Curcumin mediates polyamine metabolism and sensitizes gastrointestinal cancer cells to antitumor polyamine-targeted therapies
Fig 7
Curcumin cooperates with DFMO to inhibit cell growth.
MTS cell proliferation assays revealed enhanced growth inhibition when combining curcumin with the ODC inhibitor DFMO in AGS (A) and HCT116 (B) cells. (C) In HCT116 cells, curcumin combined with DFMO for 24 hours enhanced ODC enzyme inhibition beyond that of single agents. Untreated and curcumin-treated ODC values (~7500 and 1600 pmol/hr/mg protein, respectively) are presented in Fig 4B. *p < 0.05 relative to DFMO alone; n = 2 individual experiments, each performed in triplicate; error bars = SEM. (D) Changes in individual and total polyamine pools following combination treatment of HCT116 cells for 24 h with 1 mM DFMO and 4 μg/mL curcumin. *p < 0.05 relative to SPD concentration following DFMO or curcumin alone. n = 2 individual experiments, each measured in duplicate; error bars = SEM. In (A), *p < 0.05 for combinations with 4 μg/mL curcumin and 1 or 5 mM DFMO versus the single agents. In (B), *p < 0.005 for the combination of 6 μg/mL curcumin and 1 mM DFMO, versus single agents. Data points indicate the means of at least 3 independent experiments; error bars = SEM.