Glutaminase isoforms expression switches microRNA levels and oxidative status in glioblastoma cells

Abstract

Background Glutaminase isoenzymes GLS and GLS2 play apparently opposing roles in cancer: GLS acts as an oncoprotein, while GLS2 (GAB isoform) has context specific tumour suppressive activity. Some microRNAs (miRNAs) have been implicated in progression of tumours, including gliomas. The aim was to investigate the effect of GLS and GAB expression on both miRNAs and oxidative status in glioblastoma cells. Methods Microarray profiling of miRNA was performed in GLS-silenced LN229 and GAB-transfected T98G human glioblastoma cells and their wild-type counterparts. Results were validated by real-time quantitative RT-PCR. Oxidative status and antioxidant enzymes were determined by spectrophotometric or fluorescence assays in GLS-silenced LN229 and T98G, and GAB-transfected LN229 and T98G. Results MiRNA-146a-5p, miRNA-140-3p, miRNA-21-5p, miRNA-1260a, and miRNA-92a-3p were downregulated, and miRNA-1246 was upregulated when GLS was knocked down. MiRNA-140-3p, miRNA-1246, miRNA-1260a, miRNA-21-5p, and miRNA-146a-5p were upregulated when GAB was overexpressed. Oxidative status (lipid peroxidation, protein carbonylation, total antioxidant capacity, and glutathione levels), as well as antioxidant enzymes (catalase, superoxide dismutase, and glutathione reductase) of silenced GLS glioblastoma cells and overexpressed GAB glioblastoma cells significantly changed versus their respective control glioblastoma cells. MiRNA-1246, miRNA-1260a, miRNA-146a-5p, and miRNA-21-5p have been characterized as strong biomarkers of glioblastoma proliferation linked to both GLS silencing and GAB overexpression. Total glutathione is a reliable biomarker of glioblastoma oxidative status steadily associated to both GLS silencing and GAB overexpression. Conclusions Glutaminase isoenzymes are related to the expression of some miRNAs and may contribute to either tumour progression or suppression through certain miRNA-mediated pathways, proving to be a key tool to switch cancer proliferation and redox status leading to a less malignant phenotype. Accordingly, GLS and GAB expression are especially involved in glutathione-dependent antioxidant defence.

Identification of GLS as a cuproptosis-related diagnosis gene in acute myocardial infarction

“…Glutamate is used to produce adenosine triphosphate (ATP) by TCA cycle or for the synthesis of other amino acids and lipids, which are necessary for bioenergetics and biosynthesis (48). Up till the present moment, research on GLS has focused on oncology (49)(50)(51); however, the role in AMI is unclear. Our study suggests that GLS is a promising therapeutic target for AMI.…”

Integrated Bioinformatics Analysis Reveals Novel miRNA as Biomarkers Associated with Preeclampsia

“…In our case of the 4 miRNAs in common between placenta and plasma that we highlighted, 3 (hsa-mir-1246, hsa-mir-203a-3p and hsa-mir-378c) were known actors in the pathophysiology of PE [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ]; instead, the other 1 (hsa-mir-378e) has never been indicated as a possible biomarker of PE.…”

GLS and GLS2 Glutaminase Isoenzymes in the Antioxidant System of Cancer Cells

“…SFxL, LN229, T98G None [36] Silencing of GLS or overexpression of GLS2 decreased oxidative status and boosted antioxidant enzymes Brain (GBM 1 ) LN229, T98G None [37] GLS2 reduced the TMZ 2 -resistance of GBM 1 in vitro and in vivo through the long non-coding RNA ATXN8OS, which mediated ferroptosis and increased oxidative damage to lipids Brain (GBM 1 ) U251, U251TR U251+GLS2 transfected cells were injected into the brains of nude mice [38] p73 transcriptionally activated GLS2, increasing serine and diminishing oxidative stress NSCLC 3 , Osteosarcom a H1299, SaOs-2 None [39] GLS2 overexpression shortened oxidative stress by a GSH-independent mechanism NSCLC 3 CL1-0 None [40] Knock out of GLS2, a tumor suppressor in this study, reduced the GSH/GSSG ratio and increased oxidative damage to lipids during ferroptosis Liver (HCC 4 )…”