In vitro activity of the alfavbeta3 integrin antagonist RGDechi-hCit on malignant melanoma cells.

Background: In malignant melanoma (MM), overexpression of alfavbeta3 integrin is linked to a more metastatic phenotype. Development of anti-alfavbeta3 agents able to counteract melanoma progression would be helpful for disease treatment. A new selective ligand of alfavbeta3, RGDechi-hCit, has anti-angiogenic properties against endothelial cells in angiogenesis animal models. Aim of this study was to evaluate the in vitro effects of the RGDechi-hCit peptide on MM cell lines. Material and Methods: Cytofluorimetric analysis characterized cell surface expression of alfavbeta3 integrin on seven MM cell lines. Cell proliferation, adhesion, and migration assays were carried out using the alfavbeta3-antagonist RGDechi-hCit. Results: Proliferation was not significantly inhibited by RGDechi-hCit, though striking morphological changes were detected in MM cell lines highly expressing alfavbeta3. Conversely, assays on fibronectin-coated plates showed a significant RGDechi-hCit dose-dependent inhibitory effect on both adhesion and migration. Conclusions: Data demonstrate anti-adhesion and anti-migration, but not anti-proliferative, activities of RGDechi-hCit against MM cells.