Firstly, I would like to emphasize that dasatinib is a multi-target tyrosine kinase inhibitor which blocks the activity of bcr-Abl, Src kinases, c-KIT (CD1117), PDGF-R and ephrin-A receptor kinases, and this molecular targeting drug is currently a first line treatment in chronic myeloid leukaemia.
Malme-3M, WM266-4 and M14 cells are resistant to this drug when melanoma cell lines which showed greater than 30% growth inhibition with 155 nM dasatinib are defined as sensitive. Interestingly Sk-Mel-28 and Sk-Mel-5 cells exhibit paradoxical enhanced proliferation in the presence of dasatinib among human melanoma cell lines, probably due to the negative-feedback machinery against the chronic inhibition of Src kinases.