Browsing by Author "Pljesa-Ercegovac, Marija (16644038900)"

Background Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with around 9% of patients surviving >5 years. Asymptomatic in its initial stages, PDAC is mostly diagnosed late, when already a locally advanced or metastatic disease, as there are no useful biomarkers for detection in its early stages, when surgery can be curative. We have previously described a promising biomarker panel (LYVE1, REG1A, and TFF1) for earlier detection of PDAC in urine. Here, we aimed to establish the accuracy of an improved panel, including REG1B instead of REG1A, and an algorithm for data interpretation, the PancRISK score, in additional retrospectively collected urine specimens. We also assessed the complementarity of this panel with CA19-9 and explored the daily variation and stability of the biomarkers and their performance in common urinary tract cancers. Methods and findings Clinical specimens were obtained from multiple centres: Barts Pancreas Tissue Bank, University College London, University of Liverpool, Spanish National Cancer Research Center, Cambridge University Hospital, and University of Belgrade. The biomarker panel was assayed on 590 urine specimens: 183 control samples, 208 benign hepatobiliary disease samples (of which 119 were chronic pancreatitis), and 199 PDAC samples (102 stage I-II and 97 stage III-IV); 50.7% were from female individuals. PDAC samples were collected from patients before treatment. The samples were assayed using commercially available ELISAs. Statistical analyses were performed using non-parametric Kruskal-Wallis tests adjusted for multiple comparisons, and multiple logistic regression. Training and validation datasets for controls and PDAC samples were obtained after random division of the whole available dataset in a 1:1 ratio. The substitution of REG1A with REG1B enhanced the performance of the panel to detect resectable PDAC. In a comparison of controls and PDAC stage I-II samples, the areas under the receiver operating characteristic curve (AUCs) increased from 0.900 (95% CI 0.843-0.957) and 0.926 (95% CI 0.843-1.000) in the training (50% of the dataset) and validation sets, respectively, to 0.936 in both the training (95% CI 0.903-0.969) and the validation (95% CI 0.888-0.984) datasets for the new panel including REG1B. This improved panel showed both sensitivity (SN) and specificity (SP) to be >85%. Plasma CA19-9 enhanced the performance of this panel in discriminating PDAC I-II patients from controls, with AUC = 0.992 (95% CI 0.983-1.000), SN = 0.963 (95% CI 0.913- 1.000), and SP = 0.967 (95% CI 0.924-1.000). We demonstrate that the biomarkers do not show significant daily variation, and that they are stable for up to 5 days at room temperature. The main limitation of our study is the low number of stage I-IIA PDAC samples (n = 27) and lack of samples from individuals with hereditary predisposition to PDAC, for which specimens collected from control individuals were used as a proxy. Conclusions We have successfully validated our urinary biomarker panel, which was improved by substituting REG1A with REG1B. At a pre-selected cutoff of >80% SN and SP for the affiliated PancRISK score, we demonstrate a clinically applicable risk stratification tool with a binary output for risk of developing PDAC ('elevated' or 'normal'). PancRISK provides a step towards precision surveillance for PDAC patients, which we will test in a prospective clinical study, UroPanc. Copyright: © 2020 Debernardi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Purpose: We aimed to discern the role of glutathione (GSH) associated enzymes in maintaining high GSH levels in renal cell carcinoma (RCC) of the clear cell type and analyze RCC enzyme antioxidant capacity. Since changes in cellular redox balance in RCC might also be related to alterations of glutathione S-transferase (GST) phenotype, GST class α and π expression was also explored. Methods and materials: Human kidney specimens of tumor and distant nontumor regions were obtained from 15 patients with RCC at the time of surgery. The activities of GSH-replenishing enzymes, γ-glutamylcysteine synthetase (γ-GCS), γ-glutamyl transferase (γ-GT), and glutathione reductase (GR), as well as the activities of antioxidant enzymes glutathione peroxidase (GPX) and catalase (CAT) were determined spectrophotometrically. GST α and π class expression was determined by immunoblot. Results: In the course of renal cancerization, significant changes appear in the activities of GSH-replenishing and antioxidant enzymes. The activity of the key enzyme of GSH synthesis, γ-GCS, is up-regulated (P < 0.001), while the activities of γ-GT and GR are down-regulated in renal tumors compared to nontumor tissue (P < 0.001 and P < 0.05, respectively). Activities of GPX and CAT were also down-regulated (P < 0.001 and P < 0.05, respectively) in RCC. Changes in enzyme antioxidant capacity in RCC were associated with decreased GST class α (P < 0.001) and unchanged GST π expression at the protein level. Conclusions: Changes in redox status in RCC as a consequence of decreased enzyme antioxidant capacity, together with altered GST α expression, may be important factors in development and tumor growth. The up-regulation of γ-GCS and high levels of GSH in RCC may be an attempt to limit injury caused by oxidative stress. © 2008 Elsevier Inc. All rights reserved.

