Establishment and characterization of a cell line (OS-MM) originating from a human malignant melanoma of the oral mucosa

The prognosis for patients diagnosed with oral mucosal melanoma is poor, and the etiology of this disease remains to be elucidated. The underlying reason for this is that no malignant melanoma (MM) cell line derived from oral mucosal tissue has been successfully established to date. The establishment of a human MM cell line designated OS-MM from a tissue sample of a patient diagnosed with palatal mucosal melanoma was undertaken. For a period exceeding three decades, tumor cells have undergone uninterrupted proliferation, exhibiting a spindle-like morphology. Chromosomes exhibit a low-triploid pattern with an observed mode of 47. Heterotransplantation of the cells into SCID mice has resulted in the formation of tumor masses. The cells expressed vascular endothelial growth factor (VEGF) and its receptors. The addition of exogenous recombinant VEGF₁₆₅ did not alter proliferation but enhanced motility. A genetic analysis of OS-MM cells revealed the absence of BRAF and NRAS mutations; however, a GNAS mutation was identified. The OS-MM cell line should contribute to advances in personalized therapy for malignant oral mucosal melanoma.