Background:

A 83-01 is a small-molecule inhibitor of activin receptorlike kinase (ALK)-5 with IC50 value of 12 nM [1].

A 83-01 inhibited 68% of the transcriptional activation induced by ALK-5 at concentration of 1 μM in Mv1LuR4-2 cells that transfected with luciferase reporter gene and constitutively active ALK-5. In cells transfected with luciferase reporter gene only, A 83-01 treatment inhibited the activity of ALK-5 induced by TGF-β (IC50 value was 12 nM) but not BMP. A 83-01 also showed inhibition on the activity of ALK-4 and ALK-7 in R4-2 cells with IC50 values of 45 and 7.5 nM, respectively. For other ALK receptors such as ALK-1, 2, 3 and 6, A 83-01 showed weak inhibition. Besides that, A 83-01 was proved to reduce the cell growth inhibition [1].

参考文献:
1. Tojo M, Hamashima Y, Hanyu A, et al. The ALK-5 inhibitor A-83-01 inhibits Smad signaling and epithelial-to-mesenchymal transition by transforming growth factor-β. Cancer science, 2005, 96(11): 791-800.