Background: To get more insight into the effects of the most widely used antiepileptic drugs (AEDs) on the pro oxi dant/ antioxidant balance in epi lep sy, a comparative analysis of the byproducts of oxidative damage and antioxidant de fense mechanisms was performed in patients with epilepsy treated with la mo trigine, carbamazepine and valproic acid. Methods: Byproducts of oxidative damage to proteins (reactive carbonyl derivatives, RCD and protein thiol groups, PSH), lipids (urinary isoprostanes, 8-epi-PGF2α) and DNA (urinary 8-hydroxy-2'-deoxyguanosine, 8-OHdG), as well as the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) were measured in 60 patients with newly diagnosed seizure (at illness onset and after 6 months of treatment with lamotrigine, carbamazepine or valproic acid) and in 20 healthy controls. Results: In patients with epilepsy, RCD, urinary 8-epi-PGF2α and 8-OHdG, together with SOD and GPX activities were significantly increased, while P-SH were only slightly decreased. After 6 months of treatment with AEDs, a decrease was observed in RCD, urinary 8-epi-PGF2α and 8-OHdG to values slightly higher or similar to the control, while P-SH remained unchanged. A decrease was also observed in SOD and GPX activities, although they remained significantly in creased compared to controls. Conclusions: The results of this study have shown that treatments with lamotrigine, carbamazepine and valproic acid affect the prooxidant/antioxidant balance in patients with epi lepsy.

Background: To get more insight into the effects of the most widely used antiepileptic drugs (AEDs) on the pro oxi dant/ antioxidant balance in epi lep sy, a comparative analysis of the byproducts of oxidative damage and antioxidant de fense mechanisms was performed in patients with epilepsy treated with la mo trigine, carbamazepine and valproic acid. Methods: Byproducts of oxidative damage to proteins (reactive carbonyl derivatives, RCD and protein thiol groups, PSH), lipids (urinary isoprostanes, 8-epi-PGF2α) and DNA (urinary 8-hydroxy-2'-deoxyguanosine, 8-OHdG), as well as the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) were measured in 60 patients with newly diagnosed seizure (at illness onset and after 6 months of treatment with lamotrigine, carbamazepine or valproic acid) and in 20 healthy controls. Results: In patients with epilepsy, RCD, urinary 8-epi-PGF2α and 8-OHdG, together with SOD and GPX activities were significantly increased, while P-SH were only slightly decreased. After 6 months of treatment with AEDs, a decrease was observed in RCD, urinary 8-epi-PGF2α and 8-OHdG to values slightly higher or similar to the control, while P-SH remained unchanged. A decrease was also observed in SOD and GPX activities, although they remained significantly in creased compared to controls. Conclusions: The results of this study have shown that treatments with lamotrigine, carbamazepine and valproic acid affect the prooxidant/antioxidant balance in patients with epi lepsy.

Purpose: Urothelial bladder cancer (UBC) is the most common malignancy of urinary tract in the developed world. In metastatic UBC, systemic chemotherapy still remains the mainstay of initial treatment. Inter-individual differences in treatment outcome partially may be the consequence of genetic variations in enzymes that modulate oxidative stress. Therefore, we aimed to determine the potential prognostic role of single nucleotide polymorphism (SNP) of the two antioxidant enzymes glutathione peroxidase 1 (GPX1) and superoxide dismutase 2 (SOD2) in metastatic UBC patients treated with cisplatin-based chemotherapy. Methods: This prospective single-center hospital-based case-control study included 33 patients with metastatic UBC treated with cisplatin-based chemotherapy and 227 healthy controls. GPX1 SNP (rs1050450) was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and SOD2 SNP (rs4880) was determined by quantitative PCR (q-PCR). Overall survival (OS) was evaluated using Kaplan–Meier survival analysis during 2-year follow up period, with the log-rank test for prognostic significance. Results: No significant difference was observed in the distributions of GPX1 and SOD2 gene variants between patients and controls (p>0.05). Regarding GPX1 polymorphism, no impact of GPX1 polymorphism on OS could be demonstrated (p>0.05). Finally, Kaplan-Meier survival analysis showed no association between SOD2 polymorphism and OS (p>0.05). Conclusions: No association was found between polymorphism of GPX1 and SOD2 and OS in patients with metastatic urothelial bladder cancer treated with cisplatin-based chemotherapy. © 2018 Zerbinis Publications. All Rights Reserved.

