RYBP 通过下调 G1-S 期转换过程中的 CDC6 和 CDC45 抑制食管鳞癌细胞增殖。

RYBP inhibits esophageal squamous cell carcinoma proliferation through downregulating CDC6 and CDC45 in G1-S phase transition process.

机构信息

Department of Radiation Oncology, Second Affiliated Hospital, Xi'an Jiaotong University, 710004 Xi'an, China.

出版信息

Life Sci. 2020 Jun 1;250:117578. doi: 10.1016/j.lfs.2020.117578. Epub 2020 Mar 21.

DOI:10.1016/j.lfs.2020.117578

PMID:32209426

Abstract

AIMS

RING1 and YY1-binding protein (RYBP) is an epigenetic regulator and plays crucial roles in embryonic development. The anti-tumor effect of RYBP has been reported in several cancers recently, but the role of RYBP in esophageal squamous cell carcinoma (ESCC) has not been fully elucidated. The present study aimed to investigate the biological function and the underlying molecular mechanisms of RYBP in ESCC.

MATERIALS AND METHODS

We detected the expression of RYBP in ESCC tissue microarrays (TMA) by immunohistochemistry. Cell proliferation was assessed by CCK8 and colony formation assays. Cell cycle was analyzed by flow cytometry. Gene expression was determined by transcriptome arrays, quantitative real-time PCR (qRT-PCR) and Western blot. Four-week-old male nude mice were used to evaluate the effect of RYBP in ESCC growth.

KEY FINDINGS

We found that RYBP was downregulated in ESCC compared with adjacent normal tissues. A high level of RYBP expression predicted a better outcome of ESCC patients. Furthermore, overexpression of RYBP inhibited ESCC growth both in vitro and in vivo. Transcriptome arrays and functional studies showed that RYBP decreased the expression of genes related to cell cycles, especially CDC6 and CDC45, which were essential to initiate the DNA replication and G1-S transition.

SIGNIFICANCE

Taken together, our study suggests that RYBP suppresses ESCC proliferation by downregulating CDC6 and CDC45, thus inhibiting the G1-S transition.

摘要

目的

RING1 和 YY1 结合蛋白（RYBP）是一种表观遗传调节剂，在胚胎发育中发挥着关键作用。最近有报道称 RYBP 在几种癌症中具有抗肿瘤作用，但 RYBP 在食管鳞状细胞癌（ESCC）中的作用尚未完全阐明。本研究旨在探讨 RYBP 在 ESCC 中的生物学功能及其潜在的分子机制。

材料和方法

我们通过免疫组织化学检测 ESCC 组织微阵列（TMA）中 RYBP 的表达。通过 CCK8 和集落形成实验评估细胞增殖。通过流式细胞术分析细胞周期。通过转录组芯片、定量实时 PCR（qRT-PCR）和 Western blot 测定基因表达。使用 4 周龄雄性裸鼠评估 RYBP 对 ESCC 生长的影响。

主要发现

与相邻正常组织相比，RYBP 在 ESCC 中表达下调。高水平的 RYBP 表达预示着 ESCC 患者的预后较好。此外，RYBP 的过表达在体外和体内均抑制 ESCC 的生长。转录组芯片和功能研究表明，RYBP 降低了与细胞周期相关的基因表达，特别是细胞周期蛋白 D6（CDC6）和细胞周期蛋白 D45（CDC45），它们对于启动 DNA 复制和 G1-S 过渡至关重要。