From Six Gene Polymorphisms of the Antioxidant System, Only GPX Pro198Leu and GSTP1 Ile105Val Modulate the Risk of Acute Myeloid Leukemia

Ile105Val polymorphism in the GSTP1 gene is associated with susceptibility to acute myeloid leukemia: an updated systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Several genetic variations are associated with acute myeloid leukemia (AML) susceptibility, including the GSTP1 Ile105Val polymorphism. Even with the existing meta-analysis conducted on the topic, no consensus has been reached since none of the studies available performed in-depth data analysis. Hence, we performed an updated systematic review and meta-analysis in this paper to obtain more precise estimates.

MATERIALS AND METHODS

We searched various databases and calculated the odds ratio (OR) and 95% confidence interval (CI) to examine whether the GSTP1 Ile105Val polymorphism is associated with AML susceptibility. Further statistical analysis was also done to obtain more accurate and reliable findings.

RESULTS

A total of 15 studies are included in the systematic review, but only 9 were included in the meta-analysis due to the studies deviating from the Hardy-Weinberg equilibrium. The analysis showed significantly increased susceptibility to AML in the allelic, co-dominant, and recessive models. Furthermore, subgroup analysis noted increased AML susceptibility in the non-Asian population. Comparing the proportions of the genotypes and alleles showed a significantly higher proportion of the Val/Val genotype and Val allele in the non-Asian cohort.

CONCLUSION

The GSTP1 Ile105Val polymorphism is significantly associated with AML susceptibility, especially among non-Asians. Further investigation should be performed to strengthen the current results.

Emerging drugs targeting cellular redox homeostasis to eliminate acute myeloid leukemia stem cells

Acute myeloid leukemia (AML) is a very heterogeneous group of disorders with large differences in the percentage of immature blasts that presently are classified according to the specific mutations that trigger malignant proliferation among thousands of mutations reported thus far. It is an aggressive disease for which few targeted therapies are available and still has a high recurrence rate and low overall survival. The main reason for AML relapse is believed to be due to leukemic stem cells (LSCs) that have unlimited self-renewal capacity and long residence in a quiescent state, which promote greater resistance to traditional therapies for this cancer. AML LSCs have low oxidative stress levels, which appear to be caused by a combination of low mitochondrial activity and high activity of ROS-removing pathways. In this sense, oxidative stress has been thought to be an important new potential target for the treatment of AML patients, targeting the eradication of AML LSCs. The aim of this review is to discuss some drugs that induce oxidative stress to direct new goals for future research focusing on redox imbalance as an effective strategy to eliminate AML LSCs.

Metabolism and Anticancer Mechanisms of Selocompounds: Comprehensive Review

Selenium (Se) is an essential micronutrient with several functions in cellular and molecular anticancer processes. There is evidence that Se depending on its chemical form and the dosage use could act as a modulator in some anticancer mechanisms. However, the metabolism of organic and inorganic forms of dietary selenium converges on the main pathways. Different selenocompounds have been reported to have crucial roles as chemopreventive agents, such as antioxidant activity, activation of apoptotic pathways, selective cytotoxicity, antiangiogenic effect, and cell cycle modulation. Nowadays, great interest has arisen to find therapies that could enhance the antitumor effects of different Se sources. Herein, different studies are reported related to the effects of combinatorial therapies, where Se is used in combination with proteins, polysaccharides, chemotherapeutic agents or as nanoparticles. Another important factor is the presence of single nucleotide polymorphisms in genes related to Se metabolism or selenoprotein synthesis which could prevent cancer. These studies and mechanisms show promising results in cancer therapies. This review aims to compile studies that have demonstrated the anticancer effects of Se at molecular levels and its potential to be used as chemopreventive and in cancer treatment.

Association Between the Individual and Combined Effects of the GSTM1 and GSTT1 Polymorphisms and Risk of Leukemia: A Meta-Analysis

Background: Fourteen meta-analyses reported the individual effects of the GSTM1 and GSTT1 polymorphisms on leukemia risk. However, over 40 studies were not included in previously published meta-analyses. Moreover, one key aspect was that previous meta-analyses did not conduct the false-positive test on the aforementioned issues. Furthermore, previous meta-analyses did not observe the combined effects of GSTM1 present/null and GSTT1 present/null polymorphism with leukemia risk. Therefore, we conducted the current study to further analyze these associations.

