Synthetic Lethal Screen Demonstrates That a JAK2 Inhibitor Suppresses a BCL6-dependent IL10RA/JAK2/STAT3 Pathway in High Grade B-cell Lymphoma.

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Publication Date
2016-08ICR Author
Author
Beck, D
Zobel, J
Barber, R
Evans, S
Lezina, L
Allchin, RL
Blades, M
Elliott, R
Lord, CJ
Ashworth, A
Porter, ACG
Wagner, SD
Type
Journal Article
Metadata
Show full item recordAbstract
We demonstrate the usefulness of synthetic lethal screening of a conditionally BCL6-deficient Burkitt lymphoma cell line, DG75-AB7, with a library of small molecules to determine survival pathways suppressed by BCL6 and suggest mechanism-based treatments for lymphoma. Lestaurtinib, a JAK2 inhibitor and one of the hits from the screen, repressed survival of BCL6-deficient cells in vitro and reduced growth and proliferation of xenografts in vivo BCL6 deficiency in DG75-AB7 induced JAK2 mRNA and protein expression and STAT3 phosphorylation. Surface IL10RA was elevated by BCL6 deficiency, and blockade of IL10RA repressed STAT3 phosphorylation. Therefore, we define an IL10RA/JAK2/STAT3 pathway each component of which is repressed by BCL6. We also show for the first time that JAK2 is a direct BCL6 target gene; BCL6 bound to the JAK2 promoter in vitro and was enriched by ChIP-seq. The place of JAK2 inhibitors in the treatment of diffuse large B-cell lymphoma has not been defined; we suggest that JAK2 inhibitors might be most effective in poor prognosis ABC-DLBCL, which shows higher levels of IL10RA, JAK2, and STAT3 but lower levels of BCL6 than GC-DLBCL and might be usefully combined with novel approaches such as inhibition of IL10RA.
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Licenseref URL
https://creativecommons.org/licenses/by/4.0Version of record
Subject
Cell Line, Tumor
Animals
Humans
Mice
Mice, SCID
Burkitt Lymphoma
Carbazoles
Xenograft Model Antitumor Assays
STAT3 Transcription Factor
Proto-Oncogene Proteins c-bcl-6
Janus Kinase 2
Interleukin-10 Receptor alpha Subunit
Lymphoma, Large B-Cell, Diffuse
Research team
Gene Function
Language
eng
Date accepted
2016-05-06
License start date
2016-08
Citation
The Journal of biological chemistry, 2016, 291 (32), pp. 16686 - 16698