Abstract 1703 Effect of nanosulfides in melanoma cells with mesenchymal and epithelial phenotypes: viability and focal adhesion point studies

Melanoma cells can have mesenchymal and epithelial phenotypes. This diversity may result in complicated design of chemotherapeutic agents to reduce melanoma cell proliferation. Melanoma cells with epithelial phenotypes, for instance, are known to be more difficult to treat with chemotherapeutic agents. We have used fluorescence microscopy to study the effect of nanosulfides on the viability of melanoma cells with mesenchymal and epithelial phenotypes. We found 24-hour viability slightly over 50% in melanoma cells with either phenotype. An increase in the number of well-defined actin fibers are observed 24 hours post-treatment of melanoma cells with the mesenchymal phenotype, a trend in the opposite direction was seen for the mesenchymal control. In contrast, melanomas with epithelial phenotypes do not exhibit significant changes in the globular actin distribution as compared to its control. Vinculin delocalization was evident in melanoma cells with both phenotypes 24-hour post-treatment yet they exhibited different interactions with actin. Mesenchymal melanoma cells displayed increased vinculin co-localization with actin. The vinculin delocalization in melanomas with the epithelial cell phenotype led to a significant rise in focal adhesion points at the interphase of the cell membrane and support. These findings underscore the need to continue studies aimed to understand the interactions that result in the different response of these phenotypes to nano sulfides to advance the development of effective therapeutic strategies. NIH R25GM1271