Transcriptome profiling of HeLa-S3 cells treated with siRNAs targeting LATS1 and/or LATS2. Homo sapiens

Chromatin modifying activities for construction of appropriate epigenetic landscapes by polycomb repressive complex 2 (PRC2) play an essential role in development and tumorigenesis. However, the spatiotemporal mechanisms by which PRC2 achieves diverse epigenomes for specific tissue or cellular contexts remain poorly understood. Here, we discovered that LATS2 knockout causes dysregulation of PRC2 and subsequent transcriptome changes for differentiation in both mouse and human cells. LATS2 depletion dependent dysregulation of PRC2 also effects H3K4me3 and forms negative feedback loop for maintenance of PRC2. Further analyses reveal that LATS2 on chromatin binds to EZH2 and LATS2 has ability to phosphorylate PRC2 in vitro. These LATS2 dependent H3K27me3 targets are highly induced during neurogenesis, and statistical analysis of glioblastoma multiforme reveals that LATS2-high cases show more dedifferentiated transcriptome and poor prognosis with silencing of H3K27me3 targets. These observations suggest that LATS2-mediated epigenome coordination is pivotal for development and disease, including cancer. Overall design: Four conditions (mock, siLATS1, siLATS2 and siLATS1/LATS2) were analyzed by Agilent Whole Human Genome Microarray 4x44K v2 (eArray) one color experiments, resulting in four individual microarrays.

多梳抑制复合体2（polycomb repressive complex 2, PRC2）介导的染色质修饰活性，对于构建适宜的表观遗传图谱，在发育与肿瘤发生过程中发挥关键作用。然而，PRC2如何通过时空调控机制，在特定组织或细胞环境中形成多样表观组的分子机制仍不甚明晰。本研究发现，LATS2敲除会导致PRC2功能失调，并在小鼠与人类细胞中引发细胞分化相关的转录组改变。LATS2敲低依赖的PRC2失调同时影响组蛋白H3赖氨酸4三甲基化（H3K4me3），并形成维持PRC2功能的负反馈环路。进一步分析显示，结合于染色质的LATS2可与EZH2相互作用，且LATS2在体外具有磷酸化PRC2的能力。这些受LATS2调控的组蛋白H3赖氨酸27三甲基化（H3K27me3）靶基因在神经发生过程中显著上调；对多形性胶质母细胞瘤的统计分析表明，LATS2高表达样本呈现更为显著的去分化转录组特征，且伴随H3K27me3靶基因沉默，预后不良。上述研究结果提示，LATS2介导的表观组协调对于发育进程及包括癌症在内的多种疾病均具有关键调控作用。

实验整体设计：采用安捷伦全人类基因组微阵列4x44K v2（eArray）单通道基因芯片实验，对4组处理条件（空白对照mock、siLATS1、siLATS2及siLATS1与LATS2共敲低组）进行分析，共获得4张独立的微阵列芯片数据。