EZH2 inhibition as a therapeutic strategy for lymphoma with EZH2-activating mutations.
In eukaryotes, post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2) and is involved in repressing gene expression through methylation of histone H3 on lysine 27 (H3K27). EZH2 overexpression is implicated in tumorigenesis and correlates with poor prognosis in several tumour types. Additionally, somatic heterozygous mutations of Y641 and A677 residues within the catalytic SET domain of EZH2 occur in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma. The Y641 residue is the most frequently mutated residue, with up to 22% of germinal centre B-cell DLBCL and follicular lymphoma harbouring mutations at this site. These lymphomas have increased H3K27 tri-methylation (H3K27me3) owing to altered substrate preferences of the mutant enzymes. However, it is unknown whether specific, direct inhibition of EZH2 methyltransferase activity will be effective in treating EZH2 mutant lymphomas. Here we demonstrate that GSK126, a potent, highly selective, S-adenosyl-methionine-competitive, small-molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and markedly inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Together, these data demonstrate that pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma.
Cancer Epigenetics Discovery Performance Unit, Cancer Research, Oncology R&D, GlaxoSmithKline, 1250 S. Collegeville Road, Collegeville, Pennsylvania 19426, USA.
Michael T
MT
McCabe
Heidi M
HM
Ott
Gopinath
G
Ganji
Susan
S
Korenchuk
Christine
C
Thompson
Glenn S
GS
Van Aller
Yan
Y
Liu
Alan P
AP
Graves
Anthony
A
Della Pietra
Elsie
E
Diaz
Louis V
LV
LaFrance
Mark
M
Mellinger
Celine
C
Duquenne
Xinrong
X
Tian
Ryan G
RG
Kruger
Charles F
CF
McHugh
Martin
M
Brandt
William H
WH
Miller
Dashyant
D
Dhanak
Sharad K
SK
Verma
Peter J
PJ
Tummino
Caretha L
CL
Creasy
D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D000071221:Enhancer of Zeste Homolog 2 Protein; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007211:Indoles / Q000494:pharmacology* / Q000627:therapeutic use*; D008224:Lymphoma, Follicular / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D008745:Methylation / Q000187:drug effects; D051379:Mice; D009154:Mutation / Q000235:genetics*; D009368:Neoplasm Transplantation; D063151:Polycomb Repressive Complex 2 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011728:Pyridones / Q000494:pharmacology* / Q000627:therapeutic use*; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects; D014183:Transplantation, Heterologous
C577920:GSK-2816126; D006657:Histones; D007211:Indoles; D011728:Pyridones; D012097:Repressor Proteins; D000076983:Histone Methyltransferases; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; C498410:Ezh2 protein, mouse; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2