Expression of Different Proteoglycans in Human Breast Tumor Tissue
Composition of proteoglycans and its change during malignant transformation is an important factor that influences adhesive properties and mitotic activity of tumor cells. In this study, expression level of different proteoglycans (decorin, syndecan-1, lumican, glypican-1, and aggrecan) in tumors and normal human breast tissue were investigated. Multiplex RT-PCR data revealed different expression changes for different proteoglycans in human breast tumors -syndecan expression was activated compared to almost no expression in normal breast tissue, expression of decorin and lumican decreased 2-5 fold and 2-3 fold, respectively, and aggrecan transcription seems to be unaffected. A change in expression level of decorin correlated with expression of D-glycuronyl C5-epimerase, a key enzyme responsible for the biosynthesis of IdoUA-containing glycosaminoglycans, possessing antimitotic activity. The results suggest that changes in decorin, lumican, and syndecan-1 expession in tumor tissue could induce a distortion of proteoglycan composition and mitotic activity of cells in the human breast tumor.