Latest Findings on the Role of CD47 in Tumor Immune Evasion and Related Targeted Therapies

CD47 is an immunoglobulin that is overexpressed on the surface of a variety of cancer cells. CD47 forms a signaling complex with signal regulatory protein alpha (SIRPα), prompting the escape of cancer cells from macrophage-mediated phagocytosis. In recent years, CD47 has been shown to be highly expressed in many types of solid tumors and is associated with poor prognosis in patients. More and more studies have shown that inhibition of the CD47-SIRPα signaling pathway can promote adaptive immune responses and enhance the phagocytosis of tumor cells by macrophages. Humanized anti-CD47 IgG4 monoclonal antibody has been studied in clinical trials for the treatment of a variety of advanced solid tumors and lymphomas, demonstrating a sound safety profile and achieving partial remission in some patients. In this review we discuss the structure and function of CD47 and the mechanism of CD47 regulation in tumors, summarize the research progress in therapeutic antibody drugs targeting CD47 and a bottleneck in research that targeted drugs are more prone to result in serious adverse effects, and evaluated the potential of the applying CD47-SIRPα signaling pathway in anti-cancer therapy.