Objectives: This study aimed to investigate the association between the individual and combined effects of the GSTM1 present/null and GSTT1 present/null polymorphisms and the risk of leukemia.

Methods: A meta-analysis was performed applying Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. Moreover, false-positive report probability (FPRP) and Bayesian false discovery probability (BFDP) were applied to investigate the false-positive results.

Results: The individual GSTM1 and GSTT1 null genotypes and combined effects of the two genes were associated with a significantly increased leukemia risk in overall and several subgroup analyses, such as Asians, Caucasians, and so on. Then, further analysis was conducted using FPRP and BFDP. Significant associations were considered as “positive” results on the GSTM1 null genotype with leukemia risk in overall populations (FPRP < 0.001 and BFDP = 0.006), Asians (FPRP < 0.001 and BFDP < 0.001), and East Asian population (FPRP < 0.001 and BFDP = 0.002). For the GSTT1 null genotype, significant associations were regarded “positive” results in overall populations, acute myeloid leukemia (AML), Asians, and East Asian population. For the combined effects of the GSTM1 and GSTT1 polymorphisms, significant associations were also considered “positive” results in the overall analysis of Asians, Indians, and East Asian population.

Conclusion: This study strongly indicates that the individual GSTM1 and GSTT1 null genotypes and combined effects of the two genes are associated with increased leukemia risk in Asians, especially in the East Asian population; the GSTT1 null genotype is associated with increased AML risk; the combined effects of the two genes are associated with increased leukemia risk in Indians.

Catalase C262T genetic variation and cancer susceptibility: A comprehensive meta-analysis with meta-regression and trial sequential analysis

Background

Several genetic association studies have analyzed the link between the catalase ( CAT) C262T variant and different cancers, but the findings remain controversial. Our research centered on establishing a comprehensive correlation between the C262T variant and different cancers.

Methods

This study was conducted using RevMan 5.4 software following the PRISMA 2020 guidelines. For this meta-analysis, 53 case-control studies (18,258 cases and 47,476 controls) were chosen.

Results

The analysis revealed that three genetic models were statistically linked ( P < 0.05) to overall cancer susceptibility in codominant model 2 (COD2): odds ratio (OR) = 1.16, COD3: OR = 1.21, recessive model (RM): OR = 1.20). After stratification by ethnicity, a significant link ( P < 0.05) was found in Caucasians (COD2: OR = 1.18, COD3: OR = 1.17, over-dominant model (ODM): OR = 1.19) and Asians (COD3: OR = 1.49). Subgroup analyses revealed a significant correlation ( P < 0.05) with blood-and-bone-marrow-related cancer, skin cancer, gastrointestinal-tract-related cancer, prostate cancer, and gynecologic cancer. Three genetic models in population-based controls (COD2: OR = 1.19, COD3: OR = 1.17, RM: OR = 1.19) and two genetic models in hospital-based controls (COD3: OR = 1.40, RM: OR = 1.24) were found to be significantly correlated ( P < 0.05) with cancer. Also, three genetic models for polymerase chain reaction-restriction fragment length polymorphism (COD3: OR = 1.46; RM: OR = 1.34, ODM: OR = 0.80) and three models for MALDI-TOF + MassARRAY (COD2: OR = 1.32, RM: OR = 1.26, allele model: OR = 1.14) genotyping methods showed significant association ( P < 0.05) with cancer. The meta-regression showed that the quality scores might be a source of significant heterogeneity under the COD2 model (coefficient = 0.176, P = 0.029). Trial sequential analysis also validated the adequacy of the sample size on overall findings.

Conclusion

Our results indicate that CAT C262T variant is associated with overall cancer susceptibility, especially in Caucasians and Asians. This variant may also be associated with blood-and-bone-marrow-related, GIT-related, prostate, skin, and gynecological cancers.

