Differential expression of glutathione peroxidase 3 in cancers of the breast.

Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding glutathione peroxidase 3, GPX3, when comparing primary tumors of the breast to the tissue of origin, the normal breast. GPX3 mRNA was present at significantly lower quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of GPX3 in primary tumors of the breast was correlated with overall survival in patients with basal subtype cancer, demonstrating a relationship between primary tumor expression of a differentially expressed gene and patient survival outcomes influenced by molecular subtype. GPX3 may be of relevance to initiation, maintenance or progression of cancers of the female breast.

Glutathione peroxidase 3 (extracellular isoform) levels and functional polymorphisms in fertile and infertile men

Background Oxidative stress has an undeniable role in the impairment of sperm function and idiopathic male infertility. On the other hand, the local antioxidant system particularly glutathione peroxidase 3 (GPX3) as an extracellular enzyme protects male fertility from oxidative damages. Therefore, in the current study, we evaluated the association between two functional polymorphisms of the GPX3 gene with its levels in seminal fluid and subsequently with the risk of male infertility. Result We recruited 100 fertile and 100 infertile men for the study. Our results showed that the concentration of GPX3 was higher in the fertile group than infertile patients (p= <0.01), and there were positive correlations between GPX3 concentration in seminal fluid with sperm motility and morphology. The frequency of rs8177404 and rs3828599 genotypes and alleles was significantly different between the groups and we found that having the rs8177404 polymorphism (TC and CC genotypes) could increase the risk of idiopathic infertility more than 2-fold. On the other hand, the GG genotype (rs3828599) showed a protective effect against infertility. Our results demonstrated that men carrying CC genotype of rs8177404 polymorphism had significantly lower progressively motile sperm and higher immotile sperm compared with subjects carrying TT and TC genotypes. In the rs3828599 polymorphism, the GG carriers had significantly higher progressively motile and lower immotile sperm than AA carriers. Furthermore, men with genotypes of CC (rs8177404) and GG (rs3828599) had significantly lower and higher levels of GPX3 in the seminal fluid, respectively. Conclusion In conclusion, our results showed associations between sperm parameters with GPX3 levels and the gene polymorphisms. It seems rs8177404 and rs3828599 polymorphisms can affect GPX3 levels in seminal fluid and subsequently sperm parameters.

Glutathione Peroxidase 3 as a Biomarker of Recurrence after Lung Cancer Surgery

We aimed to examine the usefulness of serum glutathione peroxidase 3 (GPx3) as a biomarker of lung cancer recurrence after complete resection. We prospectively collected serial serum samples at the baseline, as well as 3, 6 and 12 months after surgery from complete resection cases in 2013. GPx3 levels were measured by enzyme-linked immunosorbent assay. Statistical tests including t-tests and Cox proportional hazard regression analyses were performed. Totally, 135 patients were enrolled, and 39 (28.9%) showed relapse during the median follow-up period (63.60 months; range, 0.167–81.867). The mean GPx3 change was significantly higher in the recurrence group at 6 months (0.32 ± 0.38 vs. 0.15 ± 0.29, p = 0.016) and 12 months (0.40 ± 0.37 vs. 0.13 ± 0.28, p = 0.001). The high GPx3 change group showed significantly higher 60-months recurrence rates than the low group (48.1% vs. 25.2% at 3 months, p = 0.005; 54.5% vs. 28.9% at 6 months, p = 0.018; 38.3% vs. 18.3% at 12 months, p = 0.035). High GPx3 change at 3 months were independent risk factors of recurrence (hazard ratio (HR) 3.318, 95% confidence interval (CI), 1.582–6.960, p = 0.002) and survival (HR 3.150, 95% CI, 1.301–7.628, p = 0.011). Therefore, serum GPx3 changes after surgery may be useful predictive biomarkers for recurrence in lung cancer. Larger-scale validation studies are warranted to confirm these findings.