Elucidating the mechanism and consequences of aberrant cyclin D1 gene expression

摘要 有些基因会采取激烈的措施来迫使它们的异常表达。例如，基因细胞周期蛋白D1 通常不存在于B细胞淋巴细胞中，但在血癌套细胞淋巴瘤中表达 （MCL）。MCL是所有B细胞恶性肿瘤中最具侵袭性的，是一种染色体易位事件， 早于疾病，激活细胞周期蛋白D1启动子是在正常转化的起始病变， B细胞一旦表达，转录的细胞周期蛋白D1信息（前mRNA）经历进一步加工 这使得它能够缩短其3 '非翻译区（3'UTR），从而增加转录物的半衰期。 细胞周期蛋白D1在MCL中的表达促进了过度增殖表型，并增加了MCL的遗传易感性。 B细胞不稳定和染色体异常。在我们之前的工作中，我们在大肠杆菌中鉴定了一个新的融合基因。 MCL细胞系和患者样品，其中细胞周期蛋白D1与另一个基因连接，从而导致截短的 3'UTR。该项目的目标是确定驱动缩短的分子机制。 细胞周期蛋白D1的3'UTR以及细胞周期蛋白D1驱动的染色体易位事件的影响。在这 我们将确定在细胞周期蛋白D1的前mRNA中发现的序列以及蛋白质 参与3 '端加工的基因在优化MCL中cyclin D1的表达中起作用（Aim 1）。我们将 还系统地鉴定融合基因，这是由于染色体易位事件，使用第三 第二代测序技术，使我们能够获得全长基因转录本（目的2）。虽然 已知染色体易位在MCL中以高频率发生，除了 在个别案例研究中的偶然发现，很少有人努力在一个 全球范围内，使这种类型的研究创新。此外，我们的研究将确定分子 异常3 '端形成的基础将回答该领域的一个基本问题。这将产生积极影响 通过更好地了解致病基因在人类细胞中的表达， 更有效的策略来检测和治疗疾病。

ABSTRACT Some genes take drastic measures to force their aberrant expression. As an example, the gene cyclin D1 which is not normally present in B-cell lymphocytes is expressed in the blood cancer Mantle Cell Lymphoma (MCL). MCL is the most aggressive of all B-cell malignancies and a chromosomal translocation event, that pre-dates the disease, activates the cyclin D1 promoter is the initiating lesion in the transformation of normal B-cells. Once expressed, the transcribed cyclin D1 message (pre-mRNA) undergoes further processing which enables it to shorten it's 3'untraslated region (3'UTR) thus increasing the half-life of the transcript. The expression of cyclin D1 in MCL facilitates a hyper-proliferative phenotype and increases the genetic instability and chromosomal abnormalities of B-cells. In our prior work we identified a novel fusion gene in MCL cell lines and patient samples where cyclin D1 is joined to another gene thus resulting in a truncated 3'UTR. The goal of this project is to determine the molecular mechanisms that drive the shortening of the 3'UTR of cyclin D1 as well as the effects of the cyclin D1 driven chromosomal translocation events. In this proposal we will determine how the sequences found in the pre-mRNA of cyclin D1 as well as proteins involved in 3'end processing play a role in optimizing the expression of cyclin D1 in MCL (Aim 1). We will also systematically identify fusion genes, which result from chromosomal translocation events, using third generation sequencing technology which allows us to get full length gene transcripts (Aim 2). Although chromosomal translocations are known to occur with a high degree of frequency in MCL, apart from serendipity discovery in individual case studies, little effort has been put into identifying fusion genes on a global scale making this type of research innovative. Furthermore, our study will determine the molecular basis of abnormal 3'end formation will answer a basic question in the field. This will have a positive impact by establishing better understanding of disease causing genes are expressed in human cells and will allow for more effective strategies to detect and treat disease.