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Introduction: The prognosis of relapsed/refractory acute myeloid leukemia (r/rAML) is dismal, and allogeneic hematopoietic stem cell transplant (allo-HSCT) is a potential cure. Combining anti-PD-1, hypomethylating agent (HMA), and CAG (cytarabine, aclarubicin/idarubicin, granulocyte colony-stimulating factor) regimen has showed primary efficacy in r/rAML. However, pre-transplant exposure to anti-PD-1 may lead to severe graft-versus-host disease (GVHD). This preliminary study aimed to evaluate the safety and efficacy of allo-HSCT in r/rAML patients receiving the anti-PD-1+HMA+CAG regimen., Methods: Fifteen r/rAML patients (12 related haploidentical donors [HIDs], 2 matched siblings, 1 unrelated donor) received this regimen and subsequent peripheral blood HSCT., Results: Four patients with HIDs received a GVHD prophylaxis regimen consisted of Anti-thymocyte globulin and a reduced-dose of post-transplant cyclophosphamide. The median follow-up was 20.9 months (range, 1.2-34.2). The cumulative incidences of acute GVHD grade 2-4 and grade 3-4 were 40% and 13.3%, respectively. The 2-year incidence of moderate-to-severe chronic GVHD, non-relapse mortality, and relapse were 10%, 22.3%, and 22.5%, respectively. The 2-year overall survival and GVHD-free/relapse-free survival rates were 54% and 48.6%, respectively. No death or relapse was observed in the PTCy group., Conclusion: The anti-PD-1+HMA+CAG regimen bridging to allo-HSCT for r/r AML was tolerable with promising efficacy. GVHD prophylaxis with PTCy for HID-HSCT showed preliminary survival advantage., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Wang, Su, Wang, Li, Li, Jing, Xu, Wang, Zheng, Gao, Hu, Gao and Liu.)

Objective: To confirm the direct regulatory effect of WTAP -mediated RNA m 6 A modification on the KDM4B gene in t (8;21) acute myeloid leukemia (AML) cells through MeRIP combined with reverse transcription real-time quantitative PCR (RT-qPCR) technology., Methods: The lentivirus-mediated shRNA target WTAP or KDM4B gene was used to transfect the t (8;21) AML cell lines: Kasumi-1 and SKNO-1, and cells transfected with randomly shuffled shRNA as the control. Using the Ultrapure RNA Extraction Kit (DNase I) to extract RNA. The Magna MeRIP TM m 6 A Kit was used to enrich methylated modified fragments, and detect the m 6 A methylated RNA regions by RT-qPCR, and the protein and mRNA expression levels of WTAP and KDM4B in cells were detected by Western blot and reverse transcription real-time quantitative PCR (RT-qPCR). Colony formation assays were used to detect the colony ability of cells in vitro ., Results: Silencing the expression of WTAP in Kasumi-1 cells, the enrichment of m 6 A methylation modification was significantly decreased in the 3'UTR of KDM4B mRNA( P < 0.01), and the protein( P < 0.001) and mRNA (Kasumi-1: P < 0.001; SKNO-1: P < 0.01) expression levels of KDM4B were also significantly inhibited in Kasumi-1 and SKNO-1 cells upon WTAP knockdown (all P < 0.01), accompanied by a significant decrease in the colony-forming ability of both cell lines (both P < 0.01)., Conclusion: In t(8;21) AML cell lines, WTAP could regulate the expression of KDM4B by regulating the m 6 A modification of the 3'UTR of KDM4B mRNA, and silencing the expression of KDM4B could inhibit the cellular proliferation in vitro .

