Author/Editor		Premzl, Aleš
Title		Vloga zunajceličnega in znotrajceličnega katepsina B pri invaziji in ožiljanju tumorjev
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2003
Volume		str. 112
Language		slo
Abstract		The processes of tumour angiogenesis, invasion and metastasis are related to degradation of extracellular matrix proteins, facilitated by cysteine, serine, aspartic and metallo proteases. Lysosomal cysteine protease cathepsin B plays a central role in matrix degradation, but it is not clear whether extracellular or intracellular cathepsin B is involved in this process. Cathepsin B can be inhibited by specific inhibitors, however, the inhibitors known so far are not specific enough in vivo. Our hypothesis is, that improved specificity can be achieved by 2A2 monoclonal antibody, binding cathepsin B and inhibiting its enzymatic activity. Ras transformed human breast epithelial cell line MCF-10A neoT and endothelial HUVEC cell line were used to elucidate the role of extracellular and intracellular cathepsin B in tumour invasion and angiogenesis. Both cell lines differed in degradation of fluorescein labelled DQ-collagen IV, which in MCF-10A neoT cells occured predominantly intracellularly, and in HUVEC cells extracellularly. Using general inhibitors of cysteine proteases, specific inhibitors of extracellular and intracellular cathepsin B and neutralising 2A2 monoclonal antibody, we showed, that MCF-10A neoT cell invasion and formation of capillary-like tubular structures by HUVEC cells depend on extracellular and intracellular cathepsin B activity and that proteolytic activity of cathepsin B is more important for invasion as it is for angiogenesis. Additionally, the incomplete inhibition of matrix degradation with cysteine protease inhibitors and involvement of other proteases in this process was demonstrated by microarrays. 2A2 monoclonal antibody proved to be more effective inhibitor of cathepsin B in vitro than specific synthetic inhibitors, presumably as a result of antibody internalisation in living cells and inhibition of extracellular and intracellular cathepsin B. (Abstract truncated at 2000 characters).
Descriptors		CATHEPSIN B CYSTEINE PROTEINASE INHIBITORS COLLAGEN FLUORESCEINS NEOPLASM INVASIVENESS ANTIBODIES, MONOCLONAL TUMOR CELLS, CULTURED MELANOMA, EXPERIMENTAL NEOPLASM METASTASIS LUNG NEOPLASMS MICE, INBRED BALB C