RNA contains diverse post-transcriptional modifications,and its catabolic breakdown yields numerous modified nucleosides requiring correct processing,but the mechanisms remain unknown.Here,we demonstrate that three RN...RNA contains diverse post-transcriptional modifications,and its catabolic breakdown yields numerous modified nucleosides requiring correct processing,but the mechanisms remain unknown.Here,we demonstrate that three RNA-derived modified adenosines,N6-methyladenosine(m6A),N6,N6-dimethyladenosine(m6,6A),and N6-isopentenyladenosine(i6A),are sequentially metabolized into inosine monophosphate(IMP)to mitigate their intrinsic cytotoxicity.展开更多
文摘长非编码RNA KCNQ1OT1对多种癌症的发生发展中起着重要的促进作用。然而,目前还没有研究在泛癌中对KCNQ1OT1进行系统的分析。本研究通过对KCNQ1OT1在泛癌组织中的表达水平以及对肿瘤患者的预后情况分析,阐明KCNQ1OT1在肿瘤诊断和预后中的价值,通过分析KCNQ1OT1在胃癌中的调控机制,为胃癌的诊疗提供新的分子靶点。使用Sangerbox 3.0、临床生信之家以及UALCAN数据库,发现KCNQ1OT1在7种肿瘤组织中表达增高(均P<0.05)。在Sangerbox 3.0数据库中发现KCNQ1OT1与多种肿瘤的预后不良相关。使用R软件分析胃癌患者中KCNQ1OT1高表达组和低表达组的差异基因(P<0.05,log2FoldChange>1),并使用基因本体(gene ontology,GO)和京都基因与基因组百科全书(kyoto encyclopedia of genes and genomes,KEGG)功能富集分析发现,KCNQ1OT1参与了胃癌谷氨酰胺的代谢过程。细胞计数和Western印迹检测发现,敲低KCNQ1OT1后胃癌细胞的活性、SLC1A5表达水平以及其介导的谷氨酰胺转运过程均显著下降(P<0.01)。生物信息学、RNA免疫沉淀和双荧光素酶分析验证了KCNQ1OT1竞争性结合miR-138-5p,并促进SLC1A5的表达。最后,染色质免疫沉淀测序数据检测KCNQ1OT1的基因位点具有高H3K27ac信号,并通过染色质免疫沉淀定量PCR验证了P300介导的增强子活性调控了胃癌中KCNQ1OT1的高表达。KCNQ1OT1在多种肿瘤中可以作为一种独立的诊断标志物和预后预测因子。靶向KCNQ1OT1/miR-138-5p/SLC1A5信号轴调控的谷氨酰胺代谢,为胃癌的治疗提供了新的策略和分子靶点。
文摘RNA contains diverse post-transcriptional modifications,and its catabolic breakdown yields numerous modified nucleosides requiring correct processing,but the mechanisms remain unknown.Here,we demonstrate that three RNA-derived modified adenosines,N6-methyladenosine(m6A),N6,N6-dimethyladenosine(m6,6A),and N6-isopentenyladenosine(i6A),are sequentially metabolized into inosine monophosphate(IMP)to mitigate their intrinsic cytotoxicity.
