Background:

PF-477736 is a potent, selective ATP-competitive and small-molecule inhibitor of Chk1 with a Ki of 0.49±0.29nM for the in vitro kinase activity of Chk1 [1].

PF-477736 has shown a selective inhibition of Chk1 with the IC50 values of 0.49nM, 9.9μM and 47nM for Chk1, CDK1 and Chk2, respectively. In a dot-blot assay, PF-477736 has been reported to inhibit camptothecin-induced G2 arrest with the EC50 values of 45nM, 38nM and 42nM in P53-mutated human lymphoma CA46 cells, HeLa cells and HT29 cells. Apart from these, PF-477736 has been found to selectively target p53-defective cancer cells while having minimal cytotoxic effects on normal (p53-competent) cells. In addition, PF-00477736 has been revealed to dose-dependently enhance the antitumor activity of a MTD of gemcitabine with no apparent exacerbation of systemic toxicity as assessed by monitoring body weight in the Colo205 xenograft [1].

参考文献:
[1] Blasina A1, Hallin J, Chen E, Arango ME, Kraynov E, Register J, Grant S, Ninkovic S, Chen P, Nichols T, O'Connor P, Anderes K. Breaching the DNA damage checkpoint via PF-00477736, a novel small-molecule inhibitor of checkpoint kinase 1. Mol Cancer Ther. 2008 Aug;7(8):2394-404.