Background:

GW441756 is an inhibitor of TrkA kinase and LRRK2 with IC50 value of 320nM and 2nM, respectively [1].

The activity of TrkA kinase can affect its downstream signaling and involves in many biological processes including proliferation, differentiation and apoptosis. Thereby the inhibitor of TrkA is developed for the treatment of cancers. GW441756 belongs to the oxindole series and is found to be a potent inhibitor of TrkA. It is also selective against TrkA. The IC50 values of it for cRaf1 and CDK2 are above 12μM and 7μM, respectively. In human muscle sarcoma cancer cell line HTB114, treatment of GW441756 dose-dependently suppresses neoplastic proliferation and induces apoptosis [1, 2].

In addition, GW441756 is also found to be an LRRK2 inhibitor. It inhibits the Ser935 phosphorylation of LRRK2 in cellular TR-FRET assay with IC50 value of 2.2μM. It shows no significant cytotoxicity with IC50 value of >20μM [3].

参考文献:
[1] Wood E R, Kuyper L, Petrov K G, et al. Discovery and in vitro evaluation of potent TrkA kinase inhibitors: oxindole and aza-oxindoles. Bioorganic & medicinal chemistry letters, 2004, 14(4): 953-957.
[2] Montagnoli C, Pistilli A, Stabile A M, et al. Anti-proliferative effects of GW441756, a novel inhibitor of NGFreceptor tyrosine kinase a (TRKA), in human sarcoma. Italian Journal of Anatomy and Embryology, 2010, 115(1/2): 117.
[3] Hermanson S B, Carlson C B, Riddle S M, et al. Screening for novel LRRK2 inhibitors using a high-throughput TR-FRET cellular assay for LRRK2 Ser935 phosphorylation. PloS one, 2012, 7(8): e43580.