In vitro activity: LY2157299 (also known as Galunisertib) potently inhibits the TGFβ receptor signaling. LY2157299 abolishes the TGFβ induced Smad2 phosphorylation in HUVEC cells. LY2157299 also shows dose dependent potentiation of VEGF or bFGF induced cell proliferation in HUVEC. LY2157299 also promotes VEGF induced HUVEC cell migration. LY2157299 potentiates angiogenesis in the in vitro VEGF-stimulated cord formation assay. Y2157299 inhibits TGF-β-mediated SMAD2 activation and hematopoietic suppression in primary hematopoietic stem cells in a dose-dependent manner. LY2157199 treatment stimulates hematopoiesis from primary MDS bone marrow specimens. In human glioblastoma (GBM) cells, LY2157299 treatment blocks signaling through the heteromeric TGFβ receptor complex to reduce levels of active, phosphorylated SMAD.

Kinase Assay: LY2157299 (also known as Galunisertib) is a potent, selective ATP-mimetic inhibitor of TGF-β receptor (TβR)-I activation LY2157299 (0.1, 1, 10, and 100 μM) displays a slight dose-dependent potentiation of Sorafenib in SK-Sora, HepG2, and Hep3B cell lines but not in JHH6, SK-HEP1, and HuH7 cell lines.

Cell Assay: Cell survival is determined using the MTT assay. The conversion of yellow water-soluble tetrazolium MTT into purple insoluble formazan is catalyzed by mitochondrial dehydrogenases and used to estimate the number of viable cells. In brief, cells are seeded in 96-well tissue culture plates at a density of 2×103 cells/well. After drug exposure, cells are incubated with 0.4 mg/mL MTT for 4 hours at 37°C. After incubation, the supernatant is discarded, insoluble formazan precipitates are dissolved in 0.1 mL of DMSO, and the absorbance is measured at 560 nm by use of a microplate reader. Wells with untreated cells or with drug-containing medium without cells are used as positive and negative controls respectively. For proliferation assay, MTT assay is done daily to determine the number of viable cells in untreated control and LY2157299 (0.1, 1, 10, and 10 μM)-treated group.