Blockade of USP14 potentiates type I interferon signaling and radiation-induced antitumor immunity via preventing IRF3 deubiquitination

USP14 negatively regulates IFN signaling by dampening K63-linked ubiquitination of TBK1 in black carp

USP14 regulates the immune related pathways by deubiquitinating the signaling molecules in mammals. In teleost, USP14 is also reported to inhibit the antiviral immune response through TBK1, but its regulatory mechanism remains obscure. To elucidate the role of USP14 in the RLR/IFN antiviral pathway in teleost, the homolog USP14 (bcUSP14) of black carp (Mylopharyngodon piceus) has been cloned and characterize in this paper. bcUSP14 contains 490 amino acids (aa), and the sequence is well conserved among in vertebrates. Over-expression of bcUSP14 in EPC cells attenuated SVCV-induced transcription activity of IFN promoters and enhanced SVCV replication. Knockdown of bcUSP14 in MPK cells led to the increased transcription of IFNs and decreased SVCV replication, suggesting the improved antiviral activity of the host cells. The interaction between bcUSP14 and bcTBK1 was identified by both co-immunoprecipitation and immunofluorescent staining. Co-expressed bcUSP14 obviously inhibited bcTBK1-induced IFN production and antiviral activity in EPC cells. K63-linked polyubiquitination of bcTBK1 was dampened by co-expressed bcUSP14, and bcTBK1-mediated phosphorylation and nuclear translocation of IRF3 were also inhibited by this deubiquitinase. Thus, all the data demonstrated that USP14 interacts with and inhibits TBK1 through deubiquitinating TBK1 in black carp.

The Emerging Role of Deubiquitinases in Radiosensitivity

Radiation therapy is a primary treatment for cancer, but radioresistance remains a significant challenge in improving efficacy and reducing toxicity. Accumulating evidence suggests that deubiquitinases (DUBs) play a crucial role in regulating cell sensitivity to ionizing radiation. Traditional small-molecule DUB inhibitors have demonstrated radiosensitization effects, and novel deubiquitinase-targeting chimeras (DUBTACs) provide a promising strategy for radiosensitizer development by harnessing the ubiquitin-proteasome system. This review highlights the mechanisms by which DUBs regulate radiosensitivity, including DNA damage repair, the cell cycle, cell death, and hypoxia. Progress on DUB inhibitors and DUBTACs is summarized, and their potential radiosensitization effects are discussed. Developing drugs targeting DUBs appears to be a promising alternative approach to overcoming radioresistance, warranting further research into their mechanisms.

USP14 predicts poorer survival outcomes and promotes tumor progression in endometrial carcinoma by activating NF-κB signaling

Ubiquitin-specific protease 14 (USP14), a member of the USP family, which catalyzes ubiquitin cleavage from a range of protein substrates, has been found dysregulated in several cancers. Our aim is to explore the functions and mechanism of USP14 in endometrial carcinoma (EC). Quantitative real-time PCR (qRT-PCR) and western blot (WB) were used to assess USP14 levels in EC tissues and adjacent nontumor tissues. USP14 overexpression or knockdown models were adopted to determine USP14-mediated effects on EC cell proliferation, migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT). The xenograft tumor experiment checked the effect of USP14 overexpression on tumor cell growth. Furthermore, the upstream signaling pathway of USP14 was predicted by bioinformatics. Consequently, EC tissues exhibited USP14 overexpression compared to normal paracancerous nontumor tissues. USP14 presence was linked to an adverse prognosis in EC cases. Functionally, USP14 overexpression reduced apoptosis and increased cell migration, invasion, and EMT in vivo and ex vivo. USP14 knockdown had the opposite effect. Mechanistically, NF-κB pathway activation occurred through the inhibitory effect of USP14 on I-κB expression. Conversely, NF-κB pathway inhibition attenuated USP14-mediated carcinogenic effects. Additionally, there existed a binding interaction between miR-124-3p and the 3'-UTR of USP14, resulting in USP14 activity inhibition. In summary, our research indicates that the involvement of miR-124-3p in USP14 regulation contributes to exacerbated EC progression through NF-κB pathway activation. The modulation of this pathway may be a new strategy for treating EC.