Identification of Aberrantly Methylated and Silenced Genes in Acute Myeloid Leukemia by Combined Methylation/expression Analysis
Abstract Background Aberrant genomic methylation plays an important role in pathogenic process of acute myeloid leukemia (AML) by silencing tumor suppressor genes (TSG). While the key aberrantly methylated genes and related pathways have not been well understood yet, which we aimed to reveal by combined analysis of methylation and expression datasets. The prognostic significance was validated by survival analysis derived from TCGA database. Methods Micro-array data of GSE 15061 and GSE58477 were downloaded from Gene Expression Omnibus (GEO) database. The differentially methylated regions (DMR) and differentially expressed genes (DEG) were identified using R program (R 3.6.1). Over-representation analysis was performed to obtain the enriched biological processes and pathways. Cox hazards analysis was employed to select the genes significantly associated with AML survival, using the data derived from the Cancer Genome Atlas (TCGA) database. Subgroup analysis, regarding induction type, was conducted to identify biomarkers for HMA treatment. Furthermore, SYNJ2 associated genome-wide gene/miRNA expression and methylation profile were explored. Results A total of 198 aberrant methylation related underexpressed genes were identified. Univariable analysis revealed methylation level of 6 out of 198 genes (CORO1A/MPO/SYNJ2/EHD1/GAS2L1/SLC11A1) were significantly associated with AML survival. SYNJ2 methylation was an independent predictor for OS. Notably, subgroup analysis revealed hypermethylation of CORO1A predicted better OS in HMA group. Further gene set enrichment analysis indicated SYNJ2-associated activation of PI3K-Akt/NF-kappaB/JAK-STAT signaling and checkpoint pathway. The microRNAs, such as miR217/miR485-3p/miR-889-3p, were downregulated in SYNJ2-hypermethylated group, leading to potential HOXA13 upregulation. Conclusion The prognostic methylation signature was revealed in our studies, and SYNJ2 was proved as an independent prognostic factor. Methylation of CORO1A may serve as biomarker for HMA treatment in AML.