MMP-2 alters VEGF expression via alphaVbeta3 integrin-mediated PI3K/AKT signaling in A549 lung cancer cells

Int J Cancer. 2010 Sep 1;127(5):1081-95. doi: 10.1002/ijc.25134.

Abstract

Vascular endothelial growth factor (VEGF) is one of the most important angiogenic growth factors for tumor angiogenesis. Here, we sought to explore whether RNA interference (RNAi) targeting matrix metalloproteinase-2 (MMP-2) could disrupt VEGF-mediated angiogenesis in lung cancer. MMP-2 siRNA inhibited lung cancer cell-induced tube formation of endothelial cells in vitro; addition of recombinant human-MMP-2 restored angiogenesis. MMP-2 transcriptional suppression decreased VEGF, phosphatidylinositol 3-kinase (PI3K) protein levels and AKT phosphorylation in lung cancer cells. In addition, MMP-2 suppression decreased hypoxia inducible factor-1alpha (HIF-1alpha), a transcription factor for VEGF, as determined by electrophoretic mobility shift assay (EMSA). We also show that MMP-2 suppression disrupted PI3K dependent VEGF expression; ectopic expression of myr-AKT restored VEGF inhibition. Further, MMP-2 suppression decreased the interaction of integrin-alphaVbeta3 and MMP-2 as confirmed by immunoprecipitation analyses. Studies with either function blocking integrin-alphaVbeta3 antibody or MMP-2 specific inhibitor (ARP-100) indicate that suppression of MMP-2 decreased integrin-alphaVbeta3-mediated induction of PI3K/AKT leading to decreased VEGF expression. Moreover, A549 xenograft tissue sections from mice that treated with MMP-2 siRNA showed reduced expression of VEGF and the angiogenic marker, factor-VIII. The inhibition of tumor angiogenesis in MMP-2 suppressed tumor sections was associated with decreased co-localization of integrin-alphaVbeta3 and MMP-2. In summary, these data provide new insights into the mechanisms underlying MMP-2-mediated VEGF expression in lung tumor angiogenesis.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis
  • Blotting, Western
  • Collagen / metabolism
  • Drug Combinations
  • Electrophoretic Mobility Shift Assay
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunoenzyme Techniques
  • Immunoprecipitation
  • Integrin alphaVbeta3 / metabolism*
  • Laminin / metabolism
  • Luciferases / metabolism
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • Matrix Metalloproteinase 2 / genetics
  • Matrix Metalloproteinase 2 / metabolism*
  • Matrix Metalloproteinase Inhibitors
  • Mice
  • Mice, SCID
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Proteoglycans / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA, Messenger / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism*

Substances

  • Drug Combinations
  • Integrin alphaVbeta3
  • Laminin
  • Matrix Metalloproteinase Inhibitors
  • Proteoglycans
  • RNA, Messenger
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • matrigel
  • Collagen
  • Luciferases
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • MMP2 protein, human
  • Matrix Metalloproteinase 2