Mechanism for the induction of cell death in ONS-76 medulloblastoma cells by Zhangfei/CREB-ZF
Mechanism for the induction of cell death in ONS-76 medulloblastoma cells by Zhangfei/CREB-ZF
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DOI：
10.1007/s11060-012-0927-z
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发表时间：
2012-09-01
影响因子：
3.9
通讯作者：
Misra, Vikram
中科院分区：
文献类型：
--
作者：
Bodnarchuk, Timothy W.;Napper, Scott;Misra, Vikram
来自髓母细胞瘤细胞系的细胞不含可检测量的碱性亮氨酸拉链蛋白Zhangfei。然而，我们之前已经表明，这种蛋白质在ONS-76和UW 228髓母细胞瘤细胞系中的表达导致细胞停止生长并发育出类似于神经突的过程。我们的目的是确定张飞影响ONS-76细胞的分子机制。我们用表达Zhangfei或对照蛋白LacZ的腺病毒载体感染ONS-76细胞，然后比较表达Zhangfei和LacZ的细胞中的以下参数：（a）细胞凋亡、自噬和巨胞饮的标志物，（B）参与神经发生和细胞凋亡的基因的转录物，（c）选定细胞蛋白激酶的肽靶的磷酸化，和（d）转录因子的激活。表达Zhangfei的细胞似乎屈服于凋亡。自噬囊泡染色增加，自噬反应基因表达上调，表明这些细胞正在发生自噬，可能与细胞凋亡有关。在我们的分析中，Zhangfei表达细胞的基因表达和磷酸化介导的信号转导活性模式表明，丝裂原活化蛋白激酶（MAPK）途径是活跃的。此外，我们发现转录因子Brn 3a以及参与分化的因子在Zhangfei表达细胞中也是活跃的。我们测试了张飞增强Brn 3a表达的假设，Brn 3a是一种已知的TrkA诱导剂，TrkA是神经生长因子（NGF）的高亲和力受体。然后TrkA以自分泌的方式与NGF结合，触发MAPK途径，并导致ONS-76细胞分化为神经元和胶质样细胞-这一过程最终导致细胞死亡。我们证明：（a）Zhangfei可以增强从分离的Brn 3a启动子的转录，（B）ONS-76细胞产生NGF，和（c）针对NGF的抗体和TrkA的抑制剂以及MAPK途径的选定组分可以部分恢复表达Zhangfei的ONS-76细胞的生长。
Cells from medulloblastoma lines do not contain detectable amounts of the basic leucine-zipper protein Zhangfei. However, we have previously shown that expression of this protein in cells of the ONS-76 and UW228 medulloblastoma lines causes the cells to stop growing and develop processes that resemble neurites. Our objective was to determine the molecular mechanisms by which Zhangfei influences ONS-76 cells. We infected ONS-76 cells with adenovirus vectors expressing either Zhangfei or the control protein LacZ and then compared the following parameters in Zhangfei and LacZ-expressing cells: (a) markers of apoptosis, autophagy and macropinocytosis, (b) transcripts for genes involved in neurogenesis and apoptosis, (c) phosphorylation of peptide targets of selected cellular protein kinases, and (d) activation of transcription factors. Zhangfei-expressing cells appeared to succumb to apoptosis. Increased staining for autophagic vesicles and upregulated expression of autophagy response genes in these cells indicated that they were undergoing autophagy, possibly associated with apoptosis. Within our analysis, patterns of gene expression and phosphorylation-mediated signal transduction activity in Zhangfei-expressing cells indicated that the mitogen-activated protein kinase (MAPK) pathway was active. In addition, we found that the transcription factor Brn3a as well as factors implicated in differentiation were also active in Zhangfei-expressing cells. We tested the hypothesis that Zhangfei enhances the expression of Brn3a, a known inducer of TrkA, the high-affinity receptor for nerve growth factor (NGF). TrkA then engages NGF in an autocrine manner triggering the MAPK pathway and leading to differentiation of ONS-76 cells into neuron and glia-like cells-a process that eventually brings about cell death. We showed that: (a) Zhangfei could enhance transcription from the isolated Brn3a promoter, (b) ONS-76 cells produced NGF and (c) antibodies against NGF and inhibitors of TrkA and selected components of the MAPK pathway could partially restore the growth of Zhangfei-expressing ONS-76 cells.