In vitro activity: LY2109761 treatment induces a dose-dependent low-anchorage growth inhibition of L3.6pl/GLT cells, leading to ~33% or 73% inhibition at 2 μM and 20 μM, respectively, which can be strongly enhanced when combined with gemcitabine in combination index value of 0.36581. Blocking TβRI/II kinase activity with LY2109761 (5 μM) completely suppresses both the basal and TGF-β1-stimulated migration and invasion of L3.6pl/GLT cells, significantly enhances the detachment-induced apoptosis by 26% at 8 hours treatment, and completely suppresses TGF-β–induced Smad2 phosphorylation. LY2109761 treatment at 1 nM is sufficient to significantly block the migration and invasion but not adhesion of hepatocellular carcinoma cells by increasing E-cadherin expression. LY2109761 pretreatment enhances radiosensitivity of glioblastoma cells via TGF-β signaling blockage. LY2109761 (10 μM) reduces the self-renewal and proliferation of GBM-derived cancer stem–like cells (CSLC), which can be significantly enhanced when combined with radiation.

Kinase Assay: LY2109761 is an orally active, selective TGF-β receptor type I/II inhibitor with Kis of 38 nM and 300 nM, respectively.

Cell Assay: Cells (Colo357FG/GLT, and Colo357L3.6pl/GLT) are exposed to increasing doses of LY2109761 (~10 μM) for 48 hours. The medium containing drugs is removed, the cells are washed twice with PBS, and fresh medium is added. After 5 days of incubation, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay is used to obtain relative variable cell numbers.