GSTP1 Polymorphisms Research Articles

Associations of GST Gene Polymorphisms and GST Enzyme Activity with the Development of Noise-Induced Hearing Loss in Chinese Han Males

Introduction: In noise-induced hearing loss (NIHL), glutathione S-transferases (GSTs) play a pivotal role as antioxidants in cochlear protection. Nevertheless, the variability in population and environmental factors complicates the interpretation of research findings on the association among GST gene polymorphism, GST enzyme activity, and NIHL, leading to inconsistent results. To explore the potential correlation between them, we took a cross-sectional survey. Methods: For workers with NIHL, standard 1:1 propensity score matching was applied to create a highly comparable control group. Multiplex PCR was used to detect GSTT1 and GSTM1 gene deletions, PCR-restriction fragment length polymorphism was used to detect the GSTP1 rs1695 gene polymorphism, and a GST assay kit was used to measure total plasma GST activity. Furthermore, we analyzed the relationship among GST gene polymorphism, GST enzyme activity, and NIHL. Results: This study included 144 workers with NIHL and 144 workers with normal hearing. The GSTM1 null genotype was significantly higher among workers with NIHL than controls (64.6% vs. 49.3%), regression analysis revealed a significant correlation between GSTM1 null genotype and elevated susceptibility to NIHL (p = 0.013). Workers with NIHL had significantly lower GST activity than healthy controls (p < 0.05). GST enzymes were not affected by GSTT1, GSTM1, or GSTP1 polymorphisms. Conclusion: GSTM1 null genotype but not GSTM1 alone may confer susceptibility to NIHL, and serum GST enzyme activity is linked to NIHL.

The role of TLR4 rs1927911 gene polymorphism and toll-like receptor expression in the formation of allergy and its features in children under conditions of destabilization of the environment

Introduction. Anthropogenic chemical environmental factors modify the immune response, participate in the formation of immunodeficiency in children, and contribute to the occurrence of pathological conditions associated with allergies and autoimmunity. Purpose of the study. To analyze changes in the immunological and genetic profile in the children population living in an industrial area and suffering from allergic diseases. Materials and methods. An immunological and genetic examination was carried out on one hundred forty six 7–9 years children, permanently residing in the zone affected by emissions of a large non-ferrous metallurgy enterprise. The number of subpopulations and populations of lymphocytes (CD25, CD284) was determined by the cytofluorometric method. The content of IgE specific to nickel and formaldehyde was studied using the allergosorbent method. TLR4 rs1927911 and GSTP1 rs1695 gene polymorphisms were determined by real-time PCR. Results. There was obtained data indicating an imbalance of CD284 cell differentiation clusters, general IgE by 1.8 times and tobacco-specific by more than 2 times, as well as IgE specific to nickel and formaldehyde by 1.7 and 1.8 times, respectively. In children with allergy pathology the frequency of the A allele of the TLR4 rs1927911 gene has been established to be significantly increased. Research limitations. Children living near large industrial sources for at least three years. Conclusion. Children with allergies living in the zone influenced by emissions from non-ferrous metallurgy enterprises have an increased expression of cell clusters and excessive sensitization to haptens. Allergic manifestations are associated with polymorphism of the detoxification gene GSTP1 and the congenital atopy gene TLR4.

Docetaxel-induced severe neuropathy, a case of breast cancer with GTSP1 polymorphism.

Breast cancer, the most prevalent cancer among women, often requires chemotherapy with docetaxel being a key agent. However, docetaxel-inducted peripheral neuropathy (DIPN) can adversely impact patients' quality of life. This case discusses an unusual instance of severe DIPN leading to wheelchair dependence in a 35-years old woman undergoing neoadjuvant treatment for locally advanced breast cancer. Following anthracycline and cyclophosphamide cycles without neurological symptoms, docetaxel administration resulted in progressive neuropathy. Despite dose reduction, the patient developed severe paraesthesias, foot weakness, and eventually wheelchair dependence. Docetaxel's microtubule-stabilizing mechanism, vital for cell division, may disrupt axonal structures, causing sensory and motor neuropathy. While rare, severe motor neuropathy, leading to wheelchair dependence, poses a significant challenge. The frequency of DIPN varies, with docetaxel exhibiting lower neuropathy rates than other taxanes. Risk factors include age, diabetes mellitus, cumulative dose, and genetic polymorphisms in GSTP1 and ABCB1. In our case, despite the patient being young, fit and without diabetes, severe DIPN occured, suggesting a potential genetic predisposition. Genetic variations, such as GSTP1 polymorphisms have been associated with DIPN. Our patient carried GSTP1 (I1e105Val) mutations, emphasizing the need for further research to establish their role as risk factors. This case underscores the importance of recognizing severe DIPN, even in atypical patient profiles. Genetic factors, like GSTP1 polymorphisms, may contribute to DIPN risk. Large-scale studies are crucial to establishing the significance of these genetic variations in DIPN susceptibility.