Anti-PD-1 monotherapy had limited clinical efficacy in relapsed/refractory (r/r) AML patients with higher PD-1 and PD-L1 expression. Hence, we investigated the efficacy and safety of PD-1 inhibitor with DNA hypomethylating agent (HMA) + CAG regimen in patients who had failed prior AML therapy. In this phase 2, single-arm study, r/r AML patients received azacitidine or decitabine plus CAG regimen with tislelizumab. Primary endpoints were efficacy (objective response rate [ORR]) and safety. Secondary endpoints included overall survival (OS), event-free survival (EFS) and duration of response (DOR). Statistical analyses were performed using Stata 14.0 and SPSS 20.0 software where P < 0.05 denoted significance. Twenty-seven patients were enrolled patients and completed 1 cycle, and 14 (51.9%) and 4 (14.8%) patients completed 2 and 3 cycles, respectively. ORR was 63% (14: complete remission [CR]/CR with incomplete hematologic recovery [CRi], 3: partial remission (PR), 10: no response [NR]). Median OS (mOS) and EFS were 9.7 and 9.2 months, respectively. With a median follow-up of 8.2 months (1.1-26.9), the mOS was not reached in responders (CR/CRi/PR) while it was 2.4 months (0.0-5.4) in nonresponders (P = 0.002). Grade 2-3 immune-related adverse events (irAEs) were observed in 4 (14.8%) patients and 3 nonresponders died of lung infection after treatment. Tislelizumab + HMA + CAG regimen showed improved outcomes in r/r AML patients with lower pretherapy leukemia burden. irAEs were mild and low-grade and higher pretherapy bone marrow CD4 + CD127 + PD-1 + T cells might serve as a predictor of treatment response.ClinicalTrials.gov identifier NCT04541277., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Hypoxia inducible factor 1α (HIF1α) is abnormally overexpressed in t(8;21) acute myeloid leukemia (AML) and functions as an oncogene through transactivating DNA methyltransferase 3 alpha leading to DNA hypermethylation. However, it remains unclear whether HIF1α influences RNA N 6 -methyladenosine (m 6 A) methyltransferases. Here, we show that HIF1α promotes the expression of Wilms tumor 1-associated protein (WTAP), a main component of the m 6 A methyltransferase complex, markedly alters the transcriptome-wide m 6 A distribution and enhances cell proliferation in t(8;21) AML. In agreement with this, WTAP is overexpressed and predicts poor prognosis in t(8;21) AML patients. Moreover, WTAP knockdown inhibits growth, and induces apoptosis and differentiation of leukemia cells. Mechanistically, HIF1α transactivates WTAP gene expression by directly binding to the hypoxia-response element of its promoter region. Pharmacological or genetic intervention in the HIF1α-WTAP axis results in the reduction of m 6 A level on lysine demethylase 4B (KDM4B) transcripts and increased its degradation, correlated with lower expression of KDM4B and higher trimethylation levels of histone H3 on lysine 9. KDM4B knockdown inhibits leukemia cell growth in vitro and in mice. Thus, HIF1α-mediated WTAP high expression enhances the malignant behavior of leukemia cells and drives a crosstalk between m 6 A RNA methylation and histone methylation through monitoring m 6 A-dependant KDM4B translation., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Objective: To analyze the clinical characteristics and risk factors of invasive fungal infection (IFI) occurenced in patients with acute leukemia (AL) during treatment in tropical regions., Methods: The clinical data of 68 AL patients admitted to the Hainan Hospital of PLA General Hospital from April 2012 to April 2019 was retrospectively analyzed. Logistic regression analysis was used to analyze the factors affecting the occurrence of IFI in AL patients., Results: Among the 68 patients, 44 were acute myeloid leukemia, 24 were acute lymphoblastic leukemia, 39 were male, 29 were female and the median age was 41(13-75) years old. The 68 patients received 242 times of chemotherapy or hematopoietic stem cell transplantation(HSCT), including 73 times of initial chemotherapy or inducting chemotherapy after recurrence, 14 times of HSCT, 155 times of consolidating chemotherapy. Patients received 152 times of anti-fungal prophylaxis, including 77 times of primary anti-fungal prophylaxis and 75 times of secondary anti-fungal prophylaxis. Finally, the incidence of IFI was 31 times, including 24 times of probable diagnosis, 7 times of proven diagnosis, and the total incidence of IFI was 12.8%(31/242), the incidence of IFI in inducting chemotherapy was 24.66%(18/73), the incidence of IFI in HSCT patients was 28.57% (4/14), the incidence of IFI in consolidating chemotherapy was 5.80% (9/155). Multivariate analysis showed that inducting chemotherapy or HSCT, the time of agranulocytosis ≥7 days, risk stratification of high risk were the independent risk factors for IFI in AL patients during treatment in tropical regions., Conclusion: The incidence of IFI in patients with AL in the tropics regions is significantly higher than that in other regions at homeland and abroad. Anti-fungal prophylaxis should be given to the patients with AL who have the high risk factors of inducting chemotherapy or HSCT, time of agranulocytosis ≥7 days and risk stratification of high risk.

