Simultaneous blocking of IL-6 and IL-8 is sufficient to fully inhibit CAF-induced human melanoma cell invasiveness

Histochem Cell Biol. 2016 Aug;146(2):205-17. doi: 10.1007/s00418-016-1433-8. Epub 2016 Apr 21.


Tumour microenvironment plays a critical role in cell invasion and metastasis. To investigate the role of cancer-associated fibroblasts (CAFs) in melanoma cell invasiveness, we used 3D spheroid invasion assay. The effect of conditioned media from normal fibroblasts and CAFs cultivated alone or co-cultivated with melanoma cells on BLM or A2058 melanoma spheroid invasion was analysed. We found that conditioned media from CAFs and CAFs co-cultured with melanoma cells, especially, promote invasion and migration, without significant effect on melanoma cell proliferation. We further analysed the expression of pro-invasive cytokines IL-8 and IL-6 in media and found that melanoma cells are dominant producers of IL-8 and fibroblasts are dominant producers of IL-6 in 2D monocultures, while co-cultivation of CAFs with melanoma cells induces production/secretion of IL-6 and IL-8 into the media. The analyses of IL-6 levels in 3D cultures and human melanoma samples, however, revealed that at least in some cases IL-6 is also produced directly by melanoma cells. Analysis of the role of IL-6 and IL-8 in CAF-induced melanoma invasion, using neutralising antibodies, revealed that simultaneous blocking of IL-6 and IL-8 is sufficient to fully inhibit CAF-induced human melanoma cell invasiveness. In summary, these experiments indicate the important role of CAFs and IL-8 and IL-6 cytokines in melanoma cell invasiveness.

Keywords: 3D culture of melanoma cells; Cancer microenvironment; Cancer-associated fibroblasts; Chemokine; Cytokine; Invasiveness.

MeSH terms

  • Cancer-Associated Fibroblasts / drug effects*
  • Cancer-Associated Fibroblasts / pathology
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Coculture Techniques
  • Culture Media, Conditioned / pharmacology*
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Immunohistochemistry
  • Interleukin-6 / analysis
  • Interleukin-6 / antagonists & inhibitors*
  • Interleukin-6 / metabolism
  • Interleukin-8 / analysis
  • Interleukin-8 / antagonists & inhibitors*
  • Interleukin-8 / metabolism
  • Melanoma / drug therapy*
  • Melanoma / metabolism
  • Melanoma / pathology*
  • Neoplasm Invasiveness / prevention & control*


  • Culture Media, Conditioned
  • Interleukin-6
  • Interleukin-8