Research Progress of m6A Demethylase FTO and Its Inhibitors in Acute Myeloid Leukemia --Review / 中国实验血液学杂志

Obesity-associated protein (FTO) is an important m6A demethylase that regulates RNA methylation modification and can promote the proliferation of acute myeloid leukemia(AML) cells. FTO regulates the methylation level of AML through multiple cellular signaling pathways such as FTO/RARA/ASB2, FTO/m6A/CEBPA, and PDGFRB/ERK, and participates in the occurrence, development, treatment and prognosis of AML. At present, studies have found that a variety of inhibitors targeting FTO have shown good anti-leukemia effects, and the study of FTO will provide new ideas for the treatment of AML. This review focus on the mechanism of action of FTO in AML and the research progress of FTO inhibitors in AML.

Efficacy and Safety of Decitabine Combined with Modified CAG Regimen in Patients Aged ≥ 70 Years with Newly Diagnosed Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To evaluate the clinical efficacy and safety of decitabine combined with modified CAG regimen (D-CAG regimen) in patients aged ≥70 years with newly diagnosed acute myeloid leukemia (AML).@*METHODS@#The clinical data of 59 AML patients (≥70 years old) who were newly diagnosed and treated in the Hematology Department of the First Affiliated Hospital of Nanjing Medical University from November 2010 to June 2021 were retrospectively analyzed.@*RESULTS@#Among the 59 AML patients, 28 were males and 31 were females, with a median age of 74 (70-86) years. The complete remission (CR) rate was 69.4% (34/49), and the median duration of CR was 10.7 (0.6-125.4) months after 2 courses of D-CAG treatment. According to the British Medical Research Council (MRC) classification, there was only one patient in the favorable-risk group, and the CR rate was 71.8% (28/39) in the intermediate-risk group, and 55.6% (5/9) in the adverse-risk group, respectively. There was no statistical difference in the CR rate between the intermediate-risk and adverse-risk group. Referring to ELN 2017 genetic risk classification, CR rate was 88.2% (15/17) in the favorable-risk group, 45.5% (5/11) in the intermediate-risk group, and 66.7% (14/21) in the adverse-risk group. There was no significant difference in CR rate between the favorable-risk and adverse-risk categories, but both were significantly higher than that in the intermediate-risk group (P <0.05). Next-generation sequencing (NGS) analysis showed that 11 gene mutations with a frequency of more than 10%, including TET2 mutation (35.6%), ASXL1 mutation (30.5%), NPM1 mutation (28.8%), FLT3-ITD mutation (27.1%), DNMT3A mutation (22.0%), IDH1 mutation (15.3%), CEBPA single mutation (13.6%), TP53 mutation (13.6%), IDH2 mutation (11.9%), RUNX1 mutation (11.9%), and NRAS mutation (10.2%). There were no statistical differences in mutation frequency of these 11 genes between CR group and non-CR group. Compared with normal karyotypes, patients with complex karyotypes were more likely to develop TP53 mutations (P <0.001), while FLT3-ITD and DNMT3A mutations were more likely to occur in patients with normal karyotypes (P =0.04, P =0.047). The median follow-up, overall survival (OS), and event-free survival (EFS) of all the patients was 11.7 (1.5-128.2) months, 12.3 (1.5-128.2) months, and 8.5 (1.5-128.2) months, respectively. The median OS and EFS of CR patients were 19.8 and 13.3 months, respectively, which were significantly longer than 6.4 and 5.7 months in patients experiencing treatment failure (P < 0.001, P =0.009). In regard to genes with mutation frequency >10%, there were no statistical differences in CR rate, median OS, and median EFS between mutated and wild-type patients by Chi-square test and survival analysis. Univariate analysis showed that age, hemoglobin, lactate dehydrogenase, cytogenetics and CR were factors affecting prognosis, while multivariate analysis showed that only CR failure was an independent adverse prognostic factor for OS. The major adverse reactions to D-CAG regimen were grade 3-4 myelosuppression, pulmonary infection, and fever (infection focus was not identified).@*CONCLUSION@#D-CAG regimen is safe and effective in the treatment of AML patients ≥70 years old, and can partially improve the prognosis of elderly and high-risk patients.

