Effect of QSOX1 on cell proliferation and colony formation. (A, B) Cells were plated at 5,000 cells/cm². Cell viability was estimated by counting Trypan blue excluding cells. Data are expressed relative to the living cell number at day 0. Values are expressed as mean ± SD for three experiments. (C, D) For a colony formation assay, 500 cells were plated and 28 days later, cells were fixed and stained with 2% crystal violet. Quantitative changes were evaluated by counting using Vision Capt software. (E, F) Colony assays in soft agar were done to evaluate the effects of QSOX1 on anchorage independent cell proliferation. Cells were embedded in 0.3% agar and the agar cell layers were covered with 1 ml medium containing 5% FCS. After 28 days of growth, the colonies were photographed. Pictures of colonies were superposed with a Malassez cell picture in order to determine colony size. Results indicated number and colony size from four representative fields of each well. * P <0.05, compared to control (Wilcoxon test). These experiments are representative of three separate assays.