skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Proliferative effects of apical, but not basal, matrix metalloproteinase-7 activity in polarized MDCK cells

Journal Article · · Experimental Cell Research
 [1];  [1];  [1];  [1];  [1]
  1. Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States)

Matrix metalloproteinase-7 (MMP-7) is primarily expressed in glandular epithelium. Therefore, its mechanism of action may be influenced by its regulated vectorial release to either the apical and/or basolateral compartments, where it would act on its various substrates. To gain a better understanding of where MMP-7 is released in polarized epithelium, we have analyzed its pattern of secretion in polarized MDCK cells expressing stably transfected human MMP-7 (MDCK-MMP-7), and HCA-7 and Caco2 human colon cancer cell lines. In all cell lines, latent MMP-7 was secreted to both cellular compartments, but was 1.5- to 3-fold more abundant in the basolateral compartment as compared to the apical. However, studies in the MDCK system demonstrated that MMP-7 activity was 2-fold greater in the apical compartment of MDCK-MMP-7{sup HIGH}-polarized monolayers, which suggests the apical co-release of an MMP-7 activator. In functional assays, MMP-7 over-expression increased cell saturation density as a result of increased cell proliferation with no effect on apoptosis. Apical MMP-7 activity was shown to be responsible for the proliferative effect, which occurred, as demonstrated by media transfer experiments, through cleavage of an apical substrate and not through the generation of a soluble factor. Taken together, our findings demonstrate the importance of MMP-7 secretion in relation to its mechanism of action when expressed in a polarized epithelium.

OSTI ID:
20717536
Journal Information:
Experimental Cell Research, Vol. 303, Issue 2; Other Information: DOI: 10.1016/j.yexcr.2004.09.020; PII: S0014-4827(04)00574-9; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0014-4827
Country of Publication:
United States
Language:
English