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IGF1 is a common target gene of Ewing's sarcoma fusion proteins in mesenchymal progenitor cells.

Cironi L, Riggi N, Provero P, Wolf N, Suvà ML, Suvà D, Kindler V, Stamenkovic I - PLoS ONE (2008)

Bottom Line: Whereas all MPC isolates tested could stably express EWS-FLI-1, only some sustained stable EWS-ERG expression and none could express FUS-ERG for more than 3-5 days.However, all three fusion proteins, but neither FLI-1 nor ERG-1 alone, activated the IGF1 promoter and induced IGF1 expression.Whereas expression of different ESFT-associated fusion proteins may require distinct cellular microenvironments and induce transcriptome changes of limited similarity, IGF1 induction may provide one common mechanism for their implication in ESFT pathogenesis.

View Article: PubMed Central - PubMed

Affiliation: Division of Experimental Pathology, Institute of Pathology CHUV, University of Lausanne, Lausanne, Switzerland.

ABSTRACT

Background: The EWS-FLI-1 fusion protein is associated with 85-90% of Ewing's sarcoma family tumors (ESFT), the remaining 10-15% of cases expressing chimeric genes encoding EWS or FUS fused to one of several ets transcription factor family members, including ERG-1, FEV, ETV1 and ETV6. ESFT are dependent on insulin-like growth factor-1 (IGF-1) for growth and survival and recent evidence suggests that mesenchymal progenitor/stem cells constitute a candidate ESFT origin.

Methodology/principal findings: To address the functional relatedness between ESFT-associated fusion proteins, we compared mouse progenitor cell (MPC) permissiveness for EWS-FLI-1, EWS-ERG and FUS-ERG expression and assessed the corresponding expression profile changes. Whereas all MPC isolates tested could stably express EWS-FLI-1, only some sustained stable EWS-ERG expression and none could express FUS-ERG for more than 3-5 days. Only 14% and 4% of the total number of genes that were respectively induced and repressed in MPCs by the three fusion proteins were shared. However, all three fusion proteins, but neither FLI-1 nor ERG-1 alone, activated the IGF1 promoter and induced IGF1 expression.

Conclusion/significance: Whereas expression of different ESFT-associated fusion proteins may require distinct cellular microenvironments and induce transcriptome changes of limited similarity, IGF1 induction may provide one common mechanism for their implication in ESFT pathogenesis.

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Related in: MedlinePlus

In vivo interaction of EWS-FLI-1 with the region from –2754 to –2683 of the murine IGF1 promoter.A) Quantitative RT-PCR analysis was performed on chromatin immunoprecipitates obtained from mouse MPCs expressing EWS-FLI-1, EWS-FLI-1 R340N mutant or an empty pMSCV vector. Primers specific for murine GAPDH DNA were used as input DNA control. Error bars reflect results of triplicate experiments. (B) IGF1 mRNA induction by EWS-FLI-1 and EWS-FLI-1 R340N in the MPCs used for the ChIP experiments. Quantitative RT-PCR was performed using a murine IGF1 TaqMAN probe (applied biosystems).
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pone-0002634-g006: In vivo interaction of EWS-FLI-1 with the region from –2754 to –2683 of the murine IGF1 promoter.A) Quantitative RT-PCR analysis was performed on chromatin immunoprecipitates obtained from mouse MPCs expressing EWS-FLI-1, EWS-FLI-1 R340N mutant or an empty pMSCV vector. Primers specific for murine GAPDH DNA were used as input DNA control. Error bars reflect results of triplicate experiments. (B) IGF1 mRNA induction by EWS-FLI-1 and EWS-FLI-1 R340N in the MPCs used for the ChIP experiments. Quantitative RT-PCR was performed using a murine IGF1 TaqMAN probe (applied biosystems).

Mentions: To address the interaction between EWS-FLI-1 and the IGF1 promoter in vivo, chromatin immunoprecipitates (ChIP) from lysates of mouse MPCs expressing EWS-FLI-1, the DBDM and the empty vector were subjected to quantitative RT-PCR using primers specific for the region stretching from –2754 nucleotides to –2683 nucleotides upstream of the exon 1 start codon (ENSMUSE00000369489) of the murine IGF1 promoter (Figure 6A). This 70 bp stretch corresponds to the sequence annotated as –408 to –338 of the murine IGF1 promoter in a recent report by Alfieri et al. [16] and is included in the putative murine IGF1 promoter region GXP_41004 defined by the Genomatix (http://www.genomatix.de) genome annotation tool “Eldorado”. This region shows the highest similarity (96%) to the human IGF1 promoter region GXP_79580 and, by Genomatix analysis, is suggested to contain several potential trancription factor binding sites including ets binding sites. Relative to empty vector-expressing cells, a 5 fold increase in IGF1 promoter occupancy by the fusion protein was observed in ChIP assays directed against the anti-V5 epitope on the EWS/FLI-1 fusion protein.


