OBJECTIVETo investigate the clinical characteristics of newly diagnosed acute myeloid leukemia (AML) with NPM1 mutation.

METHODSNPM1 mutation (including A, B, D mutation type) was detected in 206 patients with newly diagnosed AML by real-time quantitative RT-PCR.

RESULTSThe incidence of NPM1 mutation was 15.5% in total AML patients and 32.5% in normal karyotypes AML patients. The characteristics of 174 NPM1 wild type patients v.s. that of 32 NPM1 mutation patients was as follow, median age (46 vs 35 years old, P < 0.01), WBC counts (27 × 10(9)/L vs 8 × 10(9)/L, P < 0.01), BPC (82 × 10(9)/L vs 36 × 10(9)/L, P < 0.01), proportion of AML-M(5) (31.2% vs 5.8%, P = 0.01), incidence of normal karyotypes (92.6% vs 40.8%, P < 0.01), incidence of FLT3-ITD-positive (25.0% vs 7.5%, P < 0.01), CD34-positvie (23.3% vs 69.5%, P < 0.01), cases with fusion gene (0 vs 47.1%, P < 0.01). No statistic difference was found in sex, percentage of blasts in bone marrow, complete remission rate, overall survival between the two groups. Relapse-free survival in AML patients with NPM1-mutation and FLT3-ITD-negative tended to be higher than in those with NPM1-mutation and FLT3-ITD-positive.

CONCLUSIONIt is necessary to detect NPM1 mutation and FLT3-ITD in newly diagnosed AML patients, especially in patients with high WBC and BPC, CD34-negative, normal karyotype, which might help to molecular classification and treatment.

OBJECTIVE: To investigate the clinical features, accompanying gene mutation characteristics and prognostic factors of adult patients with acute myeloid leukemia with mutated NPM1 (NPM1AML). METHODS: Seventy-three patients with newly diagnosed adult NPM1AML were selected. The mutations of 22 genes were detected by second generation sequencing and 43 fusion genes of AML were detected by real-time fluorescent quantitative PCR. The Kaplan-Meier survival curve and Cox multivariate regression analysis were used to study the prognostic factors. RESULTS: A total of 74 NPM1 site mutations were detected in 73 patients with NPM1AML. The incidence rates were 92.0% L287fs, 2.7% Q289fs and W288fs, 1.4% L258fs and Q289H, among which 1 patient had 2 NPM1 mutations; the different mutation sites had no effect on the prognosis of NPM1AML. The median value of NPM1 variant allele frequency (VAF) was 35.4% (1.8%-56.6%). Based on the uppermost quartile of 38.4%, the patients were classified as NPM1 VAF>38.4% (NPM1AML) and NPM1 VAF≤38.4% (NPM1AML). Compared with NPM1AML, the early mortality rate was statistically significantly higher (33.3% vs 7.3%, P<0.05), and median EFS (148 d，95%CI 58-238 d vs 372 d，95%CI 264-480 d) (P<0.01) and median OS (179 d 95%CI 6-352 d vs 444 d) (P<0.01) were significantly shorter in NPM1 AML. A total of 126 accompanying gene mutation sites were detected in 87.7% of patients with NPM1AML. The patients with NRAS gene mutation displayed a higher rate of complete remission (100% vs 58%) (P<0.05) and longer median OS (not reached to 320 d, 95%CI 150-490 d) (P<0.05). The 43 fusion genes were examined in 65 out of 73 cases of NPM1AML, and in all the patients the fusion gene test was negative. Multivariate analysis showed that NPM1 VAF>38.4% was an independent prognostic factor for EFS (HR=3.1, 95% CI 1.6-6.4, P<0.01) and OS (HR=3.0, 95% CI 1.4-6.2, P<0.01). CONCLUSION The NPM1 gene mutation in AML patients often is accompanied by other gene mutations, while the coexistence of fusion genes is rare; high NPM1 mutant allele burden is an independent prognostic factor for adult AML patients with mutated NPM1.
Alleles ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Mutation ; Nuclear Proteins ; genetics ; Prognosis ; fms-Like Tyrosine Kinase 3

