Inhibition of cysteine endopeptidases activities in vitro of stomach carcinoma tissues.

Yousif Saleh1, Wojciech Kielan2, Maciej Siewinski3

1 Department of Pathology, Medical University of Wroclaw, 1 Marcinkowskiego St.,PL- 50-368 Wroclaw, tel. 4871-3209974, fax: 4871-3281029, E-mail: 2 Clinics of Surgery and Oncology, 66 Curie - Sklodowskiej , 50-368 Wroclaw, Poland 3 Department of Obstetrics an Gynaecology, Medical University of Wroclaw, Chalubinskiego 3; PL-50-368 Wroclaw, tel. 4871-3209741

Background. Degradation of the basement membrane and surrounding intracellular matrix likely represents a key step in cancer invasion and metastasis. The purpose of this study was to compare the cytosolic content of cysteine endopeptidases in malignant and normal stomach tissues. Further we try to inhibit cysteine endopeptidases by egg white cystatin and antibacterial. Methods. Findings in 30 patients who under study we have assayed cysteine endopeptidases malignant and normal tissues by fluorogenic assay. Inhibition determined by added egg cystatin to homogenates of cancer tissue, and checked the activities after treatment. Also we tested antibacterial activity by egg cystatin on plate agar. Results. Activities of cysteine endopeptidases in cancerous and noncancerous mucosal tissues from 30 patients with stomach cancer were determined with small amount of tissue homogenate. The activities of cysteine endopeptidases were significantly higher in cancerous tissues than in noncancerous tissues. Non significant observed in activities of cysteine endopeptidases after treatment the homogenates of cancerous tissues with egg white cystatin than normal tissues. Also we tested antibacterial of egg white cystatin against different bacterial species, egg cystatin specifically inhibited the growth of pathogenic human infection Pseudomonas aeruginosa. Conclusions. Our experiments demonstrated that cysteine endopeptidases may be useful in the early detection of stomach cancer. These results suggest that the activities of cysteine endopeptidases inhibited by egg white cystatin and its inhibition the growth of Pseudomonas aeruginosa.

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Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Paris, France; February 9 - 12, 2002; in the section on Diagnostic Markers.