Effect of extracellular S100A4 on melanoma cells of different phenotypes

S100A4 is a known metastasis-promoting factor, rich in the tumor microenvironment. To clarify how extracellular S100A4 execute its pro-metastatic function, we analyzed gene expression in melanoma cells stimulated with recombinant protein rS100A4 and compared it to the expression in control non-stimulated cells. Two melanoma cell lines representing two distinct phenotypes – invasive (Melmet 1) and non-invasive/proliferative (Melmet 5) – were included in the study. The response at the gene expression level was much stronger in Melmet 5 than in Melmet 1. Melmet 5 down-regulated genes associated with melanocytic differentiation, indicating that Melmet 5 cells gained dedifferentiated, more invasive phenotype after stimulation with rS100A4. The observed changes in the expression of metabolism associated genes suggested the occurrence of metabolic reprogramming. We conclude that extracellular S100A4 stimulate the transition to the invasive phenotype in poorly-invasive melanoma cells, and that this transition is associated with metabolic reprogrammingve Total RNA was isolated from Melmet 1 and Melmet 5 cells stimulated with rS100A4 protein for 48hrs compared to non-stimulated cells.