title: Activation of matrix metalloproteinase-2 and -9 by 2- and 4-hydroxyestradiol.
abstract: Breast cancer patients frequently develop metastases. This process requires the degradation of extracellular matrix proteins which act as a barrier to tumour cell passage. These proteins can be degraded by proteases, mainly the matrix metalloproteinases (MMPs). MMP-2 and -9 which are frequently detected in breast cancer tissues. ProMMPs are released from cancer cells, and their activation is considered to be a crucial step in metastases development. In breast cancer, estrogen metabolism is altered favouring the accumulation of 2- and 4-hydroxyestradiol (2- and 4-OHE(2)). These estradiol metabolites can generate free radicals. Since reactive species are known activators of proMMPs, this study was designed to determine if the free radicals generated by 2- and 4-OHE(2) can activate proMMP-2 and -9. Activation of MMPs by hydroxyestradiol was determined by monitoring the cleavage of a fluorogenic peptide and by zymography analysis. Both estradiol metabolites activated the MMP-2 and -9. 4-OHE(2) was a more potent activator than 2-OHE(2), which reflects its higher capacity to generate free radicals. ProMMPs activation was mainly mediated through O(2)*-, although the free radical HO* also activated the proMMPs but to a lesser extent. ProMMPs activation was not observed with estrogens that cannot generate free radicals, i.e. estradiol, estrone, 2- and 4-methoxyestradiol, and 16alpha-hydroxyestrone. These results demonstrate that 2- and 4-OHE(2) at a concentration as low as 10(-8)M can activate the proMMP-2 and -9 and might play an important role in the invasion of breast cancer cells.
authors: Department of Nuclear Medicine and Radiobiology, Faculty of Medicine, Université de Sherbrooke, 12th Avenue North 3001, Sherbrooke, Que., Canada J1H 5N4. benoit.paquette@usherbrooke.ca
authors: Benoit
authors: B
authors: Paquette
authors: Martine
authors: M
authors: Bisson
authors: Hélène
authors: H
authors: Therriault
authors: Rosalie
authors: R
authors: Lemay
authors: Mélanie
authors: M
authors: Paré
authors: Pascale
authors: P
authors: Banville
authors: André M
authors: AM
authors: Cantin
mesh_terms: D003300:Copper / Q000737:chemistry / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004792:Enzyme Precursors / Q000378:metabolism; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology*; D004967:Estrogens / Q000378:metabolism / Q000494:pharmacology; D002393:Estrogens, Catechol; D005456:Fluorescent Dyes / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D008353:Mannitol / Q000494:pharmacology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D010662:Phenylmercuric Acetate / Q000031:analogs & derivatives* / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D004967:Estrogens; D002393:Estrogens, Catechol; D005456:Fluorescent Dyes; D005609:Free Radicals; D010455:Peptides; D008353:Mannitol; D004958:Estradiol; C010024:4-aminophenylmercuriacetate; D003300:Copper; C001390:2-hydroxyestradiol; C014036:4-hydroxyestradiol; D013482:Superoxide Dismutase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D010662:Phenylmercuric Acetate