Research Progress of Next Generation Sequencing in Acute Leukemia --Review / 中国实验血液学杂志

With the advent of precision medicine, next-generation sequencing (NGS) is playing an increasingly important role in clinical oncology diagnosis and treatment with its advantages of high sensitivity, high accuracy, high efficiency and operability. NGS reveals the genetic characteristics of acute leukemia(AL) patients by screening for specific disease-causing genes to identify occult as well as complex genetic mutations in patients with AL, leading to early diagnosis and targeted drug therapy for AL patients, as well as to predict disease recurrence by detecting mnimal residual disease (MRD) and analyzing mutated genes to determine patient prognosis. NGS plays an increasingly important role in the diagnosis, treatment and prognosis assessment in AL, providing a direction for the pursuit of precision medicine. This paper reviews the research progress of NGS in AL.

The Effects and Regulatory Mechanism of Targeting CXC Chemokine Receptor 1/2 Combined with Ara-C on the Malignant Biological Behaviors of U937 Cells of Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate and analyze the effect of CXC chemokine receptor 1/2 (CXCR1/2) targeting inhibitor Reparixin combined with cytarabine (Ara-C) on the malignant biological behaviors of acute myeloid leukemia cells and its effect on the expression of the CXCR family, while exploring the accompanying molecular mechanism, providing scientific basis and reference for new molecular markers and targeted therapy for AML.@*METHODS@#Acute myeloid leukemia U937 cells were treated with different concentrations of Reparixin, Ara-C alone or in combination, and the cell morphology was observed under an inverted microscope; Wright-Giemsa staining was used to detect cell morphological changes; CCK-8 method was used to detect cell proliferation; the ability of cell invasion was detected by Transwell chamber method; the ability of colony formation was detected by colony formation assay; cell apoptosis was detected by Hoechst 33258 fluorescent staining and Annexin V/PI double-staining flow cytometry; monodansylcadaverine(MDC) staining was used to detect cell autophagy; the expression of apoptosis, autophagy and related signaling pathway proteins was detected by Western blot and the expression changes of CXCR family were detected by real-time quantitative polymerase chain reaction (qRT-PCR).@*RESULTS@#Reparixin could inhibit the proliferation, invasion, migration and clone formation ability of U937 cells. Compared with the single drug group, when U937 cells were intervened by Reparixin combined with Ara-C, the malignant biological behaviors such as proliferation, invasion and colony formation were significantly decreased, and the levels of apoptosis and autophagy were significantly increased (P<0.01). After Reparixin combined with Ara-C intervenes in U937 cells, it can up-regulate the expression of the pro-apoptotic protein Bax and significantly down-regulate the expression of the anti-apoptotic protein Bcl-2, and also hydrolyze and activate Caspase-3, thereby inducing cell apoptosis. Reparixin combined with Ara-C could up-regulate the expressions of LC3Ⅱ and Beclin-1 proteins in U937 cells, and the ratio of LC3Ⅱ/LC3Ⅰ in cells was significantly up-regulated compared with single drug or control group (P<0.01). MDC result showed that the green granules of vesicles increased significantly, and a large number of broken cells were seen (P<0.01). Reparixin combined with Ara-C can significantly inhibit the phosphorylation level of PI3K, AKT and NF-κB signaling molecule, inhibit the malignant biological behavior of cells by inhibiting the activation of PI3K/AKT/NF-κB pathway, and induce programmed cell death. Ara-C intervention in U937 cells had no effect on the expression of CXCR family (P>0.05). The expression of CXCR1, CXCR2, and CXCR4 mRNA could be down-regulated by Reparixin single-agent intervention in U937 cells (P<0.05), and the expression of CXCR2 was more significantly down-regulated than the control group and other CXCRs (P<0.01). When Reparixin and Ara-C intervened in combination, the down-regulated levels of CXCR1 and CXCR2 were more significant than those in the single-drug group (P<0.01), while the relative expressions of CXCR4 and CXCR7 mRNA had no significant difference compared with the single-drug group (P>0.05).@*CONCLUSION@#Reparixin combined with Ara-C can synergistically inhibit the malignant biological behaviors of U937 cells such as proliferation, invasion, migration and clone formation, and induce autophagy and apoptosis. The mechanism may be related to affecting the proteins expression of Bcl-2 family and down-regulating the proteins expression of CXCR family, while inhibiting the PI3K/AKT/NF-κB signaling pathway.

