Figure 1

Runx2 suppression increases apoptosis of invasive cells with glucose- and growth factor-deprivation. A) The stable Runx2-RNAi or control MDA-MB-231 cells were deprived of glucose and serum for 24 hours. The morphology of these cells examined in brightfield microscope (10X) is shown. B) The Runx2 knockdown or control MDA-MB-231 cells were deprived of glucose and serum for 24 hours. The cells were then stained for Annexin V and AAD by flow cytometry. A representative cell population is shown. C) The glucose- and serum-deprived cells were examined for cell cycle by propidium iodide (PI) staining in flow cytometry. A histogram of representative cell cycle stages is shown. D) A quantification of average (± standard deviation) sub-G1, G1, S and G2 stages is indicated for PI stained Runx2-RNAi or control cells. E) The Runx2-RNAi or control MDA-MB-231 cells were placed in serum-, glutamine- and glucose-deprived medium or a medium substituted with glutamine and indicated doses of glucose for 24 hours. The fixed and PI-stained cells were then examined for sub-G1 population by flow cytometry. The percentage of sub-G1 cells in control or Runx2 knockdown cells is shown. F) The Runx2 knockdown SUM-159-PT or control cells were deprived of glucose and serum for 24 hours. The cells were then stained for Annexin V and AAD by flow cytometry. A representative cell population is shown. G) The glucose- and serum-deprived SUM-159-PT cells were collected and examined for cell cycle by PI staining in flow cytometry. A histogram of representative cell cycle stages is shown. H) A quantification of average (± standard deviation) sub-G1 stage is indicated for PI stained Runx2-RNAi or control cells. * indicates P-value <0.05 derived from unpaired Student’s t-test.