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Vitamin D binding protein-macrophage activating factor directly inhibits proliferation, migration, and uPAR

Kalvin J Gregory1, Bing Zhao, Diane R Bielenberg

  • 1Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, Kentucky, United States of America.

Plos One
|October 27, 2010
PubMed
Abstract

Insights

Vitamin D binding protein-macrophage activating factor (DBP-maf) directly inhibits prostate tumor cell proliferation and migration. This novel finding reveals DBP-maf

Area of Science:

  • Oncology
  • Molecular Biology
  • Immunology

Background:

  • Vitamin D binding protein-macrophage activating factor (DBP-maf) is known to inhibit tumor growth.
  • Previous understanding attributed DBP-maf's anti-tumor effects to indirect mechanisms, primarily immune system modulation via macrophage activation and anti-angiogenesis.

Purpose of the Study:

  • To investigate the direct effects of DBP-maf on prostate tumor cells.
  • To determine if DBP-maf exhibits anti-proliferative and anti-migratory activity independent of macrophage activation.

Main Methods:

  • Proliferation assays were conducted on LNCaP and PC3 prostate cancer cell lines and their metastatic clones.
  • Flow cytometry using annexin V and propidium iodide was employed to assess apoptosis and cell death.
  • In vitro migration assays and urokinase plasminogen activator receptor (uPAR) expression analysis were performed.

Main Results:

  • DBP-maf demonstrated potent direct inhibitory activity on prostate cancer cell proliferation.
  • The observed inhibition was not mediated by apoptosis or cell death.
  • DBP-maf significantly inhibited prostate cancer cell migration and reduced uPAR expression.

Conclusions:

  • DBP-maf possesses direct anti-prostate tumor cell activity.
  • These effects are independent of macrophage activation, highlighting a novel direct mechanism of action.
  • DBP-maf's ability to inhibit migration and reduce uPAR expression suggests a role in preventing metastasis.

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