USP16 regulates castration-resistant prostate cancer cell proliferation by deubiquitinating and stablizing c-Myc

Abstract

Background c-Myc, a well-established oncogene, plays an important role in the initiation and progression of various cancers, including prostate cancer. However, its mechanism in cancer cell remains largely unknown and whether there exist a deubiquitinase targeting c-Myc also remains elusive. Methods Bioinformatic analysis and shRNA screening methods were used to identify potential deubiquitinases that correlate with c-Myc gene signature. Cell proliferation and viability were measured by Cell-Counting-Kit 8 and colony formation assays. A mouse xenograft model of PC3 cells was established to confirm the function of USP16 in vivo. The interaction between USP16 and c-Myc protein was assessed by co-immunoprecipitation and protein co-localization assays. Immunohistochemistry staining was performed to detect the expression of USP16, Ki67, and c-Myc in xenograft tissues and clinical tumour tissues. Furthermore, the correlation between USP16 and c-Myc was confirmed by RNA sequencing. Results Functional analyses identified USP16, known as a deubiquitinase, was strongly correlated with the c-Myc gene signature. Depletion of USP16 was shown to significantly suppress the growth of PCa cells both in vitro and in vivo. Co-immunoprecipitation and ubiquitination assays confirmed that USP16 served as a novel deubiquitinase of c-Myc and overexpression of c-Myc significantly rescued the effects of USP16 disruption. Immunohistochemistry staining and RNA-seq tactics were further used to confirm the positive correlation between USP16 and c-Myc expression. Expression of USP16 in human PCa tissues was higher than that seen in normal prostate tissues and its high expression was found associated with poor prognosis. Conclusions USP16 serves as a novel deubiquitinase of c-Myc. Downregulation of USP16 markedly suppressed PCa cell growth both in vitro and in vivo. USP16 regulates PCa cell proliferation by deubiquitinating and stabilizing c-Myc, making it a potential therapeutic candidate for the treatment of PCa.

Regulation of Cancer Metabolism by Deubiquitinating Enzymes: The Warburg Effect

“…There are other DUBs excluded from this paper for the same reason as described. DUBs which affect c-Myc are CYLD [136], USP2a [137][138][139], USP7 [140,141], USP13 [142], USP16 [143], USP18 [144], USP22 [145,146], USP28 [147], USP36 [148,149], and OTUD6B isoform 2 [150]. DUBs that regulate FBP1 include USP22 [151] and USP44 [114].…”

Molecular Characteristics of m6A Regulators and Tumor Microenvironment Infiltration in Soft Tissue Sarcoma: A Gene-Based Study

“…The MYC gene was a proto-oncogene, which has been studied for many decades ( Cole and McMahon, 1999 ). A recent study showed that MYC could be regulated by USP16, which further inhibited prostate cancer progression ( Ge et al, 2021 ). MYC was also found to participate in angiogenesis ( Meškytė et al, 2020 ).…”

Identification and Verification of m7G Modification Patterns and Characterization of Tumor Microenvironment Infiltration via Multi-Omics Analysis in Clear Cell Renal Cell Carcinoma

“…Immunohistochemical (IHC) staining was performed with EIF4A1 antibody (ab31217, Abcam) following the previous protocol ( 23 ). The IHC scores were calculated by staining intensity and the percentage of stained cells as reported ( 24 ).…”