Association of Glutathione Transferase M1, T1, P1 and A1 Gene Polymorphism and Susceptibility to IgA Vasculitis.

Endothelial cell injury is a hallmark of IgA vasculitis (IgAV), possibly associated with various factors, including oxidative stress. Certain single nucleotide polymorphisms (SNPs) of glutathione S-transferases (GST) genes have been shown to increase susceptibility to oxidative stress. The objective of our study was to evaluate the gene polymorphisms of GSTM1, GSTT1, GSTP1, and GSTA1 in patients with IgAV. DNA was extracted from the blood of 124 children with IgAV and 168 age-matched healthy controls. A higher frequency of the GSTM1 null genotype was observed in patients with gastrointestinal (GI) system involvement compared to those without GI system involvement (51.5% vs. 28.6%, p = 0.011). Additionally, the GSTM1 null genotype was less prevalent (30.8% vs. 69.2%, p = 0.032), while the GSTP1 Val/Val genotype was significantly more prevalent in patients who developed urogenital complications (scrotal swelling) during the course of the disease (60% vs. 40%, p = 0.039). This study is the first to suggest an association between GSTM1 and GSTP1 polymorphisms and various phenotypes observed during the clinical course of IgAV in the pediatric population. However, it was performed on a national and likely single ethnic cohort, too small for definitive conclusions, so larger studies are needed to confirm this association.

Genetic Polymorphisms in Glutathione S-Transferase (GST) Gene and Their Correlation with Toxicity of Chemotherapy in Breast Cancer Patients.

Glutathione S-Transferase (GST) is a family of phase II metabolizing enzymes contribute to detoxification and elimination of variety of endogenous as well as exogenous xenobiotics including chemotherapeutic agents. The comprehensive knowledge on the impact of genetic polymorphisms in GST) enzyme coding gene will help to understand the clinical outcomes in breast cancer patients treated with either Adriamycin or paclitaxel or combination of both. In this study we attempted to assess the genetic polymorphisms in GSTM1, GSTT1, GSTP1 and their association with Adriamycin and Paclitaxel induced toxicity reactions in breast cancer patients. Two hundred BC patients receiving Adriamycin and Paclitaxel chemotherapy were enrolled in this study and chemotherapy induced hematological and non-hematological toxicity reactions were noted. The polymorphisms in GSTM1, GSTP1 and GSTT1 gene were studied by PCR and RFLP analysis. After the univariate analysis of the genetic polymorphisms of GSTM1, GSTP1 and GSTT1 showed that GSTT1 null genotype showed significant association with neutropenia (OR=2.84, 95% CI: 1.06-7.56; p=0.036) in breast cancer patients treated with Adriamycin and GSTT1 null genotype in patients with >1 CINV toxicity confirmed significant correlation (OR=3.75, 95% CI: 1.46-9.59; p=0.005). The genetic polymorphisms of GSTP1 (exon 5) A/G heterozygous genotype was significant in grade >1 toxicity reactions of mucositis (OR=3.22, 95% CI: 1.06-9.71; p=0.037) in breast cancer patients administered with Paclitaxel chemotherapy. The findings obtained from this study proposed significant involvement of GSTT1-null genotype in hematological neutropenia toxicity in response to Adriamycin and GSTM1-null genotype showed negative association with non-hematological toxicity (bodyache) in response to Paclitaxel.

