Inhibiting Cxcr2 disrupts tumor-stromal interactions and improves survival in a mouse model of pancreatic ductal adenocarcinoma

J Clin Invest. 2011 Oct;121(10):4106-17. doi: 10.1172/JCI42754. Epub 2011 Sep 19.

Abstract

Pancreatic ductal adenocarcinoma (PDAC), one of the most lethal neoplasms, is characterized by an expanded stroma with marked fibrosis (desmoplasia). We previously generated pancreas epithelium-specific TGF-β receptor type II (Tgfbr2) knockout mice in the context of Kras activation (mice referred to herein as Kras+Tgfbr2KO mice) and found that they developed aggressive PDAC that recapitulated the histological manifestations of the human disease. The mouse PDAC tissue showed strong expression of connective tissue growth factor (Ctgf), a profibrotic and tumor-promoting factor, especially in the tumor-stromal border area, suggesting an active tumor-stromal interaction. Here we show that the PDAC cells in Kras+Tgfbr2KO mice secreted much higher levels of several Cxc chemokines compared with mouse pancreatic intraepithelial neoplasia cells, which are preinvasive. The Cxc chemokines induced Ctgf expression in the pancreatic stromal fibroblasts, not in the PDAC cells themselves. Subcutaneous grafting studies revealed that the fibroblasts enhanced growth of PDAC cell allografts, which was attenuated by Cxcr2 inhibition. Moreover, treating the Kras+Tgfbr2KO mice with the CXCR2 inhibitor reduced tumor progression. The decreased tumor progression correlated with reduced Ctgf expression and angiogenesis and increased overall survival. Taken together, our data indicate that tumor-stromal interactions via a Cxcr2-dependent chemokine and Ctgf axis can regulate PDAC progression. Further, our results suggest that inhibiting tumor-stromal interactions might be a promising therapeutic strategy for PDAC.

Publication types

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

MeSH terms

  • Animals
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / pathology
  • Carcinoma, Pancreatic Ductal / physiopathology
  • Carcinoma, Pancreatic Ductal / therapy*
  • Chemokines, CXC / physiology
  • Connective Tissue Growth Factor / genetics
  • Connective Tissue Growth Factor / physiology
  • Female
  • Gene Expression
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Nude
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / physiopathology
  • Pancreatic Neoplasms / therapy*
  • Protein-Serine-Threonine Kinases / deficiency
  • Protein-Serine-Threonine Kinases / genetics
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Proto-Oncogene Proteins p21(ras) / physiology
  • Receptor, Transforming Growth Factor-beta Type II
  • Receptors, Interleukin-8B / antagonists & inhibitors*
  • Receptors, Interleukin-8B / physiology
  • Receptors, Transforming Growth Factor beta / deficiency
  • Receptors, Transforming Growth Factor beta / genetics
  • Signal Transduction
  • Stromal Cells / pathology
  • Stromal Cells / physiology
  • Tumor Microenvironment / physiology

Substances

  • CCN2 protein, mouse
  • Chemokines, CXC
  • Receptors, Interleukin-8B
  • Receptors, Transforming Growth Factor beta
  • Connective Tissue Growth Factor
  • Protein-Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type II
  • Hras protein, mouse
  • Proto-Oncogene Proteins p21(ras)