Purpose: Urothelial bladder cancer (UBC) is the most common malignancy of urinary tract in the developed world. In metastatic UBC, systemic chemotherapy still remains the mainstay of initial treatment. Inter-individual differences in treatment outcome partially may be the consequence of genetic variations in enzymes that modulate oxidative stress. Therefore, we aimed to determine the potential prognostic role of single nucleotide polymorphism (SNP) of the two antioxidant enzymes glutathione peroxidase 1 (GPX1) and superoxide dismutase 2 (SOD2) in metastatic UBC patients treated with cisplatin-based chemotherapy. Methods: This prospective single-center hospital-based case-control study included 33 patients with metastatic UBC treated with cisplatin-based chemotherapy and 227 healthy controls. GPX1 SNP (rs1050450) was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and SOD2 SNP (rs4880) was determined by quantitative PCR (q-PCR). Overall survival (OS) was evaluated using Kaplan–Meier survival analysis during 2-year follow up period, with the log-rank test for prognostic significance. Results: No significant difference was observed in the distributions of GPX1 and SOD2 gene variants between patients and controls (p>0.05). Regarding GPX1 polymorphism, no impact of GPX1 polymorphism on OS could be demonstrated (p>0.05). Finally, Kaplan-Meier survival analysis showed no association between SOD2 polymorphism and OS (p>0.05). Conclusions: No association was found between polymorphism of GPX1 and SOD2 and OS in patients with metastatic urothelial bladder cancer treated with cisplatin-based chemotherapy. © 2018 Zerbinis Publications. All Rights Reserved.

Background: Oxidative stress in patients with end-stage renal disease (ESRD) is associated with long-term cardiovascular complications. The cytosolic family of glutathione S-transferases (GSTs) is involved in the detoxication of various toxic compounds and antioxidant protection. GST omega class members, GSTO1 and GSTO2 possess, unlike other GSTs, dehydroascorbate reductase and deglutathionylation activities. The aim of this study was to clarify the role of genetic polymorphisms of GSTO1 (rs4925) and GSTO2 (rs156697) as risk determinants for ESRD development, as well as in the survival of these patients. Methods: A total of 199 patients and 199 healthy subjects were included in the study and genotyped for both GSTO1 and GSTO2 polymorphism. Protein thiol and carbonyl groups as markers of protein oxidative damage were determined spectrophotometrically. Cox proportional hazard model and Kaplan-Meier analysis were performed to investigate the role of GSTO1 and GSTO2 genetic polymorphism on mortality of ESRD patients during the follow-up period (36 month). Results: Individuals carrying the variant GSTO2 GG genotype were at 2.45-fold higher risk of ESRD development compared to the wild type GSTO2 AA genotype (OR=2.45; 95%CI=1.18-5.07; p=0.016). The results of GSTO1/GSTO2 haplotype analysis showed that the haplotype combi - nation of GSTO1 (∗A)/GSTO2 (∗A) (GSTO1 variant/GSTO2 wild type allele) was protective for ESRD (OR=0.23 95%CI=0.12-0.44, p=0.001). Patients carrying at least one GSTO1 reference allele have shorter mean overall (Log rank=2.844, p =0.241) and cardiovascular survival probability (Log rank=4.211, p=0.122). Conclusions: GSTO polymorphisms have been shown to act as significant markers in assessing the risk of ESRD development and patients' survival. © by Tatjana Simic 2016.

