Suppression of VEGF-mediated autocrine and paracrine interactions between prostate cancer cells and vascular endothelial cells by soy isoflavones

J Nutr Biochem. 2007 Jun;18(6):408-17. doi: 10.1016/j.jnutbio.2006.08.006. Epub 2006 Dec 4.

Abstract

Angiogenesis is an essential process involved in the development and progression of prostate cancer. Vascular endothelial growth factor (VEGF) is hypothesized to be a critical regulator of angiogenesis during prostate carcinogenesis. We have reported that dietary soy products inhibit prostate tumor progression in animal models, in association with a reduction in tumor microvessel density. The goal of the present study is to investigate potential antiangiogenic mechanisms of genistein, the major soy isoflavone, using in vitro systems. Genistein (5-50 muM) significantly inhibited the growth of human umbilical vein endothelial cells (HUVECs) in control media when stimulated by supplemental VEGF or when cultured in hypoxia-exposed PC-3 prostate adenocarcinoma cell conditioned media. These in vitro studies suggest detectable inhibitory effects by 5-10 muM genistein (P<.05) with an IC(50) of approximately 20 muM or less. Genistein (10-50 muM) caused significant inhibition of basal VEGF expression and hypoxia-stimulated VEGF expression in both human prostate cancer PC-3 cells and HUVECs based on semiquantitative reverse transcription-polymerase chain reaction (P<.05). In parallel, VEGF secretion by PC-3 cells quantitated by enzyme-linked immunosorbent assay was significantly (P<.05) reduced by genistein (10-50 muM). Furthermore, genistein (10-50 muM) significantly (P<.05) reduced PC-3 nuclear accumulation of hypoxia-inducible factor-1alpha, the principle transcription factor that regulates VEGF expression in response to hypoxia. Expression of the VEGF receptor fms-like tyrosine kinase-1, but not kinase insert domain-containing kinase, in HUVECs was also reduced (P<.05) by genistein (10-50 muM). These observations support the hypothesis that genistein may inhibit prostate tumor angiogenesis through the suppression of VEGF-mediated autocrine and paracrine signaling pathways between tumor cells and vascular endothelial cells.

Publication types

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

MeSH terms

  • Cell Division / drug effects
  • Cell Line, Tumor
  • DNA Primers
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / physiology*
  • Genistein / pharmacology*
  • Humans
  • Isoflavones / pharmacology*
  • Male
  • Neovascularization, Pathologic / prevention & control
  • Neovascularization, Physiologic / drug effects*
  • Prostatic Neoplasms
  • Receptors, Vascular Endothelial Growth Factor / genetics
  • Recombinant Proteins / pharmacology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Soy Foods
  • Vascular Endothelial Growth Factor A / antagonists & inhibitors*
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / physiology*
  • Vascular Endothelial Growth Factor Receptor-1 / genetics*
  • Vascular Endothelial Growth Factor Receptor-2 / genetics*

Substances

  • DNA Primers
  • Isoflavones
  • Recombinant Proteins
  • Vascular Endothelial Growth Factor A
  • Genistein
  • Receptors, Vascular Endothelial Growth Factor
  • Vascular Endothelial Growth Factor Receptor-1
  • Vascular Endothelial Growth Factor Receptor-2