53BP1 调控食管癌模型中的细胞周期停滞。

53BP1 regulates cell cycle arrest in esophageal cancer model.

机构信息

Department of Radiotherapy, Department of Medical Oncology, Department of Chest Surgery; The Fourth Hospital of Hebei Medical University, Shijiazhuang, China.

出版信息

Eur Rev Med Pharmacol Sci. 2019 Jan;23(2):604-612. doi: 10.26355/eurrev_201901_16874.

DOI:10.26355/eurrev_201901_16874

PMID:30720168

Abstract

OBJECTIVE

This study aims to investigate effects of checkpoint kinase, mediator of DNA damage checkpoint 1 (MDC1) and p53-binding protein 1 (53BP1) silencing on p53, checkpoint kinase 1 and 2 (CHK1 and CHK2), and CHK2-T68 expression.

MATERIALS AND METHODS

Eca109 cells were divided into untransfected Eca109, Blank-vector, MDC1-RNAi transfection, and 53BP1-RNAi transfection group. Streptavidin-peroxidase (SP) immunohistochemical assay was used to examine CHK2-T68 expression. About 4 groups were used to establish esophageal carcinoma nude-mouse models, and assigned as Eca-109 control (or Eca-109 plus 15 Gy γ-rays irradiation, Eca-109+IR), Blank-vector (or Blank-vecor+IR), 53BP1-RNAi (or 53BP1-RNAi+IR), and MDC1-RNAi group (or MDC1-RNAi+IR group) by injecting. The expression of p53, CHK1, CHK2 were evaluated using SP immunohistochemical assay.

RESULTS

53BP1 and MDC1 down-regulation significantly inhibited expression of CHK2-T68 in Eca-109 cells compared to untreated group (p<0.05). There were significant differences for CHK2-T68 expressions in different time and groups (p<0.05). 53BP1 down-regulation significantly reduced p53 and enhanced CHK1 and CHK2 expression compared to that of Eca-109 control group (p<0.05) in Eca-109 cells. 53BP1 down-regulation significantly regulated CHK1, CHK2, and p53 in xenograft nude mice models exposed to γ-ray irradiation compared to that of untreated group (p<0.05). p53 was negatively correlated with CHK1 and CHK2 in xenograft nude mice models.

CONCLUSIONS

53BP1 regulated the cell cycle arrest by modulating p53, CHK1, and CHK2 expression in both Eca-109 cells and xenograft nude mice models.

摘要

目的

本研究旨在探讨 DNA 损伤检验点中介因子 1（MDC1）和 p53 结合蛋白 1（53BP1）沉默对 p53、细胞检验点激酶 1 和 2（CHK1 和 CHK2）以及 CHK2-T68 表达的影响。

材料和方法

将 Eca109 细胞分为未转染 Eca109 组、空载组、MDC1-RNAi 转染组和 53BP1-RNAi 转染组。采用链霉亲和素-过氧化物酶（SP）免疫组化法检测 CHK2-T68 表达。建立裸鼠食管癌模型，分为 Eca-109 对照组（或 Eca-109 加 15Gyγ射线照射，Eca-109+IR）、空载组（或空载+IR）、53BP1-RNAi 组（或 53BP1-RNAi+IR）和 MDC1-RNAi 组（或 MDC1-RNAi+IR），通过注射法进行分组。采用 SP 免疫组化法检测 p53、CHK1、CHK2 的表达。

结果

与未处理组相比，53BP1 和 MDC1 下调显著抑制 Eca-109 细胞中 CHK2-T68 的表达（p<0.05）。不同时间和组间 CHK2-T68 表达存在显著差异（p<0.05）。与 Eca-109 对照组相比，53BP1 下调显著降低了 p53 水平，增加了 CHK1 和 CHK2 的表达（p<0.05）。与未处理组相比，53BP1 下调显著调节了裸鼠模型中 CHK1、CHK2 和 p53 的表达（p<0.05）。裸鼠模型中 p53 与 CHK1 和 CHK2 呈负相关。