Cysteine peptidases in health and diseases.

Many investigators studied the expression and activity of peptidases in critical steps of tumor progression, invasion and metastasis processes. Recent studies, however, indicate that cysteine peptidases are involved earlier in progression in tumor growth and metastatic sites. Extracellular peptidases probably co-operatively influence matrix degradation and tumor invasion through participation of "proteolytic cascades" in many carcinogenesis processes. In present review, we discuss the effect of interaction of cysteine peptidases from tumor cells and their role in physiological processes.