title: Molecular mechanism of tenascin-C action on matrix metalloproteinase-1 invasive potential.
abstract: The aim of the current study was to confirm that tenascin-C large splice variant (TNC320) stimulates matrix metalloproteinase-1 (MMP-1) expression and to elucidate molecular mechanisms underlying this activation. The analysis of gene expression in cultured cells grown under different conditions indicated significant increases of MMP-1 mRNA steady-state levels in the cells treated with TNC320 (200%) compared with TNC220 (100%) and bovine serum albumin (BSA), which served as controls. Gel electrophoresis results demonstrated augmented MMP-1 protein in cells cultured with TNC320, whereas slight up-regulation was noticed in cells treated with TNC220 or fibronectin. Reverse transcriptase polymerase chain reaction results demonstrated significantly higher levels of MMP-1 gene expression in TNC320 cultured cells than in all other treatment groups. The result was confirmed by examining the level of MMP-1 promoter transactivation by different extracellular proteins. Data demonstrated 30-fold activation of MMP-1 promoter by TNC320 treatment in comparison with other treatments (TNC220 or fibronectin) and BSA as a control. Both invasion and collagenase activity assays demonstrated a 3-fold difference in the cells treated with TNC320 in comparison with the control. MMP-1 was quantified by enzyme-linked immunosorbent assay as well. Experiments with constitutively active expression kinases indicated that MMP-1 expression induced by TNC320 was associated with mitogen-activated protein kinase (MAPK) cascade activation. Culture with TNC320 resulted in more than 2-fold activation of MMP1-luciferase in the presence of mitogen-activated protein kinase kinase kinase 1 and also 2-fold down-regulation in the presence of mitogen-activated protein kinase kinase 1. We hypothesize that tenascin-C stimulates invasion via up-regulation of MMP-1 expression through activation of MAPK cascade signaling.
authors: Department of Orthopedics and Rehabilitation (D-27), University of Miami, PO Box 016960, Miami, FL 33136, USA.
authors: Karine A
authors: KA
authors: Galoian
authors: Nandor
authors: N
authors: Garamszegi
authors: Susanna P
authors: SP
authors: Garamszegi
authors: Sean P
authors: SP
authors: Scully
mesh_terms: D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020781:Matrix Metalloproteinase 1 / Q000096:biosynthesis*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D009361:Neoplasm Invasiveness; D020033:Protein Isoforms / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D019063:Tenascin / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D020033:Protein Isoforms; D019063:Tenascin; D012710:Serum Albumin, Bovine; D020929:Mitogen-Activated Protein Kinase Kinases; D020781:Matrix Metalloproteinase 1