Figure 5

Runx2 inhibits the G1/S phase transition of the cell cycle. A, RT-qPCR analysis of the indicated genes in C4-2B/Rx2^dox cells treated with Dox (filled bars) or vehicle (open bars) for 48 hours. B and C, MTT-based cell proliferation assays of C4-2B/Rx2^dox and C4-2B/Rx2-M^dox cells treated with Dox or vehicle as depicted for the indicated time periods. D, Relative apoptosis based on caspase 3 activity in whole cell extracts prepared from C4-2B/Rx2^dox and C4-2B/Rx2-M^dox cells after treatment with Dox or vehicle for the indicated time periods. E, FACS-based cell cycle analysis of propidium iodide-stained C4-2B/Rx2^dox cells treated with Dox for the indicated time periods. F-I, Schematic description of Dox treatment and its subsequent withdrawal from the cell cultures (F). Samples were harvested at the indicated times (arrows) and subjected to analysis of Runx2 levels by western blotting (G), cell cycle profiling by FACS analysis (H), and cell proliferation by MTT assays (I). Abbreviations: RASD1, RAS, Dexamethasone-induced 1; DUSP, Dual Specificity Phosphatase.