Chromosomal Damage, Chromosome Instability, and Polymorphisms in GSTP1 and XRCC1 as Biomarkers of Effect and Susceptibility in Farmers Exposed to Pesticides.

In the department of Boyacá, Colombia, agriculture stands as one of the primary economic activities. However, the escalating utilization of pesticides within this sector has sparked concern regarding its potential correlation with elevated risks of genotoxicity, chromosomal alterations, and carcinogenesis. Furthermore, pesticides have been associated with a broad spectrum of genetic polymorphisms that impact pivotal genes involved in pesticide metabolism and DNA repair, among other processes. Nonetheless, our understanding of the genotoxic effects of pesticides on the chromosomes (as biomarkers of effect) in exposed farmers and the impact of genetic polymorphisms (as susceptibility biomarkers) on the increased risk of chromosomal damage is still limited. The aim of our study was to evaluate chromosomal alterations, chromosomal instability, and clonal heterogeneity, as well as the presence of polymorphic variants in the GSTP1 and XRCC1 genes, in peripheral blood samples of farmers occupationally exposed to pesticides in Aquitania, Colombia, and in an unexposed control group. Our results showed statistically significant differences in the frequency of numerical chromosomal alterations, chromosomal instability, and clonal heterogeneity levels between the exposed and unexposed groups. In addition, we also found a higher frequency of chromosomal instability and clonal heterogeneity in exposed individuals carrying the heterozygous GSTP1 AG and XRCC1 (exon 10) GA genotypes. The evaluation of chromosomal alterations and chromosomal instability resulting from pesticide exposure, combined with the identification of polymorphic variants in the GSTP1 and XRCC1 genes, and further research involving a larger group of individuals exposed to pesticides could enable the identification of effect and susceptibility biomarkers. Such markers could prove valuable for monitoring individuals occupationally exposed to pesticides.

Blood and tissue levels of persistent organic pollutants and genetic susceptibility in patients with breast cancer

We investigated possible associations between the internal concentrations of POPs and correlations between blood and tumor tissue concentrations in patients who underwent surgery for breast cancer and breast reduction as controls. Genetic variations in CYP1A1, GSTP1, GSTM1, and GSTT1 and hOGG1 were evaluated to determine whether they represent risk factors for breast cancer. Certain POPs have been found to be associated with breast cancer development. GST-P1 polymorphism represented a significant risk for breast cancer with unadjusted OR. However, the GSTT1 null polymorphism represented a significant risk for breast cancer when OR adjusted for age and smoking status. CYP1A1 polymorphism was a significant risk factor for breast cancer, regardless of whether the OR was adjusted. These results suggest that exposure to certain POPs, GSTT1 and CYP1A1 polymorphisms, age, and smoking status are risk factors for breast cancer. In addition, the blood concentrations of some POPs represent surrogates for breast tissue concentrations.

GSTM1 and GSTP1 Polymorphisms Affect Outcome in Colorectal Adenocarcinoma.

Background and Objectives: Despite improvements in screening programs, a large number of patients with colorectal cancer (CRC) are diagnosed in an advanced disease stage. Previous investigations imply that glutathione transferases (GSTs) might be associated with the development and progression of CRC. Moreover, the detoxification mechanism of oxaliplatin, which represents the first line of treatment for advanced CRC, is mediated via certain GSTs. The aim of this study was to evaluate the significance of certain GST genetic variants on CRC prognosis and the efficacy of oxaliplatin-based treatment. Materials and Methods: This prospective study included 523 patients diagnosed with CRC in the period between 2014 and 2016, at the Digestive Surgery Clinic, University Clinical Center of Serbia, Belgrade. Patients were followed for a median of 43.47 ± 17.01 months (minimum 1-63 months). Additionally, 109 patients with advanced disease, after surgical treatment, received FOLFOX6 treatment as a first-line therapy between 2014 and 2020. The Kaplan-Meier method was used to analyze cumulative survival, and the Cox proportional hazard regression model was used to study the effects of different GST genotypes on overall survival. Results: Individuals with the GSTM1-null genotype and the GSTP1 IleVal+ValVal (variant) genotype had significantly shorter survival when compared to referent genotypes (GSTM1-active and GSTP1 IleIle) (log-rank: p = 0.001). Moreover, individuals with the GSTM1-null genotype who received 5-FU-based treatment had statistically significantly shorter survival when compared to individuals with the GSTM1-active genotype (log-rank: p = 0.05). Conclusions: Both GSTM1-null and GSTP1 IleVal+ValVal (variant) genotypes are associated with significantly shorter survival in CRC patients. What is more, the GSTM1-null genotype is associated with shorter survival in patients receiving FOLOFOX6 treatment.

