Proteolytic cleavage of Livin (ML-IAP) in apoptotic melanoma cells potentially mediated by a non-canonical caspase.

Background: Several inhibitor of apoptosis proteins (IAPs) are cleaved during apoptosis. Studies of the melanoma-associated IAP (ML-IAP) Livin, using recombinant molecules, have implicated both caspases 3/7 and the serine protease Omi/HtrA2 in its proteolytic cleavage.

Objective: To characterize the apoptotic cleavage of Livin in melanocytic cells, and evaluate the role of known proteases.

Activation of dual apoptotic pathways in human melanocytes and protection by survivin.

Apoptosis resistance in melanoma is a primary cause of treatment failure. Apoptotic pathways in melanocytes, from which melanoma arises, are poorly characterized. Human melanocytes were susceptible to apoptosis following exposure to UV radiation (UVB, 24-48 hours), 4-tert-butylphenol (4-TBP, 1-4 hours), and cisplatin (24-48 hours).

Novel application of a fibrin cell block method to evaluate melanocytic cell populations.

Confirming melanocytic lineage and purity is important for experiments using cultured human melanocytes. The objective of this study was to develop a simple, reliable method to evaluate and archive cultured melanocytic cells. Melanocytes were isolated from adult skin biopsies or from neonatal foreskins using standard culturing methods.