Expression data from a reversible dasatinib-resistant state in long-term dasatinib-treated c-KIT-mutated Kasumi-1 cell line

Long-term treatment of Kasumi-1 cells at clinically attained doses of dasatinib led to decreased drug-sensitivity by means of IC50 values (relative to treatment-naive cells). Changes were paralled by profound alterations in c-KIT expression and cell signaling signatures. Upon brief discontinuation of dasatinib treatment, these alterations reversed and drug sensitivity was restored. We used gene expression profiling to examine reversal of dasatinib-resistance at the molecular/expression level. Kasumi-1 cells were either treated with dasatinib for 12 weeks (R48) or left untreated (K). Subsequently, dasatinib was withdrawn from R48 cells for 1 week (PR48). RNA was extracted from R48 and K cells and hybridized on Affymetrix microarrays after 12 weeks and PR48 after a total time span of 13 weeks.