Dissecting the genetic determinants of aneuploidy's effect on cellular proliferat

描述(申请人提供)：异常核型，包括节段性和全染色体非整倍体，是癌症的标志。许多肿瘤是非整倍体，有证据表明非整倍体可能是肿瘤发生的驱动因素[27]。尽管与癌症关系密切，非整倍体却与细胞周期延迟和生长速度下降矛盾地相关[25，29]。非整倍体导致数十到数千个基因的拷贝数协调变化。这种遗传的复杂性使得人们很难理解非整倍体如何促进肿瘤的发生和细胞的增殖。酿酒酵母是一种研究广泛的模式生物，其细胞生物学的许多元素与哺乳动物细胞一样保守。在酿酒酵母中，由于酵母基因组的相对简单和许多可用菌株的收集，复杂遗传问题的研究被简化了。在一个与肿瘤发生有许多相似之处的过程中，我们实验室从24个独立的长期进化实验的子集中分离出了酿酒酵母的非整倍体克隆[7]。正如经常出现在癌细胞群体中的非整倍体被假设与增殖优势有关[17]，类似地，在目标1中，我们计划识别从这些进化实验中分离出来的高频非整倍体克隆，并在目标2中确定它们的增殖优势。进化实验的种群水平分析将使用种群DNA的阵列比较基因组杂交(ACGH)进行，而不同菌株的相对增殖优势将通过直接竞争实验来确定。在目标3中，我们将利用覆盖超过90%的蛋白质编码基因组[10，30]的条形码酵母集合和新的高通量测序技术Bar-seq[21]来确定非整倍体区域内多个基因的协调拷贝数变化如何组合在一起影响细胞增殖。我们希望，这里提出的对非整倍体的严格遗传分析将有助于我们更好地理解非整倍体在肿瘤发生和癌症进展中的作用。 与公共卫生相关：非整倍体是一种遗传异常，即细胞具有异常数量的染色体。癌症是一种以细胞无节制生长为特征的疾病，许多癌细胞本身就是非整倍体。在这项提案中，我们将使用酵母来鉴定非整倍体对细胞生长影响的遗传基础。

DESCRIPTION (provided by applicant): An abnormal karyotype, including both segmental and whole chromosomal aneuploidies, is a hallmark of cancer. Many tumors are aneuploidy and there is evidence that aneuploidy may be a driver of tumorigenesis [27]. Despite these close ties to cancer, aneuploidy is paradoxically associated with a cell cycle delay and decreased growth rates [25, 29]. Aneuploidy results in the coordinated copy-number change of tens to thousands of genes. This genetic complexity has made it difficult to understand how aneuploidy might promote tumorigenesis and cellular proliferation. Saccharomyces cerevisiae is a well-studied model organism with many elements of its cellular biology conserved with mammalian cells. The study of complex genetic problems is simplified in S. cerevisiae due to the relative simplicity of the yeast genome and by the many available strain collections. In a process with many parallels to tumorigenesis, our laboratory has isolated aneuploid clones of S. cerevisiae from a subset of 24 independent long-term evolution experiments [7]. Just as aneuploidies frequently represented in a population of cancer cells are hypothesized to be associated with a proliferative advantage [17], similarly, in Aim 1 we plan to identify high-frequency aneuploid clones isolated from these evolution experiments and in Aim 2 determine their proliferative advantage. Population-level analysis of the evolution experiments will be carried out using array comparative genomic hybridization (aCGH) of population DNA while the relative proliferative advantage of different strains will be determined by direct competition experiments. In Aim 3 we will exploit bar-coded yeast collections spanning more than 90% of the protein coding genome [10, 30] and the novel high-throughput sequencing technology Bar-seq [21] to determine how the coordinated copy- number change of multiple genes within an aneuploid region combines to affect cellular proliferation. We hope that the rigorous genetic analysis of aneuploidy proposed here will help us better understand the role of aneuploidy in tumorigenesis and cancer progression. PUBLIC HEALTH RELEVANCE: Aneuploidy is a genetic abnormality where a cell has an abnormal number of chromosomes. Cancer is a disease characterized by unbridled cellular growth and many cancer cells themselves are aneuploid [reviewed in 28]. In this proposal we will use yeast to identify the genetic basis for aneuploidy's effects on cellular growth.