| In Vitro | In vitro activity: PD 153035 shows a potent and selective inhibitory effect on tyrosine phosphorylation induced with EGF with IC50 of 15 nM and 14 nM in Swiss 3T3 fibroblast and A-431 human epidermoid carcinoma cells, respectively. PD153035 shows growth inhibitory effects in cultures of EGF receptor-overexpressing human cancer cell lines including A431, Difi, DU145, MDA-MB-468 and ME180 cells with IC50 of 0.22 μM, 0.3μM, 0.4 μM, 0.68 μM and 0.95 μM, respectively. PD153035 induces a dose-dependent growth inhibition in nasopharyngeal carcinoma (NPC) cells including NPC-TW01, NPC-TW04, and HONE1 cell lines with IC50 of 12.9 μM, 9.8 μM and 18.6μM, respectively. A recent study shows that PD153035 abolishes COX-2 expression induced by the PAR(2)-activating peptide 2-furoyl-LIGRLO-NH(2) (2fLI) in Caco-2 colon cancer cells.
Kinase Assay: Enzyme reactions are performed in a total volume of 0.1 mL containing 25 mM Hepes (pH 7.4), 5 mM MgCl2, 2 mM MnCl2, 50 μM sodium vanadate, 0.5 to 1.0 ng of enzyme (which also contains enough EGF to make the final concentrations 2 μg/mL), 10 μM ATP containing 1 μCi of [32P]ATP, varying concentrations of PD153035, and 200 μM of a substrate peptide based on a portion of phospholipase C-γl having the sequence Lys-His-Lys-Lys-Leu-Ala-Glu-Gly-Ser-Ala-Tyr472-Glu-Glu-Val. The reaction is initiated by the addition of ATP. After 10 minutes at room temperature, the reaction is terminated by addition of 2 mL of 75 mM phosphoric acid, and the solution is passed through a 2.5-cm phosphocellulose filter disk that binds the peptide. The filter is washed five times with 75 mM phosphoric acid and placed in a vial with 5 mL of scintillation fluid. The uninhibited control activity produces approximately 100,000 cpm.
Cell Assay: Cells (A431, Difi, DU145, MDA-MB-468 and ME180) are seeded in sixwell plates. The next day, cells are changed to medium containing 0.5% FBS for 18 hours, and then PD153035 is added at various concentrations to the cultures. After 72 hours of treatment, cells are washed once with PBS, harvested with 0.1% human trypsin-l mM EDTA in PBS, and counted with a Coulter counter. The CMK cells grow in suspension and, therefore, do not require trypsinization. |
|---|
