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Status |
Public on Sep 21, 2010 |
Title |
BCL6 repression of EP300 provides a basis for rational combinatorial therapy in diffuse large B cell lymphomas. |
Organism |
Homo sapiens |
Experiment type |
Expression profiling by array
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Summary |
The BCL6 transcriptional repressor is a critical oncogene in diffuse large B-cell lymphomas (DLBCL). The specific BCL6 inhibitor RI-BPI potently kills DLBCL cells. We find that RI-BPI induces a particular gene expression signature in DLBCL. In order to identify classes of drugs that might synergize with RIBPI we examined the connectivity of this signature and found a strong association with HDAC and Hsp90 inhibitors. This was explained by the discovery that BCL6 directly represses the p300 lysine acetyltransferase and its co-factor BAT3. RI-BPI induced expression of p300 and BAT3, and p300 acetyltransferase activity, resulting in acetylation of p300 targets like p53 and Hsp90. As a consequence, RI-BPI could attenuate Hsp90 chaperone function, similar to the effect of Hsp90 and HDAC inhibitors. Induction of p300 and BAT3 was required for the anti-lymphoma effects of RI-BPI since specific blockade of either protein rescued DLBCL cells from the BCL6 inhibitor. RI-BPI synergistically killed DLBCL cells in combination with HDAC inhibitors (SAHA, TSA and VPA) and Hsp90 inhibitors (17-DMAG and PUH71). The combination of RI-BPI and SAHA, or RI-BPI and PU-H71 potently suppressed or even eradicated human DLBCL in mice. BCL6 repression of EP300 thus provides a basis for rational targeted combinatorial therapy for patients with DLBCL.
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Overall design |
Direct comparison of gene expression levels in DLBCL cell lines after 24hs of treatment with either a Bcl6 inhibitor peptide or control peptide
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Contributor(s) |
Cerchietti L, Melnick A, Figueroa ME |
Citation(s) |
21041953 |
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Submission date |
Sep 20, 2010 |
Last update date |
Mar 22, 2012 |
Contact name |
Maria Eugenia Figueroa |
E-mail(s) |
mef162@miami.edu
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Organization name |
University of Miiami
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Department |
Human Genetics
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Lab |
Maria Figueroa
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Street address |
1501 NW 10th Ave, BRB 709A, Locator code C227
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City |
Miami |
State/province |
FL |
ZIP/Postal code |
33136 |
Country |
USA |
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Platforms (1) |
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Samples (14)
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Relations |
BioProject |
PRJNA132935 |