Fig 7.

ITGB1 perturbation potentiates growth inhibition by MEK inhibitor. (A) The effect of β₁ integrin perturbation/MEK inhibition on cell proliferation using ITGB1 siRNA. MDA-MB-231 or SUM159PT cells were treated with 500 nM (MDA-MB-231) or 125 nM (SUM159PT) AZD6244 or DMSO for 96 h, followed by hemocytometer cell counts. (B) Effect of β₁ integrin perturbation/MEK inhibition on SUM159PT cell growth using 2.5 μg/ml (left) or 10 μg/ml (right) β₁ integrin blocking antibody in the presence of 125 nM (left) or 40 nM (right) AZD6244. Growth inhibition was assayed by hemocytometer cell counts or CellTiter-Glo luminescence 72 h after addition of drug-antibody. Error bars represent SEMs of 3 replicates for panels A and B. *, P < 0.05, **, P < 0.01, ***, P < 0.001. (C) DNA content determined by propidium iodide flow cytometry of SUM159PT cells 96 h after ITGB1 siRNA or control siRNA treatment with or without 250 nM AZD6244. (D) Cell cycle stage quantification and percent growth inhibition from flow cytometry data in panel C.