Department of Urology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China.
Department of Urology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China.
Life Sci. 2020 Nov 15;261:118311. doi: 10.1016/j.lfs.2020.118311. Epub 2020 Aug 27.
Bladder cancer (BCa) is one of the most commonly occurring urological malignancy. DNA methylation mediated by DNA methyltransferase 1 (DNMT1) plays a crucial role in the physiological and pathological processes of cancer. However, the role of upstream regulatory factors and downstream target genes of DNA methylation mediated by DNMT1 needs further study in BCa. We aim to discover the upstream regulatory factor and downstream target gene of DNMT1, which form a signaling pathway to regulate the progression of BCa.
DNMT1 expression in BCa tissues and cells was detected by qPCR and Western Blot. Balbc/nu/nu mice were used to determine the relationship between DNMT1 expression and tumor growth. CCK8, EdU, and transwell assays were employed to measure cell viability, proliferation, and migration respectively. RNA immunoprecipitation (RIP) assays and dual luciferase reporter assays were applied to determine the relationships among DNMT1, miR-152-3p and PTEN.
A significant up-regulation of DNMT1 in BCa tissues and cells, and silencing of DNMT1 expression inhibited the tumor growth in vivo. Knockdown of DNMT1 inhibited the cell growth and migration of BCa cells. miR-152-3p inhibited the DNMT1 and over-expression of DNMT1 restored the cellular function of miR-152-3p in BCa cells. DNMT1 regulated the phosphatase and tensin homolog (PTEN) expression via modulating the status of DNA methylation in the promoter of PTEN.
This study confirmed the role and underlying mechanism of DNMT1-mediated DNA methylation and displayed a novel regulatory pathway miR-152/DNMT1/PTEN in BCa, thus, providing a potential diagnostic and therapeutic targets for BCa.
膀胱癌（BCa）是最常见的泌尿系统恶性肿瘤之一。DNA 甲基转移酶 1（DNMT1）介导的 DNA 甲基化在癌症的生理和病理过程中起着至关重要的作用。然而，DNMT1 介导的 DNA 甲基化的上游调节因子和下游靶基因在 BCa 中的作用需要进一步研究。我们旨在发现 DNMT1 的上游调节因子和下游靶基因，它们形成一个信号通路来调节 BCa 的进展。
通过 qPCR 和 Western Blot 检测 BCa 组织和细胞中 DNMT1 的表达。使用 Balbc/nu/nu 小鼠确定 DNMT1 表达与肿瘤生长之间的关系。CCK8、EdU 和 Transwell 测定分别用于测量细胞活力、增殖和迁移。RNA 免疫沉淀（RIP）测定和双荧光素酶报告基因测定用于确定 DNMT1、miR-152-3p 和 PTEN 之间的关系。
DNMT1 在 BCa 组织和细胞中显著上调，沉默 DNMT1 表达抑制体内肿瘤生长。DNMT1 敲低抑制 BCa 细胞的细胞生长和迁移。miR-152-3p 抑制 DNMT1，而过表达 DNMT1 恢复了 miR-152-3p 在 BCa 细胞中的细胞功能。DNMT1 通过调节 PTEN 启动子中 DNA 甲基化的状态来调节磷酸酶和张力蛋白同源物（PTEN）的表达。
本研究证实了 DNMT1 介导的 DNA 甲基化的作用和潜在机制，并显示了 miR-152/DNMT1/PTEN 在 BCa 中的新调节途径，为 BCa 提供了潜在的诊断和治疗靶点。
