Charakterystyka i znaczenie proteinaz cysteinowych w procesie nowotworzenia.

Cysteine proteases also known as thiol or sulfhydryl proteases are enzymes responsible for catalyzing the hydrolysis of peptide bonds in proteins. They take part in many physiological and pathological processes. Their abnormal activity can lead to a number of disease states including tumor growth. They are involved in the process of carcinogenesis at multiple levels - they participate in the invasion, transformation, angiogenesis, apoptosis and metastasis. The best characterised cysteine proteases are the lysosomal cathepsins, that belong to the papain family. So far 11 cysteine cathepsins have been identified: B, L, H, S, K, F, V, X, W, O and C. They take part in the activation of many proenzymes and prohormones, MHC-II-mediated antigen presentation, bone remodeling, reproduction and apoptosis. Research on the role of cysteine proteases in carcinogenesis showed elevated expression of mRNA or enzymatic activity of cathepsins in many human cancers, eg. breast, lung, brain, gastrointestinal tract, head and neck and melanoma. Cancer procoagulant also belongs to the group of cysteine proteases, however its structure and functions are still the subject of research for many scientists. Elevated levels of activity and concentrations of cancer procoagulant in the serum and tissues from patients with cancer disease compared to those observed in healthy people, provides the possibility of using this factor in the diagnosis of cancer. Many preclinical studies have shown that achieving a stop proliferation and reducing the metastatic potential of tumor cells is possible with the use of cysteine proteinases inhibitors. That gives great hope for the possibility of their application in anticancer therapy. [ABSTRACT FROM AUTHOR]