Knockdown of TRIM65 suppressed the proliferation and invasiveness of gastric cancer cells by restricting the ubiquitin degradation of PPM1A

Tripartite Motif-Containing Protein 65 Promotes Proliferation and Inhibits Ferroptosis in Prostate Cancer via Enhancing NKD Inhibitor of WNT Signaling Pathway 2 Ubiquitination

As a typical E3 ligase, tripartite motif-containing 65 (TRIM65), is implicated in the modulation of biological processes, such as metastasis, proliferation, and apoptosis. However, the function of TRIM65 in prostate cancer (PCa) and its potential mechanism have not yet been excavated. In this work, we affirmed Tripartite motif-containing protein 65 (TRIM65) as a new oncogene in PCa, which accelerated PCa cell proliferation and impeded cell ferroptosis. In vivo, depletion of TRIM65 inhibited PCa tumorigenesis and metastasis. Mechanically, our findings uncovered that TRIM65 enhances NKD inhibitor of WNT signaling pathway 2 (NKD2) degradation via the ubiquitin-proteasome signaling. TRIM65 facilitated proliferation and restricted ferroptosis via downregulating NKD2 levels. Moreover, TRIM65 activated the wingless-integrated/β-catenin pathway in PCa cells via inhibiting NKD2. Taken together, these data uncovered that TRIM65 controls PCa proliferation, and ferroptosis and regulates the Wnt/β-catenin signaling via directly targeting NKD2 for ubiquitination degradation. Our study provides insights into the multifaceted regulatory role of TRIM65 in the development of PCa, laying the foundation for exploring new therapeutic approaches.

The Role and Mechanism of TRIM Proteins in Gastric Cancer

Tripartite motif (TRIM) family proteins, distinguished by their N-terminal region that includes a Really Interesting New Gene (RING) domain with E3 ligase activity, two B-box domains, and a coiled-coil region, have been recognized as significant contributors in carcinogenesis, primarily via the ubiquitin-proteasome system (UPS) for degrading proteins. Mechanistically, these proteins modulate a variety of signaling pathways, including Wnt/β-catenin, PI3K/AKT, and TGF-β/Smad, contributing to cellular regulation, and also impact cellular activities through non-signaling mechanisms, including modulation of gene transcription, protein degradation, and stability via protein-protein interactions. Currently, growing evidence indicates that TRIM proteins emerge as potential regulators in gastric cancer, exhibiting both tumor-suppressive and oncogenic roles. Given their critical involvement in cellular processes and the notable challenges of gastric cancer, exploring the specific contributions of TRIM proteins to this disease is necessary. Consequently, this review elucidates the roles and mechanisms of TRIM proteins in gastric cancer, emphasizing their potential as therapeutic targets and prognostic factors.

Multifaceted role of TRIM28 in health and disease

The TRIM (tripartite motif) family, with TRIM28 as a key member, plays a vital role in regulating health and disease. TRIM28 contains various functional domains essential for transcriptional regulation, primarily through its interaction with KRAB-ZNF proteins, which influence chromatin remodeling and gene expression. Despite extensive research, the precise mechanisms by which TRIM28 impacts health and disease remain elusive. This review delves into TRIM28's multifaceted roles in maintaining health, contributing to a variety of diseases, and influencing cancer progression. In cancers, TRIM28 exhibits a dual nature, functioning as both a tumor promoter and suppressor depending on the cellular context and cancer type. The review also explores its critical involvement in processes such as DNA repair, cell cycle regulation, epithelial-to-mesenchymal transition, and the maintenance of stem cell properties. By uncovering TRIM28's complex roles across different cancers and other diseases, this review underscores its potential as a therapeutic target. The significance of TRIM28 as a versatile regulator opens the door to innovative therapeutic strategies, particularly in cancer treatment and the management of other diseases. Ongoing research into TRIM28 may yield key insights into disease progression and novel treatment options.

TRIM65 promotes renal cell carcinoma through ubiquitination and degradation of BTG3

As a typical E3 ligase, TRIM65 (tripartite motif containing 65) is involved in the regulation of antiviral innate immunity and the pathogenesis of certain tumors. However, the role of TRIM65 in renal cell carcinoma (RCC) and the underlying mechanism has not been determined yet. In this study, we identified TRIM65 as a novel oncogene in RCC, which enhanced the tumor cell proliferation and anchorage-independent growth abilities both in vitro and in vivo. Moreover, we found that TRIM65-regulated RCC proliferation mainly via direct interaction with BTG3 (BTG anti-proliferation factor 3), which in turn induced the K48-linked ubiquitination and subsequent degradation through K41 amino acid. Furthermore, TRIM65 relieved G2/M phase cell cycle arrest via degradation of BTG3 and regulated downstream factors. Further studies revealed that TRIM65 acts through TRIM65-BTG3-CyclinD1 axis and clinical sample IHC chip data indicated a negative correction between TRIM65 and BTG3. Taken together, our findings demonstrated that TRIM65 promotes RCC cell proliferation via regulation of the cell cycle through degradation of BTG3, suggesting that TRIM65 may be a promising target for RCC therapy.