MiR-185-5p suppresses acute myeloid leukemia by inhibiting GPX1

Acute myeloid leukemia (AML) has been characterized by the swift development of abnormal cells in the bone marrow. This research aimed to examine the impacts of the miR-185-5p-GPX1 axis on AML progression and differentiation. Findings indicated that miR-185-5p and GPX1 levels were significantly reduced and elevated, respectively. The upregulation of miR-185-5p was observed to restrict the proliferation and invasion abilities of AML cells, and promote differentiate and apoptosis. Moreover, the overexpression of GPX1 was noticed to enhance the growth of AML cells. In conclusion, this research suggested that by targeting GPX1, miR-185-5p inhibited AML progression and downregulated AML cells' proliferation and invasion.

TERT rs2853669 as a predictor for overall survival in patients with acute myeloid leukaemia

INTRODUCTION

the aim of the study was to investigate the contribution of TERT rs2736100 and rs2853669 gene polymorphisms in defining the genetic predisposition to acute myeloid leukaemia (AML), their association with different prognostic markers, and their impact on survival, outcome, and the prognosis of affected patients. Also, we investigated the association of TERT SNPs in AML in the presence or absence of DNMT3A (R882), NPM1, and FLT3 mutations.

MATERIAL AND METHODS

A total of 509 participants were enrolled in our study, consisting of 146 AML patients and 363 healthy participants, with no history of malignancy. TERT rs2736100 and rs2853669 polymorphisms were genotyped by using TaqMan SNP genotyping assay FLT3 (ITD, D835), DNMT3A (R882), and NPM1 c.863_864insTCTG (type A) mutations were analised in each AML case.

RESULTS

TERT rs2736100 and rs2853669 were not associated with AML risk in the codominant, dominant, recessive, or allelic models. Multivariate Cox regression showed that TERT rs2853669 was a significant predictor for overall survival in AML patients. After adjusting for age, gender, cytogenetic risk group, ECOG status, FLT3, DNMT3A, NPM1 mutation, AML subtype, and treatment, the estimated adjusted hazard ratio (HR adjusted = 1.54, 95% CI: 1.01-2.35) showed that the TERT rs2853669 variant genotype had a negative influence on survival time.

CONCLUSIONS

TERT rs2853669 and rs2736100 polymorphisms were not risk factors for developing AML in the Romanian population, but the TERT rs2853669 variant genotype had a negative effect on AML patients' overall survival in the presence of other known prognostic factors.

An investigation of the relation between catalase C262T gene polymorphism and catalase enzyme activity in leukemia patients

INTRODUCTION

Catalase (CAT), an antioxidant enzyme, catalyzes conversion of hydrogen peroxide to water and molecular oxygen, protecting cells against oxidative stress. The aim of this study was to investigate the possible association between CAT C262T polymorphism in the promoter region of the CAT gene and leukemia risk and to determine the relationship between CAT genotypes and CAT enzyme activities.

MATERIAL AND METHODS

Genotypes of 102 cases and 112 healthy controls' genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism methods. Catalase activity was measured with the method of Aebi.

RESULTS

The frequencies of the T allele among the cases and controls were 28.4% and 25.9%, respectively (p = 0.75). The frequencies of CC, CT, and TT among cases were 57.8%, 27.4%, and 14.7%, respectively, while in controls, the frequencies of CC, CT, and TT were 54.4%, 39.3%, and 6.3%, respectively, which were not significantly different. Although CAT enzyme activity was lower in leukemia patients with TT genotypes than in controls, this did not reach statistical significance (p = 0.37).

CONCLUSIONS

This is the first report showing that CAT C262T polymorphism is not a genetic predisposing factor for the risk of leukemia in the Turkish population. However, additional research is needed to confirm these findings.

Co-occurrence of PML-RARA gene fusion, chromosome 8 trisomy, and FLT3 ITD mutation in a young female patient with de novo acute myeloid leukemia and early death: A CARE case report

RATIONALE

Co-occurrence of cytogenetic and molecular abnormalities is frequently seen in patients with acute myeloid leukemia (AML). The clinical outcome and genetic abnormalities of AML may vary; therefore, genetic investigation must be complex, using several techniques, to have an appropriate characterization of the AML genome and its clinical impact. The available molecular markers can predict prognosis only partially. Acute promyelocytic leukemia subtype M3 (AML M3) is a subtype of AML characterized by the presence of promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) genes fusion. Targeted treatment with all-trans-retinoic acid (ATRA) and ATRA combined with arsenic trioxide significantly improved the survival of AML M3 patients. Unknown prognostic factors could contribute to the early death of these patients.