Background: Oxidative stress in patients with end-stage renal disease (ESRD) is associated with long-term cardiovascular complications. The cytosolic family of glutathione S-transferases (GSTs) is involved in the detoxication of various toxic compounds and antioxidant protection. GST omega class members, GSTO1 and GSTO2 possess, unlike other GSTs, dehydroascorbate reductase and deglutathionylation activities. The aim of this study was to clarify the role of genetic polymorphisms of GSTO1 (rs4925) and GSTO2 (rs156697) as risk determinants for ESRD development, as well as in the survival of these patients. Methods: A total of 199 patients and 199 healthy subjects were included in the study and genotyped for both GSTO1 and GSTO2 polymorphism. Protein thiol and carbonyl groups as markers of protein oxidative damage were determined spectrophotometrically. Cox proportional hazard model and Kaplan-Meier analysis were performed to investigate the role of GSTO1 and GSTO2 genetic polymorphism on mortality of ESRD patients during the follow-up period (36 month). Results: Individuals carrying the variant GSTO2 GG genotype were at 2.45-fold higher risk of ESRD development compared to the wild type GSTO2 AA genotype (OR=2.45; 95%CI=1.18-5.07; p=0.016). The results of GSTO1/GSTO2 haplotype analysis showed that the haplotype combi - nation of GSTO1 (∗A)/GSTO2 (∗A) (GSTO1 variant/GSTO2 wild type allele) was protective for ESRD (OR=0.23 95%CI=0.12-0.44, p=0.001). Patients carrying at least one GSTO1 reference allele have shorter mean overall (Log rank=2.844, p =0.241) and cardiovascular survival probability (Log rank=4.211, p=0.122). Conclusions: GSTO polymorphisms have been shown to act as significant markers in assessing the risk of ESRD development and patients' survival. © by Tatjana Simic 2016.

Background: Experimental data show that superoxide dismutase 2 (SOD2) is involved in ochratoxin (OTA)-induced nephrotoxicity, whereas clinical data indicate the role of SOD2 rs4880 or glutathione peroxidase 1 (GPX1) rs1050450 polymorphisms in end-stage renal disease and urothelial carcinoma risk, known to be the major complications of Balkan endemic nephropathy (BEN). Therefore, we hypothesized that SOD2 and GPX1 gene polymorphisms would influence the risk of BEN and its associated tumors. Materials and Methods: The study was conducted in 207 BEN patients and 86 controls from endemic areas. Results: Individuals with both copies of variant SOD2 allele, known for lower mitochondrial antioxidant protection, are at a significantly higher BEN risk (OR = 2.6, p = 0.021). No association was observed between GPX1 gene polymorphism and BEN risk. Combining SOD2 and GPX1 genotypes did not alter the risk of BEN development. Regarding the risk of urothelial tumors in BEN patients, none of the polymorphisms studied was significantly associated with the risk of these tumors. Conclusions: Polymorphism in SOD2 rs4880 gene affects the risk of BEN development. Hence, SOD2 genotyping could, together with a panel of other enzymes, be used as a biomarker of susceptibility in BEN areas. © 2019 by the authors. Licensee MDPI, Basel, Switzerland. T.

Background: The presence of glutathione transferase (GST) M1 null genotype (GSTM1-null) in end-stage renal disease (ESRD) patients is associated with lower overall survival rate in comparison to those with GSTM1-active variants. We examined association between GSTM1 and GSTT1 deletion polymorphisms as well as SNPs in GSTA1/rs3957357 and GSTP1/rs1695 genes with overall and cause-specific cardiovascular mortality in ESRD patients. Methods. Total of 199 patients undergoing hemodialysis were included in the study. Median value of time elapsed from dialysis initiation until the death, or the end of follow-up was 8 ± 5 years. The effect of GSTM1, GSTT1, GSTP1 and GSTA1 gene polymorphisms on predicting overall and specific cardiovascular outcomes (myocardial infarction, MI or stroke) was analyzed using Cox regression model, and differences in survival were determined by Kaplan-Meier. Results: GSTM1-null genotype in ESRD patients was found to be independent predictor of overall and cardiovascular mortality. However, after false discovery rate and Bonferroni corrections this effect was lost. The borderline effect modification by wild-type GSTA1*A/*A genotype on associations between GSTM1-null and analyzed outcomes was found only for death from stroke. Homozygous carriers of combined GSTM1*0/GSTA1*A genotype exhibited significantly shorter time to death of stroke or MI in comparison with carriers of either GSTM1-active or at least one GSTA1*B gene variant. The best survival rate regarding cardiovascular outcome was found for ESRD patients with combined GSTM1-active and mutant GSTA1*B/*B genotype. Conclusions: Combined GSTM1*0/GSTA1*A genotypes might be considered as genetic markers for cardiovascular death risk in ESRD patients, which may permit targeting of preventive and early intervention. © 2014 Suvakov et al.; licensee BioMed Central Ltd.

