Pardaxin Promoted Differentiation and Maturation of Leukemic Cells via Regulating TLR2/MyD88 Signal against Cell Proliferation

OBJECTIVE: Leukemia is a cancer of the blood cells. Leukemic THP-1 and U937 cells were used in this study as monocytic effectors cells for proliferation responses and macrophage-like cells induction in leukemia. Pardaxin is an antimicrobial peptide isolated from the marine fish species. METHODS: After treatment for 5 days, pardaxin significantly suppressed cell viability and arrested cell cycle at G0/G1 phase in leukemic cells which were evaluated. RESULTS: Pardaxin also induced cell differentiation and maturation of THP-1 and U937 cells into macrophage-like cells with phagocytotic ability. Moreover, pardaxin elevated the expression of MyD88 but not toll-like receptor (TLR)-2 in both leukemic cells. TLR-2 blocking peptide was used to confirm that pardaxin attenuated phagocytotic ability and superoxide anion production in leukemic cells via activating MyD88 protein. CONCLUSIONS: These findings suggested that pardaxin has a therapeutic potential for leukemia.