TRIM65 knockout inhibits the development of HCC by polarization tumor-associated macrophages towards M1 phenotype via JAK1/STAT1 signaling pathway

BACKGROUND & AIMS

Tumor-associated macrophages (TAMs) are main components of immune cells in tumor microenvironment (TME), and play a crucial role in tumor progression. Tripartite motif-containing protein 65 (TRIM65) has been associated with tumor progression. However, whether TRIM65 regulate the interaction of tumor cell and TAMs in HCC and the underlying mechanisms remain unknown. In this study, we investigated the role of TRIM65 in TME of HCC and explored its underlying mechanisms.

METHODS

The relation of TRIM65 expression level with tumor grades, TNM stages, and worse prognosis of HCC patients was evaluated by bioinformatics analysis, as well as immune infiltration level of macrophages. TRIM65 shRNA was transfected into HepG2 cells, and TRIM65 overexpression plasmid was transfected into Huh7 cells, and the effect of TRIM65 on cell growth was examined by EdU assay. The mouse subcutaneous Hep1-6 tumor-bearing model with WT and TRIM65-/- mice was established to study the role of TRIM65 in HCC. Immunohistochemistry staining, Immunofluorescence staining, qRT-PCR and western blot were performed to evaluate the effect of TRIM65 on TAM infiltration, TAM polarization and JAK1/STAT1 signaling pathway.

RESULTS

Bioinformatics analysis revealed that TRIM65 was upregulated in 16 types of cancer especially in HCC, and high level of TRIM65 was strongly correlated with higher tumor grades, TNM stages, and worse prognosis of patients with HCC as well as immune infiltration level of macrophages (M0, M1, and M2). Moreover, we observed that TRIM65 shRNA-mediated TRIM65 knockdown significantly inhibited the HepG2 cells growth while TRIM65 overexpression highly increased the Huh7 cells growth in vitro. TRIM65 knockout significantly inhibited the tumor growth as well as macrophages polarization towards M2 but promoted macrophages polarization towards M1 in vivo. Mechanistically, the results demonstrate that TRIM65 knockout promoted macrophage M1 polarization in conditioned medium-stimulated peritoneal macrophages and in tumor tissues by activating JAK1/STAT1 signaling pathway.

CONCLUSIONS

Taken together, our study suggests that tumor cells utilize TRIM65-JAK1/STAT1 axis to inhibit macrophage M1 polarization and promote tumor growth, reveals the role of TRIM65 in TAM-targeting tumor immunotherapy.

TRIM65 Suppresses oxLDL-induced Endothelial Inflammation by Interaction with VCAM-1 in Atherogenesis

BACKGROUND AND OBJECTIVE

Endothelial cell activation, characterized by increased levels of vascular cell adhesion molecule 1 (VCAM-1), plays a crucial role in the development of atherosclerosis (AS). Therefore, inhibition of VCAM-1-mediated inflammatory response is of great significance in the prevention and treatment of AS. The tripartite motif (TRIM) protein-TRIM65 is involved in the regulation of cancer development, antivirals and inflammation. We aimed to study the functions of TRIM65 in regulating endothelial inflammation by interacting with VCAM-1 in atherogenesis.

METHODS AND RESULTS

In vitro, we report that human umbilical vein endothelial cells (HUVECs) treated with oxidized low-density lipoprotein (oxLDL) significantly upregulate the expression of TRIM65 in a time- and dose-dependent manner. Overexpression of TRIM65 reduces oxLDL-triggered VCAM-1 protein expression, decreases monocyte adhesion to HUVECs and inhibits the production of the inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α as well as endothelial oxLDL transcytosis. In contrast, siRNA-mediated knockdown of TRIM65 promotes the expression of VCAM-1, resulting in increased adhesion of monocytes and the release of the inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α and enhances endothelial oxLDL transcytosis. In vivo, we measured the high expression of TRIM65 in ApoE-/- mouse aortic plaques compared to C57BL/6J mouse aortic plaques. Then, we examined whether the blood levels of VCAM-1 were higher in TRIM65 knockout ApoE-/- mice than in control mice induced by a Western diet. Furthermore, Western blot results showed that the protein expression of VCAM-1 was markedly enhanced in TRIM65 knockout ApoE-/- mouse aortic tissues compared to that of the controls. Immunofluorescence staining revealed that the expression of VCAM-1 was significantly increased in atherosclerotic plaques of TRIM65-/-/ApoE-/- aortic vessels compared to ApoE-/- controls. Mechanistically, TRIM65 specifically interacts with VCAM-1 and targets it for K48-linked ubiquitination.

CONCLUSION

Our studies indicate that TRIM65 attenuates the endothelial inflammatory response by targeting VCAM-1 for ubiquitination and provides a potential therapeutic target for the inhibition of endothelial inflammation in AS.