OBJECTIVE: To explore the potential pathogenetic mutations of primary hypereosinophilia（HEN）by sequencing FGFR1 FLT3, MPL and JAK2 genes, and to clarify their effect on clinical manifestation and prognosis of HEN patients. METHODS: The direct DNA sequencing was employed to detect the gene mutations of FGFR1, FLT3, MPL and JAK2 in HEN patients. RESULTS: One deletion mutation (2654_2753del) within tyrosine kinase domain of FLT3 gene was found in a patient suffered from severe symptoms and ended with dismal outcome, which induced a premature stop codon (G885fsX888). For FGFR1, a new variation described as 1014_1019del AACAGT for nucleotide change was found in 19 cases, resulting in T339_V340del at the protein level. CONCLUSION The deletion of 6 bases in the FGFR1 gene (1014_1019del AACAGT) is first reported as non-synonymous SNP (nsSNP) site in the patients with primary hypereosinophilia. Deletion mutations in the FLT3 gene may be related with malignant clinical features and poor prognosis.
Base Sequence ; Humans ; Hypereosinophilic Syndrome ; genetics ; Mutation ; Receptors, Thrombopoietin ; Sequence Deletion ; fms-Like Tyrosine Kinase 3

Nucleophosmin (NPM) is a protein that shuttles between the nucleus, nucleoplasm and cytoplasm. NPM gene mutations and aberrant cytoplasmic NPM localization have been recently described in acute myelogenous leukemia (AML) with normal karyotype and in a few myelodysplastic syndromes. Expression of NPM mutant reduces the ability of Arf to initiate a p53 response and to induce cell cycle arrest. Clinical research has revealed that NPM mutations are relative to prognosis and can be used to monitor and quantify minimal residual disease (MRD) in AML patients with normal karyotype, therefore, these findings indicate that nucleophosmin mutations might contribute to illustration of myeloid leukemogenesis. In this paper, the research progress of nucleophosmin mutations in haematological malignancies was reviewed.
Cell Nucleolus ; metabolism ; Hematologic Neoplasms ; genetics ; pathology ; Humans ; Mutation ; Nuclear Proteins ; genetics ; 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 investigate the expression of CD73 in acute myeloid leukemia (AML) patients with NPM1 mutant and wild-type, and to evaluate the therapeutic efficacy and prognosis of CD73 to the AML patients. METHODS: 160 patients with AML treated in our hospital from June 2015 to June 2019 were enrolled, and 40 non-AML bone marrow samples from healthy people were selected as controls during the same period. The expression of CD73 in healthy people, NPM1 mutation and NPM1 wild-type AML patients were compared, and the relationship between the expression of CD73 and its clinicopathological characteristics, as while as efficacy in AML patients were analyzed. The patients were followed up, and the influence of CD73 to the prognosis of different AML patients was analyzed. RESULTS: The positive expression rate of CD73 in AML patients (23.75%) was significantly higher than that in the healthy control group (0.62%), and the positive expression rate of CD73 in AML patients with NPM1 mutation (74.75%) was significantly higher than that with NPM1 wild-type (25.51%) (both P<0.001). AML patients with CD73 positive expression was associated with age, FAB typing, disease risk classification, and NPM1 gene mutation (both P<0.05). The overall survival rate of AML patients with NPM1 gene mutation was 75.98%, which was significantly higher than the patients with NPM1 wild-type (34.68%)(P<0.001), the median survival time of AML patients with NPM1 gene mutation in the CD73 CONCLUSION The expression of CD73 was increased in AML patients with NPM1 gene mutation, and CD73 showed different prognostic significance in AML patients with different NPM1 gene mutation. The combination of clinicopathologic features, CD73 expression and NPM1 gene in AML patients is helpful to determine their prognosis and guide the formulation of relevant treatment plans.
Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Nuclear Proteins/genetics* ; Prognosis ; Survival Rate ; fms-Like Tyrosine Kinase 3