PATIENT CONCERNS

We present the case of a young female (20 years old) patient, who presented at the emergency department 5 months after giving birth to her first child, complaining of asthenia, fatigue, general musculoskeletal pain, and fever (38°C), symptoms having been present for the previous 6 days. The patient denied any chronic diseases in her medical and family history.

DIAGNOSIS

Laboratory analysis revealed severe pancytopenia. Cytogenetic and molecular analyzes revealed chromosomal abnormalities (trisomy 8), PML-RARA gene fusion, and fms-like tyrosine kinase 3 (FLT3) gene mutation. The immunophenotypic analysis was also suggestive for AML M3 according to the FAB classification.

INTERVENTIONS

Specific treatment was initiated for AML M3 and for secondary conditions. Molecular and cytogenetic analyzes were performed to have a more detailed characterization of the patient's genome.

OUTCOME

Seventy-two hours after admission, she developed psychomotor agitation, confusion, coma, and convulsion. Subsequent deterioration and early death were caused by intracerebral hemorrhage with multiple localization and diffuse cerebral edema.

LESSONS

The presence of FLT3 internal tandem duplication (ITD) mutation may explain the rapid and progressive degradation of this AML M3 case and it may be used as a prognostic marker even when co-occuring with other markers such as PML-RARA gene fusion and trisomy 8. We consider that FLT3 ITD mutation analysis in young patients with AML should be performed as soon as possible. New strategies for patients' education, AML (or cancers in general) prevention, and treatment are needed.

GSTP1 and cancer: Expression, methylation, polymorphisms and signaling (Review)

Glutathione S‑transferase Pi (GSTP1) is an isozyme encoded by the GST pi gene that plays an important regulatory role in detoxification, anti‑oxidative damage, and the occurrence of various diseases. The aim of the present study was to review the association between the expression of GSTP1 and the development and treatment of various cancers, and discuss GSTP1 methylation in several malignant tumors, such as prostate, breast and lung cancer, as well as hepatocellular carcinoma; to review the association between polymorphism of the GSTP1 gene and various diseases; and to review the effects of GSTP1 on electrophilic oxidative stress, cell signal transduction, and the regulation of carcinogenic factors. Collectively, GSTP1 plays a major role in the development of various diseases.

A rare case of acute myeloid leukemia with ARHGEF12 (LARG, 11q23.3) and MAPRE1 (EB1, 20q11.21) fusion gene in an elderly patient

Introduction. We report one elderly patient diagnosed with a rare subtype of acute myeloid leukemia (AML) and also with a very rare fusion gene involving ARHGEF12 (LARG, 11q23.3) and MAPRE1 (EB1, 20q11.21) genes.

Material and methods. Clinical examination and routine analysis were performed including peripheral blood smear, immunophenotyping of the peripheral blood by flow cytometry and several molecular analyses.

Results. Peripheral blood smear showed 80% blasts with round and some with convoluted nuclei, with basophilic cytoplasm, identified as monoblast and the majority of cells as promonocytes. Peripheral blood immunophenotyping was consistent with monocytic differentiation. Molecular analysis was negative for FLT3 ITD, FLT3 D835, NPM1, and DNMT3A R882 mutations. Multiplex ligation-dependent probe amplification revealed no copy number aberration. Ligation-dependent reverse transcription polymerase chain reaction (LD-RT-PCR) analysis identified the presence of one gene fusion between ARHGEF12 (LARG, 11q23.3) and MAPRE1 (EB1, 20q11.21) genes. The patient had no significant comorbidities, the renal function was normal and Eastern Cooperative Oncology Group performance status was 2 at diagnosis and 1 after treatment. She was treated with decitabine. She became transfusion independent and a reduction of the number of blasts was obtained.

Conclusions. The outcome of our AML patient was favorable but other patients with fusion genes involving ARHGEF12 (LARG, 11q23.3) and MAPRE1 (EB1, 20q11.21) should be reported, contributing to a better characterization of the disease, to monitor the minimal residual disease and in the end to more targeted treatment options. LD-RT-PCR represent a valuable multiplex technique for fusion gene analysis.

