结肠类器官的遗传编辑提供了锯齿状癌发生的分子特异性和原位性临床前模型
今天与大家一起来学习于2018年4月17日发表在Gut（IF=16.658）上的一篇文章：Genetic editing of colonicorganoids provides a molecularly distinct and orthotopic preclinical model ofserrated carcinogenesis《结肠类器官的遗传编辑提供了锯齿状癌发生的分子特异性和原位性临床前模型》。
下面对这篇文章进行简要介绍：
OBJECTIVE:
Serratedcolorectal cancer (CRC) accounts for approximately 25% of cases and includestumours that are among the most treatment resistant and with worst outcomes.This CRC subtype is associated with activating mutations in themitogen-activated kinase pathway gene, BRAF, and epigeneticmodifications termed the CpG Island Methylator Phenotype, leading to epigeneticsilencing of key tumour suppressor genes. It is still not clear which(epi-)genetic changes are most important in neoplastic progression and we beginto address this knowledge gap herein.
目的：
锯齿状结直肠癌（CRC）约占结直肠癌病例的25％，其中包括耐药性最强且预后最差的肿瘤。这种CRC亚型与有丝分裂原活化激酶通路基因BRAF中的激活突变和CpG岛甲基化表型的表观遗传修饰相关，导致关键肿瘤抑制基因的表观遗传沉默。目前尚不清楚哪些（epi）基因改变在肿瘤进展中最重要，我们开始着手解决这方面的知识缺口。
DESIGN:
We use organoidculture combined with CRISPR/Cas9 genome engineering to sequentially introducegenetic alterations associated with serrated CRC and which regulate the stemcell niche, senescence and DNA mismatch repair.
设计：
我们使用与CRISPR / Cas9基因工程相结合的类器官培养技术依次引入与锯齿状CRC有关的基因改变，并调节干细胞巢、衰老和DNA错配修复。
RESULTS:
Targeted biallelicgene alterations were verified by DNA sequencing. Organoid growth in theabsence of niche factors was assessed, as well as analysis of downstreammolecular pathway activity. Orthotopic engraftment of complex organoid lines,but not BrafV600E alone, quickly generatedadenocarcinoma in vivo with serrated features consistent with human disease.Loss of the essential DNA mismatch repair enzyme, Mlh1, led to microsatelliteinstability. Sphingolipid metabolism genes are differentially regulated in bothour mouse models of serrated CRC and human CRC, with key members of thispathway having prognostic significance in the human setting.
结果：
通过DNA测序证实了靶向双等位基因的改变。评估缺乏生态因子的类器官生长情况，并且分析下游分子途径活性。复杂类器官系的原位植入，但不是单独的BrafV600E ，在体内迅速产生具有与人类疾病一致的锯齿状特征的腺癌。必需DNA错配修复酶Mlh1的缺失导致微卫星序列不稳定。鞘磷脂代谢基因在我们的锯齿状CRC小鼠模型和人类CRC中均有差异性调节，该通路的核心成员在人类环境中具有预测意义。
CONCLUSION:
We generate rapid,complex models of serrated CRC to determine the contribution of specificgenetic alterations to carcinogenesis. Analysis of our models alongside patientdata has led to the identification of a potential susceptibility for thistumour type.
结论：
我们制作快速、复杂的锯齿状CRC模型以确定特定基因改变对致癌的作用。 我们的模型与患者数据一起分析，引起对这种肿瘤类型潜在易感性的鉴定。
KEYWORDS:
cancer genetics;colorectal cancer; gene mutation; methylation; oncogenes
关键词：
肿瘤遗传学; 结直肠癌; 基因突变;甲基化;癌基因
补充说明：organoid的具体意思
- 来源于Wikipedia（维基百科）：An organoid isa miniaturized and simplified version of an organ produced in vitro in threedimensions that shows realistic micro-anatomy. They are derived from one or afew cells from a tissue, embryonic stem cells or induced pluripotent stemcells, which can self-organize in three-dimensional culture owing to theirself-renewal and differentiation capacities. The technique for growingorganoids has rapidly improved since the early 2010s, and it was named by TheScientist as one of the biggest scientific advancements of 2013.[ Organoids areused by scientists to study disease and treatments in a laboratory.
类器官是体外产生的器官微型和简化形式，在三维情况下可显示出其真实的显微解剖。 它们来自组织中的一个或几个细胞、胚胎干细胞或者诱导的多能干细胞，由于其自我更新和分化能力强，它们可以在三维立体培养中自我组织。自2010年初以来，种植类器官技术迅速发展，并被科学家评为2013年最大科学进展之一。科学家使用类器官在实验室研究疾病及其治疗方法。
