A possible role for selenoprotein glutathione peroxidase (GPx1) and thioredoxin reductases (TrxR1) in thyroid cancer: our experience in thyroid surgery

Abstract

BackgroundOxidative stress is responsible for some alterations in the chemical structure and, consequently, in the function of proteins, lipids, and DNA. Recent studies have linked oxidative stress to cancers, particularly thyroid cancer, but the mechanisms remain unclear. Here, we further characterize the role of oxidative stress in thyroid cancer by analyzing the expression of two selenium antioxidant molecules, glutathione peroxidase (GPx1) and thioredoxin reductase (TrxR1) in thyroid cancer cells.MethodsSamples of both healthy thyroid tissue and thyroid tumor were taken for analysis after total thyroidectomy. The expression of GPx1 and TrxR1 was revealed by Western blot analysis and quantified by densitometric analyses, while the evaluation of free radicals was performed by Electron Paramagnetic Resonance (EPR)-spin trapping technique.ResultsOur results show a decrease in the expression of GPx1 and TrxR1 (− 45.7 and − 43.2% respectively, p < 0.01) in the thyroid cancer cells compared to the healthy cells. In addition, the EPR technique shows an increase of free radicals in tumor tissue, significantly higher than that found in healthy thyroid tissue (+ 116.3%, p < 0.01).ConclusionsOur findings underscore the relationship between thyroid cancer and oxidative stress, showing the imbalance of the oxidant/antioxidant system in thyroid cancer tissue. These results suggest that either the inability to produce adequate antioxidant defense or an increased consumption of antioxidants, due to the hyper-production of free radicals, may play a crucial role in thyroid cancer.

Oxidative stress in thyroid carcinomas: biological and clinical significance

“…The role of oxidative stress in thyroid cancer was characterized by analysing the expression of two selenium antioxidant molecules, glutathione peroxidase (GPx1) and thioredoxin reductase (TrxR1) in thyroid cancer cells. Decreased expression of both proteins was observed in cancer cells compared to healthy cells and was associated with an increased level of free radicals in the tumour tissue (Metere et al 2018). The expression of catalase was also dramatically decreased in human thyroid tumours compared with normal thyroid tissue (Hasegawa et al 2002(Hasegawa et al , 2003.…”

Selenium Deficiency—From Soil to Thyroid Cancer

“…However, there are not many studies regarding the overall changes in selenoprotein genes in thyroid cancer. Selenoproteins GPx1 and TRx1 in thyroid cancer tissue are lower in patients versus controls, while DIO3 mRNA levels and activity were increased in PTC [111,115]. This increase in DIO3 mRNA levels was correlated with distant metastasis or lymph nodes.…”

Subcellular Localization of Glutathione Peroxidase, Change in Glutathione System during Ageing and Effects on Cardiometabolic Risks and Associated Diseases

“…GPx1 has an impact on signal transmission related to cell death, protein kinase phosphorylation, and activation of NF-κB via an oxidant; the anomaly of the expression of its activity would be at the base of several diseases notably cancer and chronic diseases [71]. It is known that the single nucleotide polymorphism (SNP) that alters the sequences of a particular amino acid of 201 amino acids, GPx1, is associated with certain diseases including lung, bladder, and breast cancers [72].…”