Decitabine Handling and Concentration Selection

DAC was obtained from Pfizer Comp. (Illertissen, Germany). A fresh 10 mM stock solution of DAC was dissolved in phosphate-buffered saline (PBS), respectively, for each experiment. Working solutions were prepared by serial dilution and used to expose the cells to final concentrations of 0.25 to 32 µM. After determining the cytotoxic effect of DAC, we assessed in all CRC cell lines the range of DAC concentrations that were tolerated with no to minimal cytotoxic effects. These concentrations were administered daily for different periods to modulate the gene expression of the endothelin system.