Inhibition of platelet-derived growth factor-induced cell growth signaling by a short interfering RNA for EWS-Fli1 via down-regulation of phospholipase D2 in Ewing sarcoma cells
Inhibition of platelet-derived growth factor-induced cell growth signaling by a short interfering RNA for EWS-Fli1 via down-regulation of phospholipase D2 in Ewing sarcoma cells
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DOI：
10.1074/jbc.m411626200
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发表时间：
2005-07-29
影响因子：
4.8
通讯作者：
Shimizu, K
中科院分区：
文献类型：
--
作者：
Nozawa, S;Ohno, T;Shimizu, K
EWS-Fli 1是由染色体易位t（11;22，q24;q12）引起的融合基因，在尤文肉瘤和原始神经外胚层肿瘤中发现，编码转录激活因子并促进细胞转化。然而，其产品的确切生物学功能仍然未知。为了研究EWS-Fli 1在细胞生长信号中的作用，我们用EWS-Fli 1的短干扰RNA转染尤文肉瘤TC-135细胞。EWS-Fli 1敲低降低了细胞生长和血小板衍生生长因子（PDGF）-BB诱导的生长信号酶激活。有趣的是，与对照细胞相比，磷脂酶D2（而不是PDGF-BB受体）在EWS-Fli 1敲低的TC-135细胞中显示出显著的下调。在尤文肉瘤TC-135细胞中，PDGF-BB诱导的细胞外信号调节激酶Akt、p70 S6 K磷酸化和细胞周期蛋白D3的表达被短干扰RNA磷脂酶（PL）-D2转染显著抑制。PDGF-BB诱导的生长信号的激活也被1-丁醇抑制，1-丁醇阻止磷脂酶D产生磷脂酸（但不是叔丁醇），从而暗示PLD 2在TC-135细胞中PDGF-BB介导的信号。这些结果表明，EWS-Fli 1可能发挥作用，在尤文肉瘤细胞通过PLD 2表达的肿瘤增殖信号酶的调节。
EWS-Fli1, a fusion gene resulting from a chromosomal translocation t(11;22, q24;q12) and found in Ewing sarcoma and primitive neuroectodermal tumors, encodes a transcriptional activator and promotes cellular transformation. However, the precise biological functions of its products remain unknown. To investigate the role of EWS-Fli1 in cell growth signaling, we transfected Ewing sarcoma TC-135 cells with short interfering RNAs for EWS-Fli1. EWS-Fli1 knockdown reduced cell growth and platelet-derived growth factor (PDGF)-BB-induced activation of the growth signaling enzymes. Interestingly, phospholipase D2 ( but not the PDGF-BB receptor) showed marked down-regulation in the EWS-Fli1-knocked down TC-135 cells compared with the control cells. In Ewing sarcoma TC-135 cells, the PDGF-BB-induced phosphorylation of growth signaling involving extracellular signal-regulated kinase, Akt, p70S6K, and the expression of cyclin D3 were markedly inhibited by transfection with short interfering RNA phospholipase (PL)-D2. The PDGF-BB-induced activation of growth signaling was also suppressed by 1-butanol, which prevents the production of phosphatidic acid by phospholipase D (but not by t-butyl alcohol), thereby implicating PLD2 in PDGF-BB-mediated signaling in TC-135 cells. These results suggest that EWS-Fli1 may play a role in the regulation of tumor proliferation-signaling enzymes via PLD2 expression in Ewing sarcoma cells.