Background: Autism spectrum disorders (ASD) are complex psychiatric disorders, with gene environment interaction being in the basis of their etiology. The association of perinatal complications and ASD is well established. Recent findings suggested that oxidative stress and polymorphism in genes encoding antioxidant enzymes might be involved in the development of ASD. Glutathione transferases (GSTs) have an important role in the antioxidant defense system. We aimed to establish whether the predictive effects of prenatal and perinatal complications (as possible oxidative stress inducers) on ASD risk are dependent on GST polymorphisms. Methods: The study included 113 ASD cases and 114 age-and sex group-matched healthy controls. All participants were genotyped for GSTA1, GSTM1, GSTT1, and GSTP1 polymorphisms. The questionnaire regarding prenatal and perinatal risk factors and complications was administered for all the subjects in the study. Results: The evaluated perinatal complications as a group significantly increased the risk of ASD [odds ratio (OR) = 9.415; p = 0.000], as well as individual perinatal complications, such as prematurity (OR = 11.42; p = 0.001), neonatal jaundice (OR = 8.774; p = 0.000), respiratory distress syndrome (OR = 4.835; p = 0.047), and the use of any medication during pregnancy (OR = 2.413; p = 0.03). In logistic regression model, adding GST genotypes did not modify the significant effects found for prematurity and neonatal jaundice as risk factors in ASD. However, there was a significant interaction of GST genotype with medication use during pregnancy and the use of tocolytics during pregnancy, which was predictive of ASD risk only in carriers of GSTM1-null, as opposed to carriers of GSTM1-active genotype. Conclusion: Specific perinatal complications may be significant risk factors for ASD. GSTM1 genotype may serve as a moderator of the effect of some prenatal factors on the risk of ASD such as using medication during pregnancy. It may be speculated that different oxidative stress-related genetic and environmental factors could lead to development of ASD. Apart from etiological mechanisms, possible therapeutic implications in ASD are also discussed. © 2019 Mandic-Maravic, Mitkovic-Voncina, Pljesa-Ercegovac, Savic-Radojevic, Djordjevic, Pekmezovic, Grujicic, Ercegovac, Simic, Lecic-Tosevski and Pejovic-Milovancevic.

Purpose: To get more insight into molecular mechanisms underlying oxidative stress and its role in different types of seizure, in this study, oxidative byproducts of proteins, lipids and DNA, as well as, antioxidant enzyme activities were studied in adult patients with epilepsy. Methods: Study was performed in 60 patients with epilepsy and in 25 healthy controls. Plasma protein reactive carbonyl derivatives (RCD) and protein thiol groups (P-SH), byproducts of oxidative protein damage, as well as antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPX) were studied spectrophotometrically. Urinary 8-epi-prostaglandin F2α (8-epi-PGF2α) and 8-hydroxy-2′-deoxyguanosine (8-OHdG), representative byproducts of lipid and DNA oxidative damage, respectively, were determined by enzyme immunoassay. Results: RCD levels were significantly increased (p = 0.001), while P-SH content was decreased in patients with first seizure (p = 0.052) compared to controls, independently of the seizure type. Urinary 8-epi-PGF2α and 8-OHdG were significantly increased in patients with epilepsy (p = 0.001 and p = 0.001). Rise in 8-epi-PGF2α was more pronounced in patients with generalized tonic-clonic seizure (GTCS) compared to those with partial seizure (PS). Both SOD and GPX activity were significantly increased in epileptic patients compared to controls (p = 0.001 and p = 0.001), but only SOD activity was significantly higher in patients with GTCS than in those with PS. Conclusions: Data on enhanced protein, lipid and DNA oxidation, together with upregulated antioxidant enzyme activities, confirm the existence of systemic oxidative stress in patients with epilepsy. It might be speculated that post-translational modification to existing functional proteins, particularly alterations to ion channels, might be at least partially responsible for acute early changes in neuronal networks. © 2010 British Epilepsy Association.

