Department of Neurosurgery, University of Minnesota Medical School.
Ludwig Institute for Cancer Research, University of California San Diego.
Neurol Med Chir (Tokyo). 2020 Jul 15;60(7):329-336. doi: 10.2176/nmc.ra.2020-0091. Epub 2020 Jun 15.
Genome engineering using programmable nucleases such as transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeat-associated protein nine facilitated the introduction of genetic alterations at specific genomic sites in various cell types. These tools have been applied to cancer modeling to understand the pathogenic effects of the growing catalog of mutations found in human cancers. Pertaining to brain tumors, neural progenitor cells derived from human induced pluripotent stem cells (iPSCs) engineered with different combinations of genetic driver mutations observed in distinct molecular subtypes of glioblastomas, the most common form of primary brain cancer in adults, give rise to brain tumors when engrafted orthotopically in mice. These glioblastoma models recapitulate the transcriptomic signature of each molecular subtype and authentically resemble pathobiology of glioblastoma, including inter- and intra-tumor heterogeneity, chromosomal aberrations, and extrachromosomal DNA amplifications. Similar engineering with genetic mutations found in medulloblastoma and atypical teratoid rhabdoid tumors in iPSCs have led to genetically trackable models that bear clinical relevance to these pediatric brain tumors. These models have contributed to improved comprehension of the genetic causation of tumorigenesis and offered a novel platform for therapeutic discovery. Studied in the context of three-dimensional cerebral organoids, these models have aided in the study of tumor invasion as well as therapeutic responses. In summary, modeling brain tumors through genome engineering enables not only the establishment of authentic tumor avatars driven by bona fide genetic mutations observed in patient samples but also facilitates functional investigations of particular genetic alterations in an otherwise isogenic background.
使用可编程核酸酶（如转录激活因子样效应核酸酶（TALEN））进行基因组工程，以及聚类规则间隔短回文重复相关蛋白 9（CRISPR/Cas9），可以在各种细胞类型的特定基因组位点引入遗传改变。这些工具已被应用于癌症建模，以了解在人类癌症中发现的不断增加的突变目录的致病效应。在脑肿瘤方面，源自人类诱导多能干细胞（iPSC）的神经祖细胞，经过不同组合的遗传驱动突变工程改造，这些突变在胶质母细胞瘤的不同分子亚型中观察到，是成人中最常见的原发性脑癌形式，当在小鼠中原位移植时会引发脑瘤。这些胶质母细胞瘤模型再现了每个分子亚型的转录组特征，并真实地类似于胶质母细胞瘤的病理生物学，包括肿瘤内和肿瘤间异质性、染色体异常和染色体外 DNA 扩增。在 iPSC 中发现的与髓母细胞瘤和非典型畸胎样横纹肌样瘤相关的遗传突变的类似工程导致了可遗传追踪的模型，这些模型与这些儿科脑肿瘤具有临床相关性。这些模型有助于提高对肿瘤发生的遗传原因的理解，并为治疗发现提供了新的平台。在三维大脑类器官的背景下研究这些模型，有助于研究肿瘤侵袭以及治疗反应。总之，通过基因组工程对脑肿瘤进行建模不仅可以建立由患者样本中观察到的真正遗传突变驱动的真实肿瘤模拟体，还可以在其他同基因背景下对特定遗传改变进行功能研究。
