Association of genetic polymorphisms of glutathione-S-transferase genes (GSTT1, GSTM1, and GSTP1) and susceptibility to nonalcoholic fatty liver disease in Zahedan, Southeast Iran

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

BACKGROUNDS

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Association of glutathione S-transferases (GSTT1, GSTM1 and GSTP1) genes polymorphisms with nonalcoholic fatty liver disease susceptibility: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Glutathione S-transferases (GSTs) genes single-nucleotide polymorphisms (SNPs) have been connected with the susceptibility of nonalcoholic fatty liver disease (NAFLD), but with inconsistent results across the current evidences. The present work was schemed to explore the association between GSTs genes polymorphisms and the NAFLD vulnerability via meta-analysis.

METHODS

PubMed, Web of Science, Cochrane Library, China National Knowledge Infrastructure and Wanfang were retrieved for eligible literatures previous to March 10, 2021. The odds ratio (OR) of the dichotomic variables and the standardized mean difference of quantitative variables with corresponding 95% confidence intervals (95%CIs) were computed to evaluate the strength of the associations. The quality of included studies were assessed via using Newcastle-Ottawa Scale (NOS).

RESULTS

In total, 7 case-control studies encompassing 804 NAFLD patients and 1362 disease-free controls in this meta-analysis. Ultimately, this analysis included 6, 5 and 5 studies for GSTM1, GSTT1 and GSTP1 polymorphisms, respectively. The pooled data revealed that the GSTs genes SNPs had conspicuous associations with NAFLD susceptibility: for GSTM1, null versus present, OR = 1.46, 95%CI 1.20 to 1.79, P = .0002; for GSTT1, null versus present, OR = 1.34, 95%CI 1.06 to 1.68, P = .01; for GSTP1, Ile/Val or Val/Val versus Ile/Ile, OR = 1.60, 95%CI 1.23 to 2.09, P = .0005.

CONCLUSION

This work revealed that the GSTM1 null, GSTT1 null and GSTP1-Val genotypes might be related to increased NAFLD susceptibility.

Investigation of the Effect of Curcumin on Protein Targets in NAFLD Using Bioinformatic Analysis

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a prevalent metabolic disorder. Defects in function/expression of genes/proteins are critical in initiation/progression of NAFLD. Natural products may modulate these genes/proteins. Curcumin improves steatosis, inflammation, and fibrosis progression. Here, bioinformatic tools, gene−drug and gene-disease databases were utilized to explore targets, interactions, and pathways through which curcumin could impact NAFLD. METHODS: Significant curcumin−protein interaction was identified (high-confidence:0.7) in the STITCH database. Identified proteins were investigated to determine association with NAFLD. gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were analyzed for significantly involved targets (p < 0.01). Specificity of obtained targets with NAFLD was estimated and investigated in Tissue/Cells−gene associations (PanglaoDB Augmented 2021, Mouse Gene Atlas) and Disease−gene association-based EnrichR algorithms (Jensen DISEASES, DisGeNET). RESULTS: Two collections were constructed: 227 protein−curcumin interactions and 95 NAFLD-associated genes. By Venn diagram, 14 significant targets were identified, and their biological pathways evaluated. Based on gene ontology, most targets involved stress and lipid metabolism. KEGG revealed chemical carcinogenesis, the AGE-RAGE signaling pathway in diabetic complications and NAFLD as the most common significant pathways. Specificity to diseases database (EnrichR algorithm) revealed specificity for steatosis/steatohepatitis. CONCLUSION: Curcumin may improve, or inhibit, progression of NAFLD through activation/inhibition of NAFLD-related genes.