A new form of familial platelet disorder caused by germline mutations in RUNX1 in a pedigree / 中华内科杂志

Objective: To investigate the clinical and biological characteristics of familial platelet disorder (FPD) with germline Runt-related transcription factor (RUNX) 1 mutations. Methods: Patients diagnosed with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) with RUNX1 mutations from February 2016 to December 2021 in Wuhan No.1 Hospital underwent pedigree analysis and were screened for gene mutations (somatic and germline). Patients diagnosed with FPD with germline RUNX1 mutations were enrolled and evaluated in terms of clinical characteristics and biological evolution. Bioinformatics analysis was used to assess the pathogenicity of mutations and to analyze the effect of mutated genes on the function of the corresponding protein. Results: Germline RUNX1 mutations were detected in three out of 34 patients suffering from MDS/AML who had RUNX1 mutations. A pedigree of FPD with RUNX1 (RUNX1-FPD) c.562A>C and RUNX1 c.1415T>C mutations was diagnosed, and the mutations were of patrilineal origin. Bioinformatics analysis indicated that the locus at positions 188 and 472 in the AML-1G type of RUNX1 was highly conserved across different species, and that variations might influence functions of the proteins. The mutations were evaluated to be highly pathogenic. Of the nine cases with germline RUNX1 mutations: two patients died due AML progression; one case with AML survived without leukemia after transplantation of hemopoietic stem cells; four patients showed mild-to-moderate thrombocytopenia; two cases had no thrombocytopenia. During the disease course of the proband and her son, mutations in RUNX1, NRAS and/or CEBPA and KIT appeared in succession, and expression of cluster of differentiation-7 on tumor cells was enhanced gradually. None of the gene mutations correlated with the tumor were detected in the four cases not suffering from MDS/AML, and they survived until the end of follow-up. Conclusions: RUNX1-FPD was rare. The mutations c.562A>C and c.1415T>C of RUNX1 could be the disease-causing genes for the family with RUNX1-FPD, and these mutations could promote malignant transformation. Biological monitoring should be carried out regularly to aid early intervention for family members with RUNX1-FPD.

Analysis of 7 cases of pediatric acute myeloid leukemia with DEK-NUP214 fusion gene / 中华儿科杂志

Objective: To investigate the clinical features, treatment regime, and outcome of pediatric acute myeloid leukemia (AML) with DEK-NUP214 fusion gene. Methods: The clinical data, genetic and molecular results, treatment process and survival status of 7 cases of DEK-NUP214 fusion gene positive AML children admitted to the Pediatric Blood Diseases Center of Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences from May 2015 to February 2022 were analyzed retrospectively. Results: DEK-NUP214 fusion gene positive AML accounted for 1.02% (7/683) of pediatric AML diagnosed in the same period, with 4 males and 3 females. The age of disease onset was 8.2 (7.5, 9.5) years. The blast percentage in bone marrow was 0.275 (0.225, 0.480), and 6 cases were M5 by FAB classification. Pathological hematopoiesis was observed in all cases except for one whose bone marrow morphology was unknown. Three cases carried FLT3-ITD mutations, 4 cases carried NRAS mutations, and 2 cases carried KRAS mutations. After diagnosis, 4 cases received IAE induction regimen (idarubicin, cytarabine and etoposide), 1 case received MAE induction regimen (mitoxantrone, cytarabine and etoposide), 1 case received DAH induction regimen (daunorubicin, cytarabine and homoharringtonine) and 1 case received DAE induction regimen (daunorubicin, cytarabine and etoposide). Complete remission was achieved in 3 cases after one course of induction. Four cases who did not achieved complete remission received CAG (aclarubicin, cytarabine and granulocyte colony-stimulating factor), IAH (idarubicin, cytarabine and homoharringtonine), CAG combined with cladribine, and HAG (homoharringtonine, cytarabine and granulocyte colony-stimulating factor) combined with cladribine reinduction therapy, respectively, all 4 cases reached complete remission. Six patients received hematopoietic stem cell transplantation (HSCT) after 1-2 sessions of intensive consolidation treatment, except that one case was lost to follow-up after complete remission. The time from diagnosis to HSCT was 143 (121, 174) days. Before HSCT, one case was positive for flow cytometry minimal residual disease and 3 cases were positive for DEK-NUP214 fusion gene. Three cases accepted haploid donors, 2 cases accepted unrelated cord blood donors, and 1 case accepted matched sibling donor. The follow-up time was 20.4 (12.9, 53.1) months, the overall survival and event free survival rates were all 100%. Conclusions: Pediatric AML with DEK-NUP214 fusion gene is a unique and rare subtype, often diagnosed in relatively older children. The disease is characterized with a low blast percentage in bone marrow, significant pathological hematopoiesis and a high mutation rate in FLT3-ITD and RAS genes. Low remission rate by chemotherapy only and very high recurrence rate indicate its high malignancy and poor prognosis. Early HSCT after the first complete remission can improve its prognosis.

