Drug activity assays

A library of 346 FDA-approved drugs or clinical trial anticancer compounds was screened at a concentration of 100nM (Selleckchem, Houston, Texas, USA). Compounds were diluted and stored in DMSO prior to treatment of 96-well plates. Compounds were delivered in 1 μL drug into 99 μL of media to achieve the indicated final concentrations. Comparisons of drug effect were performed using data generated on the same day. A minimum of two replicates were performed with each gene knockdown-drug pair at each concentration in library screening, and a minimum of three replicates for all other tests. Significance was determined using a 0.05 p-value as calculated using a Student's T-test (two-tailed, unpaired). The GI₅₀ (Growth Inhibition 50%) concentrations were calculated from viability curves using normalized viability data (SigmaPlot).