Gangliosides in Cutaneous Melanoma: Molecular Mechanisms, Translational Evidence Gaps, and Preclinical Natural-Compound Leads

Cutaneous melanoma remains lethal once metastatic despite advances in immune checkpoint blockade and BRAF/MEK-directed therapy. Gangliosides are surface-accessible sialylated glycosphingolipids that regulate membrane organization, adhesion, and signaling, representing potential biomarkers and therapeutic targets. This narrative review evaluated the translational readiness of ganglioside-directed strategies in cutaneous melanoma, without assuming that evidence from other GD2- or GD3-positive cancers is directly transferable. We synthesized melanoma-specific evidence on GD3-linked focal adhesion signaling, p130Cas/paxillin activity, PI3K–AKT and MAPK outputs, and distinct phenotypes associated with GD3, GD2, and GM3. We then applied an evidence-gated framework distinguishing melanoma clinical evidence, melanoma preclinical evidence, cross-tumor translational evidence, and hypothesis-generating claims. Direct contemporary clinical evidence in melanoma remains limited. Antibody, cellular, and biosynthetic enzyme strategies require diagnostic-quality antigen profiling, demonstration of surface accessibility and functional dependency, and prospective monitoring for antigen escape and neurotoxicity. Natural compounds, particularly quercetin, are mechanistic probes or formulation-enabled leads: a 2024 study reported reduced GM3/GD3 abundance and FAK/paxillin/AKT signaling in melanoma cell lines, but high in vitro concentrations and the lack of pharmacokinetic or in vivo validation preclude therapeutic conclusions. We proposed a minimum evidence package and go/no-go criteria for clinical translation, specifying experiments needed to advance ganglioside biology into biomarker-defined melanoma interventions.