Proteomic and pathway profiling of four Breast Cancer cell lines.

Biomarker discovery in breast cancer (BC) is a clinical need for therapeutics and non-invasive diagnostics. In a single study, we provide a comparative differential proteomic profile of four invasion, metastasis, angiogenesis and drug resistance. Exosome proteome profile reflects their different BC cell origin suggesting potential indicators of BC subtype. Further, our pathway inference analysis reveals a differential role of exosomes in BC signalling pathways in recipient cells, according to their protein cargo and cell origin. Our results may significantly contribute to further studies for the design of BC biomarker predictor to stratify BC patients and the development of novel therapeutic strategies.BC cell lines and their derived- exosomes, representative of the most relevant BC subtypes in clinic. Differentially-expressed proteins, in both cells and exosomes, include indicators of