PRMT4-mediated arginine methylation promotes tyrosine phosphorylation of VEGFR-2 and regulates filopodia protrusions

PRMT4 Reduced Erastin-Induced Ferroptosis in Nasopharyngeal Carcinoma Cisplatin-Resistant Cells by Nrf2/GPX4 Pathway

Nasopharyngeal carcinoma (NPC) is one of the common malignant tumors in clinic. In the current study, we aim to investigate the effects of PRMT4 on erastin-induced ferroptosis in NPC by cisplatin resistant. PRMT4 expression in patients with NPC by cisplatin was upregulated. PRMT4 upregulation promoted cell growth of erastin-induced ferroptosis in NPC cisplatin-resistant cells. PRMT4 downregulation reduced cell growth of erastin-induced ferroptosis in NPC cisplatin-resistant cells. PRMT4 promoted tumor volume in mice model of erastin-induced NPC by cisplatin. PRMT4 upregulation reduced erastin-induced ferroptosis in NPC cisplatin-resistant cells by mitochondrial damage. PRMT4 upregulation induced Nrf2 protein expression in model of erastin-induced NPC by cisplatin. Nrf2 reduced the effects of si-PRMT4 on cell growth of erastin-induced ferroptosis in NPC cisplatin-resistant cells. Nrf2 inhibitor reduced the effects of PRMT4 on cell growth of erastin-induced ferroptosis in NPC cisplatin-resistant cells. Nrf2 reduced the effects of si-PRMT4 on erastin-induced ferroptosis in NPC cisplatin-resistant cells by mitochondrial damage. PRMT4 protein interlinked with Nrf2 protein to decrease Nrf2 ubiquitination. Methylation increased PRMT4 DNA stability. Collectively, our data reveal that PRMT4 reduced erastin-induced ferroptosis in NPC cisplatin-resistant cells by Nrf2/GPX4 pathway, suggesting that targeting PRMT4 may present as a potential strategy against the development of NPC.

VEGF signaling: Role in angiogenesis and beyond

Angiogenesis is a crucial process for tissue development, repair, and tumor survival. Vascular endothelial growth factor (VEGF) is a key driver secreted by cancer cells, promoting neovascularization. While VEGF's role in angiogenesis is well-documented, its influence on the other aspects in tumor microenvironemt is less discussed. This review elaborates on VEGF's impact on intercellular interactions within the tumor microenvironment, including how VEGF affects pericyte proliferation and migration and mediates interactions between tumor-associated macrophages and cancer cells, resulting in PDL-1-mediated immunosuppression and Nrf2-mediated epithelial-mesenchymal transition. The review discusses VEGF's involvement in intra-organelle crosstalk, tumor metabolism, stemness, and epithelial-mesenchymal transition. It also provides insights into current anti-VEGF therapies and their limitations in cancer treatment. Overall, this review aims to provide a thorough overview of the current state of knowledge concerning VEGF signaling and its impact, not only on angiogenesis but also on various other oncogenic processes.

Inactivation of Minar2 in mice hyperactivates mTOR signaling and results in obesity

OBJECTIVE

Obesity is a complex disorder and is linked to chronic diseases such as type 2 diabetes. Major intrinsically disordered NOTCH2-associated receptor2 (MINAR2) is an understudied protein with an unknown role in obesity and metabolism. The purpose of this study was to determine the impact of Minar2 on adipose tissues and obesity.

METHOD

We generated Minar2 knockout (KO) mice and used various molecular, proteomic, biochemical, histopathology, and cell culture studies to determine the pathophysiological role of Minar2 in adipocytes.

RESULTS

We demonstrated that the inactivation of Minar2 results in increased body fat with hypertrophic adipocytes. Minar2 KO mice on a high-fat diet develop obesity and impaired glucose tolerance and metabolism. Mechanistically, Minar2 interacts with Raptor, a specific and essential component of mammalian TOR complex 1 (mTORC1) and inhibits mTOR activation. mTOR is hyperactivated in the adipocytes deficient for Minar2 and over-expression of Minar2 in HEK-293 cells inhibited mTOR activation and phosphorylation of mTORC1 substrates, including S6 kinase, and 4E-BP1.

CONCLUSION

Our findings identified Minar2 as a novel physiological negative regulator of mTORC1 with a key role in obesity and metabolic disorders. Impaired expression or activation of MINAR2 could lead to obesity and obesity-associated diseases.