Inhibition of AKT activity in MM cells curtails cell growth and S-phase distribution.

(A) UCLA no. 1 cells were treated with increasing concentrations of wortmannin (shown below protein bands in μM) for 2 hours and Western blot then performed with phosphospecific AKT antibody. Immunoblot for total AKT (not shown) showed no differences in expression of total AKT in all groups. Additional cells treated identically were cultured for 72 hours with the same concentrations of wortmannin and then viable cell recovery was recorded. Mean results of 4 independent experiments were used to determine LD₅₀ as described. (B) UCLA no. 1 MM cells (top panels) and UCLA no. 2 cells (bottom panels) were transiently transfected with control EGFP vector (left panels) or EGFP vector expressing DN AKT (DN-EGFP, right panels). Twenty-four hours after transfection, cells were stained with Hoechst dye and cell cycle analysis performed by gating on EGFP⁺ cells. Percent of cells in S phase or apoptotic (APOP) is shown.