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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 .

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 study the distribution characteristics of thalassemia genotype in Han Population in Sanya of Hainan Province., Methods: Gap PCR and reverse dot hybridization were used to detect and analyze the thalassemia gene in 572 suspected thalassemia carriers of Han Population in Sanya., Results: Among the 572 Han Population in Sanya, 271 cases of thalassemia gene abnormality were detected, among which 161 cases were founded to be carriers of α-thalassemia gene. A total of 9 genotypes were detected, in the following order of the detection rate was －－ SEA /αα，－α 3.7 /αα，－α 4.2 /αα，－－ SEA /－α 3.7 ，－－ SEA /－α 4.2 ，－α 4.2 /－α 4.2 ，－α 3.7 /－α 4.2 ，－α 3.7 /－α 3.7 ，－－ SEA /－－ SEA . Among them, the deletion type (－－ SEA /αα) in southeast Asia was the most common, accounting for 66 cases. 99 cases of β-thalassemia were detected, there were 7 genotypes, all of which were heterozygous. The order of the detection rate was CD41-42/βN, IVS-II-654/βN, CD17/βN, CD71-72/βN, -28/βN, －29/βN, CD27-28/βN. Among them, CD41-42/βN was the most common, accounting for 51 cases. In addition, 11 cases of combined α and β thalassemia were detected. Five kinds of genotypes were checked out, the order of detection rate was －α 3.7 /αα composite CD41-42/βN, －－ SEA /αα composite IVS-II-654/βN, －α 4.2 /－α 4.2 composite CD41-42/βN, －α 4.2 /αα composite －29/βN , －－ SEA / －α 4.2 composite CD41-42/βN., Conclusion: Han Population in Sanya of Hainan Province is a high-risk population of thalassemia, the genotype characteristics are different from other areas with high incidence of thalassemia in China. The main type of α-thalassemia is the deficiency mutation of southeast Asia, while CD41-42 heterozygous mutation is the main type of β-thalassemia.

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.