Dasatinib (BMS-354825)

Cytotoxicity by Dasatinib treatment in leukemic cells.Leukemic cell lines were exposed to Dasatinib (10 μM). Upon treatment, cell viability (a) was calculated as percentage with respect to the control vehicle cultures (set to 100% for each cell line) and induction of apoptosis (b) was calculated as percentage of Annexin V+/PI+ cells after 48 h of treatment.

Human phospho-kinase array analysis in response to Dasatinib treatment. Whole cell lysates were prepared from EHEB (p53wt) and BJAB (p53mut) B cell lines, either left untreated or exposed to Dasatinib for 24 h, and hybridized with a human Phospho-Kinase array kit. Spot densities of phospho-proteins were quantified using Image Quant TL software and normalized to those of positive controls on the same membrane. In a, intense decreases of signal of P-p38, PERK1/2 and P-CREB in response to Dasatinib are indicated by arrows in the membranes, and intensity of corresponding spots are reported as graphics. In b, analysis of modulation of phosphorylation of STAT family members in response to Dasatinib (spots not shown). The means±SD of three independent experiments are shown. Asterisk indicates P<0.05 against untreated.

c, cells were either left untreated (Unt.) or exposed to Dasatinib (Das.) for 24 h. Equal amounts of cell lysates were analyzed for ERK1/2, p38 and CREB phosphorylation by Western blot using antibodies specific for the native form of the kinases and for residues that are phosphorylated (P-) in each kinase upon activation. One of three experimentswith similar results is shown. Protein bands were quantified by densitometry and level of PERK1/2, P-p38 and P-CREB expressed as arbitrary units,were calculated for each cell line after normalization to total ERK1/2, p38 and CREB respectively

Cell vability test result. Different cell lines (A2C12, Beta D5, Gamma A3, Gamma D12, A549, CaCo2,Hep G2) were treated with different concentration of Dasatinib.

Cytotoxicity by Dasatinib and Nutlin-3 used alone or in combination in B-CLL patient leukemic cells. B-CLL patient leukemic cells were exposed to serial doses of Dasatinib or Nutlin- 3 used either alone or in combination, with a fixed ratio, for 48 hours. Dose-effect plots, to determine drug efficacy, are shown for representative B-CLL samples, including 3 patients carrying 17p- (Pt. #7, Pt. #8, and Pt. #10). The decrease of cell viability, labeled "effect" on the Y-axis, was determined in assays done at least twice in duplicate.

Dasatinib interferes with the p53 transcriptional activity induced by Nutlin-3. Leukemic cell lines were exposed for 24 hours to Dasatinib (10 mM) and Nutlin-3 (10 mM), used either alone or in combination, as indicated. Levels of p53 (A), MDM2 and p21 (B) were assessed by Western blot analysis of total cell lysates. Representative examples of Western blot results are shown. Tubulin staining is shown as loading control; after densitometric analyses, p53 as well as MDM2 and p21 protein levels are expressed as folds of protein modulation, by the indicated treatments, with respect to the control untreated cultures set to 1 (hatched line). *P < 0.05 with respect to the Nutlin-3-treated cultures.

Role of Akt in Dasatinib cytotoxicity and in DasatinibtNutlin-3 synergy. A, whole cell lysates were prepared from EHEB and BJAB cell lines treated (for 16 hours) as indicated, and hybridized with a human Phospho-Kinase array kit. Spot densities of phospho-proteins were quantified using Image Quant TL software and normalized to those of positive controls (set at 100) on the same membrane. The analysis of modulation of phosphorylation signals for P-ERK1/2, P-p38, and P-Akt are reported (*P < 0.05). Validation of phospho-kinase array results was carried out by Western blot analysis of P-Akt levels.

Impact of the TKI erlotinib, lapatinib, dasatinib, and sorafenib on the viability of MDS/AML cells. MOLM-13 (A) and HL-60 (B) cells were incubated with the indicated doses (given in mM below the x-axis) of the 4 TKI, and cellular viability was assessed by MTT assay after 24, 48 and 72 h of incubation. Changes in viability are given as percentage of cells as compared to non-treated control samples. This experiment was repeated at least three times, yielding comparable results. Graphs show representative results of one experiment carried out in duplicates (mean  standard deviation).

Capacity of the TKI to overcome the AML-typical differentiation blockage. The myeloid cell lines MOLM-13 and HL-60 were incubated for 6 days with 0.01% DMSO (serving as a negative solvent control), 1 mM of ATRA (serving as a positive control), as well as with the indicated doses of the four TKI. (A) Representative May–Gruenwald– Giemsa staining of MOLM-13 cells, (B) quantitation of the percentage of MOLM-13 cells exhibiting at least two morphological signs of differentiation (that is a decrease in cytoplasmic basophilia, a reduction of the nucleo-cytoplasmic ratio, appearance of nuclear lobulation and/or cytoplasmic granules). Percentages were evaluated by examining at least 100 cells/condition; (C) representative FACS overlays of MOLM-13 cells depicting TKI-induced CD11b expression (black line) as compared to the isotype (shaded grey); (D) quantitation of TKI-induced CD11b-expression in MOLM-13 cells; (E) representative slides depicting morphology/staining of MOLM-13 cells assessed in the NBT-reduction assay; (F) respective quantitative assessment demonstrating the NBT-reducing capacity under the different drugs; (G) representative May–Gruenwald– Giemsa staining of HL-60 cells.

Combinational treatment of kinase inhibitors induces the similar phenotype produced by PP1. All images are lateral view with dorsal to the top and anterior to the left. The combinational treatment of Dasatinib (D) or U0126 (U) with Sunitinib (SU),PTK787 (PTK), or ZM323881 (Z) resulted in the shrinkage of dorsal aorta.