VPS34 in Autophagy, Cancer, and Cancer Therapy

Autophagy is a fundamental lysosome-dependent degradation process that maintains cellular homeostasis in response to stress. VSP34 (Vacuolar Protein Sorting 34, PIK3C3) is the only class-III phosphatidylinositol 3-kinase and generates phosphatidylinositol 3-phosphate (PI3P) for auto-phagosome nucleation and maturation. Thus, it provides a critical adaptive survival pathway for cells that are experiencing metabolic stress. The VPS34-autophagy axis plays dual roles in cancer, which depend on the context: it can restrain early tumorigenesis, but in established tumors, it can promote survival in conditions of hypoxia, nutrient deprivation, and therapeutic pressure. Moreover, VPS34 shapes the tumor microenvironment (TME) through its influence on both immune and cancer cells by modulating autophagy, cGAS-STING (cyclic GMP-AMP synthase Stimulator of Interferon Genes), and STAT1 pathways. VPS34 inhibition has been reported to induce an interferon response that increases CD8⁺ T and natural killer (NK) cell infiltration and converts cold tumors into hot ones. This behavior suggests that combining VPS34 inhibitors with cancer immunotherapies could be beneficial. In this review, we summarize the molecular functions and regulations of VPS34 in autophagy and discuss recent advances linking VPS34 to tumor and cancer immunotherapy.