Objective: To analyze the clinical features, efficacy and prognosis factors of core binding factor (CBF) acute myeloid leukemia (AML) children in South China. Methods: This was a retrospective cohort study. Clinical data of 584 AML patients from 9 hospitals between January 2015 to December 2020 was collected. According to fusion gene results, all patients were divided into two groups: CBF-AML group (189 cases) and non-CBF-AML group (395 cases). CBF-AML group were divided into AML1-ETO subgroup (154 cases) and CBFβ-MYH11 subgroup (35 cases). Patients in CBF-AML group chosen different induction scheme were divided into group A (fludarabine, cytarabine, granulocyte colony stimulating factor and idarubicin (FLAG-IDA) scheme, 134 cases) and group B (daunorubicin, cytarabine and etoposide (DAE) scheme, 55 cases). Age, gender, response rate, recurrence rate, mortality, molecular genetic characteristics and other clinical data were compared between groups. Kaplan-Meier method was used for survival analysis and survival curve was drawn. Cox regression model was used to analyze prognostic factors. Results: A total of 584 AML children were diagnosed, including 346 males and 238 females. And a total of 189 children with CBF-AML were included, including 117 males and 72 females. The age of diagnosis was 7.3 (4.5,10.0)years, and the white blood cell count at initial diagnosis was 21.4 (9.7, 47.7)×10⁹/L.The complete remission rate of the first course (CR1) of induction therapy, relapse rate, and mortality of children with CBF-AML were significantly different from those in the non-CBF-AML group (91.0% (172/189) vs. 78.0% (308/395); 10.1% (19/189) vs. 18.7% (74/395); 13.2% (25/189) vs. 25.6% (101/395), all P<0.05). In children with CBF-AML, the CBFβ-MYH11 subgroup had higher initial white blood cells and lower proportion of extramedullary invasion than the AML1-ETO subgroup, with statistical significance (65.7% (23/35) vs. 14.9% (23/154), 2.9% (1/35) vs. 16.9% (26/154), both P<0.05). AML1-ETO subgroup had more additional chromosome abnormalities (75/154), especially sex chromosome loss (53/154). Compared with group B, group A had more additional chromosome abnormalities and a higher proportion of tumor reduction regimen, with statistical significance (50.0% (67/134) vs. 29.1% (16/55), 34.3% (46/134) vs. 18.2% (10/55), both P<0.05). Significant differences were found in 5-years event free survival (EFS) rate and 5-year overall survival (OS) rate between CBF-AML group and non-CBF-AML group ((77.0±6.4)%vs. (61.9±6.7)%,(83.7±9.0)%vs. (67.3±7.2)%, both P<0.05).EFS and OS rates of AML1-ETO subgroup and CBFβ-MYH11 subgroup in children with CBF-AML were not significantly different (both P>0.05). Multivariate analysis showed in the AML1-ETO subgroup, CR1 rate and high white blood cell count (≥50×10⁹/L) were independent risk factors for EFS (HR=0.24, 95%CI 0.07-0.85,HR=1.01, 95%CI 1.00-1.02, both P<0.05) and OS (HR=0.24, 95%CI 0.06-0.87; HR=1.01, 95%CI 1.00-1.02; both P<0.05). Conclusions: In CBF-AML, AML1-ETO is more common which has a higher extramedullary involvement and additional chromosome abnormalities, especially sex chromosome loss. The prognosis of AML1-ETO was similar to that of CBFβ-MYH11. The selection of induction regimen group FLAG-IDA for high white blood cell count and additional chromosome abnormality can improve the prognosis.
Male ; Female ; Humans ; Child ; Retrospective Studies ; RUNX1 Translocation Partner 1 Protein/genetics* ; Core Binding Factor Alpha 2 Subunit/therapeutic use* ; Prognosis ; Leukemia, Myeloid, Acute/genetics* ; Cytarabine/therapeutic use* ; Oncogene Proteins, Fusion/genetics* ; Chromosome Aberrations

Objective: To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. Methods: The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. Results: ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h (P<0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] (P<0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group (P<0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) (P<0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) (P<0.05) . Conclusion: This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.
Humans ; U937 Cells ; RUNX1 Translocation Partner 1 Protein ; Leukemia/genetics* ; Core Binding Factor Alpha 2 Subunit/genetics* ; Oncogene Proteins, Fusion/genetics* ; Leukemia, Myeloid, Acute/genetics*

Humans ; Core Binding Factor Alpha 2 Subunit/genetics* ; Translocation, Genetic ; Leukemia, Myeloid, Acute/genetics* ; Prognosis ; High-Throughput Nucleotide Sequencing ; RUNX1 Translocation Partner 1 Protein/genetics* ; Oncogene Proteins, Fusion/genetics*

