TG100-115 is a PI3Kγ/δ inhibitor (IC50: 83/235 nM), with fewer effects on PI3Kα/β.

PI3Kδ:235 nM, PI3Kγ:83 nM

In human umbilical vein endothelial cells, TG100-115 (10 μM) did not affect cell proliferation and VEGF-stimulated ERK phosphorylation, but blocked other vascular endothelial growth factor (VEGF) signaling pathways, such as VE-calmodulin phosphorylation, and thus inhibited the overall increase in the level of VE-calmodulin induced by VEGF. TG100-115 (0.125-10 μM) also inhibited FGF-stimulated Akt phosphorylation.The inhibitory effect of TG100-115 on PI3Kα/β was weak (IC50: 1.2/1.3 mM).TG100-115 inhibited vascular endothelial growth factor-regulated phosphorylation of p70S6 and mTOR kinase.

In human umbilical vein endothelial cells, TG100-115 (10 μM) did not affect cell proliferation and VEGF-stimulated ERK phosphorylation, but blocked other vascular endothelial growth factor (VEGF) signaling pathways, such as VE-calmodulin phosphorylation, and thus inhibited the overall increase in the level of VE-calmodulin induced by VEGF. TG100-115 (0.125-10 μM) also inhibited FGF-stimulated Akt phosphorylation.The inhibitory effect of TG100-115 on PI3Kα/β was weak (IC50: 1.2/1.3 mM).TG100-115 inhibited vascular endothelial growth factor-regulated phosphorylation of p70S6 and mTOR kinase.

PI3K assays: Forty mL of reaction buffer (20 mM Tris/4 mM MgCl2/10 mM NaCl, pH 7.4) containing 50 mM D-myo-phosphatidylinositol 4,5-bisphosphate substrate and the desired PI3K isoform are aliquoted to 96-well plates; kinase concentrations are 250-500 ng/well, such that linear kinetics are achieved over 90 min. TG100-115 is then added as 2.5 mL of a DMSO stock to final concentration range of 100 mM to 1 nM. Reactions are initiated by addition of 10 mL of ATP to a final concentration of 3 mM, and after 90 min, 50 mL of Kinase-Glo reagent added to quantify residual ATP levels; luminosity is measured using an Ultra 384 instrument. Control reactions omitting either TG100-115 or substrate are also performed. IC50 values are derived from experimental data by nonlinear curve fitting using Prism Version 4.

Cells plated in 96-well cluster plates (5 × 103 cells/well) are cultured in assay medium (containing 0.5% serum and 50 ng/ml VEGF) in the presence or absence of TG100-115, and cell numbers are quantified by XTT assay 24, 48, or 72 hours late(Only for Reference)