Expression and clinical significance of Atg3 and Atg5 genes in bone marrow mononuclear cells isolated from children with acute leukemia

Objective To detect the expression of autophagy-related gene Atg3 and Atg5 in bone marrow mononuclear cells (BMMNCs) from children with acute leukemia(AL), so as to explore the relationship between autophagy and the pathogenesis of AL in children. Methods Seventy-four bone marrow specimens were obtained from children with AL in the First Affiliated Hospital of Zhengzhou University Pediatrics Hematology Ward, including 37 cases of initially diagnosed AL without any treatment, 28 cases of AL in complete remission, 9 cases of refractory or relapse AL and 28 bone marrow specimens from children without tumor were also collected as the control group.BMMNCs were separated by Lydroxypropylmethyl Cellulose.After BMMNCs were stained by Monodansylcadaverine, the autophagy phenomenon was observed by using fluorescence microscope, and the ratio of autophagy was detected by using flow cytometry.Reverse transcription polymerase chain reaction(RT-PCR) was used to detect the expression of Atg3 mRNA and Atg5 mRNA in each group. Results It was found that autophagy phenomenon was more common in the initially diagnosed group and the refractory/relapse group, and the autophagy ratio in both groups was respectively(17.07±2.31)%, (15.37±1.59)%, respectively, which were obviously higher than that of the control group(2.71±1.57)% and that of the complete remission group.The differences were statistically significant(t=28.29, 20.96, all P 0.05). The autophagy ratio in the refractory/relapse group higher than that in the complete remission group(t=16.61, P 0.008). Conclusions The autophagy ratio and the expressions of Atg3 mRNA and Atg5 mRNA in initially diagnosed group and the refractory/relapse group were both obviously higher.It was revealed that higher autophagy activity, which was caused by upregulated expressions of Atg3 mRNA and Atg5 mRNA, had a closely connection with the mechanism of occurrence, development and resistance of AL in children. Key words: Acute leukemia; Autophagy-related gene; Atg3; Atg5; Bone marrow mononuclear cells; Child