Objective: To investigate the prognostic value of clonal gene mutations detected by second-generation sequencing in patients with positive RUNX1-RUNX1T1 acute myeloid leukemia (AML) who received high-dose chemotherapy or autologous transplantation (intensive consolidation therapy) in the first complete remission (CR(1)) state. Methods: 79 AML patients with positive RUNX1-RUNX1T1 who received intensive consolidation therapy in CR(1) state from July 2011 to August 2017 were analyzed retrospectively. Kaplan-Meier curve and Cox regression model were used to figure out the effect of leukocyte counts at onset and gene mutations for prognosis. Results: C-KIT, FLT3, CEBPA and DNMT3A gene mutations were found in 25 (31.6%) , 6 (7.6%) , 7 (8.9%) and 1 (1.3%) patient among the population. Mutations in C-KIT exon17 and C-KIT exon8 were detected in 19 (24.1%) and 5 (6.3%) cases, respectively, and mutations of FLT3-ITD were confirmed in 5 (6.3%) cases. The higher leukocyte counts presented at onset of leukemia, the shorter overall survival (OS) was seen in these patients (P=0.03) . Patients with C-KIT exon17 mutation had significantly shorter OS (P=0.01) and disease free survival (DFS) (P=0.006) compared with those without gene mutations, and patients with FLT3-ITD gene mutation got the inferior OS (P=0.048) and DFS (P=0.071) . Conclusion: In AML patients with positive RUNX1-RUNX1T1 receiving intensive consolidation therapy, the white blood cell counts at onset of leukemia, C-KIT mutations in exon 17, and FLT3-ITD gene mutations suggest poor prognosis, which would contribute to elaborate risk stratification, personalized treatment and predict prognosis for these patients.
Consolidation Chemotherapy ; Core Binding Factor Alpha 2 Subunit/genetics* ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Prognosis ; RUNX1 Translocation Partner 1 Protein/genetics* ; Retrospective Studies ; fms-Like Tyrosine Kinase 3

BACKGROUNDThe acute myeloid leukemia 1 (AML1)-eight-twenty-one (ETO) fusion protein generated by the t(8;21)(q22;q22) translocation is considered to display a crucial role in leukemogenesis in AML. By focusing on the anti-leukemia effects of eyes absent 4 (EYA4) gene on AML cells, we investigated the biologic and molecular mechanism associated with AML1-ETO expressed in t(8;21) AML.

METHODSQualitative polymerase chain reaction (PCR), quantitative reverse transcription PCR (RT-PCR), and Western blotting analysis were used to observe the mRNA and protein expression levels of EYA4 in cell lines. Different plasmids (including mutant plasmids) of dual luciferase reporter vector were built to study the binding status of AML1-ETO to the promoter region of EYA4. Chromatin immunoprecipitation assay was used to study the epigenetic silencing mechanism of EYA4. Bisulfite sequencing was applied to detect the methylation status in EYA4 promoter region. The influence of EYA4 gene in the cell proliferation, apoptosis, and cell clone-forming ability was detected by the technique of Cell Counting Kit-8, flow cytometry, and clonogenic assay.

RESULTSEYA4 gene was hypermethylated in AML1-ETO+ patients and its expression was down-regulated by 6-fold in Kasumi-1 and SKNO-1 cells, compared to HL-60 and SKNO-1-siA/E cells, respectively. We demonstrated that AML1-ETO triggered the epigenetic silencing of EYA4 gene by binding at AML1-binding sites and recruiting histone deacetylase 1 and DNA methyltransferases. Enhanced EYA4 expression levels inhibited cellular proliferation and suppressed cell colony formation in AML1-ETO+ cell lines. We also found EYA4 transfection increased apoptosis of Kasumi-1 and SKNO-1 cells by 1.6-fold and 1.4-fold compared to negative control, respectively.

CONCLUSIONSOur study identified EYA4 gene as targets for AML1-ETO and indicated it as a novel tumor suppressor gene. In addition, we provided evidence that EYA4 gene might be a novel therapeutic target and a potential candidate for treating AML1-ETO+ t (8;21) AML.

