ERGi-USU (1147-56-4) selectively inhibits the growth of ERG-positive VCaP prostate cancer cells, COLO320 colon cancer cells, KG-1 and MOLT-4 leukemia cells with minimal effect on ERG-negative cells or normal prostate or endothelial cells (IC50 = 169 nM for cell growth and 315 nM for ERG protein in VCaP cells). It selectively inhibits the kinase RIOK2 (Kd = 200 nM) causing disruption of ribosomal biogenesis and ribosomal stress.
1-(2-Thiazolylazo)-2-naphthol is a high affinity Rio Kinase 2 (RIOK2) inhibitor (Kd = 200 nM). Exhibits >6-fold selectivity for RIOK2 over a panel of 456 kinases. Inhibits ERG protein and potently inhibits growth of ERG-positive VCaP prostate cancer cells in vitro (IC50 = 169 nM) but not ERG-negative cell lines. Also inhibits growth of VCaP xenografts in mice.
1) Mohamed et al. (2018), Identification of a Small Molecule That Selectively Inhibits ERG-Positive Cancer Cell Growth; Cancer Res. 78 3659
