Nakayama Chihiro, Daigaku Yasukazu, Aoi Yuki, Fang Qi, Kimura Hiroshi, Shilatifard Ali, Tellier Michael, Nojima Takayuki
bioRxiv. 2024 Feb 1:2024.01.31.578294. doi: 10.1101/2024.01.31.578294.
Regulation of RNA polymerase II (Pol II) transcription is closely associated with cell proliferation. However, it remains unclear how the Pol II transcription program is altered in cancer to favour cell growth. Here, we find that gene expression of , a known negative elongation factor, is up-regulated in colorectal tumours. To dissect the direct role of NELF-C on Pol II transcription in such cancer, we employed an auxin-dependent protein degradation system for NELF-C in combination with nascent transcript sequencing technologies. Strikingly, we demonstrated that the acute loss of NELF-C protein globally perturbs Pol II transcription termination and also increases transcription elongation rate, independently of promoter-proximal Pol II pausing. This results in Pol II transcription into DNA replication initiation zones, and may link to failure of the cell cycle transition into S phase. We anticipate that NELF will be a potential therapeutic target to restrict colorectal cancers by promoting transcription-replication conflict.
Expression of transcript is up-regulated in colorectal tumors NELF-C protein is mandatory for the transition between G1-S phases during cell cycleNELF-C loss impairs transcription termination independently of Pol II promoter-proximal pausingNELF-C loss leads Pol II to invade DNA replication initiation zones.
RNA聚合酶II(Pol II)转录的调控与细胞增殖密切相关。然而,目前尚不清楚在癌症中Pol II转录程序是如何改变以促进细胞生长的。在这里,我们发现已知的负性延伸因子NELF-C的基因表达在结直肠肿瘤中上调。为了剖析NELF-C在这种癌症中对Pol II转录的直接作用,我们将NELF-C的生长素依赖性蛋白降解系统与新生转录本测序技术相结合。令人惊讶的是,我们证明NELF-C蛋白的急性缺失会全局扰乱Pol II转录终止,并且还会增加转录延伸率,这与启动子近端Pol II暂停无关。这导致Pol II转录进入DNA复制起始区域,并可能与细胞周期过渡到S期失败有关。我们预计NELF将成为通过促进转录-复制冲突来限制结直肠癌的潜在治疗靶点。
NELF-C转录本在结直肠肿瘤中表达上调;NELF-C蛋白是细胞周期中G1-S期转变所必需的;NELF-C缺失独立于Pol II启动子近端暂停而损害转录终止;NELF-C缺失导致Pol II侵入DNA复制起始区域。