Targeting MYCN in neuroblastoma by BET bromodomain inhibition

A Puissant, SM Frumm, G Alexe, CF Bassil, J Qi… - Cancer discovery, 2013 - AACR
A Puissant, SM Frumm, G Alexe, CF Bassil, J Qi, YH Chanthery, EA Nekritz, R Zeid…
Cancer discovery, 2013AACR
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 …
Abstract
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.
Significance: Biomarkers of response to small-molecule inhibitors of BET bromodomains, a new compound class with promising anticancer activity, have been lacking. Here, we reveal MYCN amplification as a strong genetic predictor of sensitivity to BET bromodomain inhibitors, show 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. Cancer Discov; 3(3); 308–23. ©2012 AACR.
See related commentary by Schnepp and Maris, p. 255
This article is highlighted in the In This Issue feature, p. 239
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