Diphenyl difluoroketone: a curcumin derivative with potent in vivo anticancer activity

Cancer Res. 2008 Mar 15;68(6):1962-9. doi: 10.1158/0008-5472.CAN-07-6011.


Diphenyl difluoroketone (EF24), a molecule having structural similarity to curcumin, was reported to inhibit proliferation of a variety of cancer cells in vitro. However, the efficacy and in vivo mechanism of action of EF24 in gastrointestinal cancer cells have not been investigated. Here, we assessed the in vivo therapeutic effects of EF24 on colon cancer cells. Using hexosaminidase assay, we determined that EF24 inhibits proliferation of HCT-116 and HT-29 colon and AGS gastric adenocarcinoma cells but not of mouse embryo fibroblasts. Furthermore, the cancer cells showed increased levels of activated caspase-3 and increased Bax to Bcl-2 and Bax to Bcl-xL ratios, suggesting that the cells were undergoing apoptosis. At the same time, cell cycle analysis showed that there was an increased number of cells in the G(2)-M phase. To determine the effects of EF24 in vivo, HCT-116 colon cancer xenografts were established in nude mice and EF24 was given i.p. EF24 significantly suppressed the growth of colon cancer tumor xenografts. Immunostaining for CD31 showed that there was a lower number of microvessels in the EF24-treated animals coupled with decreased cyclooxygenase-2, interleukin-8, and vascular endothelial growth factor mRNA and protein expression. Western blot analyses also showed decreased AKT and extracellular signal-regulated kinase activation in the tumors. Taken together, these data suggest that the novel curcumin-related compound EF24 is a potent antitumor agent that induces caspase-mediated apoptosis during mitosis and has significant therapeutic potential for gastrointestinal cancers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / drug therapy*
  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology
  • Animals
  • Apoptosis / drug effects
  • Benzylidene Compounds / pharmacology*
  • Cell Cycle / drug effects
  • Cell Growth Processes / drug effects
  • Cell Line, Tumor
  • Colonic Neoplasms / drug therapy*
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology
  • Cyclooxygenase 2 / biosynthesis
  • Cyclooxygenase 2 / genetics
  • HCT116 Cells
  • HT29 Cells
  • Humans
  • Interleukin-8 / biosynthesis
  • Interleukin-8 / genetics
  • MAP Kinase Signaling System / drug effects
  • Male
  • Mice
  • Mice, Nude
  • Neovascularization, Pathologic / drug therapy
  • Neovascularization, Pathologic / pathology
  • Piperidones / pharmacology*
  • Stomach Neoplasms / drug therapy*
  • Stomach Neoplasms / genetics
  • Stomach Neoplasms / metabolism
  • Stomach Neoplasms / pathology
  • Vascular Endothelial Growth Factor A / biosynthesis
  • Vascular Endothelial Growth Factor A / genetics
  • Xenograft Model Antitumor Assays


  • 3,5-bis(2-fluorobenzylidene)piperidin-4-one
  • Benzylidene Compounds
  • Interleukin-8
  • Piperidones
  • Vascular Endothelial Growth Factor A
  • Cyclooxygenase 2