WM-115 Cells

WM-115 is a human melanoma cell line derived from the primary tumor of an adult patient with cutaneous malignant melanoma. The cell line was established from a vertical growth phase (VGP) primary lesion and is part of a well-characterized series of melanoma models generated to represent distinct stages of melanoma progression. WM-115 cells grow adherently in vitro and display an epithelioid to spindle-shaped morphology typical of malignant melanocytes. Cytogenetic analyses of related primary and metastatic pairs have demonstrated non-random chromosomal abnormalities, particularly involving chromosomes 1, 6, and 7, supporting clonal evolution during melanoma progression.

Phenotypically, WM-115 expresses melanocytic lineage markers and melanoma-associated antigens, including pigmentation-related proteins and cell surface adhesion molecules. Compared to non-invasive radial growth phase lesions, vertical growth phase melanoma cells such as WM-115 exhibit increased expression of adhesion-related molecules, including integrins and extracellular matrix-associated proteins, reflecting enhanced invasive potential. Melanoma cells commonly express receptors for growth factors such as IGF-I and, variably, EGF receptor family members, supporting autocrine and paracrine growth stimulation mechanisms.

Functionally, WM-115 represents a model of primary melanoma with metastatic competence emerging at the vertical growth phase stage. Unlike normal melanocytes, which require multiple exogenous mitogens for proliferation, primary melanoma cells such as WM-115 display reduced dependence on external growth factors and may proliferate under more permissive culture conditions. As a primary tumor-derived melanoma model, WM-115 is widely used to study melanoma progression, invasion-associated phenotypes, growth factor signaling, and therapeutic response in comparison with metastatic counterparts derived from the same or related patients.