Partners in crime: VEGF and IL-4 conscript tumour-promoting macrophages

J Pathol. 2012 May;227(1):4-7. doi: 10.1002/path.4008. Epub 2012 Mar 22.


Tumour-associated macrophages (TAMs) foster tumour progression by several mechanisms, including the promotion of angiogenesis, tissue remodelling, and immunosuppression. Such pro-tumoural activities are thought to be executed by TAM subtypes that harbour features of alternatively activated (or M2-polarized) macrophages. However, the molecular signals in tumours that induce recruitment and differentiation of M2-like macrophages are not fully defined. In this issue of The Journal of Pathology, Linde et al investigate the role of the tumour-derived cytokines, VEGF and IL-4, in the recruitment and polarization of macrophages in a mouse model of skin cancer. The authors report that while VEGF-A recruits monocytes from the peripheral circulation, IL-4 induces their differentiation into tumour-promoting, M2-like macrophages. IL-4 signalling blockade was sufficient to reprogram TAMs away from the M2-like phenotype and inhibited tumour angiogenesis and growth. This study attests to the potential of reprogramming TAMs to abate their pro-angiogenic and pro-tumoural functions in tumours.

Publication types

  • Comment

MeSH terms

  • Animals
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Macrophages / pathology*
  • Skin Neoplasms / genetics*
  • Vascular Endothelial Growth Factor A / genetics*


  • Vascular Endothelial Growth Factor A
  • vascular endothelial growth factor A, mouse