背景与目的ALKBH1是重要的RNA 5-甲基胞嘧啶(m^(5)C)、3-甲基胞嘧啶(m^(3)C)和1-甲基腺嘌呤(m1A)去甲基化酶之一。目前,其在泛癌中的表达情况和预后价值尚未有系统性的研究。本研究旨在明确ALKBH1基因在泛癌中的表达情况及与患者预后的...背景与目的ALKBH1是重要的RNA 5-甲基胞嘧啶(m^(5)C)、3-甲基胞嘧啶(m^(3)C)和1-甲基腺嘌呤(m1A)去甲基化酶之一。目前,其在泛癌中的表达情况和预后价值尚未有系统性的研究。本研究旨在明确ALKBH1基因在泛癌中的表达情况及与患者预后的相关性,并探讨ALKBH1在肝癌发生、发展中的相关功能及可能机制。方法利用癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据分析ALKBH1在泛癌中的表达差异情况,并通过Kaplan-Meier和Cox回归法分析ALKBH1与各种肿瘤临床预后的相关性。聚焦ALKBH1在肝癌中的促癌机制,将TCGA肝癌队列分成ALKBH1表达高、低两组,对差异基因进行基因本体(Gene Ontology,GO)富集、京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)信号通路分析、基因集变异分析(Gene Set Variation Analysis,GSVA)和肿瘤免疫细胞浸润评估(Tumor Immune Estimation Resource,TIMER)分析。最后使用cBioPortal、DNMIVD、StarBase数据库分析ALKBH1在肝癌中表达上调的原因。结果TCGA数据分析显示,ALKBH1在多种肿瘤组织中显著高表达,特别是肝癌。生存分析结果显示ALKBH1高表达与肝癌的预后不良相关(P<0.05)。基因富集与功能分析显示ALKBH1高表达肝癌组织的免疫反应和细胞周期相关通路显著富集,且免疫细胞浸润增加。ALKBH1在肝癌中表达上调与基因拷贝数变化和启动子甲基化无关,miR-122-5p和miR-33b-5p在肝癌组织中表达下调,且与ALKBH1表达负相关,可能是肝癌中ALKBH1表达上调的主要原因。结论受miR-122-5p和miR-33b-5p共同调控的ALKBH1可能参与肝癌的发生和发展,ALKBH1在肝癌组织中高表达可作为患者预后不良的分子标志物。ALKBH1可通过调控细胞周期和免疫细胞浸润促进肝癌发生和发展,有望成为肝癌的潜在治疗靶标。展开更多
ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the...ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells （MSCs） was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.展开更多
文摘背景与目的ALKBH1是重要的RNA 5-甲基胞嘧啶(m^(5)C)、3-甲基胞嘧啶(m^(3)C)和1-甲基腺嘌呤(m1A)去甲基化酶之一。目前,其在泛癌中的表达情况和预后价值尚未有系统性的研究。本研究旨在明确ALKBH1基因在泛癌中的表达情况及与患者预后的相关性,并探讨ALKBH1在肝癌发生、发展中的相关功能及可能机制。方法利用癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据分析ALKBH1在泛癌中的表达差异情况,并通过Kaplan-Meier和Cox回归法分析ALKBH1与各种肿瘤临床预后的相关性。聚焦ALKBH1在肝癌中的促癌机制,将TCGA肝癌队列分成ALKBH1表达高、低两组,对差异基因进行基因本体(Gene Ontology,GO)富集、京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)信号通路分析、基因集变异分析(Gene Set Variation Analysis,GSVA)和肿瘤免疫细胞浸润评估(Tumor Immune Estimation Resource,TIMER)分析。最后使用cBioPortal、DNMIVD、StarBase数据库分析ALKBH1在肝癌中表达上调的原因。结果TCGA数据分析显示,ALKBH1在多种肿瘤组织中显著高表达,特别是肝癌。生存分析结果显示ALKBH1高表达与肝癌的预后不良相关(P<0.05)。基因富集与功能分析显示ALKBH1高表达肝癌组织的免疫反应和细胞周期相关通路显著富集,且免疫细胞浸润增加。ALKBH1在肝癌中表达上调与基因拷贝数变化和启动子甲基化无关,miR-122-5p和miR-33b-5p在肝癌组织中表达下调,且与ALKBH1表达负相关,可能是肝癌中ALKBH1表达上调的主要原因。结论受miR-122-5p和miR-33b-5p共同调控的ALKBH1可能参与肝癌的发生和发展,ALKBH1在肝癌组织中高表达可作为患者预后不良的分子标志物。ALKBH1可通过调控细胞周期和免疫细胞浸润促进肝癌发生和发展,有望成为肝癌的潜在治疗靶标。
基金supported by grants from the National Natural Science Foundation of China (No.81271178 and 81470777)
文摘ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells （MSCs） was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.
