AZD7762

AZD7762, a more selective Chk1 inhibitor, inhibits Chk1 phosphorylation of a cdc25C peptide by reversibly binding to the ATP-binding site of Chk1, with IC50 of 5 nM and K_i of 3.6 nM. AZD7762 induces cell arrest with EC50 of 0.620 μM, and significantly abrogates the camptothecin induced G2 arrest with an EC50 of 10 nM, by blocking the chk1 dependent degradation of Cdc25A and activation of Cyclin A. AZD7762 (300 nM) enhances the antitumor efficacy of gemcitabine against SW620 and topotecan against MDA-MB-231 by reducing the GI50 values from 24.1 nM and 2.25 μM to 1.08 nM and 0.15 μM, respectively. ^[1] AZD7762 shows cytotoxicity against a variety of neuroblastoma cell lines bearing p53 wild type, p53 mutation, Mdm2 amplification or p14 deletion with IC50 values ranging from 82.6-505.9 nM. ^[2]