Molecular features of 109 patients with chronic myelomonocytic leukemia in a single center / 中华血液学杂志

Objective: To explore the molecular features of chronic myelomonocytic leukemia (CMML) . Methods: According to 2022 World Health Organization (WHO 2022) classification, 113 CMML patients and 840 myelodysplastic syndrome (MDS) patients from March 2016 to October 2021 were reclassified, and the clinical and molecular features of CMML patients were analyzed. Results: Among 113 CMML patients, 23 (20.4%) were re-diagnosed as acute myeloid leukemia (AML), including 18 AML with NPM1 mutation, 3 AML with KMT2A rearrangement, and 2 AML with MECOM rearrangement. The remaining 90 patients met the WHO 2022 CMML criteria. In addition, 19 of 840 (2.3%) MDS patients met the WHO 2022 CMML criteria. At least one gene mutation was detected in 99% of CMML patients, and the median number of mutations was 4. The genes with mutation frequency ≥ 10% were: ASXL1 (48%), NRAS (34%), RUNX1 (33%), TET2 (28%), U2AF1 (23%), SRSF2 (21.1%), SETBP1 (20%), KRAS (17%), CBL (15.6%) and DNMT3A (11%). Paired analysis showed that SRSF2 was frequently co-mutated with ASXL1 (OR=4.129, 95% CI 1.481-11.510, Q=0.007) and TET2 (OR=5.276, 95% CI 1.979-14.065, Q=0.001). SRSF2 and TET2 frequently occurred in elderly (≥60 years) patients with myeloproliferative CMML (MP-CMML). U2AF1 mutations were often mutually exclusive with TET2 (OR=0.174, 95% CI 0.038-0.791, Q=0.024), and were common in younger (<60 years) patients with myelodysplastic CMML (MD-CMML). Compared with patients with absolute monocyte count (AMoC) ≥1×10(9)/L and <1×10(9)/L, the former had a higher median age of onset (60 years old vs 47 years old, P<0.001), white blood cell count (15.9×10(9)/L vs 4.4×10(9)/L, P<0.001), proportion of monocytes (21.5% vs 15%, P=0.001), and hemoglobin level (86 g/L vs 74 g/L, P=0.014). TET2 mutations (P=0.021) and SRSF2 mutations (P=0.011) were more common in patients with AMoC≥1×10(9)/L, whereas U2AF1 mutations (P<0.001) were more common in patients with AMoC<1×10(9)/L. There was no significant difference in the frequency of other gene mutations between the two groups. Conclusion: According to WHO 2022 classification, nearly 20% of CMML patients had AMoC<1×10(9)/L at the time of diagnosis, and MD-CMML and MP-CMML had different molecular features.

Establishment of leukemia cell model with inducible AML1-ETO expression and its effect on fatty acid metabolism in leukemia cells / 中华血液学杂志

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.

Efficacy and Survival of Venetoclax Based Regimen in the Treatment of Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the efficacy and survival of venetoclax based (VEN-based) regimen in the treatment of acute myeloid leukemia（AML）.@*METHODS@#A retrospective study was conducted in patients who received VEN-based regimen and completed at least 1 course of efficacy evaluation at the The First Affiliated Hospital of Nanchang University from July 2019 to July 2022. The incidence of complete remission （CR）/CR with incomplete hematologic recovery （CRi） rate, objective remission rate（ORR） and survival of patients with different risk strati- fication and gene subtypes were analyzed.@*RESULTS@#A total of 79 patients were enrolled, including 43 patients with newly diagnosed unfit AML （unfit AML） and 36 relapsed/refractory AML (R/R AML). The median age of the patients was 62(14-83) years old. 36 out of 79 patients achieved CR/CRi and the ORR of the whole cohort was 64.6%. The CR/CRi rate of unfit AML patients was significantly higher than that of R/R AML patients (60.5% vs 27.8%, P=0.004). In unfit AML cohort, the patients with NPM1 and IDH1/2 mutations were benefited, 8 out of 9 patients ahcieved CR/CRi, 7/8 and 5/8 patients achieved minimal residual disease (MRD) negativity, respectively. Six out of 9 patients with TET2 mutation achieved CR/CRi, 3/6 patients achieved MRD negativity. In R/R AML cohort, 2 out of 3 patients with RUNX1 mutation achieved CR/CRi, without MRD negative, while the CR/CRi rate of patients with other gene mutations was lower than 40%. The median follow-up time was 10.1(95%CI: 8.6-11.6) months. In whole cohort, the median overall survival (mOS) time was 9.1 months and the relapse free survival (RFS) time was not reached. The mOS and RFS of unfit AML patients were significantly longer than those of R/R AML patients (14.1 vs 6.8 months, P=0.013; not reached vs 3.3 months, P=0.000). In unfit AML cohort, the mOS of patients with NPM1 or IDH1/2 mutations was not reached, while that of patients without NPM1 or IDH1/2 mutations was 8.0 months (P=0.009; P=0.022). Furthermore, the mOS of patients with TP53 mutaion was significantly shorter than that of patients without TP53 mutation (5.2 vs 14.1 months， P=0.049). In R/R AML cohort, there was no significant difference in mOS between patients with mutation in each gene subtype and those without gene mutation (P>0.05). All patients had hematology adverse reactions, 91.1% patients had AE grade≥3. The most common non-hematology adverse reactions was infection, with an incidence of 91.1%. VEN-based regimen was tolerable for AML patients.@*CONCLUSION@#VEN-based regimen can achieve a high response rate, especially in unfit AML with acceptable safety, and some patients can achieve MRD negative. It is also effective in NPM1-, IDH1/2-positive patients with long survival time.

