title: Gamma-irradiation induces matrix metalloproteinase II expression in a p53-dependent manner.
abstract: Matrix metalloproteinases (MMPs) are a family of proteinases that degrade the basement membrane and have been implicated in promoting tumor metastasis. MMP-2, one member of this family, was recently found to be a p53 target and subject to p53 upregulation. In this study, we examined the correlation between the expression of MMP-2 and the increased expression of p53 after gamma-irradiation. Three human p53-positive cell lines that express wild-type p53, including U2-OS (osteosarcoma), RKO (colon carcinoma), MCF-7 (breast carcinoma), one mouse p53 positive cell line and HepG2 (liver carcinoma), and two p53-negative human cell lines, SAOS-2 (osteosarcoma) and RKO-E6 (colon carcinoma), were used in this study. The MMP-2 activity was analyzed by using gelatin zymography. The p53 level was measured by western blot analysis. Our results show that wild-type p53 induced by ionizing radiation caused a subsequent increase of MMP-2 activity in U2-OS and RKO cells but not in MCF-7, HepG2, SAOS-2, or RKO-E6 cells. These results suggest that the gamma-radiation-induced expression of MMP-2 is dependent on the cell type and presence of functional p53. Thus, ionizing radiation could activate MMP-2 activity in a subset of human cancer cells and may lead to an increase in their metastatic potential.
authors.affiliation: Department of Radiation Oncology, Division of Radiation and Cancer Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.forename: S
authors.initials: S
authors.lastname: Wu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D005720:Gamma Rays; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D014407:Tumor Cells, Cultured
chemical_list: D020778:Matrix Metalloproteinase 2