Background:

PF573228 is an inhibitor of FAK with IC50 value of 4 nM [1].

FAK (Focal adhesion kinase) is a non-receptor protein-tyrosine kinase that resides at the sites of focal adhesions. FAK protein is encoded by the FAK gene located on human chromosome 8q24 and the molecular weight is 125 kDa. FAK works as an important mediator of cell activities, like cell adhesion, growth, proliferation, survival, angiogenesis and migration, it is reported that normal tissues FAK are significantly lower than in primary and metastatic tumors [2].

PF573228 is a specific inhibitor of FAK and is regarded as potent anti-angiogenic agents. When tested with HUVEC (primary human umbilical vein endothelial cells), PF573228 treatment increased the proportion of cell apoptosis, reduced the ability of endothelial cell migration and sprout formation via inhibiting the autophosphorylation of FAK [3]. In A431 epithelial carcinoma cells, incubation with PF573228 resulted in the reduced phosphorylation of FAK with IC50 value of 11 nM and PF573228 also observed to inhibit the FAK phosphorylation in many other cancer cells, such as PC3 cells, SKOV-3 cells, L3.6p1 cells, F-G cells and MDCK cells with IC50 value of 30-500 nM [1]. When tested with MSCs (mesenchymal stem cells), PF573228 treatment depressed the MSCs pro-inflammatory response to CM from FaDu, MDA-MB-231, PC-3 and NCI-H522 via inhibiting FAK phosphorylation [4].

PF573228 is also reported functioned in the process of BK (Ca)-channel. When tested with pituitary tumor (GH (3)) cells transfected with K (Ca) 1.1 siRNAs, 3 uM PF573228 treatment stimulated the BK (Ca)-channel activity which subsequently may influence cell behavior [5].

参考文献:
[1].  Slack-Davis, J.K., et al., Cellular characterization of a novel focal adhesion kinase inhibitor. J Biol Chem, 2007. 282(20): p. 14845-52.
[2].  Golubovskaya, V.M., Focal adhesion kinase as a cancer therapy target. Anticancer Agents Med Chem, 2010. 10(10): p. 735-41.
[3].  Cabrita, M.A., et al., Focal adhesion kinase inhibitors are potent anti-angiogenic agents. Mol Oncol, 2011. 5(6): p. 517-26.
[4].  Al-toub, M., et al., Pleiotropic effects of cancer cells' secreted factors on human stromal (mesenchymal) stem cells. Stem Cell Res Ther, 2013. 4(5): p. 114.
[5].  So, E.C., et al., Evidence for activation of BK Ca channels by a known inhibitor of focal adhesion kinase, PF573228. Life Sci, 2011. 89(19-20): p. 691-701.