Figure 3

V158411 inhibits DNA damage induced Chk1 auto-phosphorylation and increases γH2AX in colon carcinoma cells. HT29 (left) or Colo205 (right) p53 defective colon carcinoma cells were treated with A. 200 nM camptothecin or 100 nM gemcitabine plus varying concentrations of V158411 for 24 hours or B. treated with the indicated concentrations of gemcitabine, camptothecin, cisplatin or etoposide with either DMSO or 200 nM V158411 for 24 hours. Protein expression was characterized by immunoblotting.