Targeting COX-2 and EP4 to control tumor growth, angiogenesis, lymphangiogenesis and metastasis to the lungs and lymph nodes in a breast cancer model

Lab Invest. 2012 Aug;92(8):1115-28. doi: 10.1038/labinvest.2012.90. Epub 2012 May 28.


We reported that cyclo-oxygenase (COX)-2 expression in human breast cancer stimulated cancer cell migration and invasiveness, production of vascular endothelial growth factor (VEGF)-C and lymphangiogenesis in situ, largely from endogenous PGE2-mediated stimulation of prostaglandin E (EP)1 and EP4 receptors, presenting them as candidate therapeutic targets against lymphatic metastasis. As human breast cancer xenografts in immuno-compromised mice have limitations for preclinical testing, we developed a syngeneic murine breast cancer model of spontaneous lymphatic metastasis mimicking human and applied it for mechanistic and therapeutic studies. We tested the roles of COX-2 and EP receptors in VEGF-C and -D production by a highly metastatic COX-2 expressing murine breast cancer cell line C3L5. These cells expressed all EP receptors and produced VEGF-C and -D, both inhibited with COX-2 inhibitors or EP4 (but not EP1, EP2 or EP3) antagonists. C3H/HeJ mice, when implanted SC in both inguinal regions with C3L5 cells suspended in growth factor-reduced Matrigel, exhibited rapid tumor growth, tumor-associated angiogenesis and lymphangiogenesis (respectively measured with CD31 and LYVE-1 immunostaining), metastasis to the inguinal and axillary lymph nodes and the lungs. Chronic oral administration of COX-1/COX-2 inhibitor indomethacin, COX-2 inhibitor celecoxib and an EP4 antagonist ONO-AE3-208, but not an EP1 antagonist ONO-8713 at nontoxic doses markedly reduced tumor growth, lymphangiogenesis, angiogenesis, and metastasis to lymph nodes and lungs. Residual tumors in responding mice revealed reduced VEGF-C and -D proteins, AkT phosphorylation and increased apoptotic/proliferative cell ratios consistent with blockade of EP4 signaling. We suggest that EP4 antagonists deserve clinical testing for chemo-intervention of lymphatic metastasis in human breast cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cyclooxygenase 2 / metabolism*
  • Cyclooxygenase 2 Inhibitors / pharmacology*
  • Female
  • Lung Neoplasms / secondary*
  • Lymphangiogenesis / drug effects
  • Mammary Neoplasms, Experimental / blood supply
  • Mammary Neoplasms, Experimental / drug therapy*
  • Mammary Neoplasms, Experimental / metabolism
  • Mammary Neoplasms, Experimental / pathology*
  • Mice
  • Mice, Inbred C3H
  • Molecular Targeted Therapy
  • Neoplasm Metastasis
  • Neovascularization, Pathologic / drug therapy
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptors, Prostaglandin E, EP4 Subtype / antagonists & inhibitors*
  • Vascular Endothelial Growth Factor C / metabolism
  • Vascular Endothelial Growth Factor D / metabolism


  • Cyclooxygenase 2 Inhibitors
  • Ptger4 protein, mouse
  • Receptors, Prostaglandin E, EP4 Subtype
  • Vascular Endothelial Growth Factor C
  • Vascular Endothelial Growth Factor D
  • vascular endothelial growth factor C, mouse
  • Ptgs2 protein, mouse
  • Cyclooxygenase 2
  • Proto-Oncogene Proteins c-akt