Are changes in olanzapine-induced liver enzyme levels associated with GSTT1, GSTM1, GSTP1, and OGG1 gene polymorphisms?

Olanzapine treatment sometimes produces transient liver biochemistry abnormalities, and such drug-induced liver injuries are mainly monitored by measuring blood levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), whereas alpha-glutathione-S-transferase (α-GST) is not routinely measured in clinics, even though it can serve as an earlier and more specific biomarker of liver damage. Susceptibility to drug-induced liver injury can much depend on the gene polymorphisms regulating the activity of DNA detoxification and repair enzymes. The aim of this study was to evaluate which of the three liver enzymes - α-GST, ALT, and AST - is the most sensitive biomarker of olanzapine-induced liver injury and how their blood levels are affected by the GSTT1, GSTM1, GSTP1, and OGG1 gene polymorphisms in 30 olanzapine-treated patients. Contrary to our hypothesis, the increase in serum α-GST levels was not significantly greater than that of the transaminases. ALT turned out to be an earlier biomarker of liver injury than the other two enzymes. No significant association was found between gene polymorphisms and liver enzyme levels, save for GSTP1 Ile/Val + Val/Val and ALT, which points to this genotype as a risk factor for drug-induced liver injury. Future studies might help to identify the underlying mechanisms of transient liver enzyme increase associated with this genotype.

Связь гена GSTP1 с функциональным состоянием почек у больных сахарным диабетом

Introduction of point genetic associations into clinical and laboratory diagnosis will allow the physician to determine the risk of severe diabetes mellitus and its complications with a focus on detection of the genetically determined disorder. The study was aimed to identify the molecular genetic markers of severe diabetic nephropathy in patients with type 1 and 2 diabetes mellitus (DM) based on the GSTP1 (I105V) gene assessment. Genotyping of the GSTP1 gene I105V locus was performed in patients with type 1 and 2 DM. Then we identified the features of oxidative status, free radical oxidation, and renal function in patients with various polymorphic variants of the studied gene. Patients with type 1 DM, who were carriers of the GSTP1 heterozygous polymorphic variant (Ile/Val), showed higher activity of the oxidative stress enzymes (glutathione-S-transferase, catalase) and malondialdehyde compared to homozygous carriers (р &lt; 0.001, р &lt; 0.001, р &lt; 0.05). They also showed a significant increase in the levels of triglycerides (1.6-fold) and the glycated hemoglobin levels (1.1-fold) (p &lt; 0.05). Patients with type 2 DM, who were carriers of the GSTP1 polymorphism homozygous for allele 2 (Val\Val), had a higher level of malondialdehyde (100.5 µmol/L, (р &lt; 0.001)), which was associated with the more severe diabetic nephropathy (average glomerular filtration rate — 48 mL/min/1.73 m2, 24-h urinary albumin excretion — 0.9 g/L; р &lt; 0.01). It has been proposed to assess the GSTP1 (I105V) gene in individuals with type 1 and 2 DM. This polymorphism that is heterozygous in individuals with type 1 DM and homozygous for allele 2 in individuals with type 2 DM is unfavorable in terms of the DM course and complications.

Evaluation of the association between glutathione S-transferase polymorphisms and susceptibility to cutaneous melanoma: a systematic review and meta-analysis.

