GW843682X is a reversible, cell-permeable polo-like kinase (PLK) inhibitor. It selectively inhibits Plk1 and Plk3 (IC50s = 2.2 and 9.1 nM, respectively) over PDGFR1β, VEGFR2, Aurora A, and Cdk2/cyclin A (IC50s = 160, 360, 4,800, and 7,600 nM, respectively), as well as over 30 other kinases, in a cell-free assay. GW843682X also inhibits Plk1 activity in vitro in HeLa cells (IC50 = 0.14 μM in a reporter assay using chimeric Plk1). It inhibits growth in nine cancer cell lines in a panel (IC50s = 0.11-0.7 μM) but not of PC3 human prostate cancer cells (IC50 = 6.82 μM) or non-cancerous human diploid fibroblasts (HDFs; IC50 = 6.14 μM). GW843682X inhibits growth of MES-SA human uterine sarcoma cells, as well as of the drug-resistant, P-glycoprotein-expressing MES-SA/Dx5 subline (IC50s = 0.21 and 0.21 μM, respectively). It also inhibits the growth of patient-derived leukemia cells (IC50s = <0.25-0.8 μM). GW843682X induces G2/M cell cycle arrest and apoptosis of H460 human lung and PALL-2 and MOLM13 human leukemia cancer cells in a concentration-dependent manner.
Selective inhibitor of polo-like kinase 1 (PLK1) and polo-like kinase 3 (PLK3) (IC 50 values are 2.2 and 9.1 nM respectively). Displays > 100-fold selectivity over ~30 other kinases tested including cdk1 and cdk2. Inhibits proliferation of most tumor cells in vitro and is selective over normal diploid fibroblasts.