Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

RNA immunoprecipitation (RIP)-Chip analysis for EWS-bound mRNA

ABSTRACT: Although EWS/FLI-1 fusion protein is responsible for most EwingM-bM-^@M-^Ys sarcoma family tumors (ESFT), the function of native EWS remains largely unknown. Here, we first showed that EWS repressed protein expression in a tethering assay. mRNAs bound to EWS were determined by RNA-immunoprecipitation Chip assay, and one of them, proline-rich Akt substrate of 40 kDa (PRAS40) mRNA, directly interacted with EWS. The inhibitor of AKT, API-2, repressed ESFT cell proliferation. We demonstrate that EWS negatively regulated PRAS40 protein expression through binding to PRAS40 3M-bM-^@M-^YUTR. Furthermore, PRAS40 knockdown inhibited the proliferation and metastatic potential of ESFT cells. Cytoplasmic lysates or whole cell lysates were prepared from HeLa S3 cells transfected with pFLAG-EWS , and incubated with anti-FLAG M2 Affinity Gel (Sigma) at 4M-BM-0C for 2 h. RNAs from lysates and immunoprecipitates were analysed using GeneChip Human Genome U133 Plus 2.0 Array (Affymetrix).

ORGANISM(S): Homo sapiens

SUBMITTER: Yuji Nakai

PROVIDER: E-GEOD-29313 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

PRAS40 is a functionally critical target for EWS repression in Ewing sarcoma.

Huang Lin L Nakai Yuji Y Kuwahara Iku I Matsumoto Ken K

Cancer research 20120112 5

Ewing sarcoma family tumors (ESFT) are highly aggressive and highly metastatic tumors caused by a chromosomal fusion between the Ewing sarcoma protein (EWS) with the transcription factor FLI-1. However, expression of the EWS/FLI-1 chimeric oncogene by itself is insufficient for carcinogenesis, suggesting that additional events are required. Here, we report the identification of the Akt substrate PRAS40 as an EWS target gene. EWS negatively regulates PRAS40 expression by binding the 3' untranslat ...[more]

PMID: 22241085

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Project description:EWS-FLI1 is a chimeric ETS transcription factor that is, due to a chromosomal rearrangement, specifically expressed in Ewing’s sarcoma family tumors (ESFT) and is thought to be the initiating event in the development of the disease. Previous genomic profiling experiments have identified a number of EWS-FLI1 regulated genes and genes that discriminate ESFT from other sarcomas, but so far a comprehensive analysis of EWS-FLI1 dependent molecular functions characterizing this aggressive cancer is lacking. In this study a molecular function map of ESFT was constructed based on an integrative analysis of gene expression profiling experiments on a uniform microarray platform following EWS-FLI1 knockdown in a panel of five ESFT cell lines, and on gene expression data from the same platform of 59 primary ESFT tumors. Based on the assumption that EWS-FLI1 is the driving transcriptional force in ESFT pathogenesis, we predicted an inverse correlation of gene expression for EWS-FLI1 regulated genes between the putative tissue of origin and the cell lines under EWS-FLI1 knockdown conditions. Consistent with recent reports, mesenchymal progenitor cells (MPC) were found to fit this hypothesis best and were therefore used as the reference tissue for the construction of the molecular function map in ESFT. The interrelations of molecular pathways were visualized by measuring the similarity among annotated gene functions by gene sharing. The molecular function map highlighted distinct clusters of activities for EWS-FLI1 regulated genes in ESFT and revealed a striking difference between EWS-FLI1 up- and down-regulated genes: EWS-FLI1 induced genes mainly belong to cell cycle regulation, proliferation and response to DNA damage, while repressed genes were associated with differentiation and cell communication. This study revealed that EWS-FLI1 combines by distinct molecular mechanisms two important functions of cellular transformation in one protein, growth promotion and differentiation blockage. By taking MPC as a reference tissue a significant EWS-FLI1 signature was discovered in ESFT that only partially overlapped with previously published EWS-FLI1 dependent gene expression patterns, identifying a series of novel targets for the chimeric protein in ESFT. Our results may guide target selection for future ESFT specific therapies. Keywords: Ewing's Sarcoma, EWS-FLI1, RNAi knock down and controls

Project description:EWS-FLI1 is a chimeric ETS transcription factor that is, due to a chromosomal rearrangement, specifically expressed in Ewingâs sarcoma family tumors (ESFT) and is thought to be the initiating event in the development of the disease. Previous genomic profiling experiments have identified a number of EWS-FLI1 regulated genes and genes that discriminate ESFT from other sarcomas, but so far a comprehensive analysis of EWS-FLI1 dependent molecular functions characterizing this aggressive cancer is lacking. In this study a molecular function map of ESFT was constructed based on an integrative analysis of gene expression profiling experiments on a uniform microarray platform following EWS-FLI1 knockdown in a panel of five ESFT cell lines, and on gene expression data from the same platform of 59 primary ESFT tumors. Based on the assumption that EWS-FLI1 is the driving transcriptional force in ESFT pathogenesis, we predicted an inverse correlation of gene expression for EWS-FLI1 regulated genes between the putative tissue of origin and the cell lines under EWS-FLI1 knockdown conditions. Consistent with recent reports, mesenchymal progenitor cells (MPC) were found to fit this hypothesis best and were therefore used as the reference tissue for the construction of the molecular function map in ESFT. The interrelations of molecular pathways were visualized by measuring the similarity among annotated gene functions by gene sharing. The molecular function map highlighted distinct clusters of activities for EWS-FLI1 regulated genes in ESFT and revealed a striking difference between EWS-FLI1 up- and down-regulated genes: EWS-FLI1 induced genes mainly belong to cell cycle regulation, proliferation and response to DNA damage, while repressed genes were associated with differentiation and cell communication. This study revealed that EWS-FLI1 combines by distinct molecular mechanisms two important functions of cellular transformation in one protein, growth promotion and differentiation blockage. By taking MPC as a reference tissue a significant EWS-FLI1 signature was discovered in ESFT that only partially overlapped with previously published EWS-FLI1 dependent gene expression patterns, identifying a series of novel targets for the chimeric protein in ESFT. Our results may guide target selection for future ESFT specific therapies. Experiment Overall Design: EWS-FLI1 knock down was performed by expressing specific siRNAs against EWS-FLI1 as small hairpin (sh) RNAs from pSUPER-based retroviral expression constructs in 5 different Ewing's sarcoma cell lines (WE68, SK-N-MC, TC252, STA-ET-1, STA-ET-7.2). As a negative control in each cell line, pSTNeg (Ambion, Applied Biosystems, Brunn am Gebirge, Austria) encoding a scrambled shRNA with no significant similarity to human sequences was used.

Dataset Information

RNA immunoprecipitation (RIP)-Chip analysis for EWS-bound mRNA

Publications

PRAS40 is a functionally critical target for EWS repression in Ewing sarcoma.

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