Metformin inhibits PANC-1 cell proliferation more potently than rapamycin or KU63794.

<p><b><i>A</i></b>, Single-cell suspensions of PANC-1 cells were plated at a density of 10⁵ cells per dish. After 24 h, the cultures were shifted to media containing 0.25% FBS without (−) or with 10 nM neurotensin and 10 ng/ml insulin (NT+Ins) in the absence (open bars) or presence (closed bars) of increasing concentrations of metformin, as indicated. After 4 days, cell numbers were determined from 6 plates per condition. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057289#s3" target="_blank">Results</a> are presented as mean ± SEM. Similar results were obtained in two independent experiments. p values compared to control were all <0.05 n = 6. <b><i>B,</i></b> Single-cell suspensions of PANC-1 cells were plated at a density of 10⁵ cells per dish. After 24 h, the cultures were shifted to media containing 2.5% FBS without (−) or with 1 mM metformin, 5 µM KU63794 (Ku) or 100 nM rapamycin (Rap) as indicated. After 4 days, cell numbers were determined from 6–8 plates per condition. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057289#s3" target="_blank">Results</a> are presented as mean ± SEM. Similar results were obtained in two independent experiments. * All p values compared to control were <0.05 n = 6. Anova analysis showed that metformin inhibition of cell proliferation was statistically significant (