Association Between Glutathione S-Transferase (GST) Polymorphisms and Schizophrenia in a Chinese Han Population

BACKGROUND

Glutathione S-transferase (GST) is an important antioxidant enzyme in the body. The weakening of the antioxidant system causes damage to the cells and tissues that make up the organism, adversely affects the function of the nervous system, and ultimately leads to schizophrenia (SCZ). Previous studies have yielded inconsistent results across different ethnic populations.

PURPOSE

This case-control study was carried out to investigate whether genetic polymorphisms in GST could be associated with SCZ in the Chinese Han population.

PATIENTS AND METHODS

A total of 794 participants, including 379 SCZ patients (case group) and 415 healthy individuals (control group), were genotyped by polymerase chain reaction-restriction fragment length for polymorphisms in GST genes.

RESULTS

The study found that the frequency of the GSTM1 null genotype was higher in case group than control group (p=0.003). The frequency of the GSTM1 and GSTT1 double null genotype was also higher in case group than control group (p=0.008).

CONCLUSION

We conclude that the GSTM1 null genotype and the GSTM1 and GSTT1 double null genotype may be related to the onset of SCZ in Chinese Han population.

Cytokine rs361525, rs1800750, rs1800629, rs1800896, rs1800872, rs1800795, rs1800470, and rs2430561 SNPs in relation with prognostic factors in acute myeloid leukemia

BACKGROUND

Cytokines were correlated with survival and disease progression in acute myeloid leukemia (AML). We aimed to evaluate the multivariate effect of TNF-α rs361525, rs1800750, rs1800629, IL-10 rs1800896, rs1800872, IL-6 rs1800795, TGF-β1 rs1800470, IFN-γ rs2430561 single nucleotide polymorphisms (SNPs) on AML risk, the multivariate effect of SNPs on overall survival (OS) in AML and the association between the investigated SNPs and prognostic factors in AML.

METHODS

All SNPs were genotyped in 226 adult AML cases and 406 healthy individuals. AML patients were investigated for FLT3 (ITD, D835), DNMT3A (R882), and NPM1 type A mutations.

RESULTS

Univariate analysis revealed that age above 65 years had a negative influence on survival (P < .001). The presence of the rs1800750 variant genotype (P = .005) or FLT3-ITD mutation (P = .009) in a cytogenetic high-risk group (P = .003) negatively influenced OS. A negative association was observed between Eastern Cooperative Oncologic Group Scale status > 2, lactate dehydrogenase (LDH) level, platelet (PLT) count <40 000 cells/mm³ , and OS. Multivariate Cox regression analysis showed that the presence of the rs1800750 variant genotype was a risk factor for death (P = .007), and that blast percentage, LDH level (≥600 IU/L), and cytogenetic high-risk were independent significant predictors for death in AML (P = .04, corrected HR = 1.20; P = .022, corrected HR = 1.24; P = .021, corrected HR = 1.34, respectively).

CONCLUSIONS

Age above 65 years, PLT count, TNF-α rs1800750 variant genotype, blast percentage, LDH level, and cytogenetic high-risk may be used as independent risk factors to assess AML mortality.

Simultaneous FLT3, NPM1 and DNMT3A mutations in adult patients with acute myeloid leukemia – case study

Background: Nowadays, cytogenetics and molecular genetics, but not only, are mandatory in acute myeloid leukemia (AML) management, as a consequence of their impact on AML pathogenesis, classification, risk-stratification, prognosis and treatment. Objective: The aim of our study was to present our algorithm for the analysis of copy number changes, aneuploidies and somatic mutations focusing on a rare AML case positive for four somatic mutations. Methods: Cytogenetic analysis, Multiplex Ligationdependent Probe Amplification (MLPA) analysis, somatic mutation analysis (for FLT3 ITD, FLT3 D835, DNMT3A R882 and NPM1 c.863_864ins) by using several PCR techniques and also next-generation sequencing (NGS) analysis were performed. Results: Cytogenetic analysis did not reveal structural or numerical chromosomal anomalies. The patient’s DNA showed no copy number changes or aberrations (CNAs) following the MLPA analysis. By using several molecular technologies we found four mutations: FLT3-ITD, FLT3 D835 (c.2504A>T, D835V), DNMT3A R882C, and NPM1 c.863_864insTCTG. Challenges, benefits, applications and the limitations of each molecular technique used for the investigation of the mentioned mutation, and not only, are also described. Conclusion: All these techniques can be useful in the diagnosis of AML patients, each of them covering the limits of the other technique. New strategies for a positive, fast, accurate and reliable diagnosis are mandatory in cases with AML.

