Activin A is anti-lymphangiogenic in a melanoma mouse model

J Invest Dermatol. 2015 Jan;135(1):212-221. doi: 10.1038/jid.2014.328. Epub 2014 Aug 1.

Abstract

Melanoma spreads primarily to the sentinel lymph nodes, and its risk correlates with lymphangiogenesis, which is mainly driven by vascular endothelial growth factor (VEGF)-C. However, anti-lymphangiogenic factors are poorly characterized. We have shown in a melanoma model that Wnt1 reduces lymphangiogenesis by reducing VEGF-C expression. Screening this model for additional potentially anti-lymphangiogenic factors identified increased activin A expression and reduced expression of the antagonist, follistatin (FST), in Wnt1(+) cells. Activin A is known to reduce blood vessel formation, but the effects on lymphangiogenesis are unknown. Here we show that human primary melanoma expresses significantly higher levels of activin A and lower levels of FST compared with nevi and melanoma metastasis. Using our mouse model with melanoma cells overexpressing Wnt1, FST, Wnt1/FST, or the inhibin βA subunit (INHBA, resulting in activin A expression), we found both activin A and Wnt1 to reduce lymphangiogenesis. Whereas Wnt1 also reduced metastasis, this was not seen with activin A. In vitro, activin A phosphorylated SMAD2 in both melanoma and lymphatic endothelium but, although it reduced sprouting of lymphatic endothelium, it enhanced the migration of melanoma cells. In conclusion, activin A is an anti-lymphangiogenic factor, but because of its pleiotropic effects on cell mobility it appears not suitable as a pharmacological target.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Movement
  • Disease Models, Animal
  • Female
  • Follistatin / metabolism
  • Humans
  • Inhibin-beta Subunits / metabolism*
  • Lymph Nodes / metabolism
  • Lymph Nodes / pathology
  • Lymphangiogenesis / physiology*
  • Lymphatic Metastasis
  • Lymphatic Vessels / metabolism
  • Lymphatic Vessels / pathology
  • Melanoma / secondary*
  • Mice, SCID
  • Neoplasm Transplantation
  • Skin Neoplasms / pathology*
  • Wnt1 Protein / metabolism

Substances

  • FST protein, human
  • Follistatin
  • WNT1 protein, human
  • Wnt1 Protein
  • inhibin beta A subunit
  • Inhibin-beta Subunits