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Milk fat globule epithelial growth factor VIII(MFG-E8) is a novel adhesion protein mainly produced by macrophages and dendritic cells; it is expressed in most of the human tissues and functions to prompt cancer progression and survival. MFG-E8 contains a signal sequence for secretion, two epidermal growth factor(EGF)-like domains at the NH2 terminus and two discoidin domains with blood-clotting factor V/factor Ⅷ(C1 and C2) at the COOH terminus. The second EGF domain contains an arginine-glycine-aspartic(RGD) integrin-binding motif that engages α_vβ_5 integrins to facilitate cell adhesion and induce integrinmediated signal transduction. Integrin α_vβ_3 associates with VEGF receptor 2, engagement of integrins can promote angiogenesis, which plays key roles in growth, proliferation, and survival of cancer cells. VEGF stimulates the expression of α_vβ_3 and α_vβ_5 integrins on angiogenic vasculature, thereby potentiating effects of VEGF receptor engagement. Mice expressing a mutant form of α_vβ_3 integrin are unable to undergo tyrosine phosphorylation, confirming the important role that this integrin plays in pathological angiogenesis and providing important mechanistic insights. The C-terminus discoidin-like domains promote binding to membrane phospholipids, functioning close to VEGF like angiogenesis. MFG-E8 is an opsonin for apoptotic cells, and it acts as a bridging protein between apoptotic cells and phagocytes. It also influences cell immunities by altering CD4~+ and/or CD8~+ cells. Antibody or small peptide works with MFG-E8 at different functional sites or interacts with EGF-like domains and/or discoidin-like domains may play an important role in anti-angiogenesis or immune restoration. Altering the structures and/or functions of MFG-E8 and/or its domains is promising for development of novel anti-cancer strategies.
Milk fat globule epithelial growth factor VIII (MFG-E8) is a novel adhesion protein mainly produced by macrophages and dendritic cells; it is expressed in most of the human tissues and functions to prompt cancer progression and survival. MFG-E8 contains a signal sequence for secretion, two epidermal growth factor (EGF) -like domains at the NH2 terminus and two discoidin domains with blood-clotting factor V / factor VIII (C1 and C2) at the COOH terminus. The second EGF domain contains an arginine- glycine- Integrin α_vβ_3 associates with VEGF receptor 2, engagement of integrins can promote angiogenesis, which plays key roles in growth, proliferation, and survival of cancer. cells. VEGF stimulates the expression of α_vβ_3 and α_vβ_5 integrins on angiogenic vasculature, thereby potentiating effects of VEGF receptor engagement. Mice expressing a muta nt form of α_vβ_3 integrin are unable to undergo tyrosine phosphorylation, confirming the important role that this integrin plays in pathological angiogenesis and providing important mechanistic insights. The C-terminus discoidin-like domains promote binding to membrane phospholipids, functioning close to VEGF like angiogenesis. MFG-E8 is an opsonin for apoptotic cells, and it acts as a bridging protein between apoptotic cells and phagocytes. It also affects cell immunities by altering CD4 ~ + and / or CD8 ~ + cells. Antibody or small peptide works with MFG-E8 at different functional sites or interacts with EGF-like domains and / or discoidin-like domains may play an important role in anti-angiogenesis or immune restoration. Altering the structures and / or functions of MFG-E8 and / or its domains are promising for development of novel anti-cancer strategies.