Proteomic profiling of exosomes isolated from invasive and proliferative melanoma cell lines and correlation with exosomes from plasma of human melanoma patients pre- and post-checkpoint inhibitor treatment

Over the last decades, exosomes have received increasing attention due to their involvement in numerous pathologies including cancer. Tumor-derived exosomes and exosomes derived from the tumor microenvironment are implicated in multiple mechanisms that support disease progression such as the escape of malignant cells from immunosurveillance, tumor cell growth, tumor angiogenesis, preparation of a pre-metastatic niche and remodeling of the extracellular matrix, thereby promoting dissemination and metastasis. Here, we performed protein expression phenotyping of exosomes derived from different invasive and proliferative melanoma cell lines (n=8) to provide a solid framework of gene expression programs, which - in a clinical setting - would be useful for prognosis and may also predict treatment response. Cell line characteristics have been published previously (Wenzina et al.,2020). Having identified a set of differentially expressed proteins in proliferative and invasive melanoma cell lines, we correlated them to the protein composition of plasma exosomes from melanoma patients pre and post immunotherapy treatment (n=7) as well as healthy controls (n=5).