Publication de 4 numéros par an
ISSN Imprimer: 2155-014X
ISSN En ligne: 2155-0158
Changes in Active Lysosomal Cysteine Cathepsins from Thyroid Papillary Carcinoma Tissues with Various Biological Characteristics
RÉSUMÉ
To clarify possible role of cysteine cathepsins H, B and L in the proteolytic processes that contribute to the progression of tumor growth in the thyroid, we studied the activity of the latter in lysosomes isolated from the tissue of papillary carcinoma. It has been shown that changes in the activity of these enzymes depend on a number of biological characteristics of the tumors. In particular, the sharp increase in the activity of cathepsin H is observed in lysosomes from T2 and T3 tissue carcinomas at both intra- and extra-thyroid and lymphatic invasion of tumor cells. An increase in the activity of cathepsin B is detected in lysosomes from the tissue of heterogeneous follicular structure, especially in the presence of solid areas, in comparison with typical papillary tumors, and in the lysosomes from tissue carcinomas at intra-thyroid invasion. An increase in the activity of cathepsin L is observed at extrathyroid invasion. A common feature of cathepsins is an increase in their activity in lysosomes from tissue nonencapsulated papillary carcinomas. These enzymes seem not to contribute to the invasion of tumor cells into blood vessels and to the mechanisms of dissemination of tumor to regional lymph nodes. The latter is evidenced by the absence of changes in the activity of cathepsins in lysosomes from tissue carcinomas category N1. The results obtained indicate the different role of cathepsins H, B and L in thyroid carcinogenesis, where each enzyme has its specifc function.