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Projekt Druckansicht

Epigenetische, genomische und funktionelle Charakterisierung der MLL-AF9 rearrangierten akuten myeloischen Leukämie

Fachliche Zuordnung Hämatologie, Onkologie
Förderung Förderung von 2012 bis 2015
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 229644315
 
Erstellungsjahr 2016

Zusammenfassung der Projektergebnisse

Homeobox (HOX) proteins and the receptor tyrosine kinase FLT3 are frequently highly expressed and mutated in acute myeloid leukemia (AML). Aberrant HOX expression is found in nearly all AMLs that harbor a mutation in the Nucleophosmin (NPM1) gene, and FLT3 is concomitantly mutated in approximately 60% of these cases. Little is known how mutant NPM1 (NPM1mut) cells maintain aberrant gene expression. Here, we demonstrate that the histone modifiers MLL1 and DOT1L control HOX and FLT3 expression and differentiation in NPM1mut AML. Using a CRISPR-Cas9 genome editing domain screen, we show NPM1mut AML to be exceptionally dependent on the menin binding site in MLL1. Pharmacological smallmolecule inhibition of the menin-MLL1 protein interaction had profound anti-leukemic activity in human and murine models of NPM1mut AML. Combined pharmacological inhibition of menin-MLL1 and DOT1L resulted in dramatic suppression of HOX and FLT3 expression, induction of differentiation, and superior activity against NPM1mut leukemia in vitro and in vivo. Taken together the key advances from this DFG-funded project are as follows. (1) Specific chromatin regulatory complexes control leukemogenic gene expression programs, including HOX, MEIS1 and FLT3 expression in NPM1mut leukemia. This opens a new arena of investigation into the control of leukemogenic gene expression by MLL1 and DOT1L complexes in genetic subtypes of AML beyond those with MLL1-rearrangement. (2) Combinatorial small molecule menin-MLL1 and DOT1L inhibition has synergistic on target activity and releases the differentiation block of NPM1mut leukemias. It is likely that this combinatorial approach will be relevant for all AMLs with high level HOX gene expression that represent ~50% of cases. (3) This is the first example of a drug combination regimen to target specific epigenetic drivers that control critical leukemogenic gene expression in NPM1mut leukemia, thereby representing a therapeutic opportunity already available for first clinical testing.

Projektbezogene Publikationen (Auswahl)

 
 

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