Role of RNA methylation in chemoresistant cancer cells

RNA甲基化在耐药癌细胞中的作用综述 目的基于我们的数据，我们认为急性髓系白血病(AML)中短暂静止的人群。 部分由RNA甲基化维持，允许合成存活和促进肿瘤的调节因子 对化疗耐药和随后的AML持久性是必要的。其主要目标是描述 RNA甲基化在耐药AML基因表达调控中的作用，有助于化疗生存。 意义：急性髓细胞白血病是一种严重的恶性肿瘤，由于异质性而表现出临床耐药性。耐药 AML细胞包括静止的(G0)细胞，这些细胞处于短暂的停滞状态，因此抵制临床治疗 仅针对周期细胞；这些细胞重新进入增殖状态，导致AML持续存在。一个主要的问题是 抵抗力监管机构仍有待发现。第二个需要是确定检测耐药细胞的标记。 这类细胞表现出独特的基因表达，允许化学生存(PNAS 2014，Mol.细胞2016，BioRxiv/ 418715)。规范的翻译减少了；但特定的mRNAs通过未知的机制表达。 需要揭示耐药AML中特定基因表达的调节&以减少AML为目标。 耐药细胞的前提图谱揭示了影响细胞存活的因素的表达。表达的mRNAs G0抗性细胞延长3？包括调控位点的未翻译区域(UTRs)，例如RNA 甲基化。腺苷(M6A)N6位甲基化是RNA上调控基因的独特标志 通过称为阅读器的RNA结合蛋白来表达，以控制不同的细胞状态。M6A在耐药AML中的作用 仍未被发现。我们发现，由于治疗诱导的信号，m6A甲基转移酶增加。我们的 数据表明，m6A是特异的基因表达和抗性所必需的。我们开发了抑制剂来阻止 治疗诱导信号&反义阻断延伸的3‘UTRs上独特的m6A位点，从而降低耐药性。 这些数据表明，m6A调节特定的基因表达，以使治疗存活。表征 在耐药细胞、体内和患者样本中被m6A修饰和表达的mRNA，它们的读取器， 它们在耐药中的作用，以及阻断M6A的抑制剂，将提供抑制耐药的标志物和治疗方法。 方法目的我将通过体内交联法对调节已知修饰的mRNAs的m6A读取器进行表征 耐药AML细胞的偶联RNA亲和纯化&体内模型。化学抑制剂诱导治疗 促进m6A和反义阻断m6A位点的信号将进行测试，以遏制耐药性。AIM II 将使用m6A抗体在全球范围内识别导致细胞系和体内模型耐药的m6A靶点 &甲基转移酶免疫沉淀。Readers和m6A mRNAs在耐药细胞和体内的作用被测试 通过耗竭和化学存活试验相结合；它们的表达将在耐药患者样本中得到验证。 结果m6A表达的mRNAs、它们的读取器、它们在急性髓系白血病细胞耐药中的作用、体内和抑制物 将确定抑制耐药性的m6A。它们在患者样本中的表达和有效性将被揭开。

Summary Role of RNA methylation in chemoresistant cancer cells Goal Based on our data, we propose that transiently quiescent populations in acute myeloid leukemia (AML) are maintained in part by RNA methylation, permitting synthesis of survival and tumor promoting regulators necessary for chemoresistance and subsequent AML persistence. The primary objective is to characterize the role of RNA methylation in regulating gene expression in resistant AML, which contributes to chemosurvival. Significance AML is a serious malignancy that displays clinical resistance due to heterogeneity. Resistant AML cells include quiescent (G0) cells that are transiently arrested states, and thus resist clinical therapy that targets only cycling cells; these cells re-enter proliferation to cause AML persistence. A primary issue is that resistance regulators remain to be uncovered. A second need is to identify markers to detect resistant cells. Such cells show distinct gene expression that permits chemosurvival (PNAS 2014, Mol. Cell 2016, Biorxiv/ 418715). Canonical translation is decreased; yet specific mRNAs are expressed by unknown mechanisms. Regulation of specific gene expression in resistant AML needs to be uncovered & targeted to curtail AML. Premise Profiling in resistant cells revealed expression of factors that affect cell survival. Expressed mRNAs in G0 resistant cells have extended 3? untranslated regions (UTRs) to include regulatory sites, such as for RNA methylation. Methylation at N6 position of adenosines (m6A) are unique marks on RNAs that regulate gene expression via RNA binding proteins called readers, to control distinct cell states. Role of m6A in resistant AML remains to be uncovered. We find the m6A methyltransferase increases due to therapy induced signals. Our data reveal that m6A is needed for specific gene expression & resistance. We developed inhibitors to block therapy induced signals & antisense to block unique m6A sites on extended 3’UTRs, which reduce resistance. These data suggest that m6A regulates specific gene expression to enable therapy survival. Characterization of mRNAs that are modified & expressed in resistant cells, in vivo & in patient samples by m6A, their readers, their role in resistance, & of inhibitors that block m6A, will provide markers & therapeutics to curb resistance. Method Aim I will characterize m6A readers that regulate known modified mRNAs, by in vivo crosslinking coupled RNA affinity purification in resistant AML cells & in vivo models. Chemical inhibitors to therapy induced signaling that promotes m6A and antisense to block mapped m6A sites will be tested to curb resistance. Aim II will globally identify m6A targets that contribute to resistance in cell lines & in vivo models, using m6A antibody & methyltransferase immunoprecipitation. Role of readers & m6A mRNAs in resistant cells & in vivo is tested by depletions coupled with chemosurvival assays; their expression will be verified in resistant patient samples. Outcomes mRNAs expressed by m6A, their readers, their role in resistance in AML cells & in vivo, & inhibitors of m6A to curb resistance will be identified. Their expression & efficacy in patient samples will be uncovered.