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

描述（由申请人提供）：异常核型，包括部分和整个染色体非整倍体，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。尽管这些与癌症密切相关，但非整倍体却与细胞周期延迟和生长速率降低相矛盾[25,29]。非整倍性导致数十到数千个基因的拷贝数发生协调变化。这种遗传复杂性使得理解非整倍体如何促进肿瘤发生和细胞增殖变得困难。酿酒酵母是一种被充分研究的模式生物，其细胞生物学的许多元素与哺乳动物细胞保守。复杂的遗传问题的研究简化了酿酒酵母由于相对简单的酵母基因组和许多可用的菌株收集。在一个与肿瘤发生有许多相似之处的过程中，我们的实验室从24个独立的长期进化实验中分离出了酿酒葡萄球菌的非整倍体克隆bb0。正如非整倍体经常出现在癌细胞群中，被假设与增殖优势b[17]有关，同样，在Aim 1中，我们计划鉴定从这些进化实验中分离出来的高频非整倍体克隆，并在Aim 2中确定它们的增殖优势。进化实验的群体水平分析将使用群体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确定。在Aim 3中，我们将利用跨越90%以上蛋白质编码基因组的条形码酵母集合[10,30]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联合影响细胞增殖。我们希望这里提出的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。

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.