The Influence of GPX1 Pro198Leu, CAT C262T and MnSOD Ala16Val Gene Polymorphisms on Susceptibility for Non-Hodgkin Lymphoma and Overall Survival Rate at Five Years from Diagnosis

Objective: The aim of the current study was to investigate possible associations between catalase C262T (CAT C262T), glutathione peroxidase 1 Pro198Leu (GPX1 Pro198Leu), manganese superoxide dismutase Ala16Val (MnSOD Ala16Val) gene polymorphisms and non-Hodgkin Lymphoma risk (NHL) in a Romanian population and the five-year overall survival rate of the NHL patients.

Methods: We included in this case-control study 406 individuals, divided into two groups: the control group (n=315) and the patients group (n=91). The DNA was extracted from peripheral blood and amplified using specific techniques.

Results: The variant homozygous genotype of GPX1 Pro198Leu represents a risk factor for NHL development and no associations regarding the risk for NHL were found for MnSOD Ala16Val and CAT C262T gene polymorphisms. Two of the studied polymorphisms were associated with the overall survival rate thus: negative association regarding MnSOD Ala16Val, associated with higher overall survival rate and a positive one regarding CAT C262T, associated with lower overall survival rate.

Conclusions: According to our results, the mentioned polymorphisms may be considered as susceptible markers of the five-year overall survival rate for NHL patients. Future studies with a larger number of patients are needed to confirm our results.

In vitro and in vivo studies of oxidative stress responses against acrylamide toxicity in zebrafish

Acrylamide (AA) is widely used in soil stabilization, water treatment, and industrial products and found in certain foods; however, its toxicity is an expanding global concern. Thus, to reveal the mechanisms involved in the development of, or protection from AA-induced toxicity has important significance. For this purpose, here we explored the intracellular stress response signaling pathways activated by AA exposure in zebrafish model. BRF41 cells derived from zebrafish were exposed to AA, and changes in the expression levels of 31 genes, including endoplasmic reticulum stress response-, oxidative stress response-, osmotic stress response-, and DNA damage and repair-related genes, were analyzed by PCR array. 12 genes upregulated in AA-exposed BRF41 cells were analyzed in zebrafish larvae by quantitative real time PCR, and the expression of all tested oxidative stress response-related genes was upregulated. Spatial expression patterns of these genes were visualized and found that their expression was upregulated and ectopically induced. In addition, AA-induced toxicity in BRF41 cells and the expression of glutathione S-transferase pi 1 (gstp1) in zebrafish larvae were reduced by N-acetylcysteine. Furthermore, inhibition of Gst activity enhanced AA toxicity. From these results, we concluded that the elicited oxidative stress response critically contributes to the protection from AA-induced toxicity.

Association between MnSOD Val16Ala Polymorphism and Cancer Risk: Evidence from 33,098 Cases and 37,831 Controls

Manganese superoxide dismutase (MnSOD) plays a critical role in the defense against reactive oxygen species. The association between MnSOD Val16Ala polymorphism and cancer risk has been widely studied, but the results are contradictory. To obtain more precision on the association, we performed the current meta-analysis with 33,098 cases and 37,831 controls from 88 studies retrieved from PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of association. We found that the polymorphism was associated with an increased overall cancer risk (homozygous: OR = 1.09, 95% CI = 1.00-1.19; heterozygous: OR = 1.07, 95% CI = 1.02-1.12; dominant: OR = 1.08, 95% CI = 1.02-1.14; and allele comparison: OR = 1.06, 95% CI = 1.02-1.11). Stratification analysis further showed an increased risk for prostate cancer, Asians, Caucasians, population-based studies, hospital-based studies, low quality and high quality studies. However, the increased risk for MnSOD Val16Ala polymorphism among Asians needs further validation based on the false-positive report probability (FPRP) test. To summarize, this meta-analysis suggests that the MnSOD Val16Ala polymorphism is associated with significantly increased cancer risk, which needs further validation in single large studies.

