美国华盛顿大学Cole Trapnell团队在研究中取得进展，他们利用单细胞遗传筛选鉴定到负责上皮间充质转化（EMT）转换过程中的调节性检查点。相关论文发表在2019年9月出版的《自然—遗传学》杂志上。

将单细胞变化轨迹分析与集中的遗传筛选相结合可以揭示参与指导发育和疾病中细胞决策的遗传结构。研究人员应用了这种方法来检测控制上皮间充质转化（EMT）的遗传回路。研究人员使用单细胞RNA测序来分析了转化生长因子-β存在与否的情况下自发产生EMT的上皮细胞。假定空间轨迹分析确定了基因调控的连续情况，而非EMT的离散“部分”阶段。KRAS负责上皮状态的消失并获得完全间充质表型。单细胞CRISPR-Cas9筛选鉴定了EMT相关受体和转录因子，包括KRAS的调节因子，其丢失阻碍了EMT的进展。

抑制KRAS效应蛋白MEK及其上游激活因子EGFR和MET的相关实验表明，关键信号事件的中断揭示了EMT连续变化过程中的调节性“检查点”并解释了EMT调控程序的相反观点。

附：英文原文

Title: A pooled single-cell genetic screen identifies regulatory checkpoints in the continuum of the epithelial-to-mesenchymal transition

Author: Jos L. McFaline-Figueroa, Andrew J. Hill, Xiaojie Qiu, Dana Jackson, Jay Shendure, Cole Trapnell

Issue&Volume: Volume 51 Issue 9

Abstract: Integrating single-cell trajectory analysis with pooled genetic screening could reveal the genetic architecture that guides cellular decisions in development and disease. We applied this paradigm to probe the genetic circuitry that controls epithelial-to-mesenchymal transition (EMT). We used single-cell RNA sequencing to profile epithelial cells undergoing a spontaneous spatially determined EMT in the presence or absence of transforming growth factor-β. Pseudospatial trajectory analysis identified continuous waves of gene regulation as opposed to discrete ‘partial’ stages of EMT. KRAS was connected to the exit from the epithelial state and the acquisition of a fully mesenchymal phenotype. A pooled single-cell CRISPR-Cas9 screen identified EMT-associated receptors and transcription factors, including regulators of KRAS, whose loss impeded progress along the EMT. Inhibiting the KRAS effector MEK and its upstream activators EGFR and MET demonstrates that interruption of key signaling events reveals regulatory ‘checkpoints’ in the EMT continuum that mimic discrete stages, and reconciles opposing views of the program that controls EMT.

DOI: 10.1038/s41588-019-0489-5

Source:https://www.nature.com/articles/s41588-019-0489-5