Department of Urology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.
School of Electrical Engineering of Zhengzhou University, Zhengzhou, China.
Apoptosis. 2024 Aug;29(7-8):1051-1069. doi: 10.1007/s10495-024-01953-6. Epub 2024 Mar 30.
Dysregulation of deubiquitination contributes to various diseases, including cancer, and aberrant expression of deubiquitinating enzymes is involved in carcinoma progression. As a member of the ovarian tumor (OTU) deubiquitinases, OTUD4 is considered a tumor suppressor in many kinds of malignancies. The biological characteristics and mechanisms of OTUD4 in clear cell renal cell carcinoma (ccRCC) remain unclear. The downregulation of OTUD4 in ccRCC was confirmed based on the TCGA database and a validation cohort of 30-paired ccRCC and para-carcinoma samples. Moreover, OTUD4 expression was detected by immunohistochemistry in 50 cases of ccRCC tissues, and patients with lower levels of OTUD4 showed larger tumor size (p = 0.015). TCGA data revealed that patients with high expression of OTUD4 had a longer overall survival rate. In vitro and in vivo studies revealed that downregulation of OTUD4 was essential for tumor cell growth and metastasis in ccRCC, and OTUD4 overexpression inhibited these malignant phenotypes. We further found that OTUD4 sensitized ccRCC cells to Erastin-induced ferroptosis, and ferrostain-1 inhibited OTUD4-induced ferroptotic cell death. Mechanistic studies indicated that OTUD4 functioned as an anti-proliferative and anti-metastasic factor through the regulation of RNA-binding protein 47 (RBM47)-mediated activating transcription factor 3 (ATF3). OTUD4 directly interacted with RBM47 and promoted its stability via deubiquitination events. RBM47 was critical in ccRCC progression by regulating ATF3 mRNA stability, thereby promoting ATF3-mediated ferroptosis. RBM47 interference abolished the suppressive role of OTUD4 overexpression in ccRCC. Our findings provide mechanistic insight into OTUD4 of ccRCC progression and indicate a novel critical pathway OTUD4/RBM47/ATF3 may serve as a potential therapeutic pathway for ccRCC.
去泛素化酶的失调导致了各种疾病,包括癌症,并且去泛素化酶的异常表达参与了癌的进展。作为卵巢肿瘤(OTU)去泛素酶的一员,OTUD4 在许多恶性肿瘤中被认为是一种肿瘤抑制因子。OTUD4 在透明细胞肾细胞癌(ccRCC)中的生物学特征和机制尚不清楚。基于 TCGA 数据库和 30 对 ccRCC 和癌旁样本的验证队列,证实了 OTUD4 在 ccRCC 中的下调。此外,通过免疫组织化学检测了 50 例 ccRCC 组织中的 OTUD4 表达,OTUD4 水平较低的患者肿瘤体积较大(p=0.015)。TCGA 数据显示,OTUD4 高表达的患者总生存率更高。体外和体内研究表明,下调 OTUD4 对 ccRCC 肿瘤细胞的生长和转移是必不可少的,而过表达 OTUD4 抑制了这些恶性表型。我们进一步发现,OTUD4 使 ccRCC 细胞对 Erastin 诱导的铁死亡敏感,而铁染色 1 抑制了 OTUD4 诱导的铁死亡细胞死亡。机制研究表明,OTUD4 通过调节 RNA 结合蛋白 47(RBM47)介导的激活转录因子 3(ATF3),发挥增殖和抗转移的作用。OTUD4 直接与 RBM47 相互作用,并通过去泛素化事件促进其稳定性。RBM47 通过调节 ATF3 mRNA 稳定性在 ccRCC 进展中起着关键作用,从而促进 ATF3 介导的铁死亡。RBM47 干扰消除了 OTUD4 过表达对 ccRCC 的抑制作用。我们的研究结果为 ccRCC 进展中的 OTUD4 提供了机制上的见解,并表明 OTUD4/RBM47/ATF3 这一新的关键途径可能作为 ccRCC 的潜在治疗途径。