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The determination of the hSNF5 target genes and the clarification of the transcriptional mechanism of hSNF5

hSNF5靶基因的确定及hSNF5转录机制的阐明

基本信息

批准号：
22890157
负责人：
KUWAHARA Yasumichi
金额：
$ 1.89万
依托单位：
Kyoto Prefectural University of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Research Activity Start-up
财政年份：
2010
资助国家：
日本
起止时间：
2010 至 2011
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22890157/
关键词：
ラブドイド腫瘍 hSNF5 NOXA SWI/SNF複合体 Mcl-1 p21 p53

项目摘要

Malignant rhabdoid tumor(MRT), a highly aggressive cancer of young children, displays inactivation of the hSNF5 gene in primary tumors and cell lines. We have previously reported that reexpression of hSNF5 in MRT cell lines causes a G1 arrest via p21WAF1/CIP1(p21) mRNA induction. However, the mechanisms of p21 promoter activation by hSNF5 remain unclear.Because p21 is a transcriptional target of the p53 tumor suppressor gene, we determined the role of p53 in hSNF5-induced p21 activation. We reexpressed hSNF5 in the A204 and TTC642 MRT cell lines, with or without stable knockdown of p53 expression, using adenoviral vectors expressing either hSNF5 and GFP or GFP. While loss of p53 expression significantly inhibited p21 transcriptional activity induced by hSNF5 in A204 cells at 24 hours, it did not alter its activity by hSNF5 after 24 hours in the TTC642 cells. These results suggested that the up-regulation p21 transcription by hSNF5 operated through p53-dependent and. independent mechani … More sms in the A204 and TTC642 cell lines, respectively. Next, we used chromatin immunoprecipitation(ChIP) analysis of the p21 promoter to determine where hSNF5 appeared at the p21 promoter and whether its recruitment altered binding of other transcription factors or the chromatin landscape. Our results indicated that reexpressed hSNF5 binds within 1 kb of transcript start site(TSS), with maximal enrichment at the TSS in both cell lines. Furthermore, histone acetyltransferases(HATs), RNA polymerase II(RNAPII), and BRG-1 are assembled with p53 and CDK8(co-activator of p53 transcriptional program) by reexpression of hSNF5 in A204 cells. In contrast, while p53 and CDK8 occupancy did not change after hSNF5 reexpression in the TTC642 cells, HATs, RNAPII, and BRG-1 levels increased at the p21 promoter. These findings correlated with the results of p53 knock-down experiments. Furthermore, histone H3K36 tri-methylation increased downstream of the TSS in both cell lines. These results suggested hSNF5 regulates the initiation activity of the p21 promoter by either itself or p53 recruitment, resulting in the mRNA elongation.Our findings demonstrate that while induction of p21 transcription by hSNF5 in A204 cells depends on p53, it occurs independently of p53 in TTC642 cells. The lack of dependence upon p53 appears to extend to other MRT cell lines tested in our laboratory. Furthermore, our results suggest that hSNF5 may alter p21 transcriptional initiation by itself or through the recruitment of other uncharacterized transcription factors. Less

恶性横纹肌样肿瘤是一种高度侵袭性的儿童癌症，在原发肿瘤和细胞系中表现出hSNF5基因的失活。我们以前曾报道，hSNF5在MRT细胞系中的重新表达通过诱导p21WAF1/CIP1(P21)mRNA导致G1期停滞。然而，hSNF5激活p21启动子的机制尚不清楚。由于p21是p53抑癌基因的转录靶点，我们确定了p53在hSNF5诱导的p21激活中的作用。我们用表达hSNF5和GFP或GFP的腺病毒载体在A204和TTC642 MRT细胞系中重新表达了hSNF5，无论是否稳定地下调了p53的表达。HSNF5对A204细胞p21转录活性有明显抑制作用，而hSNF5对TTC642细胞p21转录活性无明显影响。这些结果表明，hSNF5上调p21转录是通过p53依赖和。独立机械…分别在A204和TTC642细胞系中有较多的丹参。接下来，我们使用p21启动子的染色质免疫沉淀(ChIP)分析来确定hSNF5出现在p21启动子的哪里，以及它的招募是否改变了其他转录因子的结合或染色质的格局。我们的结果表明，重新表达的hSNF5结合在转录起始位点(TSS)的1kb范围内，在两种细胞系的TSS处都有最大的浓缩。此外，组蛋白乙酰转移酶(HATS)、RNA聚合酶II(RNAPII)和BRG-1与P53和CDK8(P53转录程序共激活因子)通过hSNF5在A204细胞中重新表达而组装在一起。相反，当hSNF5在TTC642细胞中重新表达后，p53和CDK8的占有率没有改变，但p21启动子上HATS、RNAPII和BRG-1的水平增加。这些发现与P53基因敲除实验的结果相关。此外，在两种细胞系中，组蛋白H3K36三甲基化在TSS下游增加。这些结果表明，hSNF5通过自身或P53的募集调节p21启动子的启动活性，导致mRNA的延长。我们的研究结果表明，虽然hSNF5在A204细胞中诱导p21转录依赖于P53，但在TTC642细胞中它独立于P53发生。缺乏对P53的依赖似乎延伸到了我们实验室测试的其他MRT细胞系。此外，我们的结果表明，hSNF5可能通过自身或通过招募其他未鉴定的转录因子来改变p21的转录启动。较少

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Reexpression of hSNF5 regulates the transcriptional activity of the p21 promoter through p53 dependent or independent mechanisms in malignant rhabdoid tumors

在恶性横纹肌瘤中，hSNF5 的重新表达通过 p53 依赖或独立机制调节 p21 启动子的转录活性

DOI：
发表时间：
2011
期刊：
影响因子：
0
作者：
Kuwahara Y;Durand J
通讯作者：
Durand J

Sensitivity of malignant rhabdoid tumor cell lines to PD0332991 is inverserly correlated with p16 expression

恶性横纹肌瘤细胞系对 PD0332991 的敏感性与 p16 表达呈负相关

DOI：
发表时间：
2011
期刊：
Biochem Biophys Res Commun
影响因子：
0
作者：
Katsumi Y;Iehara T;Miyachi M;Yagyu Y;Tsubai-Shimizu T;Kikuchi K;Tamura S;Itoh H;Kuwahara Y;Tsuchiya K;Kuroda H;Sugimoto T;Houghton PJ;Hosoi H
通讯作者：
Hosoi H

Reexpression of hSNF5 regulates the transcriptional activity of the NOXA promoter through p53 independent mechanisms in malignant rhabdoid tumors

在恶性横纹肌瘤中，hSNF5 的重新表达通过 p53 独立机制调节 NOXA 启动子的转录活性