Proteomic Profiling of Human Melanoma Metastatic Cell Line Secretomes

During the last few years, the incidence and mortality ofhuman melanoma have rapidly increased. Metastatic spread of malignantmelanoma is often associated with cancer progression with poor prognosisand survival. These processes are controlled by dynamic interactionsbetween tumor melanocytes and neighboring stromal cells, whose deregulationleads to the acquisition of cell proliferation capabilities and invasiveness.It is increasingly clear that a key role in carcinogenesis is played bysecreted molecules either by tumor and surrounding stromal cells. Toaddress the issue of the proteins secreted during cancer progression, theproteomic profiling of secretomes of cancer cell lines from differentmelanoma metastases of the same patient (PE-MEL-41, PE-MEL-47, andPE-MEL-43) was performed by applying a shotgun LCMS/MS-basedapproach. The results provide a list of candidate proteins associated with themetastatic potential of PE-MEL melanoma cell lines. Among them, several matricellular proteins previously reported as involved inmelanoma aggressiveness were identified (i.e., SPARC, osteopontin). In addition, the extracellular matrix protein 1 that stimulatesproliferation and angiogenesis of endothelial cells as well as the fibronectin, involved in cell adhesion and motility, were identified.The present work provides the basis to clarify the complex extracellular protein networks implicated in human melanoma cellinvasion, migration, and motility.