Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Pavillon of Applied Research on Cancer, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
Biochem Biophys Res Commun. 2020 Apr 16;524(4):798-802. doi: 10.1016/j.bbrc.2020.01.161. Epub 2020 Feb 6.
Inflammatory bowel disease (IBD) is a risk factor for the development of colorectal cancer (CRC) for which mutation to p53 is an early event leading to dysplasia. Interestingly, P2RY6 mRNA increases in both pathologies. In this study, we investigated if p53 and p53 mutant, commonly found in CRC and IBD, were involved in the transcriptional regulation of P2RY6. First, the P2RY6 promoter was defined as a region corresponding to -1600 to +273 nucleotides relative to the putative TATA-less transcriptional starting site found at position 73,264,505 of NCBI reference sequence NC_000010.11. We cloned this promoter region along with 5'-deletion constructs in the pGL4.10[luc2] vector for luciferase assays to delineate the minimal promoter region. We observed that p53 and p53 differentially regulated the transcription of the P2RY6 gene. In fact, increasing quantity of p53 enhanced the capacity of p53 to stimulate the transactivation of the P2RY6 promoter but this cooperative effect was lost when p53 was present in a ratio of 3:1. In accordance with the luciferase assays, ChIP analysis revealed that endogenous p53 was significantly associated with the P2RY6 proximal promoter, whereas the interaction of the p53 with the P2RY6 promoter was not significant. Although further studies are required to fully elucidate the molecular determinant controlling P2Y expression in diseases, we propose, for the first time, a molecular mechanism involving a collaboration between p53 and p53 to regulate the expression of this receptor.
炎症性肠病（IBD）是结直肠癌（CRC）发生的一个风险因素，p53 突变是导致发育不良的早期事件。有趣的是，P2RY6 mRNA 在这两种疾病中均增加。在这项研究中，我们研究了 p53 和 p53 突变体是否参与了 CRC 和 IBD 中常见的 P2RY6 的转录调控。首先，P2RY6 启动子被定义为与位于 NCBI 参考序列 NC_000010.11 中位置 73,264,505 的推定无 TATA 转录起始位点相对应的-1600 至+273 个核苷酸的区域。我们将该启动子区域与 5'-缺失构建体一起克隆到 pGL4.10[luc2]载体中，用于荧光素酶测定以描绘最小启动子区域。我们观察到 p53 和 p53 差异调节 P2RY6 基因的转录。事实上，增加的 p53 量增强了 p53 刺激 P2RY6 启动子转录激活的能力，但当 p53 以 3:1 的比例存在时，这种协同作用就会丧失。与荧光素酶测定一致，ChIP 分析显示内源性 p53 与 P2RY6 近端启动子显著相关，而 p53 与 P2RY6 启动子的相互作用不显著。尽管需要进一步的研究来充分阐明控制疾病中 P2Y 表达的分子决定因素，但我们首次提出了一个涉及 p53 和 p53 之间协作的分子机制来调节该受体的表达。
