[Lysosomal proteolytic enzymes in the processes of melanoma invasion and metastasis]

Spectrofluorimetry was used to study the activity of lysosomal and membrane-binding endopeptidases such as cathepsins B (CB), D (CD) and L (CL) in 72 patients with skin malignant melanoma. Lysosomal endopeptidases were measured separately in the primary tumor, normal skin adjacent to tumor and intact and metastatic lymph nodes. The activity of lysosomal CB in the primary tumor was higher than in the adjacent normal skin. The peak activity of membrane-binding KB was established in metastatic lymph nodes. A significant increase in the activity of lysosomal KB was observed in involved regional lymph nodes as compared to intact ones. The activity of membrane-binding KB in metastatic lymph nodes was 6 times that in metastasis-free ones. A significant increase in the activity of lysosomal KD was established in primary melanoma nodes compared to adjacent normal skin as well as in metastatic lymph nodes compared to intact ones. Preoperative chemo- and radiation therapy was followed by a decrease in lysosomal KB and KL activity in metastatic lymph nodes which, however, did not reach the level established for intact lymph nodes. The pathogenetic role of proteolytic endopeptidases in invasion and dissemination of malignant melanoma is discussed as well as the value of their level measurement for assessing metastatic potential of tumor and prognosis of disease on the basis of tumor site, degree of invasion regional lymph node status.