PF-477736

Kinase assays

CHK1 activity was measured by a pyruvate kinase-lactate dehydrogenase coupled, continuous spectrophotometric assay method where the phosphorylation of a CHK1 peptide substrate (Syntide-2, PLARTLSVAGLPGKK) was coupled to the oxidation of NADH and the corresponding change in absorbance intensity was measured at 340 nm. The assay was performed in a 96-well plate for 20 minutes at 30°C in 0.1 mL of assay buffer containing 50 mM TRIS pH 7.5, 0.4 M NaCl, 4 mM PEP, 0.15 mM NADH, 28 units of lactate dehydrogenase/mL, 16 units of pyruvate kinase/mL, 3 mM DTT, 0.125 mM Syntide-2, 0.15 mM ATP and 25 mM magnesium chloride. Assays were initiated with 1nM of CHK1 kinase domain. The inhibition of CHK1 activity was determined by measuring initial velocities in the presence of varying concentrations of PF-477736.

Cell lines

HT29 cell lines

Preparation method

The solubility of this compound in DMSO is >5.2mg/mL. General tips for obtaining a higher concentration: Please warm the tube at 37℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reacting condition

69 nM, 24h

Applications

The gemcitabine and PF-477736 combination induced significant potentiation of the cytotoxic activity of gemcitabine, indicating that the combination treatment caused a permanent cellular damage that cannot be overcome even after drug removal. The cell kill induced by the combination treatment is time and dose dependent.

Animal models

Colo205 Xenograft Models in Athymic Nude Mice

Dosage form

i.p., 4-60 mg/kg，q3d × 4

Application

In xenografts, PF-477736 enhanced the antitumor activity of gemcitabine in a dose-dependent manner.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

References:

[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.