A proteolytic activity in a human breast cancer cell line which is inhibited by the anticarcinogenic Bowman-Birk protease inhibitor.
Epidemiological studies suggest that human populations consuming diets rich in protease inhibitors have a reduced incidence of cancer at several sites including the breast. Protease inhibitors, such as the Bowman-Birk inhibitor (BBI) have been shown to be highly effective at suppressing carcinogenesis in a variety of experimental model systems. In this study, we have identified a protease activity in human breast epithelial cells which is inhibited by BBI. This enzyme has a molecular mass of 43 kDa, cleaves gelatin and is primarily localized in the cytosol. Protease activity is maximal at pH 8 and is inhibited by DFP, but unaffected by EDTA, indicating that this enzyme is a serine protease. The protease identified in MCF7 cells has characteristics which are similar to a protease present in human fibroblasts. Hence, our results suggest that BBI targets a common enzyme in human epithelial cells and fibroblasts.
Department of Radiation Oncology, University of Pennsylvania, School of Medicine, Philadelphia 19104.
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Moy
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Billings
D000230:Adenocarcinoma / Q000201:enzymology*; D001943:Breast Neoplasms / Q000201:enzymology*; D002478:Cells, Cultured; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008970:Molecular Weight; D013347:Subcellular Fractions / Q000201:enzymology; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000494:pharmacology*
D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D010450:Endopeptidases