LncRNA GABPB1-AS1 and GABPB1 regulate oxidative stress during erastin-induced ferroptosis in HepG2 hepatocellular carcinoma cells

Wenchuan Qi,Qiao Zhang,Longjiang Xia,Si Xu,Jiangshan Dai,Chuanfang Wu,Zhenhua Li

doi:10.1038/s41598-019-52837-8

Abstract

Ferroptosis is a non-apoptotic, iron-dependent oxidative form of cell death that is specifically induced by erastin in RAS mutant cancer cells. Ferroptotic cell death is the result of membrane lipid peroxide damage caused by the accumulation of hydroxyl radicals derived from H2O2 by the Fenton reaction. Peroxidases are key cellular antioxidant enzymes that block such damaging processes. Few studies have examined the roles of long non-coding RNAs (lncRNAs) in the regulation of cellular oxidative stress, especially in ferroptosis. Here, we demonstrated that erastin upregulated the lncRNA GABPB1-AS1, which downregulated GABPB1 protein levels by blocking GABPB1 translation, leading to the downregulation of the gene encoding Peroxiredoxin-5 (PRDX5) peroxidase and the eventual suppression of the cellular antioxidant capacity. Such effects critically inhibited the cellular antioxidant capacity and cell viability. Additionally, high expression levels of GABPB1 were correlated with poor prognosis of hepatocellular carcinoma (HCC) Patients, while high GABPB1-AS1 levels in HCC patients correlated with improved overall survival. Collectively, these data demonstrate a mechanistic link between GABPB1 and its antisense lncRNA GABPB1-AS1 in erastin-induced ferroptosis and establish GABPB1 and GABPB1-AS1 as attractive therapeutic targets for HCC.

Highlights

Ferroptosis is an oxidative form of cell death that is related to cancer suppression and neurodegenerative diseases[1,2,3]
CCK-8 assays showed that treatment of HepG2 cells with erastin for 24 h resulted in an ~40% reduction in HepG2 cell survival and that cell death was blocked by ferrostatin-1 (Fig. 1A)
We further examined the role of the peroxidase protein PRDX5 in erastin-induced oxidative stress by overexpression of PRDX5 and observed reduced reactive oxygen species (ROS) generation and MDA levels and restored cell viability (Fig. 1I,N–P)

Summary

Introduction

Ferroptosis is an oxidative form of cell death that is related to cancer suppression and neurodegenerative diseases[1,2,3]. Previous studies have reported that erastin inhibits system xc- and triggers ferroptosis by blocking the antioxidant defence from obtaining reducing equivalents from glutathione (GSH), which leads to the accumulation of lipid ROS4,5. We found that GABPB1-AS1 was upregulated by erastin which inhibited the translation of GABPB1, leading to the inhibition of peroxidase gene expression and causing the accumulation of ROS and MDA and HepG2 cell death. These findings revealed that GABPB1-AS1 may be a key molecule in HCC cell ferroptosis induced by erastin and enrich our understanding of lncRNA regulation of oxidative stress

Methods

Results

Conclusion