Purpose: To get more insight into molecular mechanisms underlying oxidative stress and its role in different types of seizure, in this study, oxidative byproducts of proteins, lipids and DNA, as well as, antioxidant enzyme activities were studied in adult patients with epilepsy. Methods: Study was performed in 60 patients with epilepsy and in 25 healthy controls. Plasma protein reactive carbonyl derivatives (RCD) and protein thiol groups (P-SH), byproducts of oxidative protein damage, as well as antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPX) were studied spectrophotometrically. Urinary 8-epi-prostaglandin F2α (8-epi-PGF2α) and 8-hydroxy-2′-deoxyguanosine (8-OHdG), representative byproducts of lipid and DNA oxidative damage, respectively, were determined by enzyme immunoassay. Results: RCD levels were significantly increased (p = 0.001), while P-SH content was decreased in patients with first seizure (p = 0.052) compared to controls, independently of the seizure type. Urinary 8-epi-PGF2α and 8-OHdG were significantly increased in patients with epilepsy (p = 0.001 and p = 0.001). Rise in 8-epi-PGF2α was more pronounced in patients with generalized tonic-clonic seizure (GTCS) compared to those with partial seizure (PS). Both SOD and GPX activity were significantly increased in epileptic patients compared to controls (p = 0.001 and p = 0.001), but only SOD activity was significantly higher in patients with GTCS than in those with PS. Conclusions: Data on enhanced protein, lipid and DNA oxidation, together with upregulated antioxidant enzyme activities, confirm the existence of systemic oxidative stress in patients with epilepsy. It might be speculated that post-translational modification to existing functional proteins, particularly alterations to ion channels, might be at least partially responsible for acute early changes in neuronal networks. © 2010 British Epilepsy Association.

Introduction: The treatment preserving the kidney for upper urinary tract (UUT) transitional cell carcinoma (TCC) is still controversial. We aimed to elucidate the results of open conservative surgery and compare them with the results of radical nephroureterectomy (RNU). Patients and Methods: The study included 107 patients with UUT TCC treated by open conservative surgery (21 patients) or nephroureterectomy (86 patients). Epidemiological, clinical and pathological characteristics of patients as well as 5-year survival rates were compared between groups. Results: Patients treated by conservative surgery had a significantly higher rate of bilateral tumors (38% vs. 3%, p = 0.0001) and smaller tumor size than those treated by radical operations (2.60 ± 1.24 vs. 3.99 ± 3.94 cm, p = 0.060). Five-year survival rates for patients treated by conservative and radical surgery were 59 and 55%, respectively. Within the group of patients treated by conservative surgery, 5-year overall survival rates of patients operated due to imperative and elective indications were 41 and 75%, respectively. In univariate analysis, RNU was a statistically significant predictor of poorer outcome of the disease in comparison with conservative surgery (HR = 2.2, 95% CI 1.1-4.6, p = 0.030). Conclusions: The mode of operation affects the outcome of UUT TCC patients, in addition to factors such as tumor grade, stage and size. © 2009 S. Karger AG, Basel.

Objectives: Glutathione S-transferase P1 (GSTP1) provides an important link between activity of regulatory stress kinases and apoptotic pathways. It can be hypothesized that up-regulated GSTP1, in TCC, might enhance apoptosis inhibition. We aimed to establish whether relationship between GSTP1 expression and executive (pro-caspase 3, cleaved caspase 3) and regulatory (Bcl-2) apoptotic pathways in TCC exists. Materials and Methods: Samples were obtained from 84 TCC patients (41 consecutive patient with muscle noninvasive and 43 consecutive patients with muscle invasive TCC tumors), who underwent surgery at the Institute of Urology and Nephrology, Clinical Centre of Serbia, during 2006 and 2007. Expression of GSTP1, pro-caspase 3 (CPP32), and Bcl-2, as well as cleaved caspase-3 labeling index (LI) were determined by immunocytochemistry. Levels of expression were correlated with tumor stage, grade, and invasiveness. Results: GSTP1 protein expression was demonstrated in all tumor samples examined. According to GSTP1 status, all tumors were divided into groups with low, moderate, or high GSTP1 status. Expression of CPP32 and cleaved caspase 3 was positive in 80% of TCC patients. Their levels differed significantly between groups with various GSTP1 expression (P < 0.05), with the lowest CPP32 expression and cleaved caspase 3 LI in tumors with high GSTP1 status. Moreover, significant negative correlation was found between GSTP1 level and cleaved caspase 3 LI (r = -0.459, P = 0.041). The positive rate of Bcl-2 protein expression was 48%. Most of the Bcl-2 positive patients exhibited at the same time high GSTP1 positivity (P = 0.078). Significant association with tumor grade and stage was found for all examined parameters except for CPP32 regarding tumor grade. Conclusions: Based on results obtained, we conclude that enhanced GSTP1 expression in TCC of urinary bladder is associated with altered apoptotic pathways. Molecular interplay between GSTP1 and members of apoptotic cascade might, at least partially, play a role in development of invasive characteristics of TCC. © 2011 Elsevier Inc.

