Figure 3.
Expression of ALDH1B1 decreases the cell proliferation rate and clonogenic efficiency in HT29 cells. (a) Growth rates of HT29/mock and HT29/ALDH1B1 cells. Cells were plated at a density of 4 × 105 cells/plate in 10-cm culture plates, and the total number of cells was determined every 24 h over 3 consecutive days. (b) Confluency of HT29/ALDH1B1 cells versus HT29/mock cells at 72 h post-seeding. Cells were seeded at a density of 4 × 103 cells/well in 96-well plates, grown for 72 h and processed for fixation and staining by the sulforhodamine B (SRB) assay. Absorbance was measured at 570 nm, and the cell viability percentage (%) was calculated and normalized relative to the control (HT29/mock) cells. (c) Representative plates of colony formation efficiency of HT29/mock and HT29/ALDH1B1 cells. Cells (1000) were seeded in 10-cm culture plates and observed for colony formation approximately 20 days following their plating. Then, cells were stained with crystal violet. (d) Quantitative assessment of colony formation efficiency. Results are expressed as mean ± SD of three independent experiments. * p < 0.05 and ** p < 0.01.