Figure 5
Metformin inhibits CMC stem cell viabilityin vitro.a) Dose–response of metformin on cell viability, measured by MTT assays, in CMC CSC cultures. A statistically significant reduction in cell viability was observed (**p < 0.01 for 1 mM metformin and ***p < 0.001 for higher concentrations vs. control). Data represent the mean ± s.e.m. b) Cell growth recovery assay in CSCs treated with metformin (10 and 20 mM) for 24-48 h and followed by drug withdrawal and growth in drug-free medium (medium change: MC) for further 24-48 h. Results from MTT assays show cytostatic and cytotoxic effects of 10 mM and 20 mM metformin, respectively (**p < 0.01, ***p < 0.001 vs. corresponding treated cultures). c) Box and whiskers plot of metformin effects on viability of CSC and differentiated (Diff) CMC cultures: boxes extend from the 25th to the 75th percentile, lines indicate the median, whiskers extend to minimum and maximum data points. A significantly higher sensitivity of CSC cultures than corresponding differentiated cells is evident stating from 1 mM metformin for 48 h (*p < 0.05; ***p < 0.001 vs. corresponding differentiated cells).