Curcumin mediates polyamine metabolism and sensitizes gastrointestinal cancer cells to antitumor polyamine-targeted therapies
Fig 4
Effects of curcumin on polyamine metabolism in HCT116 colon cancer cells.
RNA was collected from HCT116 cells treated with curcumin for 24 hours and used for qRT-PCR of genes encoding (A) the biosynthetic enzymes ODC and SAMDC (AMD1), or (C) the catabolic enzymes SMOX and SSAT (n = 3 biological experiments, each measured in triplicate). Total cell lysates were also collected and used for ODC enzyme activity assays (B; n = 2 independent experiments, each measured in triplicate) and Western blots of the catabolic enzymes (D). In (E), cells were treated for 48 hours with curcumin for either cellular proliferation assays or analysis of intracellular polyamine concentrations by HPLC (n ≥ 2, each measured in duplicate). All columns represent the means with error bars indicating SEM. *p < 0.05 relative to untreated.