OBJECTIVE: To analyze the molecular genetic spectrum of children with acute myeloid leukemia (AML), and explore its correlation with clinical characteristics and prognosis. METHODS: The clinical and molecular genetic data of 116 children with newly diagnosed AML in Wuhan Children's Hospital from September 2015 to August 2022 were retrospectively analyzed. The Fisher's exact test was used to analyze the correlation of gene mutations with clinical features, and Kaplan-Meier curve was used to analyze the influences of gene mutations on the prognosis. RESULTS: NRAS (22%), KRAS (14.9%), and KIT (14.7%) mutations were the most common genetic abnormalities in 116 children with AML. Children with KIT, CEBPA and GATA2 mutations showed a higher median onset-age than those without mutations (all P < 0.05). Children with FLT3-ITD mutation exhibited a higher white blood cell count at initial diagnosis compared to those without mutations (P < 0.05). Children with ASXL2 mutation had lower platelet count and hemoglobin at initial diagnosis than those without mutations (both P < 0.05). KIT mutations were often co-occurred with t(8;21)(q22;q22). There was no significant relationship between gene mutation and minimal residual disease (MRD) remission rate after the first and second induction therapy (P >0.05). KIT and NRAS mutations were not associated with prognosis significantly (P >0.05). The overall survival (OS) rates of children with CEBPA and FLT3-ITD mutations were superior to those without mutations, but the differences were not statistically significant (P >0.05). The 3-year OS rate of 61 children treated by allogeneic hematopoietic stem cell transplantation was 89.8%, which was significantly higher than 55.2% of those only treated by chemotherapy (P < 0.001). CONCLUSIONS Gene mutations are common in children with AML, and next-generation sequencing can significantly improve the detection rate of gene mutations, which can guide the risk stratification therapy. In addition, FLT3-ITD and KIT mutations may no longer be poor prognostic factors.
Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Prognosis ; Retrospective Studies ; fms-Like Tyrosine Kinase 3/genetics* ; Child ; Proto-Oncogene Proteins c-kit/genetics* ; Male ; Female ; CCAAT-Enhancer-Binding Proteins/genetics* ; Membrane Proteins/genetics* ; Child, Preschool ; Adolescent ; GATA2 Transcription Factor/genetics* ; GTP Phosphohydrolases/genetics* ; Proto-Oncogene Proteins p21(ras)/genetics*

The cooccurrence of NPM1, FLT3-ITD, and DNMT3A mutations (i.e., triple mutation) is related to dismal prognosis in patients with acute myeloid leukemia (AML) receiving chemotherapy alone. In this multicenter retrospective cohort study, we aimed to identify whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) could overcome the poor prognosis of DNMT3A^mutNPM1^mutFLT3-ITD^mut AML across four transplant centers in China. Fifty-three patients with triple-mutated AML receiving allo-HSCT in complete remission were enrolled. The 1.5-year probabilities of relapse, leukemia-free survival, and overall survival after allo-HSCT were 11.9%, 80.3%, and 81.8%, respectively. Multivariate analysis revealed that more than one course of induction chemotherapy and allo-HSCT beyond CR1 were associated with poor survival. To our knowledge, this work is the largest study to explore the up-to-date undefined role of allo-HSCT in patients with triple-mutated AML. Our real-world data suggest that allo-HSCT could overcome the poor prognosis of DNMT3A^mutNPM1^mutFLT3-ITD^mut in AML.
Humans ; Nucleophosmin ; Leukemia, Myeloid, Acute/mortality* ; Hematopoietic Stem Cell Transplantation/methods* ; Male ; Female ; DNA Methyltransferase 3A ; Adult ; China ; Retrospective Studies ; DNA (Cytosine-5-)-Methyltransferases/genetics* ; Middle Aged ; Prognosis ; fms-Like Tyrosine Kinase 3/genetics* ; Mutation ; Young Adult ; Transplantation, Homologous ; Nuclear Proteins/genetics* ; Adolescent ; Aged