NAT2 Gene Polymorphisms in Turkish Patients with Psoriasis Vulgaris

Psoriasis is a common, chronic, and autoimmune skin disease. Factors that play a role in etiopathogenesis of psoriasis include internal factors such as genetic susceptibility and immunological factors and external factors such as stress, infection, trauma, drug, and environmental compounds. N-acetyltransferase 2 (NAT2) is a xenobiotic enzyme that is involved in the metabolism of drugs, environmental toxins, and carcinogens. In this study, we aimed to demonstrate whether the variations in the NAT2 gene lead to a predisposition to psoriasis by affecting the enzyme's ability to metabolize drugs and environmental components or not. Three polymorphisms (rs1799929, rs1799930, and rs1799931) in NAT2 gene were genotyped and compared by real-time PCR method in 260 psoriasis vulgaris patients and 200 healthy controls. There was no difference in the genotype distributions and allele frequencies of polymorphisms between psoriasis vulgaris patients and controls. When the effects of polymorphisms on the clinical features of the disease, such as onset age and severity, are assessed, it has been found that rs1799930 and rs1799929 are, respectively, associated with early onset age and severity of the disease. In conclusion, rs1799929, rs1799930, and rs1799931 polymorphisms of the NAT-2 gene do not appear to be a risk factor for the development of psoriasis. Conversely, they may have an effect on either more severe or early onset cases of the disease.

Association between glutathione peroxidase-1 (GPX1) Rs1050450 polymorphisms and cancer risk

Glutathione peroxidase (GPX), one of the antioxidant enzymes, exerts a vital role in reducing oxidative damage. GPX1 Pro198Leu (rs1050450) polymorphism has been reported in the development of several cancers, while the results were inconsistent. We thus conducted this meta-analysis to identify the association between GPX1 (rs1050450) polymorphism and cancer risk. 52 eligible publications with 60 case-control studies were included, with 21,296 cancer patients and 30,346 controls. The results in total population suggested there was a significant association between GPX1 (rs1050450) polymorphism and cancer susceptibility in part genetic models (TT vs CT+CC: OR = 1.15, 95% CI = 1.01-1.32, P = 0.042; TT vs CC: OR = 1.15, 95% CI = 1.00-1.31, P = 0.044; T vs C: OR = 1.09, 95% CI = 1.01-1.17, P = 0.02). The stratified analysis by cancer types suggested a positive correlation between GPX1 (rs1050450) polymorphism and the development of bladder cancer (TT+CT vs CC: OR = 1.72, 95% CI = 1.09-2.70, P = 0.019; TT vs CT+CC: OR = 3.56, 95% CI = 1.42-8.94, P = 0.007; TT vs CC: OR = 3.75, 95% CI = 1.41-9.94, P = 0.008; T vs C: OR = 1.941, 95% CI = 1.17-3.22, P = 0.01) as well as head and neck cancer (TT vs CT+CC: OR = 2.19, 95% CI = 1.39-3.46, P = 0.001) and brain cancer (TT+CT vs CC: OR = 1.19, 95% CI = 1.03-1.37, P = 0.018). These results support that GPX1 (rs1050450) polymorphism might be a candidate marker for cancer risk with type-specific effects.

Glutathione peroxidases as oncotargets

Oxidative stress is a disturbance in the equilibrium among free radicals, reactive oxygen species, and endogenous antioxidant defense mechanisms. Oxidative stress is a result of imbalance between the production of reactive oxygen and the biological system's ability to detoxify the reactive intermediates or to repair the resulting damage. Mounting evidence has implicated oxidative stress in various physiological and pathological processes, including DNA damage, proliferation, cell adhesion, and survival of cancer cells. Glutathione peroxidases (GPxs) (EC 1.11.1.9) are an enzyme family with peroxidase activity whose main biological roles are to protect organisms from oxidative damage by reducing lipid hydroperoxides as well as free hydrogen peroxide. Currently, 8 sub-members of GPxs have been identified in humans, all capable of reducing H₂O₂ and soluble fatty acid hydroperoxides. A large number of publications has demonstrated that GPxs have significant roles in different stages of carcinogenesis. In this review, we will update recent progress in the study of the roles of GPxs in cancer. Better mechanistic understanding of GPxs will potentially contribute to the development and advancement of improved cancer treatment models.