Li Ran, Wu Xiaolu, Xue Kai, Feng Dandan, Li Jianyong, Li Junmin
Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Hematology, Jiangsu Province Hospital, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Personalized Cancer Medicine, Nanjing Medical University, Nanjing, China.
Biomark Res. 2023 Mar 10;11(1):30. doi: 10.1186/s40364-023-00464-x.
Although t (8;21) is in fact considered a good risk acute myeloid leukemia (AML), only 60% of the patients live beyond 5 years after diagnosis. Studies have shown that RNA demethylase ALKBH5 promotes leukemogenesis. However, the molecular mechanism and clinical significance of ALKBH5 in t (8;21) AML have not been elucidated.
The expression of ALKBH5 was assessed in t (8;21) AML patients via qRT-PCR and western blot. The proliferative activity of these cells was examined through CCK-8 or colony-forming assays, while flow cytometry approaches were used to examine apoptotic cell rates. The in vivo role of ALKBH5 promoting leukemogenesis was assessed using t (8;21) murine model, CDX, and PDX models. RNA sequencing, m6A RNA methylation assay, RNA immunoprecipitation, and luciferase reporter assay were used to explore the molecular mechanism of ALKBH5 in t (8;21) AML.
ALKBH5 is highly expressed in t (8;21) AML patients. Silencing ALKBH5 suppresses the proliferation and promotes the apoptosis of patient-derived AML cells and Kasumi-1 cells. With integrated transcriptome analysis and wet-lab confirmation, we found that ITPA is a functionally important target of ALKBH5. Mechanistically, ALKBH5 demethylates ITPA mRNA and increases its mRNA stability, leading to enhanced ITPA expression. Furthermore, transcription factor TCF15, specifically expressed in leukemia stem/initiating cells (LSCs/LICs), is responsible for the dysregulated expression of ALKBH5 in t (8;21) AML.
Our work uncovers a critical function for the TCF15/ALKBH5/ITPA axis and provides insights into the vital roles of m6A methylation in t (8;21) AML.
尽管t(8;21)事实上被认为是低危急性髓系白血病（AML），但只有60%的患者在诊断后能存活超过5年。研究表明，RNA去甲基化酶ALKBH5可促进白血病发生。然而，ALKBH5在t(8;21) AML中的分子机制和临床意义尚未阐明。
通过qRT-PCR和蛋白质免疫印迹法评估t(8;21) AML患者中ALKBH5的表达。通过CCK-8或集落形成试验检测这些细胞的增殖活性，同时采用流式细胞术检测凋亡细胞率。使用t(8;21)小鼠模型、CDX和PDX模型评估ALKBH5促进白血病发生的体内作用。采用RNA测序、m6A RNA甲基化分析、RNA免疫沉淀和荧光素酶报告基因试验，探讨ALKBH5在t(8;21) AML中的分子机制。
ALKBH5在t(8;21) AML患者中高表达。沉默ALKBH5可抑制患者来源的AML细胞和Kasumi-1细胞的增殖并促进其凋亡。通过综合转录组分析和实验室实验证实，我们发现ITPA是ALKBH5的一个功能重要靶点。机制上，ALKBH5使ITPA mRNA去甲基化并增加其mRNA稳定性，导致ITPA表达增强。此外，在白血病干细胞/起始细胞（LSCs/LICs）中特异性表达的转录因子TCF15，是t(8;21) AML中ALKBH5表达失调的原因。
我们的研究揭示了TCF15/ALKBH5/ITPA轴的关键功能，并为m6A甲基化在t(8;21) AML中的重要作用提供了见解。
