Diclofenac inhibits tumor growth in a murine model of pancreatic cancer by modulation of VEGF levels and arginase activity

PLoS One. 2010 Sep 15;5(9):e12715. doi: 10.1371/journal.pone.0012715.


Background: Diclofenac is one of the oldest anti-inflammatory drugs in use. In addition to its inhibition of cyclooxygenases (COX), diclofenac potently inhibits phospholipase A(2) (PLA(2)), thus yielding a broad anti-inflammatory effect. Since inflammation is an important factor in the development of pancreatic tumors we explored the potential of diclofenac to inhibit tumor growth in mice inoculated with PANCO2 cells orthotopically.

Methodology/principal findings: We found that diclofenac treatment (30 mg/kg/bw for 11 days) of mice inoculated with PANC02 cells, reduced the tumor weight by 60%, correlating with increased apoptosis of tumor cells. Since this effect was not observed in vitro on cultured PANCO2 cells, we theorized that diclofenac beneficial treatment involved other mediators present in vivo. Indeed, diclofenac drastically decreased tumor vascularization by downregulating VEGF in the tumor and in abdominal cavity fluid. Furthermore, diclofenac directly inhibited vascular sprouting ex vivo. Surprisingly, in contrast to other COX-2 inhibitors, diclofenac increased arginase activity/arginase 1 protein content in tumor stroma cells, peritoneal macrophages and white blood cells by 2.4, 4.8 and 2 fold, respectively. We propose that the subsequent arginine depletion and decrease in NO levels, both in serum and peritoneal cavity, adds to tumor growth inhibition by malnourishment and poor vasculature development.

Conclusion/significance: In conclusion, diclofenac shows pronounced antitumoral properties in pancreatic cancer model that can contribute to further treatment development. The ability of diclofenac to induce arginase activity in tumor stroma, peritoneal macrophages and white blood cells provides a tool to study a controversial issue of pro-and antitumoral effects of arginine depletion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / administration & dosage
  • Animals
  • Antineoplastic Agents / administration & dosage*
  • Apoptosis / drug effects
  • Arginase / genetics
  • Arginase / metabolism*
  • Cell Proliferation / drug effects*
  • Diclofenac / administration & dosage*
  • Disease Models, Animal
  • Down-Regulation / drug effects*
  • Female
  • Humans
  • Male
  • Mice
  • Neovascularization, Pathologic
  • Pancreatic Neoplasms / drug therapy*
  • Pancreatic Neoplasms / enzymology
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / physiopathology
  • Rats
  • Rats, Sprague-Dawley
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism*
  • Xenograft Model Antitumor Assays


  • Angiogenesis Inhibitors
  • Antineoplastic Agents
  • Vascular Endothelial Growth Factor A
  • Diclofenac
  • Arginase