Characterization of Matrix‐degrading Proteinases and Their Inhibitors Secreted by Human Gynecological Carcinoma Cells

Abstract

Matrix‐degrading proteinases secreted by tumor cells play crucial roles in tumor cell invasion and metastasis. Serum‐free conditioned media of 7 human gynecological carcinoma cell lines were examined for proteinases and their inhibitors by using gelatin zymography, reverse zymograpby and immunoblotting. All of three ovarian adenocarcinoma cell lines secreted urokinase‐type plasminogen activator. Among them, a mucinous cystadenocarcinoma cell line also secreted tissue‐type plasminogen activator, plasmin‐like enzyme and trypsinogen. On the other hand, two ovarian undifferentiated carcinoma cell lines mainly secreted gelatinase A or B. A choriocarcinoma cell line secreted multiple metalloproteinases in the highest amount, whereas an endometrial adenocarcinoma cell line (HEC‐1) derived from an early clinical stage hardly secreted any gelatinolytic enzyme. The five high proteinases producers hardly secreted the corresponding inhibitors, such as tissue inhibitor of metalloproteinases (TIMP)‐1,‐2 or plasminogen activator inhibitor‐1. In contrast to these highly malignant cell lines, a poor proteinase producer, HEC‐1, secreted a large amount of TIMPs. Therefore, an enhanced proteolytic tendency appears to be associated with gynecological cancer cells established from highly malignant tumors.