| Objective: MicroRNAs(miRNA)play an important role in the development and progression of acute myeloid leukemia(AML).Currently,some progress has been made in the molecular biological research of miRNA,but the role of miRNA in AML remains to be explored.The purpose of this study was to screen differentially expressed miRNAs(DE miRNAs)in relapsed or refractory normal karyotype acute myeloid leukemia(NKAML)using GEO database,and to analyze the role of DE mi RNAs in NK-AML.Methods: 1.Data on the miRNA expression profile in the bone marrow or peripheral blood of NK-AML patients was download from GEO database,involving relapsed or refractory group and relapsed-free group.Differentially expressed miRNAs were identified by R Software.Survival analyses and the survival curves were conducted by GraphPad Prism7 software.2.The target genes of DE miRNAs were obtained by online prediction.The above target genes were enriched by GO biological function analysis and KEGG pathway analysis.Meanwhile,a protein-protein interaction(PPI)networks of the target genes was constructed with the STRING database and Cytoscape software,and the key genes were identified.3.Gene expression profile in the peripheral blood of NKAML patients was download from GEO database,which divided into primary group and relapsed group.The expression levels of key genes were analyzed in the two groups.Results: 1.Microarray data of GSE55770 annotated by GPL18403 was obtained from GEO database.The Limma package of R software was used for screening,and two DE miRNAs were obtained,which are miR-202-3p and miR-15b-5p.Using the GraphPad Prism7 software,survival curves related to the expression levels of the two DE miRNAs were plotted,respectively.The results showed that the expression levels of the two DE miRNAs were significantly correlated with the prognosis of patients with NK-AML,and the overall survival of patients with low expression of mi R-202-3p and miR-15b-5p was significantly lower than that of patients with high expression(P<0.05).2.MiRTarBase and Targetscan were used to predict the target genes of the above two miRNAs and the intersections were obtained.A total of 195 target genes were predicted for miR-202-3p and 33 target genes were predicted for miR-15b-5p.3.Gene ontology analysis(GO analysis)was performed on target genes of miR-202-3p and miR-15b-5p.For miR-202-3p,in the biological process group,target genes were mainly concentrated in regulation of cellular response to stress,cellular response to growth factor stimulus,regulation of protein serine/threonine kinase activity,heart development,cellular response to hormone stimulus,positive regulation of locomotion,G1/S transition of mitotic cell cycle,mesenchyme development,response to endoplasmic reticulum stress,regulation of binding,embryonic epithelial tube formation,etc.In the molecular functional group,the target genes were mainly concentrated in RNA polymerase II regulatory region sequencespecific DNA binding,protein heterodimerization activity,histone deacetylase binding,protein C-terminus binding,translation regulator activity,growth factor binding,ironsulfur cluster binding,single-stranded RNA binding,etc.In the cellular components grouping,the target genes were mainly concentrated in the transferase complex,transport vesicle,glutamatergic synapse,lamellipodium,transcriptional repressor complex,etc.The target genes in the enrichment analysis of KEGG pathway were mainly concentrated in p53 signaling pathway,HIF-1 signaling pathway,DNA replication pathway.For miR-15b-5p,in the biological process group,target genes were mainly concentrated in ubiquitin-dependent protein catabolic process,lymphocyte activation,protein acetylation,pancreas development,cellular response to biotic stimulus,pyrimidine nucleotide biosynthetic process,antigen processing and presentation of exogenous peptide antigen via MHC class II,etc.In the molecular functional group,the target genes were mainly concentrated in ubiquitin-protein transferase activity,transcription coactivator activity,insulin receptor substrate binding,microtubule motor activity.In the cellular components grouping,the target genes were mainly concentrated in transferase complex,transferring phosphorus-containing groups,side of membrane,histone acetyltransferase complex.The target genes in the enrichment analysis of KEGG pathway were mainly concentrated in insulin resistance pathway,ubiquitin mediated proteolysis,vasopressin-regulated water reabsorption,p53 signaling pathway,HTLV-I infection,T cell receptor signaling pathway.4.A PPI network of target genes was constructed using STRING database and Cytoscape software.CytoHubba and MCODE plug-in in Cytoscape software were used to analyze the PPI network and identify the key genes of miR-202-3p and miR-15b-5p,respectively.GSE66525 chip data annotated by GPL11532 was obtained from GEO database and divided into the primary group and the relapsed group to analyze the expression level of the key genes.The results showed that among the key genes of miR-202-3p downstream target genes,the expression level of MYCN in the relapsed group was significantly higher than that in the primary group(P<0.05).Among the key genes of miR-15b-5p downstream target genes,the expression level of KLC2 in the relapsed group was significantly higher than that in the primary group(P<0.05).Conclusion: 1.In GSE55770 dataset,miR-202-3p was significantly downregulated in the relapsed or refractory group.The survival analysis results showed that the overall survival of the low expression group of miR-202-3p was significantly lower than that of the high expression group.In the GSE66525 dataset,it was found that the downstream key gene of miR-202-3p,MYCN,was highly expressed in the relapsed group,suggesting that the down-regulated miR-202-3p might be involved in the occurrence of relapsed or refractory NK-AML by upregulating the expression level of MYCN and it might be associated with shorter overall survival.2.In GSE55770 dataset,mi R-15b-5p was significantly downregulated in the relapsed or refractory group.The survival analysis results showed that the overall survival of the low expression group of miR-15b-5p was significantly lower than that of the high expression group.In the GSE66525 dataset,it was found that the downstream key gene of mi R-15b-5p,KLC2,was highly expressed in the relapsed group,suggesting that the down-regulated miR-15b-5p might be involved in the occurrence of relapsed or refractory NK-AML by upregulating the expression level of KLC2,and it might be associated with shorter overall survival. |
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