Mis-regulation of mRNA poly (A) site selection in cancer cells (PQ11)

描述(申请人提供)：癌症的一个特点是它是一种基因错误表达的疾病。这项应用解决了癌症中的基因表达是如何被添加了聚(A)尾巴的mRNA3‘端的异常成熟所干扰的。大多数人类基因都有多个聚(A)位点，因此，在不同的聚(A)位点之间做出选择几乎是基因表达中普遍存在的事件。在最近其他实验室的开创性工作中，有报道称，在癌细胞中，替代聚(A)的位置选择通常会受到干扰。这一点很重要，因为Poly(A)位点的选择可以通过决定mRNA的3‘非翻译区(UTR)中包含什么序列来对蛋白质表达产生很大影响。3‘端非编码区序列是microRNAs和RNA结合蛋白的主要靶点，它们调节mRNA的稳定性和翻译效率。例如，如果选择一个多聚(A)位点来切断这些靶序列以产生一个缩写的3‘非编码区，则mRNAs将避开这些控制。我们仍然缺乏全面的信息，关于癌细胞中异常的PolyA位点选择影响了哪些基因，以及这一过程是否在肿瘤演变过程中受到调控。此外，关于如何选择一个聚(A)位点而不是另一个进行加工的基础，人们知之甚少。癌细胞可能出了什么问题，将mRNA3‘末端处理从“正确的”聚(A)位点转移开，这是一个非常神秘的问题。我们建议解决两个广泛的基本问题：1)“在肿瘤进展过程中，癌细胞中异常的聚(A)位点选择、对低氧的适应以及对治疗的反应会影响哪些基因？”2)“癌细胞中mRNA3‘末端形成的破坏的分子基础是什么？”我们将使用全基因组RNA-SEQ和CHIP-SEQ策略来使用人类乳腺和肺癌细胞来回答这些问题。

DESCRIPTION (provided by applicant): A hallmark of cancer is that it is a disease of gene misexpression. This application addresses how gene expression in cancer is disrupted by aberrant maturation of mRNA 3' ends where the poly (A) tail is added. Most human genes have multiple poly (A) sites and, as a result, making choices between alternative poly (A) sites is an almost ubiquitous event in gene expression. In recent groundbreaking work by other labs, it was reported that alternative poly (A) site choice is commonly disrupted in cancer cells. This is important because poly(A) site choice can have a large impact on protein expression by dictating what sequences are included in an mRNA's 3' untranslated region (UTR). 3' UTR sequences are the principle targets for microRNAs and RNA binding proteins that regulate mRNA stability and translation efficiency. For example mRNAs will evade these controls if a poly (A) site is chosen that cuts off these target sequences to produce an abbreviated 3'UTR. We still lack comprehensive information about which genes are affected by abnormal poly(A) site selection in cancer cells and whether this process is regulated during tumor evolution. Furthermore little is known about the basis for how one poly(A) site is selected over another for processing. What might be going wrong in cancer cells to divert mRNA 3' end processing from the "correct" poly (A) sites is very much a mystery. We propose to tackle two broad fundamental questions: 1) "What genes are affected by aberrant poly(A) site choice in cancer cells during tumor progression, adaptation to hypoxia, and the response to therapeutics? " and 2) "What is the molecular basis for the corruption of mRNA 3' end formation in cancer cells?". We will use a genome-wide RNA-seq and ChIP-seq strategies to answer these questions using human breast and lung cancer cells.