Fig. 1

Metformin inhibited the proliferation, cell cycling and viability of bladder cancer cells. a Inhibition of cell proliferation: J82 and T24 cells were seeded 5 × 10³ per well in 96-well plates for 24 h. Then cells were treated with metformin (0, 10, 20, 40, or 60 mM) for 24 or 48 h. Cell numbers and viability was evaluated by CCK8. b Cell cycle arrested at G ₀ /G ₁ phases: J82 and T24 cells were treated with 20 mM metformin for 24 or 48 h and cell cycle were analyzed by flow cytometry. c Promotion of apoptotic cell death: J82 and T24 cells were treated with 20 and 40 mM metformin for 24 or 48 h, stained with PI and FITC-labelled Annexin V and determined by flow cytometry for the frequency of apoptotic cells. Top panel: representative histograms of cell cycling; bottom panel: summary of apoptotic cells (%) from three reproducible experiments. **, P < 0.01 when compared to control group (0 mM) in all the experiments