A hallmark of tumor cells, including bladder cancer (BLCA) cells, is metabolic reprogramming toward aerobic glycolysis (Warburg effect). The classical oncogene MYC, which is crucial in regulating glycolysis, is amplified and activated in BLCA. However, direct targeting of the c-Myc oncoprotein, which regulates glycolytic metabolism, presents great challenges and necessitates the discovery of a more clarified regulatory mechanism to develop selective targeted therapy. In this study, a siRNA library targeting deubiquitinases identified a candidate enzyme named USP43, which may regulate glycolytic metabolism and c-Myc transcriptional activity. Further investigation using functional assays and molecular studies revealed a USP43/c-Myc positive feedback loop that contributes to the progression of BLCA. Moreover, USP43 stabilizes c-Myc by deubiquitinating c-Myc at K148 and K289 primarily through deubiquitinase activity. Additionally, upregulation of USP43 protein in BLCA increased the chance of interaction with c-Myc and interfered with FBXW7 access and degradation of c-Myc. These findings suggest that USP43 is a potential therapeutic target for indirectly targeting glycolytic metabolism and the c-Myc oncoprotein consequently enhancing the efficacy of bladder cancer treatment.
肿瘤细胞的一个标志特征,包括膀胱癌(BLCA)细胞,是向有氧糖酵解(Warburg 效应)的代谢重编程。经典致癌基因 MYC 在调节糖酵解中至关重要,在 BLCA 中被扩增和激活。然而,直接针对调节糖酵解代谢的 c-Myc 癌蛋白的靶向治疗存在巨大挑战,需要发现更明确的调节机制来开发选择性靶向治疗。在这项研究中,针对去泛素化酶的 siRNA 文库鉴定出一种候选酶,名为 USP43,它可能调节糖酵解代谢和 c-Myc 转录活性。使用功能测定和分子研究的进一步调查揭示了 USP43/c-Myc 正反馈回路,有助于 BLCA 的进展。此外,USP43 通过去泛素化酶活性主要在 K148 和 K289 上去泛素化 c-Myc,从而稳定 c-Myc。此外,BLCA 中 USP43 蛋白的上调增加了与 c-Myc 相互作用的机会,并干扰了 FBXW7 对 c-Myc 的接近和降解。这些发现表明,USP43 是间接靶向糖酵解代谢和 c-Myc 癌蛋白的潜在治疗靶点,从而提高膀胱癌治疗的疗效。