Plotnik Joshua P, Hollenhorst Peter C
Biology Department, Indiana University, Bloomington, IN 47405, USA.
Medical Sciences, Indiana University School of Medicine, Bloomington, IN 47405, USA.
Nucleic Acids Res. 2017 May 5;45(8):4452-4462. doi: 10.1093/nar/gkx039.
Aberrant activation of RAS/MAPK signaling is a driver of over one third of all human carcinomas. The homologous transcription factors ETS1 and ETS2 mediate activation of gene expression programs downstream of RAS/MAPK signaling. ETS1 is important for oncogenesis in many tumor types. However, ETS2 can act as an oncogene in some cellular backgrounds, and as a tumor suppressor in others, and the molecular mechanism responsible for this cell-type specific function remains unknown. Here, we show that ETS1 and ETS2 can regulate a cell migration gene expression program in opposite directions, and provide the first comparison of the ETS1 and ETS2 cistromes. This genomic data and an ETS1 deletion line reveal that the opposite function of ETS2 is a result of binding site competition and transcriptional attenuation due to weaker transcriptional activation by ETS2 compared to ETS1. This weaker activation was mapped to the ETS2 N-terminus and a specific interaction with the co-repressor ZMYND11 (BS69). Furthermore, ZMYND11 expression levels in patient tumors correlated with oncogenic versus tumor suppressive roles of ETS2. Therefore, these data indicate a novel and specific mechanism allowing ETS2 to switch between oncogenic and tumor suppressive functions in a cell-type specific manner.
RAS/MAPK信号通路的异常激活是超过三分之一的人类癌症的驱动因素。同源转录因子ETS1和ETS2介导RAS/MAPK信号通路下游基因表达程序的激活。ETS1在许多肿瘤类型的肿瘤发生中起重要作用。然而,ETS2在某些细胞背景中可作为癌基因,而在其他背景中则作为肿瘤抑制因子,其负责这种细胞类型特异性功能的分子机制仍然未知。在这里,我们表明ETS1和ETS2可以以相反的方向调节细胞迁移基因表达程序,并首次比较了ETS1和ETS2的顺式作用元件组。这些基因组数据和一个ETS1缺失系表明,ETS2的相反功能是由于与ETS1相比,ETS2的转录激活较弱导致的结合位点竞争和转录衰减的结果。这种较弱的激活定位于ETS2的N端以及与共抑制因子ZMYND11(BS69)的特异性相互作用。此外,患者肿瘤中ZMYND11的表达水平与ETS2的致癌作用与肿瘤抑制作用相关。因此,这些数据表明了一种新的特异性机制,使ETS2能够以细胞类型特异性方式在致癌和肿瘤抑制功能之间转换。