Apoptosis ; genetics ; physiology ; Blotting, Western ; Cell Line, Tumor ; Cell Proliferation ; genetics ; physiology ; Chromatin Immunoprecipitation ; Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; DNA Methylation ; genetics ; Epigenesis, Genetic ; genetics ; Gene Silencing ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; pathology ; Oncogene Proteins, Fusion ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; RUNX1 Translocation Partner 1 Protein ; Radioimmunoprecipitation Assay ; Trans-Activators ; genetics ; metabolism

This study was aimed to investigate the expression levels of FLT3 gene in AML-M2 patients carrying AML1/ETO fusion gene, and analyze its relation with clinical and laboratorial features and prognosis. RQ-PCR method was used to detect the expression level of FLT3 in bone marrow of 21 AML-M2 patients with AML1/ETO(+). The correlation of the expression level of FLT3 with clinical features, other laboratorial examinations and disease prognosis were analyzed. The results showed that gene expression level of FLT3 (FLT3 gene/ reference gene) in patients at initial diagnosis were 1.65%-261.5%. The expression level of FLT3 over 35% was defined as high expression group (12 cases) , while the expression level below 35% was defined as low expression group (9 cases) . The proportion of patients with extramedullary infiltration in high expression group was higher than that in low expression group (25% vs 0%, P = 0.2286). The proportion of patients at initial diagnosis with white blood cell count > 10×10(9)/L in high expression group was higher than that in low expression group (66.67% vs 22.22%), but there was no statistical significance (P = 0.0805). No significant difference was observed at the age (P = 0.1369) and the rate of bone marrow blasts (P = 0.6923) between the above mentioned two groups. The differences in complete remission rate (66.67% vs 88.89%, P = 0.3383), the relapse rate (66.67% vs 22.22%,P = 0.0805) and the mortality rate (50% vs 22.22%, P = 0.3666) between the two group were not significant, but there was a clear trend that the low expression group has a higher CR rate and a lower relapse rate and mortality rate. It is concluded that FLT3 gene high expression in AML-M2 patients with AML1/ETO(+) have a higher rate of relapse and hence poor prognosis. Therefore, detection of FLT3 expression level in routine clinical practice is important for patient's risk stratification, prognostic evaluation and effective treatment selection.
Core Binding Factor Alpha 2 Subunit ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Oncogene Proteins, Fusion ; genetics ; Prognosis ; RUNX1 Translocation Partner 1 Protein ; fms-Like Tyrosine Kinase 3 ; genetics

This study was purposed to analyse the clinical efficacy of autologous peripheral blood stem cell transplantation (APBSCT) in 13 Patients with AML1/ETO (+) acute myeloid leukemia, and to evaluate the role of quantitative detecting the AML1/ETO gene in treatment of AML patients. A total of 13 patients with AML1/ETO (+) acute myeloid leukemia treated with APBSCT from August 2007 to November 2012 were retrospectively analyzed. The median follow-up time was 26 (7.8-75.8)months. Kaplan-Meier analysis was used to calculate the overall survival (OS), leukemia-free survival (LFS) and cumulative relapse rate (RR). Log rank method was used to perform univariate analysis. The results showed that the 3 year-OS, LFS, and RR were (70.5 ± 15.3)%, (51.3 ± 16.7)%, 48.7%, respectively. The AML1/ETO expression level in 4 cases out of 5 relapsed patients was quantified during and after therapy, and the result showed that AML1/ETO expression level significantly increased before morphological relapse. In univariate analysis, there was no statistic significance in terms of age, sex, count of white blood cells at diagnosis, interval from diagnosis to transplantation, count of MNC for infusion. It is concluded that APBSCT has good therapeutic effect on AML1/ETO (+) AML, and regular quantitative monitoring of AML1/ETO expression level can predict early recurrence. Allogeneic hematopoietic stem cell transplantation after relapse may contribute to obtain opportunity to achieve the long-term survival for intermediate and high risk patients.
Adolescent ; Adult ; Chromosomes, Human, Pair 21 ; Core Binding Factor Alpha 2 Subunit ; genetics ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; therapy ; Male ; Middle Aged ; Oncogene Proteins, Fusion ; genetics ; Peripheral Blood Stem Cell Transplantation ; RUNX1 Translocation Partner 1 Protein ; Transplantation, Autologous ; Young Adult

