Enhanced prolidase activity and decreased collagen content in breast cancer tissue

Summary Adherent interactions between integrins and extracellular matrix (ECM) proteinsplay an important role in tumorigenicity and invasiveness. The major component ofECM is collagen that plays a central role in the interaction with integrins. Theexpression of certain collagenases (gelatinases) by tumour cells is one of the charac-teristic features of the so-called metastatic phenotype, presumably by breaking downECM barriers as well by altering the ECM–cell interaction. Although extracellularcollagenases initiate the breakdown of collagen, the final step of collagen degrada-tion is catalysed by intracellular prolidase. Collagen deposition, gelatinolytic andprolidase activities, expression of b 1 -integrin receptor and their possible relationshipswere studied in seven operable breast cancer cases. In breast cancer tissue, we havefound significant decrease in the amount of collagen. The decrease in collagen depo-sition in breast cancer tissue was accompanied by increase in the tissue gelatinolyticand prolidase activities. Simultaneously, a slight decrease in the expression ofb