Oncogene最新文献

Proteasome inhibitor (PI) resistance remains a major barrier in the treatment of multiple myeloma (MM), underscoring the urgent need to elucidate underlying mechanisms and identify actionable therapeutic targets. Here, we uncover METTL16 as a regulator of MM progression and PI sensitivity via an m6A methyltransferase activity-independent mechanism of translational control. Mechanistically, METTL16 overexpression is associated with altered PERK-eIF2α interaction and reduced eIF2α phosphorylation, accompanied by increased translation of key transcripts, including PSMB5 and CCND1. Consistently, these translational outputs coincide with increased proteasome activity and proliferative capacity. Notably, pharmacological targeting of METTL16 enhances the efficacy of multiple PIs in MM cells. These findings not only expand the functional landscape of METTL16 beyond RNA methylation, but also suggest that METTL16 represents a potential target for improving PI-based therapy in MM.

Metastasis is the primary cause of mortality in advanced prostate cancer, and the emergence of resistance to androgen receptor (AR)-targeted therapies highlights the urgent need for alternative therapeutic strategies. Metabolic reprogramming has increasingly been recognized as a key driver of metastatic progression. In this study, we uncover a novel tumor-suppressive role for cereblon (CRBN), a substrate receptor of the CRL4^CRBN E3 ubiquitin ligase complex, in modulating prostate cancer metastasis through regulation of 6-phosphogluconate dehydrogenase (6PGD), a critical enzyme in the oxidative pentose phosphate pathway (oxPPP). CRBN directly binds a conserved C-terminal α-helix in 6PGD, promoting its polyubiquitination and proteasomal degradation independently of immunomodulatory drugs (IMiDs). Genetic or pharmacological loss of CRBN via CRISPR/Cas9, RNA interference, or PROTAC-mediated degradation stabilized 6PGD and elevated the NADPH/NADP⁺ ratio. Conversely, re-expression of wild-type CRBN reduced 6PGD levels, restored NADPH/NADP⁺ ratio, and suppressed cell migration and invasion. Transcriptomic profiling revealed CRBN-induced upregulation of CDH1 and downregulation of the EMT marker MMP1, while CRBN degradation produced the opposite pattern-both effects were reversed by 6PGD inhibition. These regulatory effects were conserved across multiple cancer cell lines and observed in CRBN-deficient mouse tissues. Functional studies using intra-splenic xenograft models further demonstrated that CRBN suppresses metastatic dissemination. Collectively, our findings identify 6PGD as a novel endogenous substrate of CRBN and establish the CRBN-6PGD axis as a critical metabolic checkpoint in prostate cancer metastasis. Therapeutic targeting of this pathway may offer promising strategies for CRBN-deficient or 6PGD-driven cancers.

Suppressors of variegation 3-9 homolog 1 (SUV39H1), the enzyme responsible for establishing histone H3 lysine 9 trimethylation (H3K9me3) marks in heterochromatin, is frequently dysregulated in cancers. However, the mechanisms underlying SUV39H1 dysregulation in breast cancer remain largely unclear. Here, we report that protein arginine methyltransferase 1 (PRMT1) directly interacts with SUV39H1 and dimethylates it at arginine 378 (R378). PKC signaling-mediated phosphorylation of SUV39H1 at S391 enhances this interaction, thereby promoting its methylation. Notably, PRMT1 binds to SUV39H1 with higher affinity and binding free energy than MDM2, causing a structural clash that blocks MDM2-mediated ubiquitination of SUV39H1. Moreover, methylated SUV39H1 exhibits enhanced H3K9me3 methyltransferase activity and promotes tumor cell growth. A SUV39H1-derived peptide (TAT-SUV-peptide) disrupts the interaction between PRMT1 and SUV39H1, thereby reducing SUV39H1 methylation. Administration of TAT-SUV-peptide remarkably suppresses mammary tumor growth. Taken together, our findings reveal a critical phosphorylation-methylation-ubiquitination axis in controlling SUV39H1 stability and highlight its therapeutic potential through targeting SUV39H1 methylation.