Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California San Diego School of Medicine, La Jolla, CA, USA.
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Nat Genet. 2019 Apr;51(4):705-715. doi: 10.1038/s41588-019-0360-8. Epub 2019 Mar 4.
Cancer genomes are frequently characterized by numerical and structural chromosomal abnormalities. Here we integrated a centromere-specific inactivation approach with selection for a conditionally essential gene, a strategy termed CEN-SELECT, to systematically interrogate the structural landscape of mis-segregated chromosomes. We show that single-chromosome mis-segregation into a micronucleus can directly trigger a broad spectrum of genomic rearrangement types. Cytogenetic profiling revealed that mis-segregated chromosomes exhibit 120-fold-higher susceptibility to developing seven major categories of structural aberrations, including translocations, insertions, deletions, and complex reassembly through chromothripsis coupled to classical non-homologous end joining. Whole-genome sequencing of clonally propagated rearrangements identified random patterns of clustered breakpoints with copy-number alterations resulting in interspersed gene deletions and extrachromosomal DNA amplification events. We conclude that individual chromosome segregation errors during mitotic cell division are sufficient to drive extensive structural variations that recapitulate genomic features commonly associated with human disease.
癌症基因组通常具有染色体数目和结构异常。在这里,我们将着丝粒特异性失活方法与条件必需基因选择相结合,提出了一种称为 CEN-SELECT 的策略,以系统地研究有丝分裂过程中错误分离染色体的结构景观。我们发现,单个染色体错误分离到微核中可以直接引发广泛的基因组重排类型。细胞遗传学分析表明,错误分离的染色体更容易发生七种主要类型的结构异常,包括易位、插入、缺失以及通过与经典非同源末端连接相结合的染色体重排。对克隆增殖重排的全基因组测序鉴定了具有拷贝数改变的聚类断点的随机模式,导致基因缺失和染色体外 DNA 扩增事件的散布。我们的结论是,有丝分裂细胞分裂过程中单个染色体的分离错误足以驱动广泛的结构变异,这些变异重现了与人类疾病相关的基因组特征。