Alternative splicing in arsenical skin carcinogenesis

项目摘要 长期接触砷，最常见的是通过受污染的饮用水，困扰着2亿多人 在包括美国在内的70多个国家。砷是一种多器官毒性物质，是慢性砷中毒 接触会导致几种慢性疾病，包括多种器官的癌症，皮肤癌是最常见的 共同虽然有几种机制被认为是负责砷诱导的致癌作用， 目前情况尚不明朗。众所周知，慢性砷暴露从根本上改变了 转录组学和蛋白质组学特征，但这种席卷全球的变化的潜在机制 还没有被清楚地理解。差异选择性剪接在肿瘤发生中起作用， 在砷诱导的致癌作用中起作用。我们采用了最先进的RNA-Seq分析， 砷诱导的皮肤癌的良好建立的模型（HaCaT细胞连续暴露于100 nM钠 亚砷酸盐32周）进行纵向研究，以了解 转化过程我们的数据表明，在每一个细胞中发生了>600个差异可变剪接事件。 研究的时间点（暴露7、19、28周）。这个差异剪接程序，通过极大地改变 蛋白质组，可能是砷诱导的皮肤细胞转化的关键角色。现时的建议 目的是检查在每个时间点显著差异剪接事件对 致癌过程。我们将特别仔细检查，如果我们预测的重大剪接事件， 转录组学研究可与蛋白质同种型表达谱相关。此外，我们还致力于 研究是否预测在转录物的5'或3' UTR中发生的显著不同的剪接同种型可以 与来自暴露和未暴露细胞的成熟mRNA样品中的表达谱相关。的 这项研究的结果将进一步加深我们对选择性剪接如何塑造细胞事件的理解， 发生在HaCaT细胞变恶性之前、期间和之后。此外，我们的研究将 希望详细阐述一个上游调节性选择性剪接因子的变化的机制基础， 可以通过连续的信号放大引起全基因组同步的可变剪接变化， 步骤，导致改变蛋白质组，并最终对健康产生不利影响。

Project Summary Chronic exposure to arsenic, most commonly through contaminated drinking water, plagues over 200 million individuals in over 70 countries including the USA. Arsenic is a multi-organ toxicant and chronic arsenic exposure causes several chronic diseases including cancer in multiple organs, skin cancer being the most common. While several mechanisms are postulated to be responsible for arsenic-induced carcinogenesis, a clear picture is yet to emerge. It is well known that chronic arsenic exposure radically changes the transcriptomic and proteomic signatures, but the underlying mechanism for such sweeping global changes are not yet clearly understood. Differential alternative splicing plays a role in carcinogenesis and may be at play in arsenic-induced carcinogenesis. We employed state-of-the-art RNA-Seq analysis in a well-established model of arsenic-induced skin cancer (HaCaT cells exposed continuously to 100 nM sodium arsenite for 32 weeks) in a longitudinal study to understand the global changes in splicing occurring during the transformation process. Our data indicate >600 differential alternative splicing events occurred at each of the time points studied (7, 19, 28 weeks of exposure). This differential splicing program, by dramatically changing the proteome, could be a key player in the arsenic-induced transformation of skin cells. The present proposal aims to examine the contribution of significant differential splicing events at each time point towards the process of carcinogenesis. We will specifically scrutinize if the significant splicing events predicted by our transcriptomic studies can be correlated with protein isoform expression profiles. Furthermore, we also aim to study if predicted significantly different spliced isoforms that take place in the 5' or 3' UTR of transcripts can be correlated to expression profile in the mature mRNA samples from exposed and unexposed cells. The outcomes from this study will further our understanding of how alternative splicing shapes the cellular events taking place before, during and after the time the HaCaT cells become malignant. In addition, our study will look to elaborate the mechanistic basis of how one change in an upstream regulatory alternative splicing factor can cause genome-wide synchronized alternative splicing changes by signal amplification through successive steps, leading to altered proteome and ultimately adverse health effects.