Identification and validation of prognosis‐related DLX5 methylation as an epigenetic driver in myeloid neoplasms

Abstract

The deregulated DLX gene family members DLX1/2/3/4/5/6 ( DLXs ) caused by DNA methylation has been demonstrated in various cancers with therapeutic target value. However, the potential role of DLXs methylation in myeloid neoplasms such as acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) remains to be elucidated. Clinical significance of DLXs methylation/expression was analyzed in patient with AML and MDS. The functional roles of DLXs were determined in vitro. In the identification stage, we found that lower DLX5 expression was correlated with prognosis in AML among all DLXs analyzed by The Cancer Genome Atlas datasets. In the validation stage, we revealed that reduced DLX5 expression was frequently occurred, and was also correlated with promoter hypermethylation in AML evaluated by targeted bisulfite sequencing. Epigenetic studies also showed that DLX5 promoter DNA methylation was associated with its expression. By quantitative polymerase chain reaction, we also validated that DLX5 hypermethylation was frequent event in both AML and MDS, and also correlated with MDS transformation to leukemia. Moreover, DLX5 hypermethylation was associated with lower rate of complete remission and shorter time of leukemia‐free/overall survival, and was also confirmed by Logistic/Cox regression analysis. Functional studies revealed the antiproliferative and pro‐apoptotic effects of DLX5 in MDS‐derived AML cell‐line SKM‐1. Finally, bioinformatics analysis demonstrated that DLX5 functioned in leukemogenesis may be through the association with PI3K/Akt signaling pathway. Collectively, our findings demonstrated that DLX5 methylation, negatively correlated DLX5 expression, was a potential prognostic and predictive indicator in patients with AML and MDS, which could also act as an epigenetic driver in myeloid neoplasms.

EZH2/EHMT2 Histone Methyltransferases Inhibit the Transcription of DLX5 and Promote the Transformation of Myelodysplastic Syndrome to Acute Myeloid Leukemia

“…And upregulation of DLX5 could repress SKM-1 cell proliferation. Zhang et al have also exhibited that DLX5 has antiproliferative and pro-apoptotic in uences on SKM-1 cells [26]. Moreover, we found that DLX5 expression was negatively correlated with the Hoxa9 expression.…”

“…The DLX genes serve as DNA-binding transcriptional regulators, controlling considerable downstream effector genes [41]. Notably, DLX5 hypermethylation is reported to be a common event in AML and MDS, and also concerned with the transformation from MDS to leukemia [26]. We showed that dual inhibition of EZH2 and EHMT2 in SKM-1 cells elevated the DLX5 expression to the highest level.…”

“…The high methylation and low expression of DLX5 are frequent in AML and MDS, and are related to the transformation from MDS to AML [26]. We detected the transcription level of DLX5 in SKM-1 cells of each group and found that transfection of si-EZH2 alone or si-EHMT2 alone could promote the DLX5 mRNA level (Fig.…”

Genome-wide methylation sequencing identifies progression-related epigenetic drivers in myelodysplastic syndromes

“…The primers used for selected genes were listed in Table S2. The MethylTarget assay was described clearly as reported 16,17 .…”

“…A total of 486 genes were identified and five genes (GFRA1, IRX1, NPY, PRRT4, and ZNF300) were selected, of which may have biological functions in cancers analyzed by Coremine analysis (http://www.coremine.com/ medical/#search), for further targeted bisulfite sequencing in additional 35 MDS, 111 AML patients and 25 controls using MethylTarget (GENESKY, Shanghai, China) 17 . The mean bait coverage attached 1694×, and Q30 was 75.56% 17 . As showed in Fig.…”