MDA-MB-231 blebbisome proteomics

Cells secrete a large variety of extracellular vesicles (EVs) to engage in cell-to-cell and cell-to-environment intercellular communication. EVs are functionally involved in many physiological and pathological processes by interacting with cells that facilitate transfer of proteins, lipids and genetic information. However, our knowledge of EVs is incomplete. We show that cells actively release exceptionally large (up to 20 µm) membrane-enclosed vesicles that exhibit active blebbing behavior, and we therefore have termed them blebbisomes. Blebbisomes contain an array of cellular organelles that include functional mitochondria and multivesicular endosomes yet lack a definable nucleus. We provide proteomic analysis of blebbisomes, large and small EVs released from metastatic MDA-MB-231 breast cancer cells. Blebbisomes are released from normal and cancer cells, can be observed by direct imaging of cancer cells in vivo, and are present in normal bone marrow.