Glutathione S-transferase (GST) enzymes play a crucial role in detoxification by catalysing the conjugation of many hydrophobic and electrophilic compounds with reduced glutathione. Polymorphisms in GST genes may influence the susceptibility to various cancers, including melanoma. We reported a systematic review and meta-analysis to evaluate the association between GST polymorphisms and susceptibility to cutaneous melanoma. A comprehensive search of four databases, namely PubMed, Scopus, Cochrane Library, and Web of Science, was conducted to gather pertinent studies up until 24 August 2023. No restrictions were imposed during the search. The analysis included 32 studies and was broken down into subgroups based on ethnicity, control source, control matching, quality score, and sample size. The forest plot analyses on GSTM1, GSTT1, combined GSTM1/GSTT1, and GSTP1 polymorphisms in relation to melanoma risk showed no statistically significant differences between the case and control groups, except for the recessive model of GSTP1 polymorphism. The analysis revealed significant associations between GSTM1 polymorphisms and melanoma risk in Asians and in studies with a sample size of less than 200. For the combined GSTM1/GSTT1 polymorphisms, a significant association was found in hospital-based controls. While this study enhances our understanding of the genetic factors influencing melanoma risk, it also highlights the need for further research. The current evidence is not sufficient to confirm or reject the intervention effect. Future research should consider gene-gene and gene-environment interactions, which could offer a more comprehensive understanding of the complex biology of melanoma.

Bioaccumulation of Chloropyrifos Organo-pesticide and Its Toxicogenic Association with Antioxidant GSTP1 in Pakistani Pest Control Workers.

Synthetic pesticides are employed to enhance agricultural production. Chronic exposure to organophosphate (OP) pesticides may be a source of health problems. The present study was designed to examine an association of GSTP1 (rs1695) polymorphism with OP pesticide chronic exposure. A case-control study was recruited with 250 subjects comprising exposed (n = 100) and controls (n = 150). A survey was conducted to determine the pesticide type to which workers had exposed. According to recorded survey assessment, two compounds of OP pesticides chloropyrifos and malathion were investigated in the blood samples of exposed study subjects using high-performance liquid chromatography (HPLC). For screening of genetic polymorphism in GSTP1 (rs1695) polymerase chain reaction, restriction length polymorphism (PCR-RFLP) and agarose gel electrophoresis were performed. Statistically, data were analyzed using SPSS v. 20.0 and MedCal© software. Total chrom© navigator programmer was used for detection of OP residues in serum and local pesticide solution. chloropyrifos-OP pesticide residues were detected in serum of estimated chronically exposed subjects at 206nm HPLC optimal conditions. The pattern of GSTP1 (rs1695) genotypic frequencies depicted that heterozygous genotype was higher in Chloropyrifos exposed subjects (0.56) when compared with controls (0.44). Statistical outcomes showed an insignificant association with GSTP1 (rs1695) polymorphism and chloropyrifos-OP pesticide toxicity (Fisher's exact test 1.0, p = 0.25). An insignificant allelic investigation reflected a protective effect of mutant allele G against chloropyrifos-OP pesticide toxicity in exposed subjects. Findings may be helpful in identifying bioaccumulated pesticide residues, but in studied Pakistani exposed workers, no significant association of GSTP1 (rs1695) variant with chloropyrifos-OPs was demonstrated.

Candidate germline biomarkers of lenalidomide efficacy in mantle cell lymphoma: the Fondazione Italiana Linfomi MCL0208 trial.

In the Fondazione Italiana Linfomi MCL0208 phase 3 trial, lenalidomide maintenance (LEN) after autologous stem cell transplantation (ASCT) in mantle cell lymphoma (MCL) improved progression-free survival (PFS) vs observation (OBS). The host pharmacogenetic background was analyzed to decipher whether single-nucleotide polymorphisms (SNPs) of genes encoding transmembrane transporters, metabolic enzymes, or cell-surface receptors might predict drug efficacy. Genotypes were obtained via real-time polymerase chain reaction of the peripheral blood germ line DNA. Polymorphisms of ABCB1 and VEGF were found in 69% and 79% of 278 patients, respectively, and predicted favorable PFS vs homozygous wild-type (WT) in the LEN arm was 3-year PFS of 85% vs 70% (P< .05) and 85% vs 60% (P< .01), respectively. Patients carrying both ABCB1 and VEGF WT had the poorest 3-year PFS (46%) and overall survival (76%); in fact, in these patients, LEN did not improve PFS vs OBS (3-year PFS, 44% vs 60%; P= .62). Moreover, the CRBN polymorphism (n= 28) was associated with lenalidomide dose reduction or discontinuation. Finally, ABCB1, NCF4, and GSTP1 polymorphisms predicted lower hematological toxicity during induction, whereas ABCB1 and CRBN polymorphisms predicted lower risk of grade ≥3 infections. This study demonstrates that specific SNPs represent candidate predictive biomarkers of immunochemotherapy toxicity and LEN efficacy after ASCT in MCL.

