Mesenchymal transition and dissemination of cancer cells is driven by myeloid-derived suppressor cells infiltrating the primary tumor

PLoS Biol. 2011 Sep;9(9):e1001162. doi: 10.1371/journal.pbio.1001162. Epub 2011 Sep 27.


In order to metastasize, cancer cells need to acquire a motile phenotype. Previously, development of this phenotype was thought to rely on the acquisition of selected, random mutations and thus would occur late in cancer progression. However, recent studies show that cancer cells disseminate early, implying the existence of a different, faster route to the metastatic motile phenotype. Using a spontaneous murine model of melanoma, we show that a subset of bone marrow-derived immune cells (myeloid-derived suppressor cells or MDSC) preferentially infiltrates the primary tumor and actively promotes cancer cell dissemination by inducing epithelial-mesenchymal transition (EMT). CXCL5 is the main chemokine attracting MDSC to the primary tumor. In vitro assay using purified MDSC showed that TGF-β, EGF, and HGF signaling pathways are all used by MDSC to induce EMT in cancer cells. These findings explain how cancer cells acquire a motile phenotype so early and provide a mechanistic explanation for the long recognized link between inflammation and cancer progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement
  • Cell Proliferation
  • Chemokines / genetics
  • Chemokines / metabolism
  • Epithelial-Mesenchymal Transition*
  • Gene Expression Profiling
  • Granulocytes / metabolism
  • Granulocytes / pathology
  • Intramolecular Oxidoreductases / metabolism
  • Lung / metabolism
  • Lung / pathology
  • Lymph Nodes / metabolism
  • Lymph Nodes / pathology
  • Melanoma, Experimental / metabolism
  • Melanoma, Experimental / pathology*
  • Mice
  • Mice, Transgenic
  • Microphthalmia-Associated Transcription Factor / metabolism
  • Real-Time Polymerase Chain Reaction
  • Receptors, Interleukin-8B / metabolism
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / secondary*
  • Tumor Cells, Cultured
  • Uveal Neoplasms / metabolism
  • Uveal Neoplasms / pathology*


  • Chemokines
  • Microphthalmia-Associated Transcription Factor
  • Mitf protein, mouse
  • Receptors, Interleukin-8B
  • Intramolecular Oxidoreductases
  • dopachrome isomerase