Tumor-derived extracellular vesicles (tEVs) are important communication tools used by tumor cells to impact the function of other cells in the body. Accumulating evidence indicate that tEVs could impair the ability of immune cells in effectively attacking cancer cells. In our study, we find that proteins carried in tEVs are crucial for the immune-suppressive function of tEVs. In this study, we identified the proteins present in tEVs isolated from three different tumor cell lines: MCF7, A375, and A549. Proteins were extracted from the isolated tEVs, digested with trypsin, and analyzed by LC-MS/MS to identify the proteins. The identified proteins are listed in this dataset. Among the proteins identified, a total of 321 proteins were shared in all three tEVs, indicating tEVs use a core set of proteins to exert their suppressive function.

Tumor-derived extracellular vesicles (tEVs) were isolated from A375, MCF7, and A549 tumor cells, respectively. Around 200 micrograms of proteins from each tEV sample were used for the proteomic analysis conducted at the Creative Proteomics Company. Proteins were precipitated using cold acetone, and the protein pellets were dissolved in 2 M urea. Samples were then treated with 10 mM DTT and incubated at 56 Celsius for 1 h followed by alkylation with 50 mM IAA. Concentrated ammonium bicarbonate was added into the solution to make a final concentration of 50 mM ammonium bicarbonate with pH of 7.8. Proteins in the samples were digested with trypsin at 37 Celsius for 15 h. The resulting peptides were purified with C18 SPE column to remove salt, resuspended in 20 microliters of 0.1% formic acid and subjected to LC-MS/MS analysis on Ultimate 3000 Nano UHPLC system. Data were analyzed and searched based on the human protein database using Maxquant (1.6.2.14).