BACKGROUND:Myelodysplastic syndrome has worse hazards of acute myeloid leukemia transformation,and some studies have revealed that immune infiltration plays a vital part in the two.Nevertheless,more studies are required to confirm the relationship between immune infiltration and related differentially expressed gene regulation. OBJECTIVE:To screen the differentially expressed genes with prognostic significance between myelodysplastic syndrome and acute myeloid leukemia by bioinformatics analysis and explore the possible roles and mechanisms among these differentially expressed genes and immune infiltration mechanisms in the occurrence and progression of diseases. METHODS:The differentially expressed genes were screened for bioinformatics analysis using the GEO datasets,and analyzed by DO,GO,KEGG and GSEA.The TCGA prognostic database was used to plot the K-M curves of differentially expressed genes and receiver operating characteristic curve analysis was applied to evaluate the clinical diagnostic performance.Finally,CIBERSORT analysis was used to intuitively demonstrate the correlation between critical prognostic genes and the distribution of immuno-infiltrated cells.RT-qPCR was employed to detect peripheral blood samples from healthy controls,myelodysplastic syndrome and acute myeloid leukemia patients so as to verify the crucial genes preliminarily. RESULTS AND CONCLUSION:(1)A total of 150 differentially expressed genes were obtained between myelodysplastic syndrome and acute myeloid leukemia,among which 16 genes were up-regulated and 134 were down-regulated.(2)The results of DO,GO,KEGG and GSEA analysis suggested that differentially expressed genes might promote the development of myelodysplastic syndrome to acute myeloid leukemia by regulating the immune response.CIBERSORT revealed the differences in immune infiltration between myelodysplastic syndrome and acute myeloid leukemia.The distribution of CD4+ T cells,monocytes,neutrophils and M1 macrophages decreased in acute myeloid leukemia patients.In contrast,the distribution of inflammatory suppressor cells M2 macrophages increased,suggesting that it may be related to the immunosuppression of acute myeloid leukemia.(3)K-M curve and receiver operating characteristic curve analysis of 150 differentially expressed genes screened out four genes relevant to immunity and prognosis with good diagnostic performance:MANSC1,FLT3,BMX and CXCR2.(4)The results of RT-qPCR exhibited that MANSC1,BMX and CXCR2 were low expressed,while FLT3 was highly expressed in acute myeloid leukemia patients.These findings verify that the differential expression of MANSC1,FLT3,BMX and CXCR2 in patients with myelodysplastic syndrome and acute myeloid leukemia is not only significantly correlated with the prognosis of patients but may also affect the occurrence and development of myelodysplastic syndrome and acute myeloid leukemia by regulating the immune infiltration of patients.They can be used as potential biomarkers and therapeutic targets of the transformation from myelodysplastic syndrome to acute myeloid leukemia,providing a new direction for clinical diagnosis and treatment of the transformation of myelodysplastic syndrome.

BACKGROUND:U937 cells can be used as a cell model for studying the biological characteristics,signaling pathways,and therapeutic targets of acute myeloid leukemia.Although it has been reported that long non-coding RNA KIAA0125 is highly expressed in acute myeloid leukemia,its biological function in U937 cells remains unclear,and its mechanism of action in the occurrence and development of acute myeloid leukemia needs to be further clarified. OBJECTIVE:To investigate the expression level of long non-coding RNA KIAA0125 in peripheral blood of patients with acute myeloid leukemia and its effect on the proliferation and apoptosis of U937 cells. METHODS:RNA-sequencing was used to analyze the bone marrow monocyte samples from acute myeloid leukemia patients,and the differentially expressed gene long non-coding RNA KIAA0125 was screened.The expression of long non-coding RNA KIAA0125 in peripheral blood of patients with acute myeloid leukemia was detected by qRT-PCR.The relationship between long non-coding RNA KIAA0125 mRNA expression and prognosis in bone marrow cells of 173 acute myeloid leukemia patients and 70 healthy people was statistically analyzed by GEPIA database.Subsequently,recombinant lentivirus technology and CRISPR/Cas9-SAM technology were used to construct U937 cell lines with knockdown/overexpression of long non-coding RNA KIAA0125.qRT-PCR was used to detect the knockdown/overexpression efficiency of long non-coding RNA KIAA0125.Next,CCK-8 assay,flow cytometry,and western blot assay were used to detect the effects of knockdown/overexpression of long non-coding RNA KIAA0125 on the proliferation and apoptosis of U937 cells.Finally,western blot assay was used to detect the effect of knockdown/overexpressed long non-coding RNA KIAA0125 on Wnt/β-catenin signaling pathway-related proteins. RESULTS AND CONCLUSION:(1)The results of qRT-PCR showed that long non-coding RNA KIAA0125 was highly expressed in peripheral blood of acute myeloid leukemia patients.The results of GEPIA database showed that long non-coding RNA KIAA0125 was highly expressed in bone marrow cells of acute myeloid leukemia patients,and the high expression group had worse overall survival.(2)The knockdown efficiency of long non-coding RNA KIAA0125 in knockdown group was 70%,and the U937 cells that stably down-regulated long non-coding RNA KIAA0125 expression were successfully constructed.The expression of long non-coding RNA KIAA0125 in overexpression group was four times that of vector group,and stable U937 cells were successfully constructed.(3)Knockdown of long non-coding RNA KIAA0125 inhibited the proliferation of U937 cells and promoted their apoptosis.Overexpression of long non-coding RNA KIAA0125 promoted the proliferation of U937 cells but had no significant effect on the apoptosis of U937 cells.(4)Knockdown of long non-coding RNA KIAA0125 inhibited the activity of Wnt/β-catenin signaling pathway,while overexpression of long non-coding RNA KIAA0125 activated Wnt/β-catenin signaling pathway.These results confirm that long non-coding RNA KIAA0125 is highly expressed in acute myeloid leukemia peripheral blood.Long non-coding RNA KIAA0125 may affect the proliferation and apoptosis of U937 cells by regulating the Wnt/β-catenin signaling pathway,and may be a potential prognostic marker for acute myeloid leukemia.