BackgroundIncreased oxidative stress is a hallmark of end-stage renal disease (ESRD). Glutathione S-transferases (GST) are involved in the detoxification of xenobiotics and protection of oxidative damage. We hypothesized that genetic polymorphism in antioxidant enzymes GSTA1, GSTM1, GSTP1 and GSTT1 is more frequent in ESRD and modulates the degree of oxidative stress in these patients.MethodsGSTA1, GSTM1, GSTP1 and GSTT1 genotypes were determined in 199 ESRD patients and 199 age-and gender-matched controls. Markers of protein and lipid oxidative damage [thiol groups, carbonyl groups, advanced oxidative protein products, nitrotyrosine, malondialdehyde (MDA) and MDA adducts], together with total oxidant status and pro-oxidant-antioxidant balance were determined. Results Individual GST polymorphisms influence vulnerability to both protein and lipid oxidation, with GSTM1-null gene variant having the most pronounced effect. Furthermore, a strong combined effect of null/low-activity GSTM1, GSTT1, GSTA1 and GSTP1 genotypes in terms of susceptibility towards oxidative and carbonyl stress was found in ESRD patients. When patients were stratified according to GSTM1 and GSTT1, the highest oxidant damage was noted in those with the GSTM1-null/GSTT1-null genotype. The observed effect was even stronger in patients with the third low-activity GSTP1 or GSTA1 genotype. Finally, the level of oxidative and carbonyl stress was most pronounced in the subgroup of patients with all four null or low-activity GSTM1, GSTT1, GSTP1 and GSTA1 genotypes.ConclusionsAccording to the GST genotype, ESRD patients may be stratified in terms of the level of oxidative and carbonyl stress that might influence cardiovascular prognosis, but could also improve efforts towards individualization of antioxidant treatment. © 2013 The Author.

Background: Glutathione S-transferase omega-1 and 2 have a unique range of enzymatic activities, including the regeneration of ascorbate by their dehydroascorbate reductase activities. Because these enzymes could have a protective role from oxidative damage in the lens, the question of whether the two coding glutathione S-transferase omega polymorphisms confer the risk of age-related cataract was addressed. Methods: rs4925 (Ala140Asp) of glutathione S-transferase omega-1 and rs156697 (Asn142Asp) of glutathione S-transferase omega-2 polymorphisms in 100 patients with age-related cataract and 130 controls were assessed. Results: Presence of one mutant GSTO1*Asp or GSTO2*Asp allele did not contribute independently towards the risk of cataract; however, homozygous carriers of GSTO1*Asp/GSTO2*Asp haplotype demonstrated 3.42-fold enhanced risk of cataract development (95% confidence interval=0.84-13.93; P=0.086). When GSTO genotype was analysed in association with smoking or professional exposure to ultraviolet irradiation, carriers of at least one mutant GSTO2*Asp allele had increased risk of cataract development in comparison with individuals with wild-type GSTO2*Asn/Asn with no history of smoking or ultraviolet exposure (odds ratio=6.89, 95% confidence interval=1.81-16.21, P=0.005; odds ratio=4.10, 95% confidence interval=1.23-13.74, P=0.022, respectively). Regarding the distribution of particular glutathione S-transferase omega genotype and cataract type, the highest frequency of mutant GSTO2*Asp allele was found in patients with nuclear cataract. Conclusion: The results indicate that mutant GSTO2*Asp genotype is associated with increased risk of age-related cataract in smokers and ultraviolet-exposed subjects, suggesting a role of inefficient ascorbate regeneration in cataract development. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

