Current treatments for advanced melanoma and introduction of a promising novel gene therapy for melanoma (Review).

Metastatic melanoma is a fatal form of skin cancer that has a tendency to proliferate more rapidly than any other solid tumor. Since 2010, treatment options for metastatic melanoma have been developed including chemotherapies, checkpoint inhibition immunotherapies, e.g., anti‑cytotoxic T‑lymphocyte antigen‑4 (CTLA‑4) and anti‑programmed death‑1 (PD‑1), and molecular-targeted therapies, e.g., BRAF and MEK inhibitors. These treatments have shown not only high response rates yet also side‑effects and limitations. Notwithstanding its limitations, stem cell therapy has emerged as a new auspicious therapy for various tumor types. Since stem cells possess the ability to serve as a novel vehicle for delivering therapeutic or suicide genes to primary or metastatic cancer sites, these cells can function as part of gene‑directed enzyme prodrug therapy (GDEPT). This review focuses on introducing engineered neural stem cells (NSCs), which have tumor‑tropic behavior that allows NSCs to selectively approach primary and invasive tumor foci, as a potential gene therapy for melanoma. Therapy using engineered NSCs with cytotoxic agents resulted in markedly reduced tumor volumes and significantly prolonged survival rates in preclinical models of various tumor types. This review elucidates current treatment options for metastatic melanoma and introduces a promising NSC therapy.