OBJECTIVE: To observe the clinical significance of translocator proteins (TSPO) gene in the treatment of FLT3-ITD/DNMT3A R882 double-mutated acute myeloid leukemia (AML). METHODS: Seventy-six patients with AML hospitalized in the Department of Hematology of the Affiliated People's Hospital of Ningbo University from June 2018 to June 2020 were selected, including 34 patients with FLT3-ITD mutation, 27 patients with DNMT3A R882 mutation, 15 patients with FLT3-ITD/DNMT3A R882 double mutation, as well as 19 patients with immune thrombocytopenia (ITP) hospitalized during the same period as control group. RNA was routinely extracted from 3 ml bone marrow retained during bone puncture, and TSPO gene expression was detected by transcriptome sequencing (using 2-deltadeltaCt calculation). RESULTS: The expression of TSPO gene in FLT3-ITD group and DNMT3A R882 group at first diagnosis was 2.02±1.04 and 1.85±0.76, respectively, which were both higher than 1.00±0.06 in control group, but the differences were not statistically significant (P=0.671, P=0.821). The expression of TSPO gene in the FLT3-ITD/DNMT3A R882 group was 3.98±1.07, wich was significantly higher than that in the FLT3-ITD group and DNMT3A R882 group, the differences were statistically significant (P=0.032, P=0.021). The expression of TSPO gene in patients who achieved complete response after chemotherapy in the FLT3-ITD/DNMT3A R882 group was 1.19±0.87, which was significantly lower than that at first diagnosis, and the difference was statistically significant (P=0.011). CONCLUSION TSPO gene may be used as an indicator of efficacy in FLT3-ITD /DNMT3A R882 double-mutated AML.
Humans ; DNA (Cytosine-5-)-Methyltransferases/genetics* ; DNA Methyltransferase 3A ; Mutation ; Leukemia, Myeloid, Acute/drug therapy* ; Nucleophosmin ; Prognosis ; fms-Like Tyrosine Kinase 3/genetics* ; Receptors, GABA/therapeutic use*

Acute myeloid leukemia (AML) is a heterogeneous hematopoietic tumor originated from hematopoietic stem cells. FLT3 is an important receptor tyrosine kinase in cell signal transduction pathway and one of the common mutated genes in AML. AML patients with FLT3-ITD mutation have a poor prognosis and tendency to relapse. Therefore, early identification of FLT3 gene mutation and selection of appropriate treatment are particularly important. Currently, the small moleculetargeted drugs have been new treatment methods for AML patients with FLT3-ITD mutation, but accompanied drug resistance need to be solved. This paper reviews the mechanism of FLT3 mutation, the clinical significance of FLT3 mutation in AML, FLT3 inhibitors and drug resistance mechanism.
Humans ; Mutation ; Protein Kinase Inhibitors/therapeutic use* ; Signal Transduction ; Receptor Protein-Tyrosine Kinases/therapeutic use* ; Leukemia, Myeloid, Acute/drug therapy* ; fms-Like Tyrosine Kinase 3/genetics*

OBJECTIVE: To explore the efficacy of venetoclax (VEN) plus azacitidine (AZA) in patients with FLT3-ITD mutated relapsed/refractory acute myeloid leukemia (FLT3-ITD^mut R/R AML) and analyze the molecular genetic characteristics of the patients. METHODS: Clinical baseline characteristics and follow-up data of 16 R/R AML patients treatd with VEN plus AZA in the hematology department of Shenzhen Second People's Hospital from November 2018 to April 2021 were collected. Leukemia related genes were detected by next-generation sequencing(NGS) or PCR. The relationship between the efficacy of VEN plus AZA and molecular genetics characteristics of patients with FLT3-ITD^mut R/R AML were analyzed. RESULTS: 14.3% (1/7) of the patients in FLT3-ITD^mut group and 22.2% (2/9) of the patients in FLT3-ITD^wt group achieved complete remission (CR)/CR with incomplete blood count recovery (CRi), respectively, with no significant difference (P=0.69). There was no significant difference in overall response rate (ORR) (CR/CRi+PR) between FLT3-ITD^mut group and FLT3-ITD^wt group [42.9%(3/7) vs 44.4%(4/9), P=0.95], too. The median overall survival (OS) time of FLT3-ITD^mut patients was significantly shorter than that of FLT3-ITD^wt patients (130 vs 300 days, respectively) (P =0.02). Co-existing mutations of FLT3-ITD and IDH1 were detected in one patient who achieved CR. Co-existing mutations of FLT3-ITD and SF3B1 were found in one patient who achieved PR. Three FLT3-ITD^mut R/R AML patients accompanied with NPM1 mutation had no response to VEN plus AZA. CONCLUSION VEN plus AZA showed a certain effect on patients with FLT3-ITD^mut R/R AML. To improve OS of the patients, bridging transplantation is need. IDH1 and SF3B1 mutations might predict that patients with FLT3-ITD^mut R/R AML have treatment response to VEN plus AZA, while the combination of NPM1 mutation may indicate poor response.
Humans ; Nucleophosmin ; Prognosis ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Azacitidine/therapeutic use* ; fms-Like Tyrosine Kinase 3/genetics*