Objective: To investigate the relationship between hypoxia inducible factor 1 (HIF1α) and Wilms' tumor 1associating protein (WTAP) expression level in t(8;21) acute myeloid leukemia cells., Methods: The t(8;21) acute myeloid leukemia cell lines, including SKNO-1 and Kasumi-1 were treated by Echinomycin for 24 h, RT-qPCR and Western blot were used to detect the expression levels of WTAP mRNA and the protein. The CoCl 2 was used to induce the hypoxia of the cells for 24 h, the expression levels of HIF1α, WTAP protein were detected by Western blot., Results: The expression level of WTAP mRNA and the protein in the echinomycin treated group was significantly lower than those in the control group (P<0.01). The expression level of WTAP protein in the CoCl 2 treated group was significantly higher than those in the control group (P<0.05)., Conclusion: The inhibition of HIF1-α could down-regulates the expression of WTAP, while the up-regulation of HIF1α could up-regulates the expression of WTAP, which shows that there is a positive correlation of HIF1α and WTAP expression. This result suggesting that HIF1α may be involves in the expression regulation of WTAP gene.

The t(8;21) fusion product, AML1/ETO, and hypoxia-inducible factor 1α (HIF1α) form a feed-forward transcription loop that cooperatively transactivates the DNA methyltransferase 3a gene promoter that leads to DNA hypermethylation and drives leukemia cell growth. Suppression of the RNA N 6 -methyladenosine (m 6 A)-reader enzyme YTH N 6 -methyladenosine RNA binding protein 2 (YTHDF2) specifically compromises cancer stem cells in acute myeloid leukemia (AML) but promotes hematopoietic stem cell expansion without derailing normal hematopoiesis. However, the relevance of expression between AML1/ETO-HIF1α loop and YTHDF2, and its functional relationship with t(8;21) AML have not been documented. Here, we show that YTHDF2 is highly expressed in t(8;21) AML patients and associated with a higher risk of relapse and inferior relapse-free survival. Knockdown of YTHDF2 in leukemia cells causes an impaired cell proliferation rate in vitro and in mice. Mechanistically, HIF1α is able to bind to the hypoxia-response elements of the 5'-untranslated region of the YTHDF2 gene and promotes the transactivity of the YTHDF2 promoter. Knockdown and overexpression of either AML1/ETO or HIF1α resulted in decreased and increased YTHDF2 protein and mRNA expression in t(8;21) AML cells. In particular, knockdown of YTHDF2 resulted in increased global mRNA m 6 A levels in t(8;21) AML cells, accompanied by increased TNF receptor superfamily member 1b (TNFRSF1b) mRNA and protein expression levels. Last, we demonstrated that the m 6 A methylation and expression levels of the TNFRSF1b gene were both negatively correlated with HIF1α expression levels. In conclusion, YTHDF2 is a downstream target of the AML1/ETO-HIF1α loop and promotes cell proliferation probably by modulating the global m 6 A methylation in t(8;21) AML.

