Increased sensitivity of ERG positive tumor cells to AR inhibitors in combination with NOTCH inhibitor. A, B & C (upper panels), Treatment of VCaP cells with NOTCH inhibitor, GSI-1, in combination with either Abiraterone (Abi), Bicalutamide (Bic), or Enzalutamide (Enz) augmented their effects on the inhibition of AR, ERG, PSA, NOTCH1 and NOTCH2 expression and induced cleavage of PARP1 and Caspase 7. A, B & C (lower panels), GSI-1 increases sensitivity of ERG positive CaP cells to AR inhibitors. Concomitant treatment of GSI-1 with Abiraterone, Bicalutamide, or Enzalutamide significantly enhanced the inhibition of cell growth in VCaP cells. Each experiment were performed three times and results are shown as mean ±SD, * p> 0.05, ** p< 0.05.