title: L-carnosine inhibits metastasis of SK-Hep-1 cells by inhibition of matrix metaoproteinase-9 expression and induction of an antimetastatic gene, nm23-H1.
abstract: Antioxidants have been suggested to inhibit the expression of matrix metalloproteinases (MMPs), especially MMP-9, which plays a critical role in tumor metastasis. Because of its antioxidant activity and the ability to chelate divalent cations, L-carnosine (LC) was tested for inhibition of MMP-9 in a highly invasive hepatocarcinoma, SK-Hep-1 cells. We found that LC (50-1,000 microM) did not directly inhibit the activity of MMP-9 in a cell-free system. However, LC significantly inhibited the expression and activity of MMP-9 protein in SK-Hep-1 cells [inhibitory concentration of 50% (IC(50))| = 105 and 63 muM, respectively). Whereas LC did not inhibit the viability of SK-Hep-1 cells at concentrations up to 1,000 microM within 3 days of incubation, this dipeptide significantly inhibited cell migration (IC(50) = 82 microM) and invasion (IC(50) = 113 microM). LC significantly (P < 0.05) and dose dependently enhanced the expression of an antimetastatic gene, nonmetastatic cells 1, protein (nm23)-H1, at both protein and messenger ribonucleic acid (mRNA) levels. MMP-9 activity inversely correlated significantly with the expression of protein (r(2) = 0.77, P < 0.001) and mRNA (r(2) = 0.65, P < 0.001) of nm23-H1 in LC-treated cells. Thus, LC can inhibit the migration and invasion of SK-Hep-1 cells, and the effect is likely associated with upregulation of nm23-H1 and downregulation of MMP-9 expression.
authors.affiliation: Department of Food and Nutrition, Hungkuang University, Taichung County, Taiwan, Republic of China.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Chuang
authors.forename: Miao-Lin
authors.initials: ML
authors.lastname: Hu
mesh_terms: D006528:Carcinoma, Hepatocellular; D002336:Carnosine / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D054778:NM23 Nucleoside Diphosphate Kinases / Q000235:genetics*; D009361:Neoplasm Invasiveness / Q000517:prevention & control; D009362:Neoplasm Metastasis / Q000235:genetics* / Q000517:prevention & control*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D054778:NM23 Nucleoside Diphosphate Kinases; D012333:RNA, Messenger; D002336:Carnosine; D020780:Matrix Metalloproteinase 9