This study was aimed to investigate the c-kit mutation in acute myeloid leukemia (AML) patients with AML1-ETO and analyze its relation with clinical and laboratorial features and prognosis. PCR and sequencing methods were used to detect the c-kit 17 exon mutations in 31 AML patients with AML1-ETO. The relation of the c-kit mutation with clinical features, results of laboratorial examination and prognosis of disease were analyzed. The results showed that the c-kit mutation was found in 14 out of 31 AML patients and the mutation frequency was 45.16%. Male patients had a higher incidence of c-kit mutation than that of female patients (P = 0.020). The proportion of patients with newly diagnosed white blood cell>10×10(9)/L and with extramedullary infiltration in mutated group were higher than those in unmutated group respectively. No significant difference was observed at the age (P = 0.437) and the rate of bone marrow blasts(P = 0.510) between the above mentioned two groups. The difference in complete remission rate (64.29% vs 80%, P = 0.344)and relapse rate (58.33% vs 21.43%, P = 0.054) between c-kit mutated and c-kit unmutated groups were not significant. While the c-kit mutated group had a significant higher death rate as compared with c-kit unmutated group (57.14% vs 20%, P = 0.039). It is concluded that the c-kit mutation is frequent in AML patients with AML1-ETO and the c-kit mutated patients have a poor prognosis. It is important to detect c-kit mutation in routine clinical practice for patient's risk stratification, evaluation of prognosis and selection of effective treatment.
Adolescent ; Adult ; Aged ; Core Binding Factor Alpha 2 Subunit ; genetics ; DNA Mutational Analysis ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; pathology ; Male ; Middle Aged ; Mutation ; Oncogene Proteins, Fusion ; genetics ; Prognosis ; Proto-Oncogene Proteins c-kit ; genetics ; RUNX1 Translocation Partner 1 Protein ; Treatment Outcome ; Young Adult

This study was aimed to investigate the effect of AML1-ETO fusion protein on the anti-apoptotic gene BCL-2 in leukemic cells and to explore its role in leukemogenesis. The apoptotic levels of U937-WT, U937-Mock and U937-A/E1-4 cells were examined by flow cytometry. And cleaved caspase-3 protein expression was detected by Western blot. BCL-2 gene expression both in AML1-ETO-expressing cells or U937 nonexpressing cells and in leukemia cells of AML patients with or without t(8;21) was assessed by quantitative PCR. The chromatin immunoprecipitation (ChIP)-based PCR was used to investigate the direct interaction between the AML1-ETO and BCL-2 promoter in AML1-ETO positive leukemia cell line. The results indicated that in U937-A/E cells but not in U937-WT or U937-Mock cells, apoptotic cells statistically significantly increased, and AML1-ETO expression also significantly enhanced activation of caspase-3. AML1-ETO-expressing cell subclones displayed significantly low levels of BCL-2 mRNA in comparison with the non-transfected U937. In primary bone marrow cells of acute myeloid leukemia containing AML1-ETO, levels of BCL-2 mRNA were markedly lower as compared with other acute myeloid leukemias lacking this translocation. The enriched regions in transfected cells were located within BCL-2 promoter. It is concluded that BCL-2 is the direct target gene of AML1-ETO. AML1-ETO can down-regulate the expression of BCL-2.
Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RUNX1 Translocation Partner 1 Protein ; U937 Cells

OBJECTIVETo explore the effects and the molecular mechanism of puerariae radix flavones (PRF) on acute myeloid leukemia cell line Kasumi-1 cells in vitro.

METHODSKasumi-1 cells treated by PRF for 48 hours were observed with Wright's and Hoechst 33258 dying. The apoptotic cells were analyzed by flow cytometry with AnnexinV/PI staining. The expression levels of bcl-2, Bim and Caspase-3/-8/-9 protein were assayed by Western blot and the AML1-ETO fusion gene was detected by real-time polymerase chain reaction.

RESULTSPRF could induce Kasumi-1 cells to apoptosis effectively. The proportion of apoptotic cells in 50, 200 and 500 µg/ml PRF treatment groups were (14.1 ± 0.8)%, (17.7 ± 1.3)% and (32.4 ± 1.4)%, respectively, and significantly higher than that of control \[(7.8 ± 0.7)%\]. The relative expression levels of the anti-apoptotic Bcl-2 protein were 0.85 ± 0.05, 0.62 ± 0.07 and 0.43 ± 0.05; the apoptotic Bim protein were 0.21 ± 0.06, 0.39 ± 0.04 and 0.75 ± 0.05; the caspase-3 and caspase-9 were 0.92 ± 0.04, 1.21 ± 0.07, 1.33 ± 0.04 and 0.35 ± 0.05, 0.53 ± 0.03, 0.69 ± 0.07, respectively. Compared to the blank control group, all these changes were significant (P < 0.01). Nevertheless, nearly no changes could be observed on the expression level of AML1-ETO fusion gene and caspase-8 protein.

CONCLUSIONApoptosis of Kasumi-1 cells induced by PRF might correlate to the down-regulation of Bcl-2 protein expression and the activation of caspase-3 and caspase-8 protein in the cells. It seemed that all these effects had no relationship with the AML1-ETO fusion gene.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Flavones ; pharmacology ; Humans ; Oncogene Proteins, Fusion ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Pueraria ; RUNX1 Translocation Partner 1 Protein