CRISPR-based technology to silence the expression of IncRNAs.
CRISPR-based technology to silence the expression of IncRNAs.
复制标题
基于 CRISPR 的技术可沉默 IncRNA 的表达。
DOI：
10.1073/pnas.2003702117
复制
发表时间：
2020
影响因子：
11.1
通讯作者：
Staudt,LouisM
中科院分区：
文献类型：
--
作者：
Phelan,JamesD;Staudt,LouisM
人类基因组包含超过30亿个碱基对，一些估计表明，近75%的基因组可能被转录(1)，但只有一小部分（1 - 2%）编码蛋白质编码区的基因组被系统地探测了功能。转录基因组由短非编码rna （ncRNAs）和长非编码rna （lncRNAs）组成。lncrna被定义为长度大于200个核苷酸，可以像蛋白质编码基因一样被盖住、聚腺苷化和剪接。根据定义，lncRNAs不包含超过50个氨基酸的开放阅读框，但最近的工作发现了一个由lncRNAs编码的更小的“微蛋白”的新世界(2)。lncrna的其他功能包括它们形成适配体的能力，适配体结合并调节蛋白质复合物(3)。lncrna可以通过增强子捕获(4)和将组蛋白修饰子募集到染色质（5,6）来调节基因表达。尽管有这些例子，大多数lncrna的功能是未知的。在PNAS上，Raffeiner等人(7)开发了基于crispr的技术来沉默lncrna的表达，并利用他们的技术鉴定了受癌基因MYC调控的功能性lncrna。最近鉴定功能性lncrna的工作依赖于CRISPR技术，该技术可以精确地将CRISPR相关（Cas）蛋白靶向到特定的基因组位置。这项技术开创了功能基因组学的新时代，其中大规模筛选大大增加了我们对复杂基因型-表型关系的理解（8-10）。CRISPR-Cas9联合筛选已成为癌症研究的支柱（11,12），揭示了基因的重要性、合成致死率、对靶向治疗和免疫治疗的耐药机制，以及无数其他表型。这些筛选大多依赖于cas9诱导的DNA双链断裂，当修复时，引入小的插入或缺失，最终产生突变或截短的蛋白质。cas9诱导的基因组编辑也被用于改变基因表达
The human genome contains more than 3 billion base pairs, and some estimates suggest that nearly 75% of the genome may be transcribed (1), yet only a small fraction (1 to 2%) of the genome that encodes for protein coding regions has been systematically probed for function. The transcribed genome consists of both short noncoding RNAs (ncRNAs) and long ncRNAs (lncRNAs). The lncRNAs are defined as being greater than 200 nucleotides in length and may be capped, polyadenylated, and spliced like protein-coding genes. By definition, lncRNAs do not contain open reading frames of greater than 50 amino acids, but recent work has uncovered a new world of smaller “microproteins” that are encoded by lncRNAs (2). Other functions of lncRNAs include their ability to form aptamers, which bind and regulate protein complexes (3). The lncRNAs can modulate gene expression by enhancer trapping (4), and by recruiting histone modifiers to chromatin (5, 6). These examples notwithstanding, the function of most lncRNAs is unknown. In PNAS, Raffeiner et al.(7) develop CRISPR-based technology to silence the expression of lncRNAs, and use their technology to identify functional lncRNAs that are regulated by the oncogene MYC.Recent efforts to identify functional lncRNAs have relied on CRISPR technology, which can exquisitely target CRISPR-associated (Cas) proteins to specific genomic locations. This technology has ushered in a new era of functional genomics in which large-scale screens have exponentially increased our understanding of complex genotype− phenotype relationships (8–10). CRISPR-Cas9 pooled screens have become a mainstay of cancer research (11, 12), revealing gene essentiality, synthetic lethality, and mechanisms of resistance to targeted therapy and immunotherapy, among countless other phenotypes. Most of these screens have relied on Cas9-induced DNA double-stranded breaks that, when repaired, introduce small insertions or deletions, ultimately producing either mutant or truncated proteins. Cas9-induced genome editing has also been used to alter gene expression