Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter best known for its role in mood regulation, but it also plays roles in cell proliferation, angiogenesis, immune response, and gut physiology—all of which are relevant to cancer biology.
🧠 PRO: Serotonin Promotes Cancer🧬 Mechanisms Proposed:Cell Proliferation: Serotonin can stimulate growth in certain cancer cells (e.g., breast, prostate, colorectal).
Angiogenesis: Serotonin promotes blood vessel formation, which tumors need to grow.
Immunosuppression: High serotonin may help tumors evade the immune system.
Autocrine/Paracrine Signaling: Some tumors produce serotonin themselves, acting on their own or nearby cells to enhance survival and spread.
Breast Cancer: Increased serotonin receptor expression in some subtypes.
Colorectal Cancer: Elevated serotonin levels associated with faster tumor progression.
Lung and Prostate Cancer: Serotonin receptors implicated in promoting metastasis.
Context Matters: The role of serotonin depends on receptor subtype, tumor type, and microenvironment.
Immune Modulation: Serotonin may enhance anti-tumor immunity in some contexts.
Apoptosis Promotion: In some cell lines, serotonin can trigger cell death rather than proliferation.
SSRI Use in Cancer Patients: Some studies show no increase or even reduced cancer risk with selective serotonin reuptake inhibitors (SSRIs), though results are mixed.