To explore the characteristics and prognostic significance of genetic mutations in acute myeloid leukemia (AML), we screened the gene mutation profile of 171 previously untreated AML patients using a next-generation sequencing technique targeting 127 genes with potential prognostic significance. A total of 390 genetic alterations were identified in 149 patients with a frequency of 87.1%. Younger age and high sensitivity to induction chemotherapy were associated with a lower number of mutations. NPM1 mutation was closely related to DNMT3A and FLT3-internal tandem duplication (FLT3-ITD) mutations, but mutually exclusive with ASXL1 mutation and CEBPA double mutation . In univariate analysis, ASXL1 or TET2 mutation predicted shorter overall survival (OS) or relapse-free survival (RFS), DNMT3A, FLT3-ITD, or RUNX1 mutation predicted a higher likelihood of remission-induction failure, whereas NRAS mutation or CEBPA double mutation predicted longer OS. Concurrent DNMT3A, FLT3-ITD, and NPM1 mutations predicted shorter OS. Hypomethylation agents could improve the OS in patients with DNA methylation-related mutations. According to multivariate analysis, TET2 mutation was recognized as an independent prognostic factors for RFS. In summary, our study provided a detailed pattern of gene mutations and their prognostic relevance in Chinese AML patients based on targeted next-generation sequencing screening., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Objective: To analyze the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for treatment of acute leukemia in the tropical area., Methods: Twelve acute leukemia patients who were underwent allo-HSCT from April 2013 to November 2018 in Hainan Hospital of Chinese PLA General Hospital were selected, including 5 cases of acute lymphoblastic leukemia (ALL) and 7 case of acute myeloid leukemia (AML). Three cases received HLA matched sibling hematopoietic stem cell transplantation, 8 cases received haploidentical hematopoietic stem cell transplantation, 1 cases received partially mismatched unrelated hematopoietic stem cell transplantation. Pretreatment regimen: 9 cases received modified BU/CY+ATG pretreatment regimen, 3 cases received BU/CY pretreatment regimen. Graft-versus-host disease (GVHD) prevention regimen: all patients received cyclosporine A, mycophenolate mofetil combined with short-term methotrexate regimen. The clinical efficacy of allo-HSCT in treatment of acute leukemia in the tropical area was analyzed by detecting hematopoietic reconstitution, GVHD, infection, relapse and survival after transplantation., Results: All the 12 patients achieved granulocyte reconstruction and megakaryocyte reconstruction. The median time of granulocyte reconstruction was 11.5 (6-14) days, and the median time of megakaryocytic reconstruction was 12.5 (10-22) days. Within 100 days after transplantation, the acute GVHD occurved in 8 cases, including 6 cases of Ⅱ-Ⅳ degree acute GVHD and 2 cases of Ⅲ-Ⅳ degree acute GVHD, 11 cases survived more than 100 days after transplantation, and the chronic GVHD occurred in 1 case, which was mildly limited. Pulmonary infection occurred in 7 cases, cytomegaloviremia occurred in 6 cases, EB viremia occurred in 6 cases, and hemorrhagic cystitis occurred in 5 cases. 2 cases relapsed and eventually died, and the remaining 10 patients survived without disease until the date of follow-up. The median follow-up time was 4 (1-68) months, 83.3% (10/12) survived without disease, and 16.7% (2/12) relapsed., Conclusion: Allo-HSCT is an effective method for the treatment of acute leukemia in adults. Leukemia patients should be transplanted as soon as possible after remission. The incidence of pulmonary fungal infection in transplanted patients in tropics is high, therefore the prevention and treatment of fungal infection should be strengthened.