Background: Autism spectrum disorders (ASD) are a heterogeneous group of developmental disorders, with different levels of symptoms, functioning, and comorbidities. Recent findings suggested that oxidative stress and genetic variability in glutathione S-transferases (GSTs) might increase the risk of ASD development. We aimed to determine whether GST polymorphisms influence the severity of symptoms as well as the cognitive and adaptive abilities in children with ASD. Methods: The sample included 113 ASD cases. All participants were genotyped for GSTA1, GSTM1, GSTT1, and GSTP1 polymorphisms. The clinical characteristics were determined with Autism Diagnostic Interview-Revised (ADI-R) in all of the participants. In non-verbal participants, we explored the adaptive functioning using the Vineland Adaptive Behavior Scale II, while in verbal participants, we used the Wechsler Abbreviated Scale of Intelligence (WASI). Results: It was shown that the GSTA1*CC genotype was a predictor of a lower non-verbal communication impairment as well as of a lower chance of having seizures during life. GSTM1-active genotype predicted a higher adaptive functioning. The predictive effect of GSTA1, GSTM1, and GSTT1 genotype was moderated by exposure during pregnancy (maternal smoking and medication). The GSTP1*IleIle genotype was significantly associated to a better cognitive functioning in children with ASD. Conclusion: Besides the complex gene-environment interaction for the specific risk of developing ASD, there is also a possible complexity of interactions between genetic and environmental factors influencing the level of symptoms and impairment in people with ASD. Detoxification and antioxidant enzymes, such as GSTA1, might contribute to the core of this complexity. © Copyright © 2021 Mandic-Maravic, Mitkovic-Voncina, Pljesa-Ercegovac, Savic-Radojevic, Djordjevic, Ercegovac, Pekmezovic, Simic and Pejovic-Milovancevic.

Objectives: Our aim was to perform a comprehensive analysis of the antioxidant capacity of transitional cell carcinoma (TCC) of urinary bladder and discern the role of enzymes associated with glutathione (GSH) in maintaining high GSH levels in these tumours. Because the redox-sensitive protein glutathione S-transferase P1 (GSTP1) might provide an important link between high antioxidant capacity and inhibition of apoptotic pathways, we also explored how the redox state in tumour cells interacts with the expression of GSTP1. Methods: We examined spectrophotometrically the specific activities of GSH-replenishing enzymes involved in GSH synthesis (γ-glutamylcysteine synthetase, γ-GCS), GSH regeneration (glutathione reductase, GR), and antioxidant protection (glutathione peroxidase, GPX; superoxide dismutase, SOD) in the cytosolic fraction of tumours and the surrounding normal tissue of 30 TCC patients. GSTP1-1 expression was also analyzed. Results: We found a significant increase in the activity of both GSH-replenishing and antioxidant enzymes as well as enhanced GSTP1-1 expression in tumours in comparison with adjacent normal uroepithelium. Mean γ-GCS and GR activities in tumours were about 4- and 2-fold higher, respectively, than in corresponding normal tissue. Expression of GSTP1 correlated significantly with GSH level and γ-GCS and GR activities. GPX and SOD activities in TCC were also markedly increased. Conclusions: Enhanced GSH-replenishing pathways account for increased GSH levels in TCC. Upregulated GPX and SOD also contribute to high antioxidant potential in TCC. Under such conditions, expression of redox-sensitive GSTP1 protein is upregulated. © 2007 European Association of Urology.

Exposure to potential carcinogens is an etiologic factor for renal cell carcinoma (RCC) and transitional cell carcinoma (TCC) of the urinary bladder. Cytosolic glutathione S-transferases (GSTs) are a superfamily of enzymes that protect normal cells by catalyzing conjugation reactions of electrophilic compounds, including carcinogens, to glutathione. Some GST enzymes possess antioxidant activity against hydroperoxides. The most well characterized classes have been named alpha (GSTA), mu (GSTM), pi (GSTP) and theta (GSTT); each of these classes contains several different isoenzymes. Several types of allelic variation have been identified within classes, with GSTM1-null, GSTT1-null and GSTP1-Ile105/Ile105 conferring impaired catalytic activity. The effects of GSTM1 and GSTT1 polymorphism on susceptibility to RCC depend on exposure to specific chemicals. Individuals with the GSTM1-null genotype carry a higher risk for TCC. The roles of GSTT1 polymorphism in TCC and GSTP1 polymorphisms in both cancers are still controversial. During kidney cancerization, expression of GSTA isoenzymes tends to decrease, which promotes the pro-oxidant environment necessary for RCC growth. In the malignant phenotype of TCC of the bladder, upregulation of various GST classes occurs. Upregulation of GSTT1 and GSTP1 might have important consequences for TCC growth by providing a reduced cellular environment and inhibition of apoptotic pathways. © 2009 Macmillan Publishers Limited. All rights reserved.