FTO and RNA methylation in arsenic tumorigenicity

项目摘要/摘要 接触受污染饮用水中的无机砷继续对环境公众构成威胁 对全球数亿人的健康构成威胁。砷是一种人类致癌物质。一个主要目标 砷的器官是皮肤。砷引起的皮肤损害是砷暴露和 毒性，并是后续癌症的风险因素。然而，砷的作用机制 对于肿瘤的发生仍然知之甚少。最近，我们发现FTO(脂肪量和 肥胖相关蛋白)作为一种N6-甲基腺苷(M6A)RNA去甲基酶在砷诱导的恶性肿瘤中的作用 角质形成细胞的转化与小鼠致瘤性。M6A RNA甲基化是最普遍的 在大多数真核生物的信使核糖核酸中发生的修饰。这项建议的目的是 确定FTO作为m6A擦除剂调节砷诱导的皮肤致瘤性的机制。我们的 初步数据表明，FTO作为一种m6A橡皮擦，在砷诱导的皮肤肿瘤发生中起着至关重要的作用。因此， 我们推测，FTO作为一种m6A擦除剂，在砷的肿瘤发生中起着关键作用。 转录调控其主要靶基因的表达。为了验证这一假设，我们将使用 几种新的方法，包括转录组范围的m6A作图、eCLIP-seq和RIP-seq，以及一种新的和 使用皮肤特异性FTO缺失的小鼠建立临床相关模型，以确定FTO在砷中的作用 诱发皮肤肿瘤。我们的假设将在三个具体目标上得到检验。目标1将决定机制 FTO通过其调控砷诱导的致瘤性。目标2将确定FTO的分子机制 砷对角质形成细胞的上调作用。目标3将确定砷中FTO抑制的后果- 皮肤特异性FTO缺失小鼠的致瘤作用。圆满完成拟议工作 将为砷诱导肿瘤发生的分子基础提供新的机制见解， 功能性RNA修饰对砷致瘤性的影响。由此产生的发现也可能建立FTO和/或其 下游通路是预防和/或治疗砷引起的皮肤肿瘤的新的可用药靶点。 鉴于砷和FTO与多种疾病的关联，我们的发现将不仅适用于皮肤 癌症，但也可能与砷中毒有关。

Project Summary/Abstract Exposure to inorganic arsenic in contaminated drinking water continues to poses an environmental public health threat for hundreds of millions of people worldwide. Arsenic is a human carcinogen. A major target organ of arsenic is the skin. Arsenic-induced skin lesions are an early manifestation of arsenic exposure and toxicity, and are a risk factor for subsequent cancers. However, the mechanism by which arsenic contributes to tumorigenesis remains poorly understood. Recently, we discovered a critical role for FTO (fat mass and obesity-associated protein) as an N6-methyladenosine (m6A) RNA demethylase in arsenic-induced malignant transformation of keratinocytes and tumorigenicity in mice. m6A RNA methylation is the most prevalent modification that occurs in the messenger RNA of most eukaryotes. The objective of this proposal is to determine the mechanism by which FTO as an m6A eraser regulates arsenic-induced skin tumorigenicity. Our preliminary data suggest that FTO, as an m6A eraser, is crucial for arsenic-induced skin tumorigenesis. Thus we hypothesize that FTO, as an m6A eraser, plays a critical role in arsenic tumorigenesis through post- transcriptionally regulating the expression of its essential target genes. To test this hypothesis, we will employ several new methods including transcriptome-wide m6A mapping, eCLIP-seq, and RIP-seq, and a new and clinically relevant model using mice with skin-specific FTO deletion, to determine the role of FTO in arsenic- induced skin tumors. Our hypothesis will be tested in three Specific Aims. Aim 1 will determine the mechanism by which FTO regulates arsenic-induced tumorigenicity. Aim 2 will determine the molecular mechanism of FTO up-regulation by arsenic in keratinocytes. Aim 3 will determine the consequences of FTO inhibition in arsenic- induced tumorigenesis in mice with skin-specific deletion of FTO. Successful completion of the proposed work will provide new mechanistic insights into the molecular basis for arsenic-induced tumorigenesis, linking functional RNA modifications to arsenic tumorigenicity. The resulted findings may also establish FTO and/or its downstream pathways as new druggable targets for preventing and/or treating arsenic-induced skin tumors. Given the association of arsenic and FTO with multiple diseases, our findings will not only be applicable to skin cancers, but may also be relevant to arsenic toxicity in general.