Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
Oncode Institute, Utrecht, the Netherlands.
Nat Genet. 2021 Aug;53(8):1187-1195. doi: 10.1038/s41588-021-00891-2. Epub 2021 Jul 1.
Central to tumor evolution is the generation of genetic diversity. However, the extent and patterns by which de novo karyotype alterations emerge and propagate within human tumors are not well understood, especially at single-cell resolution. Here, we present 3D Live-Seq-a protocol that integrates live-cell imaging of tumor organoid outgrowth and whole-genome sequencing of each imaged cell to reconstruct evolving tumor cell karyotypes across consecutive cell generations. Using patient-derived colorectal cancer organoids and fresh tumor biopsies, we demonstrate that karyotype alterations of varying complexity are prevalent and can arise within a few cell generations. Sub-chromosomal acentric fragments were prone to replication and collective missegregation across consecutive cell divisions. In contrast, gross genome-wide karyotype alterations were generated in a single erroneous cell division, providing support that aneuploid tumor genomes can evolve via punctuated evolution. Mapping the temporal dynamics and patterns of karyotype diversification in cancer enables reconstructions of evolutionary paths to malignant fitness.
肿瘤进化的核心是遗传多样性的产生。然而,新的核型改变在人类肿瘤中出现和传播的程度和模式尚不清楚,特别是在单细胞分辨率下。在这里,我们提出了一种 3D Live-Seq-a 方案,该方案将肿瘤类器官生长的活细胞成像与每个成像细胞的全基因组测序相结合,以重建连续细胞代中不断进化的肿瘤细胞核型。使用源自患者的结直肠癌细胞类器官和新鲜肿瘤活检,我们证明了不同复杂程度的核型改变很常见,并且可以在几个细胞代内出现。亚染色体无着丝粒片段易于在连续细胞分裂中复制和集体错误分离。相比之下,大量全基因组的核型改变是在一个错误的细胞分裂中产生的,这为非整倍体肿瘤基因组可以通过间断进化来进化提供了支持。对癌症中核型多样化的时间动态和模式进行映射,可以重建向恶性适应性进化的路径。