RESUMO
The aim of this study was to investigate the in vitro effect of interleukin-24 (IL-24) on apoptosis of bone marrow mononuclear cells (BMMNC) in children with acute leukemia. Every group of acute lymphocytic leukemia (ALL) and acute myeloid leukemia (ANLL) had 20 children who did not receive any therapy. The bone marrow was taken from patients and controls, the MNC were isolated from bone marrow, DNA was detected by glucose electrophoresis. Apoptosis of BMMNC was assayed by flow cytometry with propidium iodine staining. RT-PCR was used to detect the expression level of bcl-2, caspase-3 mRNA, and to analyze the effect of IL-24 on them. The results showed that the IL-24 induced apoptosis of BMMNC in children with acute leukemia. After acute leukemia BMMNC were exposed to IL-24 for 48 hours, DNA ladder fragment appeared, and the apoptotic rate of the group treated with IL-24 of 50 ng/ml was obviously higher than that of the control group (0 ng/ml). IL-24 decreased the bcl-2 mRNA expression level, enhanced caspase-3 mRNA expression level of BMMNC from AL patients. It is concluded that the IL-24 can induce apoptosis of AL BMMNC in vitro, which may be due to decreasing of bcl-2 mRNA level and enhancing of caspase-3 mRNA level.