Background: Acute myeloid leukemia (AML) is a group of highly heterogeneous diseases, for which approximately 35-40% of patients younger than 60 years old can be cured. However, the multi-omics characteristics and immune cell infiltration (ICI) status of adult long-term survival patients with AML patients compared with healthy controls are still relatively under-explored.
Methods: A total of 10 healthy transplant donors (control group) and 11 long-term survival patients with AML with de novo sampling from 2019 to 2020 at the Institute of Hematology in the Hospital of Blood Diseases were enrolled. We simultaneously performed 850 K methylation and bulk RNA-seq on these 21 patients for comparing the differential gene methylation and expression levels between the two groups. The analysis of immune cell gene expression was based on 4 algorithms single sample gene set enrichment analysis (ssGSEA), EPIC, ESTIMATE and immunophenotype score (IPS) on the bulk RNA-seq data.
Results: The differential methylation positions (DMPs) of the control group was significantly higher than that of the long-term survival group (P<0.01). The hypomethylated probes for Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment is summarized as follows: the significant pathway was related to NK-cell-mediated cytotoxicity and amino acid metabolism. We also found the Differential expression genes (DEGs) of long-term survival AML were roughly similar, and the DEGs were highly relevant to the cellular amino acid metabolic process pathway by gene set enrichment analysis (GSEA). Based on the further univariate and multivariate Cox survival analyses in GSE37642, genes crosslinked of DEGs and DMPs: LOXL1 and PDZRN4, which characterized as hypomethylated and upregulated, may become an AML prognostic marker (P<0.05). Besides, compared with the long-term-survival AML patients who discontinued chemotherapy after >3 years and the healthy donors, T cell-, natural killer cell-, MHC- and effector cell (EC)-related genes were downregulated; suppressor cells (SC) and checkpoint (CP) cells were significantly upregulated in the long-term-survival AML patients who discontinued chemotherapy after <3 years.
Conclusions: In terms of DNA methylation, RNA expression and ICI, AML patients with long-term survival were slightly different than that of healthy people. The profile of long-term AML survivors, especially those who discontinued chemotherapy less than 3 years, still differed from that of healthy people.
Keywords: Acute myeloid leukemia (AML); RNA-seq; immune cell infiltration (ICI); long-term survival.
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