Fig. 4

Metformin inhibited G1 cell cycle regulators and induces G1 cell cycle arrest in both RSCL and RRCL. a RSCL and RRCL were exposed to DMSO or metformin (16 mM) for 48 h, and then cell cycle distribution changes was determined by flow cytometry. Cumulative results of G1/S/G2-M phases are shown as mean ± standard error of the mean (SEM) (n = 3). Column, results are mean + SD of 3 independent experiments. Asterisk means P < 0.05. b Effect of metformin on cell cycle proteins. Western blot of G1 cell cycle regulatory proteins levels in metformin-induced RSCL and RRCL. c, d Effects of metformin on transcriptional levels of C-Myc and PCNA. Cells were treated with metformin 16 mM for 24 h. C-Myc and PCNA mRNA levels were analyzed by real-time qPCR