• Molecules and Cells
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• v.46 no.10
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• pp.611-626
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• 2023

Acute myeloid leukemia (AML) is a heterogeneous disease caused by distinctive mutations in individual patients; therefore, each patient may display different cell-type compositions. Although most patients with AML achieve complete remission (CR) through intensive chemotherapy, the likelihood of relapse remains high. Several studies have attempted to characterize the genetic and cellular heterogeneity of AML; however, our understanding of the cellular heterogeneity of AML remains limited. In this study, we performed single-cell RNA sequencing (scRNAseq) of bone marrow-derived mononuclear cells obtained from same patients at different AML stages (diagnosis, CR, and relapse). We found that hematopoietic stem cells (HSCs) at diagnosis were abnormal compared to normal HSCs. By improving the detection of the DNMT3A R882 mutation with targeted scRNAseq, we identified that DNMT3A-mutant cells that mainly remained were granulocyte-monocyte progenitors (GMPs) or lymphoid-primed multipotential progenitors (LMPPs) from CR to relapse and that DNMT3A-mutant cells have gene signatures related to AML and leukemic cells. Copy number variation analysis at the single-cell level indicated that the cell type that possesses DNMT3A mutations is an important factor in AML relapse and that GMP and LMPP cells can affect relapse in patients with AML. This study advances our understanding of the role of DNMT3A in AML relapse and our approach can be applied to predict treatment outcomes.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.239-246
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• 2010

Background: Monoclonal antibodies (mAbs) recognizing Class III epitope of CD34 are essential for flow cytometric diagnosis of leukemia. Methods: 27H2 mAb was developed from a mouse alternatively immunized with human acute leukemia cell lines, KG1 and Molm-1. Using flow cytometric analysis of various leukemic cell lines and peripheral blood, immunohistochemical study of frozen tonsil, we characterized 27H2 mAb. Antigen immunoprecipitated with 27H2 mAb immunobloted with anti-CD34 mAb. A case of bone marrow sample of acute lymphoblastic leukemia (ALL) patient was obtained at CBNU Hospital. For epitope identification enzyme treatment with neuraminidase and O-sialoglycoprotein endopeptidase (OSGE) and blocking assay with known classIII mAb (HPCA-2) were done. Results: Only KG1 and Molm-1 revealed positive immunoreactivity. Immunohistochemical staining disclosed strong membranous immunoreactivity on high endothelial venules. Antigen immunoprecipitated by 27H2 mAb showed approximately 100 kDa sized band immunoblotted with anti-CD34 under non-reducing conditions. Epitope recognized by 27H2 mAb disclosed resistancy to both neuraminidase and OSGE treatment and completely blocked with known class III mAb preincubation. CD34 positive leukemic cells in BM of pre B cell ALL patient detected by FITC-conjugated 27H2 and HPCA-2 were identified with similar sensitivity. Conclusion: A novel murine mAb recognizing class III epitope of human CD34 with high affinity, which is useful for flow cytometric diagnosis of leukemia, was developed.

• BMB Reports
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• v.29 no.3
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• pp.241-247
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• 1996

The Philadelphia (Ph) chromosome is the single most intensively studied chromosome alteration characterizing a human malignancy. The specific genetic alteration of chronic myelogenous leukemia (CML) is the formation of the BCR/abl fusion gene in leukemic cells. The presence of the BCR/abl gene has important diagnostic and prognostic implications in CML. The detection of BCR/abl transcripts by reverse transcriptase based polymerase chain reaction (RT-PCR) was investigated in patients with CML in whom the Ph chromosome abnormality was documented by cytogenetic analysis. In a total of 68 CML patient cases, the Ph chromosome was found in 53 cases (77.9%) by cytogenetic analysis. On the other hand, sixty two cases (91.2%) were detected to have BCR/abl gene rearrangement Of these, b3a2 was 44 cases (64.7%) and b2a2 was 17 cases (25,0%). There was one case with both b3a2 and b2a2 (1.5%). Of the fifteen cases of Ph chromosome negative by cytogenetic anlaysis, the BCR/abl gene was observed in nine cases, The results of BCR/abl fusion gene confirmed by the direct sequencing method correlated well with PCR analysis, The amplified PCR products were detected by $1{\times}10^{-5}$ dilutions. In conclusion, PCR technique is sensitive, rapid and relatively simple for a laboratory test in detecting the BCR/abl fusion gene with CML regardless of the result of cytogenetic analysis.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.549-551
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• 1998

Although dysphagia in patients with acute leukemia is usually related to reflux esophagitis, infectious esophagitis, chemotherapy1) and leukemic infiltration2), acute esophageal stricture resulting from chemotherapy in the patient with leukemia is very rare. A 40-year-old man with acute myelogenous leukemia was admitted for operation of esophageal stricture which was developed within 1 month of chemotherapy. An esophagectomy and esophagogastrostomy with pyloroplasty was carried out. Histology showed mucosal infiltration of mononuclear cells and transmural fibrosis involving submucosa and the muscle layer.