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 investigate the characteristics of gene mutation in elderly patients with acute myeloid leukemia (AML) and its effect on prognosis. METHODS: The clinical and laboratorial characteristics of 54 AML patients (≥60 years old) in Department of Hematology, Tangdu Hospital were analyzed retrospectively during April 2016 to October 2019. Thirty-four AML/myelodysplastic syndrome/myeloproliferative neoplasm related mutant genes were detected by second-generation sequencing technology, and their clinical characteristics, treatment effect, and influence on prognosis were analyzed. RESULTS: All the patients received DAC+CAG induction treatment, after 1-2 couses of treatment, 36 cases (66.7%) achieved complete response, with a total effective rate of 75.9%, and the median survival time was 17 months. The most frequent mutant genes were TET2 (33.3%), CEBPA (31.5%), DNMT3A (18.5%), ASXL1 (16.7%), NRAS (14.8%), RUNX1 (14.8%), FLT3-ITD (12.9%), TP53 (12.9%), NPM1 (12.9%), and IDH2 (12.9%). Among 7 patients with TP53 mutation, 6 cases obtained complete response after 1-2 courses of induction treatment, but there was no statistically significant difference in the effect on prognosis. Patients with FLT3-ITD and NRAS mutations had shorter overall survival time compared with who had no mutation (P=0.47, P=0.48). Multivariate analysis showed that FLT3-ITD and NRAS mutations were poor prognostic factors. CONCLUSION The incidence of TET2 gene mutation is high in elderly AML patients. AML patients with TET2 and TP53 mutations may benefit from Decitabine-based chemotherapy. However, patients with FLT3-ITD and NRAS mutations have a short survival time, and may have a poor prognosis.
Aged ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Middle Aged ; Mutation ; Nucleophosmin ; Prognosis ; Retrospective Studies ; fms-Like Tyrosine Kinase 3

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*

To analyze the possible microRNA (miRNA) target sites in the 3' untranslated region (3'-UTR) of FMS-like tyrosine kinase 3 (FLT3) gene, a FLT3 3'-UTR-luciferase reporter vector was constructed and the effect of miRNA on its activity was evaluated in 293T cell line. The 3'-UTR fragment of FLT3 gene was amplified by PCR from genomic DNA of HepG2 cells. PCR products were cloned into PstI/EcoRI-modified pGL3-control reporter vector (pGL3-control-m). The miRNA targeting FLT3 3'-UTR was predicted by Target Scan 5.1 software. The luciferase reporter vector and miRNA eukaryotic expression vector were transferred into 293T cells using FuGENE HD transfection reagent. The Dual-Luciferase Reporter Assay System was used to quantitate the reporter activity. The results showed that a 804-bp 3'-UTR fragment of FLT3 gene was successfully cloned into the pGL3-control-m reporter vector, which authenticated by PstI/EcoRI digestion and DNA sequencing. The predicted miRNA targeting FLT3 3'-UTR included miRNA-15a, miRNA-15b, miRNA-16, miRNA-195, miRNA-424 and miRNA-497. The luciferase activity of reporter construct treated with miRNA-15a, miRNA-15b or miRNA-195 was decreased respectively about 20% compared with the control group. It is concluded that the FLT3 3'-UTR-luciferase reporter vector has been successfully constructed. The luciferase activity of the reporter can be suppressed by miRNA-15a, miRNA-15b or miRNA-195.
3' Untranslated Regions ; Base Sequence ; Cell Line ; Genetic Vectors ; Humans ; Luciferases ; genetics ; MicroRNAs ; genetics ; Transfection ; fms-Like Tyrosine Kinase 3 ; genetics