OBJECTIVE: To assess the influence of FLT3 expression on the prognosis of patients with acute myeloid leukemia (AML) by cell experiment and clinical data analysis. METHODS: Models for FLT3 over-expression and interference-expression in AML cells were constructed. The level of BAK gene expression and its protein product was determined, along with the proliferation and apoptosis of leukemia cells. FLT3 gene expression and FLT3-ITD variant were determined among patients with newly diagnosed AML. RESULTS: Compared with the interference-expression group, the level of BAK gene expression and its protein in FLT3 over-expression AML cells was significantly lower (P < 0.001), which also showed significantly faster proliferation (P < 0.001) and lower rate of apoptosis (P < 0.001). The expression level of FLT3 gene among patients with newly diagnosed AML was also significantly higher compared with the healthy controls (P < 0.001). The FLT3 gene expression of FLT3-ITD positive AML patients was higher than that of FLT3-WT patients (P = 0.002). Survival analysis showed that AML patients with high FLT3 expression in the medium-risk group had a lower complete remission rate and overall survival rate compared with those with a low FLT3 expression (P < 0.001). CONCLUSION Over-expression of FLT3 may influence the course of AML by promoting the proliferation of leukemia cells and inhibiting their apoptosis, which in turn may affect the prognosis of patients and serve as a negative prognostic factor for AML.
Humans ; Apoptosis/genetics* ; Data Analysis ; Leukemia, Myeloid, Acute/genetics* ; Gene Expression ; fms-Like Tyrosine Kinase 3/genetics*

OBJECTIVE: To explore the effect of age on the time of neutropenia after initial induction therapy for newly diagnosed acute myeloid leukemia (AML) patients. METHODS: Data of 18-65 years old AML patients treated in our hospital from Junuary 2015 to July 2020 were retrospectively analyzed. The clinical characteristics, time of neutropenia after initial induction treatment, early responses, and related influencing factors for the time of neutropenia were analyzed and compared between 18-40 years old group and 41-65 years old group. RESULTS: There were 112 patients enrolled in this study, including 66 (58.9%) males, and their median age was 46 years old. Compared with 18-40 years old group, the incidence of FLT3-ITD gene mutation increased (P=0.039) but core binding factor (CBF) decreased (P=0.003) significantly in 41-65 years old group. The incidence of neutropenia was 97.3%, and the average time was (18.70±1.192) days. The time of neutropenia was (21.43±1.736) days in 41-65 years old group, which was longer than (14.91±1.356) days in 18-40 years old group (P=0.006). The time of neutropenia in CBF positive group was shorter than that in negative group (P=0.012), as well as in patients with remission (CR+CRi) (≤ 2 courses) than those with non-remission (NR) (P=0.024), while in high-risk group was longer than that in low-risk group (P=0.040). Multivariate analysis showed that age, FLT3-ITD gene mutation positive, and non-remission (NR) after two courses of treatment were independent risk factors for the time of neutropenia. CONCLUSION In non-elderly patients with newly diagnosed AML, age is an influencing factor for the time of neutropenia. Key words　　;
Adolescent ; Adult ; Aged ; Humans ; Induction Chemotherapy ; Leukemia, Myeloid, Acute/drug therapy* ; Male ; Middle Aged ; Mutation ; Neutropenia ; Prognosis ; Remission Induction ; Retrospective Studies ; Young Adult ; fms-Like Tyrosine Kinase 3

