Oncotarget

Research Papers:

Inhibition of BRD4 attenuates tumor cell self-renewal and suppresses stem cell signaling in MYC driven medulloblastoma

Sujatha Venataraman, Irina Alimova, Peter Harris, Diane K Birks, Illango Balakrishnan, Marc Remke, Michael D Taylor, Michael Handler, Nicholas K Foreman, Rajeev Vibhakar _

PDF |  HTML  |  Supplementary Files  |  Author Information  |  Order a Reprint

Oncotarget. 2014; 5:2355-2371. doi: 10.18632/oncotarget.1659

Metrics: PDF 2072 views  |   HTML 927 views  |   ?  


Abstract

Sujatha Venkataraman1*, Irina Alimova1*, Ilango Balakrishnan1, Peter Harris1, Diane K Birks2, Andrea Griesinger1, Vladimir Amani1, Brian Cristiano1, Marc Remke3, Michael D Taylor3, Michael Handler2, Nicholas K Foreman1 and Rajeev Vibhakar1

1 Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

2 Department of Neurosurgery, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

3 Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, ON, Canada

* These two authors contributed equally to this work.

Correspondence:

Rajeev Vibhakar, e-mail: Rajeev.Vibhakar@ucdenver.edu

Keywords: Medulloblastoma, MYC, BRD4, JQ1, Senescence

Received: December 05, 2013      Accepted: March 19, 2014      Published: March 31, 2014

ABSTRACT

Medulloblastoma is a pediatric brain tumor with a variable prognosis due to clinical and genomic heterogeneity. Among the 4 major genomic sub-groups, patients with MYC amplified tumors have a particularly poor prognosis despite therapy with surgery, radiation and chemotherapy. Targeting the MYC oncogene has traditionally been problematic. Here we report that MYC driven medulloblastoma can be targeted by inhibition of the bromodomain protein BRD4. We show that bromodomain inhibition with JQ1 restricts c-MYC driven transcriptional programs in medulloblastoma, suppresses medulloblastoma cell growth and induces a cell cycle arrest. Importantly JQ1 suppresses stem cell associated signaling in medulloblastoma cells and inhibits medulloblastoma tumor cell self-renewal. Additionally JQ1 also promotes senescence in medulloblastoma cells by activating cell cycle kinase inhibitors and inhibiting activity of E2F1. Furthermore BRD4 inhibition displayed an anti-proliferative, pro-senescence effect in a medulloblastoma model in vivo. In clinical samples we found that transcriptional programs suppressed by JQ1 are associated with adverse risk in medulloblastoma patients. Our work indicates that BRD4 inhibition attenuates stem cell signaling in MYC driven medulloblastoma and demonstrates the feasibility BET domain inhibition as a therapeutic approach in vivo.

Author Information

Sujatha Venataraman
1Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Irina Alimova
1Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Peter Harris
1Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Diane K Birks
Department of Neurosurgery, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Illango Balakrishnan
Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Marc Remke
Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, ON, Canada,

Michael D Taylor
Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, ON, Canada

Michael Handler
Department of Neurosurgery, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Nicholas K Foreman
Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA

Rajeev Vibhakar
Primary Contact  _

Department of Pediatrics, Children’s Hospital Colorado and University of Colorado, Denver, CO, USA


Creative Commons License All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.
PII: 1659