Dasatinib (BMS-354825) is a tyrosine kinase inhibitor that inhibits Src and Bcr-Abl (Ki=16/30 pM) and is orally active and ATP-competitive. Dasatinib has antitumor activity and is used in the treatment of leukemia and lymphoma.

Abl:0.6 nM (cell free), Src:0.8 nM (cell free), lck:0.4 nM, c-Kit (WT):79 nM (cell free), yes:0.5 nM, p210 (BCR-ABL):1.0 nM, MEK:1700 nM, p38:100 nM, FGFR1:880 nM, Her1:180 nM, c-Kit (D816V):37 nM (cell free), Her2:710 nM, PDGFRβ:28 nM

Kinase assays using wild-type and mutant glutathione S-transferase (GST)–Abl fusion proteins (c-Abl amino acids 220-498) were done as described, with minor alterations. GST-Abl fusion proteins were released from glutathione-Sepharose beads before use; the concentration of ATP was 5 μmol/L. Immediately before use in kinase autophosphorylation and in vitro peptide substrate phosphorylation assays, GST-Abl kinase domain fusion proteins were treated with LAR tyrosine phosphatase according to the manufacturer's instructions. After 1-hour incubation at 30°C, LAR phosphatase was inactivated by addition of sodium vanadate (1 mmol/L). Immunoblot analysis comparing untreated GST-Abl kinase to dephosphorylated GST-Abl kinase was routinely done using phosphotyrosine-specific antibody 4G10 to confirm complete (>95%) dephosphorylation of tyrosine residues and c-Abl antibody CST 2862 to confirm equal loading of GST-Abl kinase. The inhibitor concentration ranges for IC50 determinations were 0 to 5,000 nmol/L (imatinib and AMN107) or 0 to 32 nmol/L (BMS-354825). The BMS-354825 concentration range was extended to 1,000 nmol/L for mutant T315I. These same inhibitor concentrations were used for the in vitro peptide substrate phosphorylation assays. The three inhibitors were tested over these same concentration ranges against GST-Src kinase and GST-Lyn kinase [1].

Ba/F3 cell lines were plated in triplicate and incubated with escalating concentrations of imatinib, AMN107, or BMS-354825 for 72 hours. Proliferation was measured using a methanethiosulfonate-based viability assay. IC50 and IC90 values are reported as the mean of three independent experiments done in quadruplicate. The inhibitor concentration ranges for IC50 and IC90 determinations were 0 to 2,000 nmol/L (imatinib and AMN107) or 0 to 32 nmol/L (BMS-354825). The imatinib concentration range was extended to 6,400 nmol/L for mutants with IC50 >2,000 nmol/L. The BMS-354825 concentration range was extended to 200 nmol/L for mutant T315I [1].

For in vivo studies, dasatinib (50 mg/kg) was prepared for daily oral gavage (5 d/wk) in 80 mmol/L sodium citrate buffer, pH 3.0. For the orthotopic murine model, mice were randomized on day 10 based on bioluminescence activity to receive drug or vehicle. In the metastatic murine model, mice received dasatinib or vehicle, as described earlier, starting 2 days before intracardiac injection (pretreatment), or on day 11 following randomization (posttreatment) [4].