靶标信息
Exosomes are important intercellular communication molecules. Exosomes are produced in both normal and pathophysiological conditions. The number of exosomes secreted by cancer cells is more than that of normal cells. The exon markers included in the kit were Alix, annexin V, ICAM-1, CD9, GM130, EpCAM, flotillin and HSP70. Alix is a cytosolic scaffold protein, which regulates many cellular processes, including endocytosis membrane transport and cell adhesion, by interacting with ESCRT (endosome classification complex for transport), endocyton and cell adhesion protein. CIN85 (CBL interacting protein of 85kda) annexin V is a protein of about 30kda, which binds to phospholipids in a calcium dependent manner. All annexins contain a putative PKC binding site, but only annexin V has been identified as an inhibitor of this pathway. Intracellular adhesion molecule-1 (CD54 or ICAM-1) is a cell surface glycoprotein, belonging to the immunoglobulin superfamily (IgSF) of adhesion molecules. CD54 was expressed at low level in different types of cells, which was regulated by cytokines (TNF – α)- α、 IL-1) and lipopolysaccharide. Apical localization of endothelial cells (or basolateral localization of epithelial cells) is a prerequisite for leukocyte transport through the endothelial (or epithelial) barrier. CD9 antigen belongs to the tetrapeptide family of cell surface glycoproteins. Tetrapeptides interact with a variety of cell surface proteins and intracellular signaling molecules in specialized tetrapeptide enriched domains (tems), and mediate a series of processes, including adhesion, movement, membrane tissue and signal transduction. Further studies have shown that CD9 is an important component of exosomes and may play a role in the fusion of these secretory vesicles with receptor cells. During Golgi assembly, GM130 is required to mediate the formation of ribbons. The function of Golgi body is to modify, organize and transport proteins and membranes that target other parts of the cell, such as plasma membrane, lysosome and endosome. This regulated transport is very important for proper protein localization, secretion and signal transduction. Epithelial cell adhesion and activation molecule (EpCAM / CD326) is a transmembrane glycoprotein, which mediates the calcium independent hemophilic adhesion on the basolateral surface of most epithelial cells. EpCAM is one of the earliest tumor associated antigens, and has long been a marker of epithelial and tumor tissues. Studies have shown that EpCAM is highly expressed in cancer cells, which can be used as a biomarker to detect tumor derived exposure. Flotillins belong to the complete membrane protein family associated with lipid rafts. They are widely expressed and located on the lipid rafts on the cytoplasmic membrane. They support signal transduction and regulate the movement and localization of lipid rafts. In addition to co localization with lipid rafts on the plasma membrane, flotillin-1 also exists in the compartments of endocytosis and autophagy pathways, such as circulatory / late endosome, Golgi complex and nucleus. Hsp70 is a constitutively expressed chaperone under normal conditions, which can maintain protein homeostasis and be induced to express under environmental stress. HSP70 can interact with unfolded proteins to prevent irreversible aggregation, and catalyze the refolding of its substrates in ATP and chaperone dependent ways. Heat shock protein (HSP) is excreted from the exosomes of tumor cells and induces immune response.
