In vitro activity: KPT-9274 interferes with PAK4 and NAD biosynthetic pathways resulting in reduction of G2/M transit as well as induction of apoptosis and decrease in cell invasion and migration in several human RCC cell lines. The inhibition of the PAK4 pathway by KPT-9274 attenuates nuclear β-catenin as well as the Wnt/β-catenin targets cyclin D1 and c-Myc

Kinase Assay: KPT-9274 is a non-competitive dual inhibitor of PAK4 and NAMP with an IC50 of ~120 nM for NAMPT in a cell-free enzymatic assay.

Cell Assay: cell migration and invasion assays were performed using transwell chambers. For the transwell migration assay, 1.5×104 cells were seeded on top of the polycarbonate filters, and 0.6 ml of growth medium with DMSO or KPT-9274 (1μM and 5μM) was added to both the upper and lower wells. After incubation for 12 hours, the filters were swabbed with a cotton swab, fixed with methanol, and then stained with Giemsa solution. For the in vitro invasion assay, filters were coated with Matrigel, and 2.5×104 cells were seeded onto the Matrigel and incubated for 20 hours. The cells attached to the lower surface of the filter were counted under a light microscope (10× magnification).