NVP-LDE225 induces apoptosis and cell cycle modification in sensitive MM cell lines. (A) OPM1 cells were treated with 5μM and 10μM of compound for 24 hours, stained with annexin V–FITC and PI, and analyzed by a FACSCanto II flow cytometer. Percentages of early apoptotic (annexin V–FITC⁺/PI⁻) and late apoptotic/necrotic (annexin V–FITC⁺/PI⁺) cells are presented. (B-C) OPM1 cells were treated with 5μM and 10μM of compound for 24 hours, and the distribution of cells in G₀/G₁, S and G₂/M phase was analyzed by flow cytometry and MultiCycle AV DNA analysis. Percentage of sub-G₁ fraction was obtained from analysis of side scatter versus log FL3 dot plot using De Novo FCS Express Version 3 software. Data are from 3 independent experiments and presented as mean ± SD. *P < .05, control versus the different treatment. (D) Immunoblot experiment of protein lysate from OPM1 cells treated with NVP-LDE225 (5μM) for 12, 24, and 36 hours and fractionated by electrophoresis and stained with different Abs as shown in figure (left). Cells were treated with different concentrations of NVP-LDE225 for 12 hours and cell lysate fractionated by electrophoresis and stained with anticaspase-3 Ab (right).