Syndecan-1 expression is induced in the stroma of infiltrating breast carcinoma.
Loss of expression of the heparan sulfate proteoglycan syndecan-1 leads to reduced cell adhesion, increased invasive potential, and dysregulated growth of mammary epithelial cells in vitro. We compared syndecan-1 expression in malignant and nonmalignant breast tissues using immunohisto-chemistry with monoclonal antibody B-B4. Staining for syndecan-1 is greatly diminished on malignant cells within infiltrating ductal carcinomas (n = 20) as compared with ductal epithelium of both normal breast (n = 14) and stromal-epithelial neoplasms (n = 10), which exhibit extensive basolateral epithelial staining. Surprisingly, comparison of malignant and nonmalignant breast tissue also reveals a striking difference in expression of syndecan-1 within the stromal compartment. In infiltrating ductal carcinomas, strong staining for syndecan-1 is present both within the connective tissue and on stromal cell surfaces, whereas syndecan-1 expression is absent in the stroma of both normal breast and stromal-epithelial neoplasms. Because syndecan-1 interacts with heparin-binding growth factors such as FGF-2, accumulation of syndecan-1 within the tumor stroma may contribute to the extensive angiogenesis and stromal proliferation characteristic of infiltrating breast carcinoma. Moreover, the induction of syndecan-1 within the stroma, coupled with the loss of syndecan-1 on malignant cells, suggests that changes in syndecan-1 expression are critical in promoting the metastatic phenotype of infiltrating ductal carcinoma of the breast.
Stanley
M J
MJ
Department of Surgery, Hennepin County Medical Center, Minneapolis, MN 55415, USA.
Stanley
M W
MW
Sanderson
R D
RD
Zera
R
R
D001943:Breast Neoplasms / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D018226:Fibroadenoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011509:Proteoglycans / Q000096:biosynthesis*; D017154:Stromal Cells / Q000378:metabolism; D053668:Syndecan-1; D053667:Syndecans
D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D011509:Proteoglycans; C508241:SDC1 protein, human; D053668:Syndecan-1; D053667:Syndecans