Efficacy and Recurrence Factors of Veneclax Combined with Aza- citidine in the Treatment of Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To observe the efficacy of veneclax combined with azacitidine in acute myeloid leukemia(AML) patients and explore the predictors of treatment response and recurrence.@*METHODS@#The clinical data of 30 AML patients who received venetecla combined with azacitidine in the Affiliated Hospital of Southwest Medical University from January 2021 to September 2022 were retrospectively analyzed, composite complete remission (CRc) rate, overall response rate(ORR), and disease free survival(DFS) of patients were observed.@*RESULTS@#After one course of trea- tment, CRc was 16 cases and ORR was 23/30. Patients with TP53 mutation had poor treatment response (P=0.009). After 1-2 courses, 25 patients reached CR/CRi. Finally, 24 patients who obtained CR/CRi were included to observe the duration of remission. 17 patients had relapse, with a median recurrence time of 3.9 (0.6-15.9) months. The Kaplan-Meier curve showed that MRD negative was a favorable factor for maintaining DFS status (HR=0.5647,95%CI:0.2179-1.464,P=0.007), while NRAS mutation was an adverse factor for maintaining DFS (HR=2.036,95%CI:0.6639-6.245,P=0.0003). Univariate combined multivariate cox regression analysis showed that NRAS mutation was an independent risk factor affecting DFS in patients (HR=5.569, P<0.05). In addition, the cases number of early recurrence in MRD negative group (n=8) and MRD non-negative group (n=9) was 0 and 5, respectively, the difference was statistically significant (P=0.012). There were 3 cases of early recurrence in the NRAS mutant group (n=4) and 2 cases in the NRAS wild-type group (n=13), the difference was statistically significant (P=0.022).@*CONCLUSION@#TP53 mutation is a predictor of poor response to veneclax in combination with azacitidine. With the conti-nuation of the combination chemotherapy regimen described above, NRAS mutation is an independent risk factor for DFS in patients. Moreover, the patients with non-negative MRD and NRAS mutations are at high risk of early recurrence.

Safety and the Short-Term Efficacy of Venetoclax Combined with Azacitidine Followed by Cladribine in Children with Refractory/Relapsed Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the safety and the short-term efficacy of venetoclax combined with azacitidine followed by cladribine (VAC regimen) in children with refractory/ relapsed acute myeloid leukemia (AML).@*METHODS@#The clinical data, treatment outcomes, complications, and blood product consumption of 6 children with refractory/relapsed AML treated with VAC regimen in the Children's Hospital of Soochow University from August 2021 to December 2021 were retrospectively analyzed.@*RESULTS@#Among the 6 children, there were 1 male and 5 females. 5 cases were refractory AML, and 1 case was relapsed AML, which recurred again 16 months after allogeneic hematopoietic stem cell transplantation. 4 children were accompanied by chromosomes or genes that predicted poor prognosis, such as RUNX1, FLT3-ITD, KMT2A exon 2-exon 8 dup, MLL-AF6, 7q-, KMT2A exon 2-exon 10 dup, etc. After received VAC regimen, 4 cases achieved CR+CRi, 1 case achieved PR (only MRD did not relieve, MRD was 0.59%), and 1 case was NR (but the proportion of bone marrow blasts decreased). All 6 patients had grade Ⅳ neutropenia, and 4 patients had grade Ⅳ thrombocytopenia. During the period of neutropenia, none of the 6 children developed symptoms of infection such as fever, cough, and diarrhea. No treatment-related death occurred.@*CONCLUSION@#Venetoclax combined with azacitidine followed by cladribine provides a new treatment option for patients with relapsed/refractory AML who have poor efficacy in early induction remission theragy, showing good efficacy and safety.

