| Reference | 1. Leukemia. 2013 Apr;27(4):813-22. doi: 10.1038/leu.2012.327. Epub 2012 Nov 9.
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Abrogation of MLL-AF10 and CALM-AF10-mediated transformation through genetic
inactivation or pharmacological inhibition of the H3K79 methyltransferase Dot1l.
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Chen L(1), Deshpande AJ, Banka D, Bernt KM, Dias S, Buske C, Olhava EJ, Daigle
SR, Richon VM, Pollock RM, Armstrong SA.
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Author information: <br>
(1)Division of Hematology/Oncology, Children/’s Hospital, Dana Farber Cancer
Institute and Harvard Medical School, Boston, MA 02215, USA.
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The t(10;11)(p12;q23) translocation and the t(10;11)(p12;q14) translocation,
which encode the MLL (mixed lineage leukemia)-AF10 and CALM (clathrin assembly
lymphoid myeloid leukemia)-AF10 fusion oncoproteins, respectively, are two
recurrent chromosomal rearrangements observed in patients with acute myeloid
leukemia and acute lymphoblastic leukemia. Here, we demonstrate that MLL-AF10 and
CALM-AF10-mediated transformation is dependent on the H3K79 methyltransferase
Dot1l using genetic and pharmacological approaches in mouse models. Targeted
disruption of Dot1l using a conditional knockout mouse model abolished in vitro
transformation of murine bone marrow cells and in vivo initiation and maintenance
of MLL-AF10 or CALM-AF10 leukemia. The treatment of MLL-AF10 and CALM-AF10
transformed cells with EPZ004777, a specific small-molecule inhibitor of Dot1l,
suppressed expression of leukemogenic genes such as Hoxa cluster genes and Meis1,
and selectively impaired proliferation of MLL-AF10 and CALM-AF10 transformed
cells. Pretreatment with EPZ004777 profoundly decreased the in vivo
spleen-colony-forming ability of MLL-AF10 or CALM-AF10 transformed bone marrow
cells. These results show that patients with leukemia-bearing chromosomal
translocations that involve the AF10 gene may benefit from small-molecule
therapeutics that inhibit H3K79 methylation.
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2. Nat Commun. 2012;3:1288. doi: 10.1038/ncomms2304.
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Catalytic site remodelling of the DOT1L methyltransferase by selective
inhibitors.
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Yu W(1), Chory EJ, Wernimont AK, Tempel W, Scopton A, Federation A, Marineau JJ,
Qi J, Barsyte-Lovejoy D, Yi J, Marcellus R, Iacob RE, Engen JR, Griffin C, Aman
A, Wienholds E, Li F, Pineda J, Estiu G, Shatseva T, Hajian T, Al-Awar R, Dick
JE, Vedadi M, Brown PJ, Arrowsmith CH, Bradner JE, Schapira M.
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Author information: <br>
(1)Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7,
Canada.
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Erratum in<br>
Nat Commun. 2013;4:1893.
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Selective inhibition of protein methyltransferases is a promising new approach to
drug discovery. An attractive strategy towards this goal is the development of
compounds that selectively inhibit binding of the cofactor, S-adenosylmethionine,
within specific protein methyltransferases. Here we report the three-dimensional
structure of the protein methyltransferase DOT1L bound to EPZ004777, the first
S-adenosylmethionine-competitive inhibitor of a protein methyltransferase with in
vivo efficacy. This structure and those of four new analogues reveal remodelling
of the catalytic site. EPZ004777 and a brominated analogue, SGC0946, inhibit
DOT1L in vitro and selectively kill mixed lineage leukaemia cells, in which DOT1L
is aberrantly localized via interaction with an oncogenic MLL fusion protein.
These data provide important new insight into mechanisms of cell-active
S-adenosylmethionine-competitive protein methyltransferase inhibitors, and
establish a foundation for the further development of drug-like inhibitors of
DOT1L for cancer therapy.
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3. Cancer Cell. 2011 Jul 12;20(1):53-65. doi: 10.1016/j.ccr.2011.06.009.
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Selective killing of mixed lineage leukemia cells by a potent small-molecule
DOT1L inhibitor.
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Daigle SR(1), Olhava EJ, Therkelsen CA, Majer CR, Sneeringer CJ, Song J, Johnston
LD, Scott MP, Smith JJ, Xiao Y, Jin L, Kuntz KW, Chesworth R, Moyer MP, Bernt KM,
Tseng JC, Kung AL, Armstrong SA, Copeland RA, Richon VM, Pollock RM.
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Author information: <br>
(1)Epizyme, Inc., Cambridge, MA 02139, USA.
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Mislocated enzymatic activity of DOT1L has been proposed as a driver of
leukemogenesis in mixed lineage leukemia (MLL). The characterization of
EPZ004777, a potent, selective inhibitor of DOT1L is reported. Treatment of MLL
cells with the compound selectively inhibits H3K79 methylation and blocks
expression of leukemogenic genes. Exposure of leukemic cells to EPZ004777 results
in selective killing of those cells bearing the MLL gene translocation, with
little effect on non-MLL-translocated cells. Finally, in vivo administration of
EPZ004777 leads to extension of survival in a mouse MLL xenograft model. These
results provide compelling support for DOT1L inhibition as a basis for targeted
therapeutics against MLL.
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