Асоціація поліморфізмів генів GSTP1(A313G), MTHFR (С677T) та IL-10 (C819T) із ризиком виникнення гліобластоми

гліобластома одна з найбільш поширених злоякісних пухлин головного мозку з вкрай низькою виживаністю. Незважаючи на досягнення у вивченні молекулярного патогенезу та біології пухлин мозку, причини виникнення гліобластоми залишаються нез’ясованими. Дослідження останніх років вказують, що зміни у генах, які беруть участь у проліферації, диференціації та апоптозі клітин, можуть впливати на ризик виникнення онкологічних захворювань. Тож метою роботи було дослідити поліморфізми генів GSTP1(A313G), MTHFR (С677Т) та IL-10 (C819T) у хворих на гліобластому та проаналізувати їх зв’язок із ризиком розвитку цієї патології. Біологічним матеріалом для аналізу поліморфізмів генів GSTP1, MTHFR та IL-10 слугувала периферична кров хворих на гліобластому та практично здорових людей. Дослідження поліморфізмів генів проводилось за допомогою методу алель-специфічної ПЛР із використанням власних пар детекторів TaqMan MGB на основі флуоресцентних барвників, що призначені для виявлення однонуклеотидних замін. Встановлено, що частота мутантного алеля G гена GSTP1 у хворих становила 53,6% проти 32% у групі практично здорових людей. Розподіл генотипів гена GSTP1 у групі хворих відповідав закону генетичної рівноваги Харді-Вайнберга та статистично відрізнялась від показника у групі практично здорових людей і становив 0,538 проти 0,320 (χ2 = 13,10, р = 0,003). Визначено, що ризик виникнення гліобластоми є в 4,88 разів вищим у осіб, що є гомозиготними носіями мутантного алелю гена GSTP1 (генотип G313G) у порівнянні з іншими поліморфними варіантами. В результаті наших досліджень, було встановлено, що частота мутантного алеля С гена IL-10 у хворих становила 48,8%, що значно перевищує відповідний показник у групі практично здорових людей – 25%. Встановлено, що розподіл генотипів гена IL-10 у групі хворих відповідав закону генетичної рівноваги Харді-Вайнберга, частота мутантного алеля С гена IL-10 статистично відрізнялась від показника у групі практично здорових людей та становила 0,488 проти 0,250 (χ2 = 18,32, р = 0,00002). Встановлено, що існує асоціація між поліморфізмом гена IL-10 (C819T) та ризиком виникнення гліобластоми, у гомозиготних носіїв із генотипом Т819Т, ризик захворіти збільшується у 6,40 рази. Також нами було встановлено, що частота мутантного алелю Т гена MTHFR у хворих становила 35,0% проти 28,1% у групі практично здорових людей. Розподіл генотипів гена MTHFR у групі хворих відповідав закону генетичної рівноваги Харді-Вайнберга, а розподіл частот поліморфних варіантів ген показав відсутність статистично достовірних відмінностей між групою хворих та групою практично здорових людей (χ2 = 1,43 р = 0,23). Не було встановлено асоціації між поліморфізмом гена MTHFR (С677Т) і ризиком виникнення гліобластоми.

Absence of GSTT1 and polymorphisms in GSTP1 and TP53 are associated with the incidence of acne vulgaris.

