モチヅキ　マキコ   Mochidzuki Makiko   望月　牧子    所属   医学部 医学科    職種   助教
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	The loss of Ezh2 drives the pathogenesis of myelofibrosis and sensitizes tumor-initiating cells to bromodomain inhibition.
掲載誌名	正式名：The Journal of experimental medicine 略　 称：J Exp Med ISSNコード：15409538/00221007
掲載区分	国外
巻・号・頁	213(8),pp.1459-77
著者・共著者	Sashida Goro, Wang Changshan, Tomioka Takahisa, Oshima Motohiko, Aoyama Kazumasa, Kanai Akinori, Mochizuki-Kashio Makiko, Harada Hironori, Shimoda Kazuya, Iwama Atsushi
発行年月	2016/07
概要	EZH2 is a component of polycomb repressive complex 2 (PRC2) and functions as an H3K27 methyltransferase. Loss-of-function mutations in EZH2 are associated with poorer outcomes in patients with myeloproliferative neoplasms (MPNs), particularly those with primary myelofibrosis (MF [PMF]). To determine how EZH2 insufficiency is involved in the pathogenesis of PMF, we generated mice compound for an Ezh2 conditional deletion and activating mutation in JAK2 (JAK2V617F) present in patients with PMF. The deletion of Ezh2 in JAK2(V617F) mice markedly promoted the development of MF, indicating a tumor suppressor function for EZH2 in PMF. The loss of Ezh2 in JAK2(V617F) hematopoietic cells caused significant reductions in H3K27 trimethylation (H3K27me3) levels, resulting in an epigenetic switch to H3K27 acetylation (H3K27ac). These epigenetic switches were closely associated with the activation of PRC2 target genes including Hmga2, an oncogene implicated in the pathogenesis of PMF. The treatment of JAK2(V617F)/Ezh2-null mice with a bromodomain inhibitor significantly attenuated H3K27ac levels at the promoter regions of PRC2 targets and down-regulated their expression, leading to the abrogation of MF-initiating cells. Therefore, an EZH2 insufficiency not only cooperated with active JAK2 to induce MF, but also conferred an oncogenic addiction to the H3K27ac modification in MF-initiating cells that was capable of being restored by bromodomain inhibition.
DOI	10.1084/jem.20151121
PMID	27401345