Rab3B Proteins: Cellular Functions, Regulatory Mechanisms, and Potential as a Cancer Therapy Target.

RAB3 proteins, a pivotal subgroup within the Rab protein family, are known to be highly expressed in brain and endocrine gland tissues, with detectable levels also observed in exocrine glands, adipose tissue, and other peripheral tissues. They play an indispensable role in the trafficking of cellular products from the endoplasmic reticulum (ER) to the Golgi apparatus and ultimately to secretory vesicles, participating in vesicle transport, mediating cell membrane adhesion, and facilitating membrane fusion during exocytosis. Among these, Rab3B, a specific subtype of RAB3, is a low-molecular-weight (approximately 25 kD) GTP-binding protein (GTPase) characterized by its typical GTPase fold, composed of seven β-strands (six parallel and one antiparallel) surrounded by six α-helices. Previous studies have proved the significant roles of Rab3B in vesicle transport and hormone trafficking. However, its involvement in cancer remains largely unexplored. This review aims to dig into the potential mechanisms of Rab3B in various cancers, including hepatocellular cancer, lung adenocarcinoma, pancreatic cancer, breast cancer, prostate cancer, neuroblastoma and cervical cancer. Given its pivotal functions and underexplored status in oncology, Rab3B stands out as a promising target for both diagnosis and therapy in cancer treatment, with investigations into its biological mechanisms in tumorigenesis offering significant potential to advance future diagnostic and therapeutic strategies across various malignancies.