| In situ zymography using crosslinked carboxymethylated transferrin , a substrate of MMP 7 , demonstrated proteinase activity on and around CD 151 stable transfectants and CaR 1 cells , while the activity was abolished by their treatment with MMP inhibitors , anti MMP 7 antibody or anti CD 151 antibody . ^^^ In human lung adenocarcinoma tissues , colocalization of MMP 7 and CD 151 was demonstrated on the carcinoma cells . ^^^ Metalloproteinase activity was present in these tissues and could be inhibited by antibodies to MMP 7 or CD 151 . ^^^ These data demonstrate for the first time that proMMP 7 is captured and activated on the cell membranes through interaction with CD 151 , and suggest the possibility that similar to the MT 1 MMP / MMP 2 system , MMP 7 is involved in the pericellular activation mechanism mediated by CD 151 , a crucial step in proteolysis on the cell membranes under various pathophysiological conditions including cancer invasion and metastasis . . ^^^ |