Host pigment epithelium-derived factor (PEDF) prevents progression of liver metastasis in a mouse model of uveal melanoma

Clin Exp Metastasis. 2013 Dec;30(8):969-76. doi: 10.1007/s10585-013-9596-3. Epub 2013 Jun 22.

Abstract

Uveal melanoma (UM) has a 30 % 5-year mortality rate, primarily due to liver metastasis. Both angiogenesis and stromagenesis are important mechanisms for the progression of liver metastasis. Pigment epithelium-derived factor (PEDF), an anti-angiogenic and anti-stromagenic protein, is produced by hepatocytes. Exogenous PEDF suppresses metastasis progression; however, the effects of host-produced PEDF on metastasis progression are unknown. We hypothesize that host PEDF inhibits liver metastasis progression through a mechanism involving angiogenesis and stromagenesis. Mouse melanoma cells were injected into the posterior ocular compartment of PEDF-null mice and control mice. After 1 month, the number, size, and mean vascular density (MVD) of liver metastases were determined. The stromal component of hepatic stellate cells (HSCs) and the type III collagen they produce was evaluated by immunohistochemistry. Host PEDF inhibited the total area of liver metastasis and the frequency of macrometastases (diameter >200 μm) but did not affect the total number of metastases. Mice expressing PEDF exhibited significantly lower MVD and less type III collagen production in metastases. An increase in activated HSCs was seen in the absence of PEDF, but this result was not statistically significant. In conclusion, host PEDF inhibits the progression of hepatic metastases in a mouse model of UM, and loss of PEDF is accompanied by an increase in tumor blood vessel density and type III collagen.

Publication types

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

MeSH terms

  • Animals
  • Disease Models, Animal*
  • Disease Progression
  • Eye Proteins / physiology*
  • Humans
  • Immunoenzyme Techniques
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / prevention & control*
  • Liver Neoplasms / secondary
  • Melanoma / metabolism
  • Melanoma / pathology
  • Melanoma / prevention & control*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Neovascularization, Pathologic / prevention & control*
  • Nerve Growth Factors / physiology*
  • Serpins / physiology*
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / pathology
  • Skin Neoplasms / prevention & control*
  • Stromal Cells / metabolism
  • Stromal Cells / pathology
  • Tumor Cells, Cultured
  • Uveal Neoplasms / metabolism
  • Uveal Neoplasms / pathology
  • Uveal Neoplasms / prevention & control*

Substances

  • Eye Proteins
  • Nerve Growth Factors
  • Serpins
  • pigment epithelium-derived factor

Supplementary concepts

  • Uveal melanoma