タキザワ マキコ   TAKIZAWA Makiko
  滝沢 牧子
   所属   埼玉医科大学  医学部 総合医療センター 医療安全管理学
   職種   教授
論文種別 学術雑誌(原著)
言語種別 英語
査読の有無 査読あり
表題 Mouse model of endemic Burkitt translocations reveals the long-range boundaries of Ig-mediated oncogene deregulation.
掲載誌名 正式名:Proceedings of the National Academy of Sciences of the United States of America
掲載区分国外
巻・号・頁 109(27),10972-7頁
著者・共著者 Alexander L Kovalchuk,Camilo Ansarah-Sobrinho,Ofir Hakim,Wolfgang Resch,Helena Tolarová,Wendy Dubois,Arito Yamane,Makiko Takizawa,Isaac Klein,Gordon L Hager,Herbert C Morse 3rd,Michael Potter,Michel C Nussenzweig,Rafael Casellas
発行年月 2012/07/03
概要 Human Burkitt lymphomas are divided into two main clinical variants: the endemic form, affecting African children infected with malaria and the Epstein-Barr virus, and the sporadic form, distributed across the rest of the world. However, whereas sporadic translocations decapitate Myc from 5' proximal regulatory elements, most endemic events occur hundreds of kilobases away from Myc. The origin of these rearrangements and how they deregulate oncogenes at such distances remain unclear. We here recapitulate endemic Burkitt lymphoma-like translocations in plasmacytomas from uracil N-glycosylase and activation-induced cytidine deaminase-deficient mice. Mapping of translocation breakpoints using an acetylated histone H3 lysine 9 chromatin immunoprecipitation sequencing approach reveals Igh fusions up to ∼350 kb upstream of Myc or the related oncogene Mycn. A comprehensive analysis of epigenetic marks, PolII recruitment, and transcription in tumor cells demonstrates that the 3' Igh enhancer (Eα) vastly remodels ∼450 kb of chromatin into translocated sequences, leading to significant polymerase occupancy and constitutive oncogene expression. We show that this long-range epigenetic reprogramming is directly proportional to the physical interaction of Eα with translocated sites. Our studies thus uncover the extent of epigenetic remodeling by Ig 3' enhancers and provide a rationale for the long-range deregulation of translocated oncogenes in endemic Burkitt lymphomas. The data also shed light on the origin of endemic-like chromosomal rearrangements.
DOI 10.1073/pnas.1200106109
PMID 22711821