Epigenetic alteration to activate Bmp2-Smad signaling in Raf-induced senescence

作     者：Mai Fujimoto Yasunobu Mano Motonobu Anai Shogo Yamamoto Masaki Fukuyo Hiroyuki Aburatani Atsushi Kaneda 

作者机构：Genome Science DivisionResearch Center for Advanced Science and Technologythe University of Tokyo Department of Molecular OncologyGraduate School of MedicineChiba University Laboratory for Systems Biology and MedicineResearch Center for Advanced Science and Technologythe University of Tokyo CRESTJapan Agency for Medical Research and Development 

出 版 物：《World Journal of Biological Chemistry》 (世界生物化学杂志（英文版）（电子版）)

年 卷 期：2016年第7卷第1期

页      面：188-205页

学科分类：0710[理学-生物学] 07[理学] 08[工学] 071008[理学-发育生物学] 09[农学] 071007[理学-遗传学] 0901[农学-作物学] 0836[工学-生物工程] 090102[农学-作物遗传育种] 

基　　金：Supported by The CREST program,Japan Agency for Medical Research and Development to Kaneda A grants from the Uehara Memorial Foundation Takeda Science Foundation Public Trust Surgery Research Fund to Kaneda A 

主　　题：Senescence Epigenome Raf H3K27me3 Histone Ras 

摘      要：AIM: To investigate epigenomic and gene expression alterations during cellular senescence induced by oncogenic Raf. METHODS: Cellular senescence was induced into mouse embryonic fibroblasts(MEFs) by infecting retrovirus to express oncogenic Raf(RafV 600E). RNA was collected from RafV 600 E cells as well as MEFs without infection and MEFs with mock infection, and a genome-wide gene expression analysis was performed using microarray. The epigenomic status for active H3K4me3 and repressive H3K27me3 histone marks was analyzed by chromatin immunoprecipitation-sequencing for RafV 600 E cells on day 7 and for MEFs without infection. These data for Raf-induced senescence were compared with data for Ras-induced senescence that were obtained in our previous study. Gene knockdown and overexpression were done by retrovirus infection. RESULTS: Although the expression of some genes including secreted factors was specifically altered in either Ras- or Raf-induced senescence, many genes showed similar alteration pattern in Raf- and Ras-induced senescence. A total of 841 commonly upregulated 841 genes and 573 commonly downregulated genes showed a significant enrichment of genes related to signal and secreted proteins, suggesting the importance of alterations in secreted factors. Bmp2, a secreted protein to activate Bmp2-Smad signaling, was highly upregulated with gain of H3K4me3 and loss of H3K27me3 during Raf-induced senescence, as previously detected in Ras-induced senescence, and the knockdown of Bmp2 by sh RNA lead to escape from Raf-induced senescence. Bmp2-Smad inhibitor Smad6 was strongly repressed with H3K4me3 loss in Raf-induced senescence, as detected in Ras-induced senescence, and senescence was also bypassed by Smad6 induction in Raf-activated cells. Different from Ras-induced senescence, however, gain of H3K27me3 did not occur in the Smad6 promoter region during Raf-induced senescence. When comparing genome-wide alteration between Ras- and Raf-induced senescence, genes