The PRR11-SKA2 Bidirectional Transcription Unit Is Negatively Regulated by p53 through NF-Y in Lung Cancer Cells.
The PRR11-SKA2 Bidirectional Transcription Unit Is Negatively Regulated by p53 through NF-Y in Lung Cancer Cells.
复制标题
肺癌细胞中 PRR11-SKA2 双向转录单位受 p53 通过 NF-Y 负向调节
DOI：
10.3390/ijms18030534
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发表时间：
2017-03-01
影响因子：
5.6
通讯作者：
Bu Y
中科院分区：
文献类型：
--
作者：
Wang Y;Weng H;Zhang Y;Long Y;Li Y;Niu Y;Song F;Bu Y
我们以前确定富含脯氨酸的蛋白11（PRR 11）作为一种新的癌症相关基因，参与细胞周期和肿瘤发生的调控。我们最近的研究表明，PRR 11和它的相邻基因，动粒相关2（SKA 2），构成了一个经典的头对头基因对，是协调调节的核因子Y（NF-Y）。在本研究中，我们进一步表明PRR 11-SKA 2双向转录单位是肿瘤抑制基因p53的间接靶点。荧光素酶报告基因分析显示，野生型p53的过表达，而不是突变型p53，显着抑制PRR 11-SKA 2双向启动子的基础活性和NF-γ介导的反式激活。PRR 11-SKA 2启动子的缺失和突变分析显示，p53介导的PRR 11-SKA 2抑制依赖于功能性NF-Y结合位点的存在。此外，免疫共沉淀分析显示，p53与NF-Y在肺癌细胞中的关联，染色质免疫沉淀分析显示，p53通过减少PRR 11-SKA 2启动子区域中NF-Y的结合量来抑制PRR 11-SKA 2转录。一致地，p53下调PRR 11-SKA 2转录的能力在siRNA介导的核因子Y亚基β（NF-YB）耗竭后显著减弱。值得注意的是，与其他具有p53突变和/或PRR 11或SKA 2的较高表达的患者相比，PRR 11或SKA 2沿着野生型p53的较低表达的肺癌患者表现出最好的总体生存率。综上所述，我们的研究结果表明，p53负调控PRR 11-SKA 2双向转录单位通过NF-γ的表达，这表明不能抑制PRR 11-SKA 2双向转录单位后，p53的损失可能有助于肿瘤的发生。
We previously identified proline-rich protein 11 (PRR11) as a novel cancer-related gene that is implicated in the regulation of cell cycle and tumorigenesis. Our recent study demonstrated that PRR11 and its adjacent gene, kinetochore associated 2 (SKA2), constitute a classic head-to-head gene pair that is coordinately regulated by nuclear factor Y (NF-Y). In the present study, we further show that the PRR11-SKA2 bidirectional transcription unit is an indirect target of the tumor suppressor p53. A luciferase reporter assay revealed that overexpression of wild type p53, but not mutant p53, significantly represses the basal activity and NF-Y mediated transactivation of the PRR11-SKA2 bidirectional promoter. Deletion and mutation analysis of the PRR11-SKA2 promoter revealed that p53-mediated PRR11-SKA2 repression is dependent on the presence of functional NF-Y binding sites. Furthermore, a co-immunoprecipitation assay revealed that p53 associates with NF-Y in lung cancer cells, and a chromatin immunoprecipitation assay showed that p53 represses PRR11-SKA2 transcription by reducing the binding amount of NF-Y in the PRR11-SKA2 promoter region. Consistently, the ability of p53 to downregulate PRR11-SKA2 transcription was significantly attenuated upon siRNA-mediated depletion of nuclear factor Y subunit beta (NF-YB). Notably, lung cancer patients with lower expression of either PRR11 or SKA2 along with wild type p53 exhibited the best overall survival compared with others with p53 mutation and/or higher expression of either PRR11 or SKA2. Taken together, our results demonstrate that p53 negatively regulates the expression of the PRR11-SKA2 bidirectional transcription unit through NF-Y, suggesting that the inability to repress the PRR11-SKA2 bidirectional transcription unit after loss of p53 might contribute to tumorigenesis.