Efficacy of Venetoclax Plus Azacitidine in Relapsed/Refractory Acute Myeloid Leukemia Patients with FLT3-ITD Mutation / 中国实验血液学杂志

OBJECTIVE@#To explore the efficacy of venetoclax (VEN) plus azacitidine (AZA) in patients with FLT3-ITD mutated relapsed/refractory acute myeloid leukemia (FLT3-ITDmut 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-ITDmut R/R AML were analyzed.@*RESULTS@#14.3% (1/7) of the patients in FLT3-ITDmut group and 22.2% (2/9) of the patients in FLT3-ITDwt 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-ITDmut group and FLT3-ITDwt group [42.9%(3/7) vs 44.4%(4/9), P=0.95], too. The median overall survival (OS) time of FLT3-ITDmut patients was significantly shorter than that of FLT3-ITDwt 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-ITDmut 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-ITDmut R/R AML. To improve OS of the patients, bridging transplantation is need. IDH1 and SF3B1 mutations might predict that patients with FLT3-ITDmut R/R AML have treatment response to VEN plus AZA, while the combination of NPM1 mutation may indicate poor response.

Analysis of CSF3R Gene Mutations and Clinical Characteristics in Patients with t(8;21) Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the occurrence of CSF3R mutation in patients with t(8;21) acute myeloid leukemia (AML) and its correlation with some clinical parameters.@*METHODS@#The clinical and laboratory data of 167 newly diagnosed AML patients with t(8;21) translocation were analyzed retrospectively. High-throughput DNA sequencing technology combined with Sanger sequencing method was used to detect 112 gene mutations. The occurrence of CSF3R gene mutation and its influence on the remission rate after chemotherapy were analyzed.@*RESULTS@#Among 167 patients with t(8;21) AML, 15 patients (9.0%) carried CSF3R mutations, including 6 cases of membrane proximal region mutations and 9 cases of truncation mutations in the cytoplasmic tail. The most common coexisting mutations of CSF3R were KIT (40.0%), TET2 (33.3%), DNMT3A (26.7%), FLT3 (20.0%), CBL (20.0%), IDH1 (13.3%), etc. Compared with the wild type, the CSF3R mutant group had a higher mutation rate of DNA methylation-related genes（P <0.001）. The median peripheral white blood cell (WBC) count of patients with CSF3R gene mutation was 5.80 (3.20-8.56)×109/L at initial diagnosis, which was significantly lower than 8.80 (5.26-19.92)×109/L of the CSF3R wild-type patients (P =0.017). There was no significant difference between the two groups in sex, median age, FAB classification, hemoglobin level, platelet count, etc. (P >0.05). The CR rate of the CSF3R gene mutation group (100%) was significantly higher than that of the wild-type group (86.8%), but the difference was not statistically significant (P >0.05). The CSF3R gene mutation group had a significantly higher CD19 positive rate and a higher -X rate than the wild group (86.7% vs 47.4%, P =0.004; 33.3% vs 13.2%, P =0.037).@*CONCLUSION@#There is a high incidence of CSF3R mutation in t (8;21) AML patients. The clinical characteristics and coexisting mutation genes of CSF3R mutation-positive patients are different from those of wild-type patients.

High-Throughput Sequencing Technology for Detection of Gene Mutations in Myeloid Malignancies and Its Clinical Prognostic Significance / 中国实验血液学杂志

OBJECTIVE@#To detect the gene mutations in patients with myeloid malignancies by high-throughput sequencing and explore the correlation between gene mutations and prognosis.@*METHODS@#A retrospective analysis was performed on 56 patients with myeloid malignancies who were hospitalized in the department of hematology, Peking University International Hospital from January 2020 to May 2021. The genetic mutations of the patients were detected by next-generation sequencing technology, and the correlation between the genetic mutations and prognosis of myeloid malignancies was analyzed.@*RESULTS@#In 56 patients, the number of mutated genes detected in a single patient is 0-9, with a median of 3. Sequencing results showed that the most common mutated genes were RUNX1(21.4%), TET2(17.9%), DNMT3A(17.9%), TP53(14.3%) and ASXL1(14.3%), among which the most common mutations occurred in the signaling pathway-related genes (23.3%) and the transcription factor genes (18.3%). 84% of the patients carried multiple mutated genes (≥2), and correlation analysis showed there were obvious co-occurring mutations between WT1 and FLT3, NPM1 and FLT3-ITD, and MYC and FLT3. TP53 mutation was more common in MDS patients.The overall survival time of patients with NRAS mutation was significantly shortened (P =0.049). The prognosis of patients with TP53 mutation was poor compared with those without TP53 mutation, but the difference wasn't statistically significant (P =0.08).@*CONCLUSION@#The application of next-generation sequencing technology is of great significance in myeloid malignancies, which is helpful to better understand the pathogenesis of the disease, to judge the prognosis and to find possible therapeutic targets.