Donor lymphocyte infusion (DLI) might be used prophylactically to reduce relapse after allogeneic hematopoietic stem cell transplantation for very high-risk leukemia/lymphoma without effective targeted therapy. To compare the safety and efficacy of prophylactic DLI for prevention of relapse after allogeneic peripheral blood stem cell transplantation from haploidentical donors (HID-SCT) and matched-sibling donors (MSD-SCT) in patients with very high-risk acute myeloid leukemia (AML), we performed a retrospective analysis in a cohort of 21 HID-SCT and 13 MSD-SCT recipients, displaying similar baseline characteristics except for donor's gender distribution. Grade 2-4 acute graft-versus-host disease (GVHD) at 100-day post-DLI was higher in HID-SCT group than that in MSD-SCT group (59.5% vs. 30.8%, p = 0.05). The grade 3-4 acute GVHD (17.5% vs. 7.7%), 1-year chronic GVHD (36.6% vs. 33.2%), and severe chronic GVHD (15.3% vs. 27.3%) were not statistically significant different between groups. One-year non-relapse mortality was higher in HID-SCT group than that in MSD-SCT group with marginal significance (27.9% vs. 0.0%, p = 0.061). One-year relapse rate was not statistically significant different between HID-SCT group and MSD-SCT group (21.6% vs. 36.5%, p = 0.543). For HID-SCT recipients, 1-year relapse rate was lower in patients receiving prophylactic DLI than that in a control cohort of eight patients with same very high-risk features but not receiving prophylactic DLI (62.5% vs. 28.3%, p = 0.037). No statistically significant difference was observed in 1-year overall survival (OS, 55.1% vs. 83.9%, p = 0.325) and relapse-free survival (RFS, 50.1% vs. 74.0%, p = 0.419) rates between HID-SCT group and MSD-SCT group. In multivariate analyses, non-remission status prior to transplant, poor-risk gene mutations, and donor's age ≥ 48 years predicted a higher risk of relapse after DLI. Non-remission status prior to transplant predicted inferior OS and RFS. Patient's age ≥ 40 years also predicted an inferior OS. In conclusion, prophylactic DLI was very safe and efficient for reducing relapse in patients with very high-risk AML receiving MSD-SCT. In the recipients of HID-SCT, the application of prophylactic DLI could reduce the risk of relapse, although with a higher incidence of DLI-associated acute GVHD than those of MSD-SCT.

Objective: To summarize the clinical characteristics of peripheral blood, immune phenotypes, fusion genes and cytogenetics of patients with t(8;21) acute myeloid leukemia(AML) through the retrospective analysis of 586 patients with t(8;21) AML from 15 blood disease research centers in Northern area of China., Methods: The factors affecting prognosis of patients with t(8;21) AML were investigated by using univariate and multivariate COX regression., Results: The immune type of t(8;21) AML patients was mainly with HLA-DR + , CD117 + , CD34 + , MPO + , CD38 + , CD13 + and CD33 + (>95%), part of them with CD19 + and CD56 + ; the most common accompanied mutation of t(8;21) AML patients was C-KIT mutation (37.8%); in addition to t(8;21) ectopic, the most common chromosomal abnormality was sex chromosome deletions (38.9%). The univariate analysis revealed a significant survival superiority of OS and PFS in t(8;21) AML patients of WBC≤3.5×10 9 /L without C-KIT mutation, the newly diagnosed ones achieved HSCT(P<0.05), only survival superiority on OS in t(8;21) AML patients with extramedullary infiltration and CD19 positive; the results of multivariate analysis showed a significant survival superiority on OS and PFS in t(8;21) AML patients with WBC≤3.5×10 9 /L(P<0.05)., Conclusion: The clinical features of t(8;21) AML patients in China are similar to those in other countries, WBC≤3.5×10 9 /L is a good prognostic factor while the C-KIT mutation is a poor one in t(8;21) AML patients.

Mutations and/or overexpression of c-Kit proto-oncogene frequently occur in subsets of acute myeloid leukemia (AML) and contribute to abnormal cell proliferation and poor outcomes. We showed that c-Kit expression was subject to post-transcriptional regulation by microRNA (miRNA)-193b. Notably, miR-193b was significantly down-regulated in the examined AML cells and its levels were inversely correlated with c-Kit levels. Restoration of miR-193b expression in AML cells resulted in distinctly reduced c-Kit expression and inhibited cell growth. These data reveal a role for miR-193b dysregulation in myeloid leukemogenesis and the therapeutic promise of regulating miR-193b expression for c-Kit-positive AML., (Copyright © 2011 Elsevier Ltd. All rights reserved.)