OBJECTIVE: To explain the clinicobiological heterogeneity of NPM1 mutated (NPM1^mut) acute myeloid leukemia (AML) by analyzing the association between next-generation sequencing (NGS) profiles and MICM characteristics in patients with this AML subtype. METHODS: Data of 238 NPM1^mut patients with available NGS information on 112 genes related to blood disease was collected, and χ² test and nonparametric test were used to analyze the distribution association between NGS-detecting mutations and conventional MICM parameters. RESULTS: In entire NPM1^mut cohort, totaling 240 NPM1 mutation events were identified, of whom 10 (10/240, 4.2%) were missense mutations, which did not involve any W288 or W290 locus and were found exclusively in NPM1^mut/FLT3-ITD^- group. All but one of these missense mutations (9/10, 90%) were accompanied by AML subtype-defining recurrent cytogenetic or molecular abnormalities, of which 7 cases were in the low risk and 2 in the high risk. NPM1^mut occurred solely as an insertion/deletion (indel) type in the NPM1^mut/FLT3-ITD⁺ group. The incidence of favorable plus unfavorable karyotypes in NPM1^mut/FLT3-ITD^- group was higher than in NPM1^mut/FLT3-ITD⁺ group (6.4% vs. 0, P=0.031). The positive rates of CD34 and CD7 in NPM1^mut/FLT3-ITD⁺ group were significantly higher than in NPM1^mut/FLT3-ITD^- group (CD34: 47.9% vs. 20.6%, P<0.001; CD7: 61.5% vs. 29.9%, P<0.001). Logistic analysis showed that FLT3-ITD independently predicted for CD34⁺ and CD7⁺ [odds ratio (OR)=5.29, 95%CI: 2.64-10.60, P<0.001; OR=3.47, 95%CI: 1.79-6.73, P<0.001; respectively]. Ras-pathway mutations independently predicted for HLA-DR⁺ (OR=4.05, 95%CI: 1.70-9.63, P=0.002), and KRAS mutation for MPO^- (OR=0.18, 95%CI: 0.05-0.62, P=0.007). TET2/IDH1 mutations independently predicted for CD34^- and CD7^- (OR=0.26, 95%CI: 0.11-0.62, P=0.002; OR=0.30, 95%CI: 0.14-0.62, P=0.001; respectively), and MPO⁺ (OR=3.52, 95%CI: 1.48-8.38, P=0.004). DNMT3A-R882 independently predicted for CD7⁺ and HLA-DR⁺ (OR=3.59, 95%CI: 1.80-7.16, P<0.001; OR=13.41, 95%CI: 4.56-39.45, P<0.001; respectively), and DNMT3A mutation for MPO^-(OR=0.35, 95%CI: 1.48-8.38, P=0.004). CONCLUSION Co-existing FLT3-ITD in NPM1^mut AML independently predicts for CD34⁺ and CD7⁺, co-existing Ras-pathway mutation for HLA-DR⁺ and MPO^-, co-existing TET2/IDH1 mutation for CD34^-, CD7^-, and MPO⁺, and co-existing DNMT3A mutation for HLA-DR⁺, CD7⁺, and MPO^-, thereby providing a new mechanism explanation for the immunophenotypic heterogeneity of these AML patients.
High-Throughput Nucleotide Sequencing ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Nuclear Proteins/genetics* ; Nucleophosmin ; Prognosis ; fms-Like Tyrosine Kinase 3/genetics*

