Departamento de Biología Molecular y Bioquímica and Instituto de Investigación de Biomedicina de Málaga (IBIMA), Universidad de Málaga, Málaga, Spain.
Department of Cell and Developmental Biology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil.
J Biomed Sci. 2021 Feb 20;28(1):14. doi: 10.1186/s12929-021-00712-y.
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.
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.
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.
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.
谷氨酰胺酶同工酶 GLS 和 GLS2 在癌症中显然起着相反的作用：GLS 作为癌蛋白起作用，而 GLS2（GAB 同工型）具有特定于上下文的肿瘤抑制活性。一些 microRNAs（miRNAs）已被牵连到肿瘤的进展中，包括神经胶质瘤。目的是研究 GLS 和 GAB 表达对神经胶质瘤细胞中 microRNAs 和氧化状态的影响。
在 GLS 沉默的 LN229 和 GAB 转染的 T98G 人神经胶质瘤细胞及其野生型对照中进行 miRNA 的微阵列分析。通过实时定量 RT-PCR 验证结果。在 GLS 沉默的 LN229 和 T98G 以及 GAB 转染的 LN229 和 T98G 中，通过分光光度法或荧光法测定氧化状态和抗氧化酶。
当 GLS 被敲低时，miRNA-146a-5p、miRNA-140-3p、miRNA-21-5p、miRNA-1260a 和 miRNA-92a-3p 下调，而 miRNA-1246 上调。当 GAB 过表达时，miRNA-140-3p、miRNA-1246、miRNA-1260a、miRNA-21-5p 和 miRNA-146a-5p 上调。与各自的对照神经胶质瘤细胞相比，沉默 GLS 神经胶质瘤细胞和过表达 GAB 神经胶质瘤细胞的氧化状态（脂质过氧化、蛋白质羰基化、总抗氧化能力和谷胱甘肽水平）以及抗氧化酶（过氧化氢酶、超氧化物歧化酶和谷胱甘肽还原酶）均发生显著变化。miRNA-1246、miRNA-1260a、miRNA-146a-5p 和 miRNA-21-5p 已被确定为与 GLS 沉默和 GAB 过表达相关的神经胶质瘤增殖的强生物标志物。总谷胱甘肽是与 GLS 沉默和 GAB 过表达相关的神经胶质瘤氧化状态的可靠生物标志物。
谷氨酰胺酶同工酶与某些 miRNAs 的表达有关，可能通过某些 miRNA 介导的途径促进肿瘤的进展或抑制，证明是一种关键工具，可以切换癌症的增殖和氧化还原状态，导致较少恶性的表型。相应地，GLS 和 GAB 的表达特别参与谷胱甘肽依赖的抗氧化防御。
