The small extracellular matrix
proteoglycan decorin which possesses a potent antitumor activity has been shown to be present in various amounts in the stroma of several
tumors including those of the breast. Regarding
decorin in breast
malignancies the published data are conflicting, i.e., whether
breast cancer cells express it or not. Here, we first compared
decorin gene expression levels between healthy human breast tissue and selected types of human
breast cancer using GeneSapiens databank. Next, we localized
decorin mRNA in tissue specimen of normal human breast, intraductal breast
papillomas and various histologic types of human
breast cancer using in situ hybridization (ISH) with
digoxigenin-labeled
RNA probes for
decorin. We also examined the effect of
decorin transduction on the behavior of cultured human
breast cancer MCF7 cells. Analysis of GeneSapiens databank revealed that in various human breast
cancers decorin expression is significant. However, ISH results clearly demonstrated that human
breast cancer cells independently of the type of the
cancer do not express
decorin mRNA. This was also true for
papilloma-forming cells of the human breast. Indeed,
decorin gene expression in healthy human breast tissue as well as in benign and malignant
tumors of human breast was shown to take place solely in cells of the original stroma.
Decorin transduction using
decorin adenoviral vector in
decorin-negative MCF7 cells resulted in a significant decrease in the proliferation of these cells and changed cell cohesion.
Decorin-transduced MCF7 cells also exhibited increased apoptosis. In conclusion, our study shows that in human breast tissue only cells of the original stroma are capable of
decorin gene expression. Our study also shows that transduction of
decorin in
decorin-negative human
breast cancer cells markedly modulates the growth pattern of these cells.