P70S6K Enzyme Assay: P70S6K inhibitor compounds are diluted and plated in 96 well plates. A reaction mixture including the following components is then added to the compound plate to initiate the enzyme reaction; P70S6K (3 nM, T412E mutant, Millipore) is mixed with 24 uM ATP in an assay buffer containing 100 mM Hepes (pH 7.5), 5 mM MgCl2, 1 mM DTT, 0.015% Brij and 1 uM of the substrate peptide FITC-AHA-AKRRRLSSLRA-OH (derived from the S6 ribosomal protein sequence, FITC=fluorescein isothiocyanate, AHA=6-aminohexanoic acid). The reaction is incubated for 90 min at 25.degree. C., before the addition of 10 mM EDTA to stop the reaction. The proportion of substrate and product (phosphorylated) peptide is analysed on a Caliper Life Sciences Lab Chip 3000, using a pressure of -1.4 psi, and upstream and downstream voltages of -3000 and -700 respectively. Product peaks are resolved before substrate peaks on the resulting chromatograms.
AKT Enzyme Assay: A TTP Mosquito liquid handling instrument is used to place 125 nl of the appropriate concentration of inhibitor in 100% DMSO (for a dose response curve calculation) into each well of a 384-well plate. To this reaction components are added to a final volume of 12.5 .mu.l: 0.1 ng/.mu.l His-AKT (Full Length), (Invitrogen, Part # P2999, Lot #641228C). 160 uM ATP (Fluka, 02055) 1 mM DTT (Sigma, D0632) 1 mM MgCl2 (Sigma, M1028) 1 .mu.M substrate peptide (sequence FITC-AHA-GRPRTSSFAEG-NH2), synthesized by Tufts Peptide Synthesis service. 100 mM HEPES pH 7.5 (Calbiochem, 391338)0.015% Brij-35 (Sigma, B4184)The reaction is incubated for 90 min at 25 C, and then stopped by the addition of 70 .mu.l of Stop buffer (100 mM HEPES pH 7.5, 0.015% Brij-35, 10 mM EDTA (Sigma, E7889)).The plate is read on a Caliper LC 3000 in an Off-Chip mobility shift assay format, using the following parameters for a 12-sipper chip: screening pressure -2.3 psi, upstream voltage -500, and downstream voltage -3000.