title: MMP-2 alters VEGF expression via alphaVbeta3 integrin-mediated PI3K/AKT signaling in A549 lung cancer cells.
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.
authors.affiliation: Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, IL 61605, USA.
authors.forename: Chandramu
authors.initials: C
authors.lastname: Chetty
authors.forename: Sajani S
authors.initials: SS
authors.lastname: Lakka
authors.forename: Praveen
authors.initials: P
authors.lastname: Bhoopathi
authors.forename: Jasti S
authors.initials: JS
authors.lastname: Rao
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D003094:Collagen / Q000378:metabolism; D004338:Drug Combinations; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D039302:Integrin alphaVbeta3 / Q000378:metabolism*; D007797:Laminin / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D016513:Mice, SCID; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D004338:Drug Combinations; D039302:Integrin alphaVbeta3; D007797:Laminin; D061965:Matrix Metalloproteinase Inhibitors; D011509:Proteoglycans; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C059485:matrigel; D003094:Collagen; D008156:Luciferases; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2