OBJECTIVE: Two sgRNAs transfected FLT3-ITD⁺AML cell line MV411 with different binding sites were introduced into CRISPR/cas9 to obtain MV411 cells with miR-155 gene knockout. To compare the efficiency of miR-155 gene knockout by single and double sgRNA transfection and their effects on cell phenotypes. METHODS: The lentiviral vectors were generated containing either single sgRNA or dual sgRNAs and packaged into lentivirus particles. PCR was conducted to measure gene editing efficiency, and miR-155 expression was evaluated by qPCR. CCK-8 assay was used to evaluate the cell proliferation, and calculate drug sensitivity of cells to adriamycin and quizartinib. Annexin V-APC/7-AAD staining was used to label cell apoptosis induced by adriamycin and quizartinib. RESULTS: In the dual sgRNAs transfected cells, a cleavage band could be observed, meaning the success of gene editing. Compared with the single sgRNA transfected MV411 cells, the expression level of mature miR-155-5p was lower in the dual sgRNA transfected cells. And, dual sgRNA transfected MV411 were more sensitive to adriamycin and quizartinib with lower IC₅₀ and higher apoptosis rate. CONCLUSION The inhibition rate of miR-155 gene expression transfected by dual sgRNA is higher than that by single sgRNA. Dual sgRNA transfection can inhibit cell proliferation, reverse drug resistance, and induce apoptosis more significantly. Compared with single sgRNA transfection, dual sgRNA transfection is a highly efficient gene editing scheme.
CRISPR-Cas Systems ; Doxorubicin/pharmacology* ; Drug Resistance ; Gene Editing ; Humans ; Leukemia, Myeloid, Acute/genetics* ; MicroRNAs/genetics* ; RNA, Guide/genetics* ; fms-Like Tyrosine Kinase 3/genetics*

OBJECTIVE: To investigate the coexisting mutations and clinical significance of Homo sapiens neuroblastoma RAS viral oncogene homolog (NRAS) gene in acute myeloid leukemia (AML) patients. METHODS: High-throughput DNA sequencing and Sanger sequencing were used to detect 51 gene mutations. The occurrence, clinical characteristics and treatment efficacy of coexisting genes with NRAS were investigated. RESULTS: A total of 57 NRAS mutations (17.5%) were detected in 326 patients with AML. Compared with the patients in NRAS non-mutation group, patients in the mutant group were younger (P=0.018) and showed lower platelet count (P=0.033), but there was no significant difference in peripheral leukocyte count, hemoglobin, and sex. For FAB classification, NRAS mutation and M2 subtype showed mutually exclusive (P=0.038). Among 57 patients carried with NRAS mutation, 51 (89.5%) patients carried with other gene mutations, 25 (43.9%) carried with double gene mutations, 10 (17.5%) carried with 3 gene mutations, and 16 (28.1%) corried with ≥ 4 gene mutations. The most common coexisting gene mutation was KRAS (24.6%, 14/57), followed by FLT3-ITD (14.0%, 8/57), RUNX1 (12.3%, 7/57), NPM1 (10.5%, 6/57), PTPN11 (10.5%, 6/57), DNMT3A (10.5%, 6/57) and so on. The age (P=0.013, P=0.005) and peripheral platelet count (P=0.007, P=0.021) of patients with NPM1 or DNMT3A mutations were higher than those of the patients with wild type, but there was no significant difference in peripheral leukocyte count and hemoglobin. Also, there was no significant difference in age, peripheral leukocyte count, hemoglobin, and peripheral platelet count between the patients in KRAS, FLT3-ITD, RUNX1 or PTPN11 mutant group and the wild group. Patients with FLT3-ITD mutations showed a lower complete remission (CR) rate (P=0.044). However, there was no significant difference in CR rate between the patients with KRAS, NPM1, RUNX1, PTPN11 or DNMT3A mutations and the wild group. The CR rate of the patents with single gene mutation, double gene mutations, 3 gene mutations, and≥ 4 gene mutations were decreased gradually, and there was no significant difference in CR rate between pairwise comparisons. CONCLUSION The mutation rate of NRAS mutation is 17.5%, 89.5% of AML patients with NRAS mutation coexist with additional gene mutations. The type of coexisting mutations has a certain impact on clinical characteristics and CR rate of patients with AML.
Core Binding Factor Alpha 2 Subunit/genetics* ; GTP Phosphohydrolases/genetics* ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Membrane Proteins/genetics* ; Mutation ; Nucleophosmin ; Prognosis ; Proto-Oncogene Proteins p21(ras)/genetics* ; fms-Like Tyrosine Kinase 3