ETO2-GLIS2 Hijacks Transcriptional Complexes to Drive Cellular Identity and Self-Renewal in Pediatric Acute Megakaryoblastic Leukemia

Publication date: 13 March 2017
Source:Cancer Cell, Volume 31, Issue 3
Author(s): Cécile Thirant, Cathy Ignacimouttou, Cécile K. Lopez, M'Boyba Diop, Lou Le Mouël, Clarisse Thiollier, Aurélie Siret, Phillipe Dessen, Zakia Aid, Julie Rivière, Philippe Rameau, Céline Lefebvre, Mehdi Khaled, Guy Leverger, Paola Ballerini, Arnaud Petit, Hana Raslova, Catherine L. Carmichael, Benjamin T. Kile, Eric Soler, John D. Crispino, Christian Wichmann, Françoise Pflumio, Jürg Schwaller, William Vainchenker, Camille Lobry, Nathalie Droin, Olivier A. Bernard, Sébastien Malinge, Thomas Mercher
Chimeric transcription factors are a hallmark of human leukemia, but the molecular mechanisms by which they block differentiation and promote aberrant self-renewal remain unclear. Here, we demonstrate that the ETO2-GLIS2 fusion oncoprotein, which is found in aggressive acute megakaryoblastic leukemia, confers megakaryocytic identity via the GLIS2 moiety while both ETO2 and GLIS2 domains are required to drive increased self-renewal properties. ETO2-GLIS2 directly binds DNA to control transcription of associated genes by upregulation of expression and interaction with the ETS-related ERG protein at enhancer elements. Importantly, specific interference with ETO2-GLIS2 oligomerization reverses the transcriptional activation at enhancers and promotes megakaryocytic differentiation, providing a relevant interface to target in this poor-prognosis pediatric leukemia.

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Teaser

Thirant et al. show that the ETO2-GLIS2 fusion protein found in acute megakaryoblastic leukemia confers megakaryocytic identity via the GLIS2 moiety, but requires both ETO2 and GLIS2 domains to drive self-renewal. Disruption of ETO2-GLIS2 oligomerization inhibits the maintenance of ETO2-GLIS2⁺ human AMKL blasts.


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