胰岛素样生长因子结合蛋白基因在U87胶质瘤细胞中的表达及其缺氧调节取决于内质网应激的ERN1介导信号通路。

Expression of insulin-like growth factor binding protein genes and its hypoxic regulation in U87 glioma cells depends on ERN1 mediated signaling pathway of endoplasmic reticulum stress.

作者信息

Minchenko D O, Kharkova A P, Karbovskyi L L, Minchenko O H

出版信息

Endocr Regul. 2015 Apr;49(2):73-83. doi: 10.4149/endo_2015_02_73.

DOI:10.4149/endo_2015_02_73

PMID:25960008

Abstract

OBJECTIVE

The aim of the present study was to examine the association between the expression of insulin-like growth binding protein-1 and -2 (IGFBP1 and IGFBP2), insulin-like growth factor 2 mRNA binding protein 3/KH domain containing protein over-expressed in cancer (IGF2BP3/KOC1), and HtrA serine peptidase 1/serine protease with IGF-binding domain (HTRA1/PRSS11) genes and function of endoplasmic reticulum stress signaling mediated by ERN1 (endoplasmic reticulum to nucleus signaling 1) as well as the regulation of these genes by hypoxia in U87glioma cells.

METHODS

The expression of IGFBP1, IGFBP2, IGF2BP3, and HTRA1 genes in U87 glioma cells and its subline with ERN1 signaling enzyme loss of function, were analyzed by qPCR. Cells underwent to hypoxia exposure (3% oxygen, 16 h).

RESULTS

The blockade of both enzymatic activities (kinase and endoribonuclease) of ERN1 in glioma cells led to a significant down-regulation of the expression of IGFBP1, IGFBP2, and IGF2BP3 genes and strong up-regulation of HTRA1. At the same time, the inhibition of ERN1 endoribonuclease significantly increased the expression of IGFBP1, IGFBP2, and HTRA1 genes and did not affect the IGF2BP3 gene expression. Hypoxia up-regulated the expression of IGFBP1 and IGFBP2 genes in control glioma cells, with more significant changes in IGFBP1 gene. Furthermore, effect of hypoxia on these gene expressions was significantly lower in glioma cells without ERN1 signaling enzyme function.

CONCLUSIONS

Results of this study demonstrate the dependence of insulin-like growth binding proteins as well as IGF2BP3 and HTRA1 gene expressions in U87 glioma cells on ERN1 signaling enzyme function and hypoxia, indicating its participation in the regulation of metabolic and proliferative processes via IGF/INS receptors, because endoplasmic reticulum stress is an important component of tumor growth and metabolic diseases.

摘要

目的

本研究旨在探讨胰岛素样生长结合蛋白-1和-2（IGFBP1和IGFBP2）、在癌症中过表达的胰岛素样生长因子2 mRNA结合蛋白3/含KH结构域蛋白（IGF2BP3/KOC1）以及HtrA丝氨酸蛋白酶1/具有IGF结合结构域的丝氨酸蛋白酶（HTRA1/PRSS11）基因的表达与由ERN1（内质网到细胞核信号转导1）介导的内质网应激信号功能之间的关联，以及缺氧对U87胶质瘤细胞中这些基因的调控。

方法

采用qPCR分析U87胶质瘤细胞及其具有ERN1信号酶功能丧失的亚系中IGFBP1、IGFBP2、IGF2BP3和HTRA1基因的表达。细胞进行缺氧暴露（3%氧气，16小时）。

结果

胶质瘤细胞中ERN1的两种酶活性（激酶和核糖核酸内切酶）被阻断导致IGFBP1、IGFBP2和IGF2BP3基因表达显著下调，HTRA1强烈上调。同时，ERN1核糖核酸内切酶的抑制显著增加了IGFBP1、IGFBP2和HTRA1基因的表达，且不影响IGF2BP3基因表达。缺氧上调了对照胶质瘤细胞中IGFBP1和IGFBP2基因的表达，IGFBP1基因变化更显著。此外，在没有ERN1信号酶功能的胶质瘤细胞中，缺氧对这些基因表达的影响显著降低。