Activation of matrix metalloproteinase‐2 in human breast cancer cells overexpressing cyclooxygenase‐1 or ‐2

Abstract

Human breast cancer cell line Hs578T was stably transfected with cDNA for cyclooxygenase‐1 or ‐2. When the cells overexpressing cyclooxygenase‐1 or ‐2 were stimulated with concanavalin A, the processing of matrix metalloproteinase‐2 was observed with the aid of gelatin zymography. This processing was not seen in mock‐transfected and original cells which did not express detectable cyclooxygenase activity. Furthermore, Northern blotting showed 8–13 fold induction of membrane‐type 1 matrix metalloproteinase which processed matrix metalloproteinase‐2 in the cells expressing cyclooxygenases. These findings suggest that both isoforms of cyclooxygenase mediate the processing of matrix metalloproteinase‐2 through induction of membrane‐type 1 metalloproteinase in breast cancer cells.