Acne vulgaris is a chronic inflammatory skin disease of the pilosebaceous unit affecting most teenagers and numerous adults throughout the world. The present study was designed to assess the association of the presence or absence of GSTM1, GSTT1, and single nucleotide polymorphisms rs1695 in GSTP1 and rs1042522 in TP53 gene with acne vulgaris. The cross-sectional case-control study was conducted at the Institute of Zoology from May 2020 to March 2021 and included acne vulgaris patients (N=100) and controls (N=100) enrolled in Dera Ghazi Khan district, Pakistan. Multiplex and tetra-primer amplification refractory mutation system-polymerase chain reactions were applied to investigate the genotype in analyzed genes. The association of rs1695 and rs1042522 with acne vulgaris was studied either individually or in various combinations with GATM1 and T1. A significant association of absence of GSTT1 and mutant genotype at rs1695 (GG) and at rs1042522 (CC) in GSTP1 and TP53, respectively, was found to be associated with acne vulgaris in enrolled subjects. Subjects aged 10-25 years and smokers were more susceptible to acne vulgaris. Our results suggest that genotypes of glutathione S-transferases (GSTs) and TP53 are involved in protection against oxidative stress and may influence disease progression in acne vulgaris.

GSTM1 and GSTT1 polymorphisms associated with pain in a chemotherapy-induced peripheral neuropathy cohort

PurposeChemotherapy induced peripheral neuropathy (CIPN) is a debilitating condition that is a direct consequence of receiving cancer treatment. The molecular aetiology of CIPN is not well understood, and it is theorised that there may be a genetic component. Genetic polymorphisms in Glutathione-S Transferase (GST) genes, including GSTT1, GSTM1 and GSTP1, encode for enzymes known to metabolise drugs used in chemotherapy, and have been theorised to be associated with CIPN. This study aimed to investigate four markers in these genes for an association in a mixed cancer cohort in relation to CIPN (n = 172).MethodsCIPN was measured using the neuropathy item from the Patient Reported Outcome Common Terminology Criteria for Adverse Event (PRO-CTCAE) assessment. Genotyping for all samples was performed using PCR for the GSTM1 and GSTT1 null variants and restriction fragment length polymorphisms for the GSTP1 and GSTM1 polymorphisms.ResultsNo associations were found for the GST gene markers in relation to CIPN within our study, or CIPN severity. Longitudinal stratification of the CIPN phenotypes to examine links for neuropathy, identified nominally significant protective associations with the GSTM* null allele (p-value = 0.038, OR = 0.55) and the presence of pain at month 2 of treatment, as well as a risk factor for pain related month 2 of treatment for individuals with the GSTT1*null allele (p-value = 0.030, OR = 1.64). Higher severity of pain in patients with CIPN persisted at each time-point compared to those without CIPN.ConclusionNo significant results for an association between CIPN with polymorphisms in GSTM1, GSTT1 and GSTP1 were identified. However, associations for the GSTM1¬-null and GSTT1-null polymorphisms with pain at month 2 following chemotherapy were identified.

Genetic Risk Scores for the Determination of Type 2 Diabetes Mellitus (T2DM) in North India

Globally, type 2 diabetes mellitus (T2DM) is one of the fastest-growing noncommunicable multifactorial and polygenic diseases, which leads to many health complications and significant morbidity and mortality. South Asians have a high genetic predisposition to T2DM, with India being home to one in six diabetics. This study investigates the association of selected genetic polymorphisms with T2DM risk and develops a polygenic risk score (PRS). A case-control study recruited fully consented participants from a population of Jat Sikhs in north India. DNA samples were genotyped for a range of polymorphisms and odds ratios were calculated under several genetic association models. Receiver operating characteristic (ROC) curves were produced for combinations of the PRS and clinical parameters. The GSTT1(rs17856199), GSTM1(rs366631), GSTP1(rs1695), KCNQ1(rs2237892), ACE(rs4646994), and TCF7L2(rs12255372; rs7903146; rs7901695) polymorphisms were associated with increased T2DM risk (p ≤ 0.05). No association was observed with IGF2BP2(rs4402960) or PPARG2(rs1801282). The weighted PRS was found to be significantly higher in patients (mean = 15.4, SD = 3.24) than controls (mean = 11.9, SD = 3.06), and t(454) = -12.2 (p < 0.001). The ROC curve analysis found the weighted PRS in combination with clinical variables to be the most effective predictor of T2DM (area under the curve = 0.844, 95%CI = 0.0.808-0.879). Several polymorphisms were associated with T2DM risk. PRS based on even a limited number of loci improves the prediction of the disease. This may provide a useful method for determining T2DM susceptibility for clinical and public health applications.