Characteristics of genetic variants in 134 patients with Acute myeloid leukemia / 中华医学遗传学杂志

OBJECTIVE@#To analyze the characteristics of genetic variants in 134 patients diagnosed with Acute myeloid leukemia (AML).@*METHODS@#Clinical data of the 134 patients with AML (non-acute promyelocytic leukemia) initially diagnosed at the 940th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army from June 2017 to June 2022 were retrospectively analyzed. Potential variants of AML-related genes were detected by next-generation sequencing, and the frequency of variants was analyzed by using SPSS v26.0 software, and likelihood ratio χ2 test and Fisher exact test were used for data analysis.@*RESULTS@#The patients had included 72 males and 62 females, with a gender ratio of 1.7 : 1 and a median age of 51 years (9 ~ 86 years old). One hundred twenty patients (76.1%) had harbored at least one genetic variant, including 26 (19.4%) having a single variant, 27 (20.1%) having two variants, and 49 (36.6%) having >= 3 variants. 32 (23.9%) had no detectable variants. Genetic variants detected in over 10% of the 134 patients had included NPM1 (n = 24, 17.91%), FLT3-ITD (n = 21, 15.67%), DNMT3A (n = 20, 14.93%), CEBPA (single variant; n = 14, 10.45%), TET2 (n = 14, 10.45%), and NRAS (n = 14, 10.45%). The patients were also divided into low risk, intermediate risk and high risk groups based on their chromosomal karyotypes. The mutational rates for genes in different groups have varied, with 19 patients from the low risk group harboring variants of NRAS (n = 4, 21.05%), KRAS (n = 4, 21.05%), and KIT (n = 2, 10.53%); and 96 patients from the intermediate risk group harboring variants of NPM1 (n = 24, 25.00%), FLT3-ITD (n = 20, 20.83%), DNMT3A (n = 18, 18.75%), CEBPA (n = 12, 12.50%), and TET2 genes (n = 12, 12.50%). The mutational frequencies for the 19 patients from the high risk group were ASXL1 (n = 7, 21.05%), NRAS (n = 3, 15.97%), TP53 (n = 3, 15.79%), and EZH2 (n = 2, 10.53%). A significant difference was found in the frequencies of KIT, NPM1, FLT3-ITD, DNMT3A, and ASXL1 gene variants among the low-risk, medium-risk, and high-risk groups.@*CONCLUSION@#AML patients have a high frequency for genetic variants, with 76.1% harboring at least one variant. The frequency of genetic variants have varied among patients with different chromosomal karyotypes, and there are apparent dominant variants. KIT, NPM1, FLT3-ITD, DNMT3A, and ASXL1 may be used as prognostic factors for evaluating their prognosis.

Preliminary study on the regulation of acute myeloid leukemia by FLT3 gene expression / 中华医学遗传学杂志

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.

Clinical features and prognosis of core binding factor acute myeloid leukemia children in South China: a multicenter study / 中华儿科杂志

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.

Effect of clonal hematopoiesis in remission on hematopoiesis recovery in patients with NPM1 mutated acute myeloid leukemia after chemotherapy / 中华血液学杂志

