DNMT3A intragenic hypomethylation is associated with adverse prognosis in acute myeloid leukemia.

DNA methyltransferase 3A (DNMT3A), a member of de novo methyltransferases, has been found with overexpression in several cancers including acute myeloid leukemia (AML). The present study was aimed to investigate the methylation status of DNMT3A intragenic differentially methylated region 2 (DMR2) using real-time quantitative methylation-specific PCR (RQ-MSP) and analyze its clinical significance in AML. Aberrant hypomethylation of DNMT3A gene was found in 55.3% (84/152) of AML cases, but the status of DNMT3A hypomethylation was not correlated with the expression of four DNMT3A isoforms as well as DNMT3A mutation. There was no significant difference in the rates of complete remission (CR) between patients with and without DNMT3A hypomethylation. However, the patients with DNMT3A hypomethylation had shorter overall survival (OS) time than those without DNMT3A hypomethylation (7 months vs. 11 months, P=0.034). Moreover, the patients with DNMT3A hypomethylation also showed significantly shorter OS than those without DNMT3A hypomethylation in cytogenetically normal AML (CN-AML) (7 months vs. 25 months, P=0.011). Multivariate analysis confirmed the independent adverse impact of DNMT3A hypomethylation in CN-AML. Our data suggest that DNMT3A DMR2 hypomethylation is a negative prognostic hallmark in CN-AML.