MATRIX METALLOPROTEINASE EXPRESSION IN HUMAN BREAST-CANCER - AN IMMUNOHISTOCHEMICAL STUDY INCLUDING CORRELATION WITH CATHEPSIN-D, TYPE-IV COLLAGEN, LAMININ, FIBRONECTIN, EGFR, C-ERBB-2 ONCOPROTEIN, P53, STEROID-RECEPTORS STATUS AND PROLIFERATIVE INDEXES

Matrix metalloproteinases (MMPs) are a group of enzymes thought to be responsible for both normal connective tissue matrix remodelling and a ccelerated breakdown associated..with tumour development. The current study aimed to investigate the immunohistochemical expression of matri x metalloproteinase 3 (MMP-3,stromelysin-1) in correlation with the ex pression of Basement Membrane (BM) antigen (type IV collagen, laminin) , fibronectin, cathepsin D, p53, c-erbB-2 proliferative activity (Ki-6 7, PCNA), steroid receptor content as well as to the other conventiona l clinicopathological parameters in breast cancer. This study was perf ormed on a series of frozen and paraffin sections from 84 breast cance r specimens by immunohistochemistry using the monoclonal antibody MMP- 3 (Ab-1). Stromelysin-1 (ST1) was observed in about 10% of epithelial cells in the cona ol groups (cases of fibrocystic and benign prolifera tive breast disease), while expression (>10% of expression) was detect ed in 89. 7% of tumours. The expression of ST1 in carcinoma cells was strongly associated with its presence in the stroma (p<0.001). A signi ficantly positive correlation was found between ST1 expression, and p5 3 tumour suppressor gene product (p=0.004), and a relationship with c- erbB-2 protein and progesterone receptor status was also indicated The se findings suggest that ST1 expression in breast cancer tissue is irr espective of the expression of the extracellular matrix component, the proteolytic enzyme cathepsin D and the growth fraction of the turnout ; and that it could be a potential new prognostic marker in breast can cer.