OCI-AML3 cells were infected with lentiviral Mcl-1 shRNA or scrambled shRNA as described in the Materials and Methods.
(A) Cells were cultured in the presence of escalating doses of GDC-0941 and ABT-737 using fixed ratios. After 48 hours, the effects on cell growth were evaluated by viable cell counts using the trypan blue exclusion method. Graphs show the mean ± SEM of results of three independent experiments. (B) Combination index (CI) plots were generated using CalcuSyn software. (C) The viable cells number was measured by trypan blue exclusion assay. (D,E) Annexin V–positive fractions (D) and DNA content (E) were measured by flow cytometry. Graphs show the means ± SEM of results of three independent experiments. *p<0.05, ** p<0.01.
(F) Expression of various proteins in OCI-AML cells transfected Mcl-1 shRNA or scrambled control shRNA that had been treated for 24 hours with 0.5μM GDC-0941 and/or 0.25μM ABT-737 under normoxic or hypoxic conditions. α–tubulin was used to confirm equal loading of proteins. Results are representative of three independent experiments. Intensity of the immunoblot signals after background subtraction was quantified using ImageJ software, and the relative intensity compared to that of α–tubulin was calculated.