PDF(Pubmed)
Abstract：
Glioblastoma (GBM) is an aggressive tumor that frequently exhibits gain of chromosome 7, loss of chromosome 10, and aberrantly activated receptor tyrosine kinase signaling pathways. Previously, we identified Mesenchyme Homeobox 2 (MEOX2), a gene located on chromosome 7, as an upregulated transcription factor in GBM. Overexpressed transcription factors can be involved in driving GBM. Here, we aimed to address the role of MEOX2 in GBM.
Patient-derived GBM tumorspheres were used to constitutively knockdown or overexpress MEOX2 and subjected to in vitro assays including western blot to assess ERK phosphorylation. Cerebral organoid models were used to investigate the role of MEOX2 in growth initiation. Intracranial mouse implantation models were used to assess the tumorigenic potential of MEOX2. RNA-sequencing, ACT-seq, and CUT&Tag were used to identify MEOX2 target genes.
MEOX2 enhanced ERK signaling through a feed-forward mechanism. We identified Ser155 as a putative ERK-dependent phosphorylation site upstream of the homeobox-domain of MEOX2. S155A substitution had a major effect on MEOX2 protein levels and altered its subnuclear localization. MEOX2 overexpression cooperated with p53 and PTEN loss in cerebral organoid models of human malignant gliomas to induce cell proliferation. Using high-throughput genomics, we identified putative transcriptional target genes of MEOX2 in patient-derived GBM tumorsphere models and a fresh frozen GBM tumor.
We identified MEOX2 as an oncogenic transcription regulator in GBM. MEOX2 increases proliferation in cerebral organoid models of GBM and feeds into ERK signaling that represents a core signaling pathway in GBM.
Patient-derived GBM tumorspheres were used to constitutively knockdown or overexpress MEOX2 and subjected to in vitro assays including western blot to assess ERK phosphorylation. Cerebral organoid models were used to investigate the role of MEOX2 in growth initiation. Intracranial mouse implantation models were used to assess the tumorigenic potential of MEOX2. RNA-sequencing, ACT-seq, and CUT&Tag were used to identify MEOX2 target genes.
MEOX2 enhanced ERK signaling through a feed-forward mechanism. We identified Ser155 as a putative ERK-dependent phosphorylation site upstream of the homeobox-domain of MEOX2. S155A substitution had a major effect on MEOX2 protein levels and altered its subnuclear localization. MEOX2 overexpression cooperated with p53 and PTEN loss in cerebral organoid models of human malignant gliomas to induce cell proliferation. Using high-throughput genomics, we identified putative transcriptional target genes of MEOX2 in patient-derived GBM tumorsphere models and a fresh frozen GBM tumor.
We identified MEOX2 as an oncogenic transcription regulator in GBM. MEOX2 increases proliferation in cerebral organoid models of GBM and feeds into ERK signaling that represents a core signaling pathway in GBM.
摘要：
背景：胶质母细胞瘤（GBM）是一种侵袭性肿瘤，通常表现为7号染色体的增加，10号染色体的丢失和异常激活的受体酪氨酸激酶信号通路。以前,我们确定了MesenchymeHomeobox2（MEOX2），位于7号染色体上的基因，作为GBM中上调的转录因子。过表达的转录因子可参与驱动GBM。这里,我们旨在解决MEOX2在GBM中的作用。
方法:患者来源的GBM肿瘤球用于组成型敲低或过表达MEOX2,并进行包括蛋白质印迹的体外测定以评估ERK磷酸化。脑类器官模型用于研究MEOX2在生长启动中的作用。使用颅内小鼠植入模型来评估MEOX2的致瘤潜力。RNA测序，ACT-seq和CUT&Tag用于鉴定MEOX2靶基因。
结果：MEOX2通过前馈机制增强ERK信号。我们将Ser155鉴定为MEOX2同源盒结构域上游的推定的ERK依赖性磷酸化位点。S155A取代对MEOX2蛋白水平有重要影响并改变其亚核定位。在人类恶性神经胶质瘤的脑类器官模型中，MEOX2过表达与p53和PTEN丢失协作以诱导细胞增殖。利用高通量基因组学，我们在患者来源的GBM肿瘤球体模型和新鲜冷冻的GBM肿瘤中鉴定了MEOX2的推定转录靶基因。
结论：我们确定MEOX2是GBM中的致癌转录调节因子。MEOX2增加GBM的脑类器官模型中的增殖并进入代表GBM中的核心信号通路的ERK信号传导。
方法:患者来源的GBM肿瘤球用于组成型敲低或过表达MEOX2,并进行包括蛋白质印迹的体外测定以评估ERK磷酸化。脑类器官模型用于研究MEOX2在生长启动中的作用。使用颅内小鼠植入模型来评估MEOX2的致瘤潜力。RNA测序，ACT-seq和CUT&Tag用于鉴定MEOX2靶基因。
结果：MEOX2通过前馈机制增强ERK信号。我们将Ser155鉴定为MEOX2同源盒结构域上游的推定的ERK依赖性磷酸化位点。S155A取代对MEOX2蛋白水平有重要影响并改变其亚核定位。在人类恶性神经胶质瘤的脑类器官模型中，MEOX2过表达与p53和PTEN丢失协作以诱导细胞增殖。利用高通量基因组学，我们在患者来源的GBM肿瘤球体模型和新鲜冷冻的GBM肿瘤中鉴定了MEOX2的推定转录靶基因。
结论：我们确定MEOX2是GBM中的致癌转录调节因子。MEOX2增加GBM的脑类器官模型中的增殖并进入代表GBM中的核心信号通路的ERK信号传导。
