Zhao Xin, Tian Xin, Kajigaya Sachiko, Cantilena Caroline R, Strickland Stephen, Savani Bipin N, Mohan Sanjay, Feng Xingmin, Keyvanfar Keyvan, Dunavin Neil, Townsley Danielle M, Dumitriu Bogdan, Battiwalla Minoo, Rezvani Katayoun, Young Neal S, Barrett A John, Ito Sawa
Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
Office of Biostatistics Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
Br J Haematol. 2016 Nov;175(3):427-439. doi: 10.1111/bjh.14244. Epub 2016 Jul 19.
Although recent observations implicate the importance of telomerase activity in acute myeloid leukaemia (AML), the roles of epigenetic regulations of the TERT gene in leukaemogenesis, drug resistance and clinical prognosis in AML are not fully understood. We developed a quantitative pyrosequencing-based methylation assay covering the TERT proximal promoter and a partial exon 1 (TERTpro/Ex1) region and tested both cell lines and primary leukaemia cells derived from AML and AML with preceding myelodysplastic syndrome (AML/MDS) patients (n = 43). Prognostic impact of methylation status of the upstream TERT promoter region was assessed by the Kaplan-Meier method. The activity of the telomerase inhibitor, imetelstat, was measured using leukaemia cell lines. The TERTpro/Ex1 region was highly methylated in all cell lines and primary leukaemia cells showed diverse methylation profiles. Most cases showed hypermethylated regions at the upstream TERTpro/Ex1 region, which were associated with inferior patient survival. TERTpro/Ex1 methylation status was correlated with the cytotoxicity to imetelstat and its combination with hypomethylating agent enhanced the cytotoxicity of imetelstat. AML cell lines and primary blasts harbour distinct TERTpro/Ex1 methylation profiles that could serve as a prognostic biomarker of AML. However, validation in a large cohort of patients is necessary to confirm our findings.
尽管最近的观察结果表明端粒酶活性在急性髓系白血病（AML）中具有重要意义，但TERT基因的表观遗传调控在AML白血病发生、耐药性和临床预后中的作用尚未完全明确。我们开发了一种基于焦磷酸测序的定量甲基化检测方法，覆盖TERT近端启动子和部分外显子1（TERTpro/Ex1）区域，并对来自AML和伴有既往骨髓增生异常综合征（AML/MDS）的AML患者的细胞系和原发性白血病细胞（n = 43）进行了检测。采用Kaplan-Meier法评估TERT启动子上游区域甲基化状态的预后影响。使用白血病细胞系测定端粒酶抑制剂艾美拉唑的活性。TERTpro/Ex1区域在所有细胞系中均高度甲基化，原发性白血病细胞表现出不同的甲基化谱。大多数病例在TERTpro/Ex1上游区域显示高甲基化区域，这与患者较差的生存率相关。TERTpro/Ex1甲基化状态与对艾美拉唑的细胞毒性相关，其与去甲基化剂联合使用可增强艾美拉唑的细胞毒性。AML细胞系和原发性母细胞具有不同的TERTpro/Ex1甲基化谱，可作为AML的预后生物标志物。然而，需要在大量患者队列中进行验证以证实我们的发现。
