Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0278883 (metastatic melanoma)
 6,224 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemokine processing by proteases is emerging as an important regulatory mechanism of leukocyte functions and possibly also of cancer progression. We screened a large panel of chemokines for degradation by cathepsins B and D, two proteases involved in tumor progression. Among the few substrates processed by both proteases, we focused on CCL20, the unique chemokine ligand of CCR6 that is expressed on immature dendritic cells and subtypes of memory lymphocytes. Analysis of the cleavage sites demonstrate that cathepsin B specifically cleaves off four C-terminally located amino acids and generates a CCL20(1-66) isoform with full functional activity. By contrast, cathepsin D totally inactivates the chemotactic potency of CCL20 by generating CCL20(1-55), CCL20(1-52), and a 12-aa C-terminal peptide CCL20(59-70). Proteolytic cleavage of CCL20 occurs also with chemokine bound to glycosaminoglycans. In addition, we characterized human melanoma cells as a novel CCL20 source and as cathepsin producers. CCL20 production was up-regulated by IL-1alpha and TNF-alpha in all cell lines tested, and in human metastatic melanoma cells. Whereas cathepsin D is secreted in the extracellular milieu, cathepsin B activity is confined to cytosol and cellular membranes. Our studies suggest that CCL20 processing in the extracellular environment of melanoma cells is exclusively mediated by cathepsin D. Thus, we propose a model where cathepsin D inactivates CCL20 and possibly prevents the establishment of an effective antitumoral immune response in melanomas.
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PMID:Function of liver activation-regulated chemokine/CC chemokine ligand 20 is differently affected by cathepsin B and cathepsin D processing. 1670 8

Metastatic melanoma is one of the most aggressive forms of skin cancer and has a poor prognosis. We have previously identified Annexin A1 (ANXA1) as a potential murine melanoma-spreading factor that may modulate cell invasion by binding to formyl peptide receptors (FPRs). Here, we report that (1) in a B16Bl6 spontaneous metastasis model, a siRNA-induced decrease in tumoral ANXA1 expression significantly reduced tumoral MMP2 activity and number of lung metastases; (2) in a retrospective study of 61 patients, metastasis-free survival was inversely related to ANXA1 expression levels in primary tumors (HR 3.15 [1.03-9.69], p = 0.045); (3) in human melanoma cell lines, ANXA1 level was positively correlated with in vitro invasion capacity whereas normal melanocytes contained low ANXA1 levels, and (4) the ANXA1 N-terminal peptide ANXA12-26 stimulated MMP2 activity after interaction with FPRs and significantly stimulated the in vitro invasion of melanomas by acting on FPRs. These findings identify ANXA1 as a proinvasive protein in melanoma that holds promise as a potential prognostic marker and therapeutic target.
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PMID:Annexin A1 in primary tumors promotes melanoma dissemination. 2499 93