OSU-03012(AR-12) is a potent inhibitor of recombinant PDK-1 with IC50 of 5 μM and 2-fold increase in potency over OSU-02067.

OSU-03012 induces apoptotic death in PC-3 cells with IC50 of 5 μM and reduces the activity of immunoprecipitated p70S6K. OSU-03012 completely suppress cell growth in a diverse range of tumor cell lines at concentrations of 3–5 μm, as compared with the concentration of at least 50 μm required for celecoxib. OSU-03012 promotes cell killing to a greater extent in glioma cells than in nontransformed astrocytes. OSU-03012 causes a dose-dependent induction of cell death that is not altered by p53 mutation, expression of ERBB1 VIII, or loss of phosphatase and tensin function due to a homolog deletion on chromosome 10. OSU-03012 and ionizing radiation cause an additive, caspase-independent elevation in cell killing. OSU-03012 lethality as a single agent or when combined with signaling modulators is not modified in cells lacking expression of BIM or of BAX/BAK. OSU-03012 promotes the release of cathepsin B from the lysosomal compartment and that of AIF from mitochondria. The lethality of OSU-03012 is attenuated in protein kinase R-like endoplasmic reticulum kinase-/- cells, which correlated with the reduced cleavage of BID and suppression of cathepsin B and AIF release into the cytosol. OSU-03012 inhibits cell growth of hepatocellular carcinoma cell lines including Huh7, Hep3B and HepG2 cells with IC50 values below 1 μM. OSU-03012 does not suppress PDK1 or AKT activity or induce cellular apoptosis but induces autophagy in Huh7 cells. Moreover, accumulation of reactive oxygen species (ROS) is detected after OSU-03012 treatment.