Actively proliferating cells experience blocks at certain checkpoints in the cell cycle when DNA damage is detected. These checkpoints allow for DNA damage repair before further cell cycle progression. Targeting signaling pathways to selectively inhibit repair at these checkpoints in tumor cells is of considerable interest to cancer therapeutics. AZD 7762 selectively inhibits the activity of checkpoint kinases (Chk) 1 and Chk2 (IC
50s = 5 nM) by competitively and reversibly binding their respective ATP-
binding sites (K
i = 3.6 nM for Chk1).
1 AZD 7762 abrogates DNA damage-
induced S and G
2 checkpoints with an EC
50 value of 10 nM and potentiates the efficacy of DNA-
damage repair prohibitive agents, gemcitabine and topotecan, both
in vitro and in various tumor xenografts by modulating downstream checkpoint pathway proteins.
1,2,3