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 zymography 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 glatinase 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.