USP22 Functions as an Oncogenic Driver in Prostate Cancer by Regulating Cell Proliferation and DNA Repair

Abstract

Emerging evidence indicates the deubiquitinase USP22 regulates transcriptional activation and modification of target substrates to promote pro-oncogenic phenotypes. Here, in vivo characterization of tumor-associated USP22 upregulation and unbiased interrogation of USP22-regulated functions in vitro demonstrated critical roles for USP22 in prostate cancer. Specifically, clinical datasets validated that USP22 expression is elevated in prostate cancer, and a novel murine model demonstrated a hyperproliferative phenotype with prostate-specific USP22 overexpression. Accordingly, upon overexpression or depletion of USP22, enrichment of cell-cycle and DNA repair pathways was observed in the USP22-sensitive transcriptome and ubiquitylome using prostate cancer models of clinical relevance. Depletion of USP22 sensitized cells to genotoxic insult, and the role of USP22 in response to genotoxic insult was further confirmed using mouse adult fibroblasts from the novel murine model of USP22 expression. As it was hypothesized that USP22 deubiquitylates target substrates to promote protumorigenic phenotypes, analysis of the USP22-sensitive ubiquitylome identified the nucleotide excision repair protein, XPC, as a critical mediator of the USP22-mediated response to genotoxic insult. Thus, XPC undergoes deubiquitylation as a result of USP22 function and promotes USP22-mediated survival to DNA damage. Combined, these findings reveal unexpected functions of USP22 as a driver of protumorigenic phenotypes and have significant implications for the role of USP22 in therapeutic outcomes. Significance:The studies herein present a novel mouse model of tumor-associated USP22 overexpression and implicate USP22 in modulation of cellular survival and DNA repair, in part through regulation of XPC.

USP22 Protects Against Myocardial Ischemia–Reperfusion Injury via the SIRT1-p53/SLC7A11–Dependent Inhibition of Ferroptosis–Induced Cardiomyocyte Death

“…Another focus of the current study, the USP22 protein is a member of the deubiquitinase family, which comprises of more than 70 members (McCann et al, 2020). USP22 has further been correlated with enhanced intestinal tissue regeneration following intestinal I/R injury (Ji et al, 2019).…”

Molecular Mechanisms of DUBs Regulation in Signaling and Disease

“…USP22 promotes the advance of gastric cancer by stabilizing BMI1 protein [129]. Also, USP22 plays a carcinogenic effect in prostate cancer by regulating cell proliferation and DNA repair [130]. The active site residues of Ubp8 are catalytically well-arranged in the absence of ubiquitin [119,121,124].…”

Post-Translational Modifications That Drive Prostate Cancer Progression

“…Depletion of USP22 sensitizes cells to genotoxic insult; analysis of the USP22-sensitive ubiquitylome identified the nucleotide excision repair protein, XPC, as a critical mediator of the USP22-mediated response to genotoxic insult. [36] Knockdown of E6AP in DU145 cells and analysis of a proteome.…”

“…Of these, DEK stabilization was shown to promote prostate epithelial cell invasion [38]. Other proteome studies revealed clusterin as a novel target of E6AP with roles in cell growth [37] and XPC, as a critical mediator of the USP22-mediated response to genotoxic insult [36] (Table 1).…”