CD47: a potential immunotherapy target for eliminating cancer cells

The relationship between the immune system and cancer growth and aggravation has been discussed over a century. A number of molecules have been shown to participate in this process. CD47, a normal universally expressed member of the immunoglobulin superfamily, plays multiple functions in immune system. Researches demonstrated that CD47 was also highly expressed on the surface of tumor cells as well as cancer stem cells (CSCs). Whether the highly expressed CD47 was associated with tumor growth, metastasis, recurrence, or drug resistance has become the hotspot. Besides the roles of CD47 in tumor immunoregulation, the monoclonal antibodies targeting CD47 used in acute myelogenous leukemia (AML) and bladder CSCs were reported, which shed new light on tumor treatment. CSCs have been recognized as the root of tumor drug resistance and recurrence. Whether CD47 on CSCs could serve as a potential target for future anti-cancer treatment forms the focus of our review. Here we highlight the potential roles of CD47 in immune system, and discuss the promising therapeutic application of anti-CD47 antibodies for eliminating tumor cells.