Objective: To investigate the effect of clonal hematopoiesis (CH) in remission on hematopoiesis recovery in patients with NPM1 mutated acute myeloid leukemia (AML) after chemotherapy. Methods: Retrospective analysis was performed on 86 patients with NPM1(mut) AML newly diagnosed and treated in the First Affiliated Hospital of Soochow University between July 2016 and June 2019. Their clinical data and NGS test results at diagnosis were analyzed. Moreover, bone marrow samples in remission were tested using Sanger sequencing. The log-rank test was used to analyze the difference in hematopoietic recovery, and Cox proportional hazard models were used to analyze the prognostic factors affecting hematopoietic recovery. Results: The median age of the 86 NPM1(mut) AML patients was 50 years (15-69 years). There were 39 males and 47 females. Forty-one patients were induced with intensity chemotherapy ("7 + 3"), whereas 45 patients were treated with low-dose cytarabine-based induction chemotherapy. At diagnosis, The most common mutations in the patients were FLT3, DNMT3A, TET2, and IDH1/IDH2 mutations. CH-associated mutations persisted in 21 patients during remission, and the mutations were DNMT3A, TET2, ASXL1, and IDH1/IDH2. The recovery time of neutrophils in patients with CH-associated mutations in remission was consistent with that in patients without CH in remission (P=0.282) but the recovery time of platelets in patients with CH in remission was significantly longer[26 (95% CI 21-32) days vs 25 (95% CI 23-26) days, P=0.032]. Furthermore, univariate analysis indicated that age, induced chemotherapy program, and CH in remission were risk factors for platelet recovery, whereas multivariate analysis indicated that induced chemotherapy program and CH in remission were independent risk factors for platelet recovery (HR=0.454, P=0.001 and HR=0.520, P=0.027, respectively) . Conclusion: CH in remission delays the hematopoietic recovery of patients with NPM1(mut) AML after chemotherapy.

Comparison of the efficacy of IA and HAD induction regimens in the treatment of patients with newly diagnosed acute myeloid leukemia: a single-center study / 中华血液学杂志

Objective: To compare the efficacy of two induction regimens, namely, idarubicin combined with cytarabine (IA) versus the combination of homoharringtonine, daunorubicin, and cytarabine (HAD) , in adult patients with newly diagnosed de novo acute myeloid leukemia (AML) . Methods: From May 2014 to November 2019, 199 patients diagnosed with AML receiving either the IA or HAD regimens were assessed for overall survival (OS) , relapse-free survival (RFS) , as well as the CR rate and the MRD negative rate after induction therapy. The differences in prognosis between the two induction therapy groups was assessed according to factors, including age, white blood cell (WBC) count, NPM1 mutation, FLT3-ITD mutation, 2017 ELN risk stratification, CR(1) transplantation, and the use of high-dose cytarabine during consolidation therapy, etc. Results: Among the 199 patients, there were 104 males and 95 females, with a median age of 37 (15-61) years. Ninety patients received the IA regimen, and 109 received the HAD regimen. Comparing the efficacy of the IA and HAD regimens, the CR rates after the first induction therapy were 71.1% and 63.3%, respectively (P=0.245) , and the MRD negative rates after the first induction therapy were 53.3% and 48.6%, respectively (P=0.509) . One patient in the IA group and two in the HAD group died within 60 days after induction. The two-year OS was 61.5% and 70.6%, respectively (P=0.835) , and the two-year RFS was 51.6% and 57.8%, respectively (P=0.291) . There were no statistically significant differences between the two groups. Multivariate analysis showed that the ELN risk stratification was an independent risk factor in both induction groups; CR(1) HSCT was an independent prognostic factor for OS and RFS in the IA patients and for RFS in the HAD patients but not for OS in the HAD patients. Age, WBC level, NPM1 mutation, and FLT3-ITD mutation had no independent prognostic significance. Conclusion: The IA and HAD regimens were both effective induction regimens for AML patients.

Analysis of clinical significance and prognostic impact of TET2 single nucleotide polymorphism I1762V in patients with acute myeloid leukemia / 中华血液学杂志

Objective: This study aimed to investigate the clinical and prognostic significance of TET2 single nucleotide polymorphism I1762V in patients with acute myeloid leukemia (AML) . Methods: The high-throughput sequencing method was used to sequence 58 hematological tumor-related genes in bone marrow samples from 413 patients with AML. TET2 I1762V and other somatic mutations were annotated and compared with patients' clinical information and prognosis. Results: I1762V was found in 154 patients with AML, which was significantly different from the general population in NyuWa Chinese Population Variant Database (χ(2)=72.4, P<0.001) . I1762V was not related to sex, age, and karyotype of patients with AML (P>0.05) . Patients with I1762V had a significantly higher proportion of NPM1 and KIT gene mutations than others (P<0.001) . NPM1 and KIT mutations were mutually exclusive. The survival analysis results revealed that the overall survival (OS) and progression-free survival (PFS) of patients with AML with I1762V were significantly greater than those of wild-type patients (HR=0.57, P=0.030; HR=0.55, P=0.020) , whereas the OS and PFS in patients with AML with DNMT3A mutation (with or without I1762V mutation) were lower than those of wild-type patients (HR=1.79, P=0.030; HR=1.74, P=0.040) . Conclusion: TET2 SNP I1762V has been linked to AML. I1762V is a prognostic factor of patients with AML, which can be used to guide the treatment and evaluate the prognosis of AML.