IGF1 is a common target gene of Ewing's sarcoma fusion proteins in mesenchymal progenitor cells.

Cironi L, Riggi N, Provero P, Wolf N, Suvà ML, Suvà D, Kindler V, Stamenkovic I - PLoS ONE (2008)

In vivo interaction of EWS-FLI-1 with the region from –2754 to –2683 of the murine IGF1 promoter.A) Quantitative RT-PCR analysis was performed on chromatin immunoprecipitates obtained from mouse MPCs expressing EWS-FLI-1, EWS-FLI-1 R340N mutant or an empty pMSCV vector. Primers specific for murine GAPDH DNA were used as input DNA control. Error bars reflect results of triplicate experiments. (B) IGF1 mRNA induction by EWS-FLI-1 and EWS-FLI-1 R340N in the MPCs used for the ChIP experiments. Quantitative RT-PCR was performed using a murine IGF1 TaqMAN probe (applied biosystems).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2481291&req=5

pone-0002634-g006: In vivo interaction of EWS-FLI-1 with the region from –2754 to –2683 of the murine IGF1 promoter.A) Quantitative RT-PCR analysis was performed on chromatin immunoprecipitates obtained from mouse MPCs expressing EWS-FLI-1, EWS-FLI-1 R340N mutant or an empty pMSCV vector. Primers specific for murine GAPDH DNA were used as input DNA control. Error bars reflect results of triplicate experiments. (B) IGF1 mRNA induction by EWS-FLI-1 and EWS-FLI-1 R340N in the MPCs used for the ChIP experiments. Quantitative RT-PCR was performed using a murine IGF1 TaqMAN probe (applied biosystems).
Mentions: To address the interaction between EWS-FLI-1 and the IGF1 promoter in vivo, chromatin immunoprecipitates (ChIP) from lysates of mouse MPCs expressing EWS-FLI-1, the DBDM and the empty vector were subjected to quantitative RT-PCR using primers specific for the region stretching from –2754 nucleotides to –2683 nucleotides upstream of the exon 1 start codon (ENSMUSE00000369489) of the murine IGF1 promoter (Figure 6A). This 70 bp stretch corresponds to the sequence annotated as –408 to –338 of the murine IGF1 promoter in a recent report by Alfieri et al. [16] and is included in the putative murine IGF1 promoter region GXP_41004 defined by the Genomatix (http://www.genomatix.de) genome annotation tool “Eldorado”. This region shows the highest similarity (96%) to the human IGF1 promoter region GXP_79580 and, by Genomatix analysis, is suggested to contain several potential trancription factor binding sites including ets binding sites. Relative to empty vector-expressing cells, a 5 fold increase in IGF1 promoter occupancy by the fusion protein was observed in ChIP assays directed against the anti-V5 epitope on the EWS/FLI-1 fusion protein.

Bottom Line: Whereas all MPC isolates tested could stably express EWS-FLI-1, only some sustained stable EWS-ERG expression and none could express FUS-ERG for more than 3-5 days.However, all three fusion proteins, but neither FLI-1 nor ERG-1 alone, activated the IGF1 promoter and induced IGF1 expression.Whereas expression of different ESFT-associated fusion proteins may require distinct cellular microenvironments and induce transcriptome changes of limited similarity, IGF1 induction may provide one common mechanism for their implication in ESFT pathogenesis.

View Article: PubMed Central - PubMed

Affiliation: Division of Experimental Pathology, Institute of Pathology CHUV, University of Lausanne, Lausanne, Switzerland.

ABSTRACT

Background: The EWS-FLI-1 fusion protein is associated with 85-90% of Ewing's sarcoma family tumors (ESFT), the remaining 10-15% of cases expressing chimeric genes encoding EWS or FUS fused to one of several ets transcription factor family members, including ERG-1, FEV, ETV1 and ETV6. ESFT are dependent on insulin-like growth factor-1 (IGF-1) for growth and survival and recent evidence suggests that mesenchymal progenitor/stem cells constitute a candidate ESFT origin.

Methodology/principal findings: To address the functional relatedness between ESFT-associated fusion proteins, we compared mouse progenitor cell (MPC) permissiveness for EWS-FLI-1, EWS-ERG and FUS-ERG expression and assessed the corresponding expression profile changes. Whereas all MPC isolates tested could stably express EWS-FLI-1, only some sustained stable EWS-ERG expression and none could express FUS-ERG for more than 3-5 days. Only 14% and 4% of the total number of genes that were respectively induced and repressed in MPCs by the three fusion proteins were shared. However, all three fusion proteins, but neither FLI-1 nor ERG-1 alone, activated the IGF1 promoter and induced IGF1 expression.

Conclusion/significance: Whereas expression of different ESFT-associated fusion proteins may require distinct cellular microenvironments and induce transcriptome changes of limited similarity, IGF1 induction may provide one common mechanism for their implication in ESFT pathogenesis.

Show MeSH
Related in: MedlinePlus