Context-dependent roles of 5-HT and its receptors in tumor growth and wound healing: Mechanisms and therapeutic implications

Serotonin (5-hydroxytryptamine, 5-HT), a neurotransmitter known for its roles in the central nervous system, showing dual effects in various pathological conditions, including tumor progression and wound healing. This review explores the complex and context-dependent actions of 5-HT, highlighting its contrasting roles in promoting tumor growth and facilitating wound repair. 5-HT can enhance tumor growth, survival, and metastasis via its receptors, but it also accelerates wound healing by stimulating cell proliferation, migration, and angiogenesis. This duality emphasizes the intricate balance of 5-HT and its receptors in the body. We discuss the synthesis, storage, secretion, and metabolism of 5-HT, as well as the classification and mechanisms of its receptors (5-HTRs) in different cell types under pathological conditions. We further examine the potential roles of 5-HT in both tumor progress and wound healing, proposing targeted strategies for each disease state. For tumors, "blocking therapy" involving receptor antagonists or gene silencing may inhibit tumor progression, while "activation therapy" can stimulate wound healing by enhancing receptor activation on skin cells. Challenges in clinical application, including issues related to targeting, specificity, and dosage, are addressed, alongside the promise of nanotechnology for improving targeted drug delivery. The review also explores emerging research on 5-HT's interaction with the immune system, offering insights into potential immunotherapeutic strategies for both cancer and wound healing. By balancing 5-HT's diverse effects, personalized treatments can be developed to optimize therapeutic outcomes in both contexts.