CP-466722S2245

In vitro, CP-466722 is identified as a potential inhibitor to decrease the activity of purified ATM kinase to phosphorylate GST-p53(1–101) substrate. In addition, CP-466722 also shows the inhibitory activities against abl and src kinases. ^[1] In HeLa cells, CP-466722 at doses of 6μM, results in the inhibition in ATM-dependent phosphorylation by reversibly inhibiting ionizing radiation (IR)-induced ATM kinase activity. Besides, ATM-dependent p53 induction is also inhibited by CP-466722 in MCF-7 human breast cancer cells and primary and immortalized diploid human fibroblasts. ^[1] In response to IR, CP-466722 increased proportion of cells with G2/M DNA content and reduces proportion of cells with G1-phase DNA content in HeLa cells. ^[1] Transient exposure to CP-466722 for a period of 4 hours sensitizes HeLa cells to IR without affecting cell plating nor cell viability. ^[1]