The cells were seeded in 96-well plates, allowed to recover for 24 h in complete medium, and were then exposed to TG02 for acute 72 h growth inhibition assays (high seeding density) or for assessment of clonogenic survival (low seeding density). Metabolic activity was measured by 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay (Sigma). It was previously confirmed to reflect numbers of colonies or spheres.24 Induction of cell death at 72 h treatment was evaluated by annexin V (AnxV) and propidium iodide (PI) (BD PharMingen and Sigma) flow cytometry. Staurosporine-induced apoptosis was used as a positive control. Fluorescence for each condition was recorded in a BD FACSuite™ (BD Biosciences) flow cytometer and analyzed by BD FACSuite™ software (BD, Allschwil, Switzerland). For cell cycle analysis, the cells were fixed, permeabilized with ice-cold 70% ethanol, washed, RNA was digested with RNase A (Gibco), and DNA was stained with PI (Sigma-Aldrich).