BN82002 hydrochloride is a potent, selective, and irreversible inhibitor of the CDC25 phosphatase family. It inhibits CDC25A, CDC25B2, CDC25B3, CDC25C, and 25C-cat with IC50 values of 2.4, 3.9, 6.3, 5.4, and 4.6 μM, respectively. Additionally, BN82002 hydrochloride exhibits approximately 20-fold greater selectivity over CD45 tyrosine phosphatase.
PD-321852 is a small-molecule Chk1 inhibitor, which potentiates gemcitabine-induced clonogenic death in a panel of pancreatic cancer cell lines and evaluated the relationship between endpoints associated with Chk1 inhibition and chemosensitization. Gemcitabine chemosensitization by minimally toxic concentrations of PD-321852 ranged from minimal (<3-fold change in survival) in Panc1 cells to >30-fold in MiaPaCa2 cells. PD-321852 inhibited Chk1 in all cell lines as evidenced by stabilization of Cdc25A; in combination with gemcitabine, a synergistic loss of Chk1 protein was observed in the more sensitized cell lines.