Exosomes in extracellular communications and biomarker research

Exosomes are 40-100 nm diameter membrane enclosed extracellular vesicles released by various cell types, including cancer cells. For tumors to progress, bidirectional crosstalk between different cells occurs within the tumor and its surrounding supporting tissue. A tumor can be considered as a complex tissue or organ with abnormal cells harbouring genetic mutations, typically referred to as tumor or cancer cells, enmeshed within the surrounding and interwoven stroma, the epithelial parenchyma, which provides the connective tissue of the tumor. Stromal elements include the extracellular matrix as well as other cell types that are activated and/or recruited to the tumor microenvironment such as fibroblasts, immune and inflammatory cells, fat cells and endothelial cells of the blood and lymphatic circulation.

Recent literature indicated that all aspects of cellular tumorigenicity are profoundly influenced by reciprocal interactions between responding normal cells, their mediators, structural components of the extracellular matrix, and genetically altered neoplastic cells. Exosomes have recently been recognized as important mediators of the cross-talk in the tumor microenvironment. Exosomes derived from tumor cells have been shown to have both pro- and anti-tumorigenic properties. Our lab is interested in studying the role of exosomes in the tumor microenvironment.