Thrombospondin-1 and Inhibition of Tumor Growth / 체질인류학회지

ABSTRACT

Thrmobospondin-1 is the multifunctional protein that modulates endothelial cell and tumor cell behavior via several cell surface receptors and inhibits angiogenesis. In vitro, thrombospondin-1 alters adhesion, proliferation, motility, and survival of endothelial and cancer cells. Studies have confirmed that increased TSP-1 expression suppresses growth or metastasis of some tumors and inhibits angiogenesis. In the past three decades, inhibitors of angiogenesis have been developed as regulators target the vascular endothelial growth factor (VEGF) signaling pathway and small molecule tyrosine kinase inhibitors have been clinically approved. TSP-1 has several functional domain structures and inhibits tumor angiogenesis by engaging receptors CD36 and CD47. TSP-1 binding to CD47 dissociates it from VEGFR2, inhibiting downstream AKT activation and functional responses of endothelial cells to VEGF. Recently, macrophage phagocytosis and cytotoxic T-cell induction of tumor cells mediated by CD47-specific blocking antibodies have been proposed. These findings provide a new therapeutic paradigm for elinination of cancer cells and inhibition of angiogenesis of tumor by TSP-1.