Targeting MYCN: a good BET for improving neuroblastoma therapy?
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ABSTRACT:
SUBMITTER: Schnepp RW
PROVIDER: S-EPMC3709873 | biostudies-literature | 2013 Mar
REPOSITORIES: biostudies-literature
Publications
Targeting MYCN: a good BET for improving neuroblastoma therapy?
Schnepp Robert W RW Maris John M JM
Cancer discovery 20130301 3
Direct targeting of oncogenic MYC proteins has been an elusive goal of many cancer drug development efforts. In this issue of Cancer Discovery, Stegmaier and colleagues demonstrate that pharmacologically interfering with the bromodomain and extraterminal (BET) class of proteins potently depletes MYCN in neuroblastoma cells, resulting in cellular cytotoxicity and thus providing a novel approach with a potential impact on a previously undruggable major oncogene. ...[more]
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Project description:Bromodomain inhibition comprises a promising therapeutic strategy in cancer, particularly for hematologic malignancies. To date, however, genomic biomarkers to direct clinical translation have been lacking. We conducted a cell-based screen of genetically defined cancer cell lines using a prototypical inhibitor of BET bromodomains. Integration of genetic features with chemosensitivity data revealed a robust correlation between MYCN amplification and sensitivity to bromodomain inhibition. We characterized the mechanistic and translational significance of this finding in neuroblastoma, a childhood cancer with frequent amplification of MYCN. Genome-wide expression analysis showed downregulation of the MYCN transcriptional program accompanied by suppression of MYCN transcription. Functionally, bromodomain-mediated inhibition of MYCN impaired growth and induced apoptosis in neuroblastoma. BRD4 knockdown phenocopied these effects, establishing BET bromodomains as transcriptional regulators of MYCN. BET inhibition conferred a significant survival advantage in 3 in vivo neuroblastoma models, providing a compelling rationale for developing BET bromodomain inhibitors in patients with neuroblastoma.
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Project description:Bromodomain inhibition comprises a promising therapeutic strategy in cancer, particularly for hematologic malignancies. To date, however, genomic biomarkers to direct clinical translation have been lacking. We conducted a cell-based screen of genetically-defined cancer cell lines using a prototypical inhibitor of BET bromodomains. Integration of genetic features with chemosensitivity data revealed a robust correlation between MYCN amplification and sensitivity to bromodomain inhibition. We characterized the mechanistic and translational significance of this finding in neuroblastoma, a childhood cancer with frequent amplification of MYCN. Genome-wide expression analysis demonstrated downregulation of the MYCN transcriptional program accompanied by suppression of MYCN transcription. Functionally, bromodomain-mediated inhibition of MYCN impaired growth and induced apoptosis in neuroblastoma. BRD4 knock-down phenocopied these effects, establishing BET bromodomains as transcriptional regulators of MYCN. BET inhibition conferred a significant survival advantage in three in vivo neuroblastoma models, providing a compelling rationale for developing BET bromodomain inhibitors in patients with neuroblastoma. Significance: Biomarkers of response to small-molecule inhibitors of BET bromodomains, a new compound class with promising anti-cancer activity, have been lacking. Here, we reveal MYCN amplification as a strong genetic predictor of sensitivity to BET bromodomain inhibitors, demonstrate a mechanistic rationale for this finding, and provide a translational framework for clinical trial development of BET bromodomain inhibitors for pediatric patients with MYCN-amplified neuroblastoma. JQ1 is a novel thieno-triazolo-1,4-diazepine, which displaces BET bromodomains from chromatin by competitively binding to the acetyl lysine recognition pocket. BE(2)-C and Kelly cells were treated in triplicate with 1 µM JQ1 or DMSO for 24 hours. RNA was extracted and a decrease in MYCN transcript was confirmed by real time RT-PCR as described above. The samples were profiled using the Affymetrix PrimeView Human Gene Expression Array (Affymetrix) at Beth Israel Deaconess Medical Center (Boston, MA, USA).
2013-02-25 | E-GEOD-43392 | biostudies-arrayexpress
Project description:Bromodomain inhibition comprises a promising therapeutic strategy in cancer, particularly for hematologic malignancies. To date, however, genomic biomarkers to direct clinical translation have been lacking. We conducted a cell-based screen of genetically-defined cancer cell lines using a prototypical inhibitor of BET bromodomains. Integration of genetic features with chemosensitivity data revealed a robust correlation between MYCN amplification and sensitivity to bromodomain inhibition. We characterized the mechanistic and translational significance of this finding in neuroblastoma, a childhood cancer with frequent amplification of MYCN. Genome-wide expression analysis demonstrated downregulation of the MYCN transcriptional program accompanied by suppression of MYCN transcription. Functionally, bromodomain-mediated inhibition of MYCN impaired growth and induced apoptosis in neuroblastoma. BRD4 knock-down phenocopied these effects, establishing BET bromodomains as transcriptional regulators of MYCN. BET inhibition conferred a significant survival advantage in three in vivo neuroblastoma models, providing a compelling rationale for developing BET bromodomain inhibitors in patients with neuroblastoma. Significance: Biomarkers of response to small-molecule inhibitors of BET bromodomains, a new compound class with promising anti-cancer activity, have been lacking. Here, we reveal MYCN amplification as a strong genetic predictor of sensitivity to BET bromodomain inhibitors, demonstrate a mechanistic rationale for this finding, and provide a translational framework for clinical trial development of BET bromodomain inhibitors for pediatric patients with MYCN-amplified neuroblastoma.
2013-02-25 | GSE43392 | GEO
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