Background: M2 macrophages, as the most prominent immune cells in Burkitt lymphoma (BL), are promising targets and anti-CD47 antibody could enhance the phagocytosis but be unable to eradicate tumor cells. JQ1, a C-MYC inhibitor, may enhance the function of macrophages and be a choice for combination therapy.
Methods: The effect JQ1, on the expression of CD47 was measured. Then the synergy of JQ1 and anti-CD47 antibody was measured using phagocytosis assays. The effect of JQ1 on the polarization of macrophages was also detected. Finally, the efficiency and safety of JQ1 and anti-CD47 antibody combination therapy was explored in a groin orthotopically implanted Raji tumor model.
Results: JQ1 could suppress the expression of CD47 on the surface of BL cells, thus synergize with anti-CD47 antibody to enhance the phagocytosis of macrophages. JQ1 could polarize macrophages from M2 to M1 while inhibiting the proliferation, inducing the apoptosis and blocking the cell cycle of BL cells. Finally, JQ1 and anti-CD47 antibody combination therapy could repress the progression of BL in NOD/SCID mice.
Conclusions: Macrophages may be a promising target in BL and JQ1 combined with anti-CD47 antibody may be a potential therapeutic choice, providing theoretical basis for the use of this new targeted immunotherapy in clinical practice.