Chronic Mercury Exposure and GSTP1 Polymorphism in Munduruku Indigenous from Brazilian Amazon.

Genetic polymorphisms may be involved with mercury levels and signs and symptoms of intoxication from this exposure. Therefore, the aims were to describe the frequency of the GSTP1 polymorphism and to evaluate its effects on mercury levels and neurological signs in three Munduruku indigenous villages in the Brazilian Amazon. One-hundred-and-seven indigenous (over 12 years old) were included and genotyped (rs1695) using a TaqMan validated assay. Then, associations were evaluated by binary logistic regression, using odds ratios (OR) and 95% confidence intervals (CI). Mean age was 27.4 ± 13.9 years old, 52.3% were male, mean hair mercury concentration was 8.5 ± 4.3, exceeding the reference limit (≥6.0 µg/g), and were different among the three villages: 13.5 ± 4.6 µg/g in Sawré Aboy, 7.4 ± 2.3 µg/g in Poxo Muybu and 6.9 ± 3.5 µg/g in Sawré Muybu. The minor allele frequency of GSTP1 G was significantly different among the villages: 57% Sawré Muybu, 21% Poxo Muybu and 15% Sawré Aboy. Finally, after adjustment, GSTP1 GG and GA genotypes were associated with lower levels of Hg (OR = 0.13; CI95% = 0.03-0.49) and abnormal somatosensory signs (OR = 3.7; 95%IC = 1.5-9.3), respectively. In conclusion, monitoring this population is imperative to identify individuals at higher risk of developing signs of chronic mercury exposure based on the genetic profile.

The GSTO2 (rs156697) Polymorphism Modifies Diabetic Nephropathy Risk.

Background and Objectives: In the development of type 2 diabetes mellitus (T2DM) and its complications, genetic and environmental factors play important roles. Diabetic nephropathy (DN), one of the major microangiopathic chronic diabetic complications, is associated with an increased risk of major cardiovascular events and all-cause mortality. The present study was designed to investigate the possible modifying effect of glutathione transferase polymorphisms (GSTM1, GSTT1, GSTP1 rs1138272/rs1695, GSTO1 rs4925 and GSTO2 rs156697) in the susceptibility to T2DM and diabetic nephropathy. Materials and Methods: GSTM1 and GSTT1 deletion polymorphisms were determined by multiplex PCR, whereas GSTO1, GSTO2, and GSTP1 polymorphisms were determined by the real-time PCR in 160 T2DM patients and 248 age- and gender-matched controls. Advanced glycation end products (AGEs) were measured by ELISA. Results: Among six investigated GST polymorphisms, a significant association between the GST genotypes and susceptibility for development of diabetes mellitus was found for the GSTM1, GSTT1, GSTP1 (rs1138272) and GSTO1 polymorphisms. When the GST genotypes’ distribution in diabetes patients was assessed in the subgroups with and without diabetic nephropathy, a significant association was found only for the GSTO2 rs156697 polymorphism. Diabetic patients, carriers of the GSTM1 null, GSTT1 null and variant GSTO1*AA genotypes, had significantly increased levels of AGEs in comparison with carriers of the GSTM1 active, GSTT1 active and referent GSTO1*CC genotypes (p < 0.001, p < 0.001, p = 0.004, respectively). Conclusions: The present study supports the hypothesis that GST polymorphisms modulate the risk of diabetes and diabetic nephropathy and influence the AGEs concentration, suggesting the potential regulatory role of these enzymes in redox homeostasis disturbances.

Genetic association between rs1695 in glutathione S-transferase P1 and risk of periodontitis: a pilot study.

The present study aims to determine the association between a genetic polymorphism of GSTP1 (rs1695) and the risk of periodontitis. This study used a cross-sectional design and included subjects from the South Indian population. A total of 100 individuals enrolled at Saveetha Dental College and Hospital, Tamil Nadu were included in this study. The participants were divided into control (n=50) and periodontitis (n=50) based on clinical examination. Blood samples were collected. Genotyping was performed using specific primers spanning the polymorphic site. The genotypic frequencies for the rs1695 polymorphism were not significantly different between cases and controls.