Target Deconvolution of Fenofibrate in Nonalcoholic Fatty Liver Disease Using Bioinformatics Analysis

Background

Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of liver damage, affecting ~25% of the global population. NAFLD comprises a spectrum of liver pathologies, from hepatic steatosis to nonalcoholic steatohepatitis (NASH), and may progress to liver fibrosis and cirrhosis. The presence of NAFLD correlates with metabolic disorders such as hyperlipidemia, obesity, blood hypertension, cardiovascular, and insulin resistance. Fenofibrate is an agonist drug for peroxisome proliferator-activated receptor alpha (PPARα), used principally for treatment of hyperlipidemia. However, fenofibrate has recently been investigated in clinical trials for treatment of other metabolic disorders such as diabetes, cardiovascular disease, and NAFLD. The evidence to date indicates that fenofibrate could improve NAFLD. While PPARα is considered to be the main target of fenofibrate, fenofibrate may exert its effect through impact on other genes and pathways thereby alleviating, and possibly reversing, NAFLD. In this study, using bioinformatics tools and gene-drug, gene-diseases databases, we sought to explore possible targets, interactions, and pathways involved in fenofibrate and NAFLD.

Methods

We first determined significant protein interactions with fenofibrate in the STITCH database with high confidence (0.7). Next, we investigated the identified proteins on curated targets in two databases, including the DisGeNET and DISEASES databases, to determine their association with NAFLD. We finally constructed a Venn diagram for these two collections (curated genes-NAFLD and fenofibrate-STITCH) to uncover possible primary targets of fenofibrate. Then, Gene Ontology (GO) and KEGG were analyzed to detect the significantly involved targets in molecular function, biological process, cellular component, and biological pathways. A P value < 0.01 was considered the cut-off criterion. We also estimated the specificity of targets with NAFLD by investigating them in disease-gene associations (STRING) and EnrichR (DisGeNET). Finally, we verified our findings in the scientific literature.

Results

We constructed two collections, one with 80 protein-drug interactions and the other with 95 genes associated with NAFLD. Using the Venn diagram, we identified 11 significant targets including LEP, SIRT1, ADIPOQ, PPARA, SREBF1, LDLR, GSTP1, VLDLR, SCARB1, MMP1, and APOC3 and then evaluated their biological pathways. Based on Gene Ontology, most of the targets are involved in lipid metabolism, and KEGG enrichment pathways showed the PPAR signaling pathway, AMPK signaling pathway, and NAFLD as the most significant pathways. The interrogation of those targets on authentic disease databases showed they were more specific to both steatosis and steatohepatitis liver injury than to any other diseases in these databases. Finally, we identified three significant genes, APOC3, PPARA, and SREBF1, that showed robust drug interaction with fenofibrate.

Conclusion

Fenofibrate may exert its effect directly or indirectly, via modulation of several key targets and pathways, in the treatment of NAFLD.

Glutathione-S-transferases genes-promising predictors of hepatic dysfunction

One of the most commonly known genes involved in chronic diffuse liver diseases pathogenesis are genes that encodes the synthesis of glutathione-S-transferase (GST), known as the second phase enzyme detoxification system that protects against endogenous oxidative stress and exogenous toxins, through catalisation of glutathione sulfuric groups conjugation and decontamination of lipid and deoxyribonucleic acid oxidation products. The group of GST enzymes consists of cytosolic, mitochondrial and microsomal fractions. Recently, eight classes of soluble cytoplasmic isoforms of GST enzymes are widely known: α-, ζ-, θ-, κ-, μ-, π-, σ-, and ω-. The GSTs gene family in the Human Gene Nomenclature Committee, online database recorded over 20 functional genes. The level of GSTs expression is considered to be a crucial factor in determining the sensitivity of cells to a broad spectrum of toxins. Nevertheless, human GSTs genes have multiple and frequent polymorphisms that include the complete absence of the GSTM1 or the GSTT1 gene. Current review supports the position that genetic polymorphism of GST genes is involved in the pathogenesis of various liver diseases, particularly non-alcoholic fatty liver disease, hepatitis and liver cirrhosis of different etiology and hepatocellular carcinoma. Certain GST allelic variants were proven to be associated with susceptibility to hepatological pathology, and correlations with the natural course of the diseases were subsequently postulated.

Spinach consumption and nonalcoholic fatty liver disease among adults: a case-control study

BACKGROUND

Spinach has high antioxidants and polyphenols and showed protective effects against liver diseases in experimental studies. We aimed to assess the association between dietary intake of spinach and odds of nonalcoholic fatty liver disease (NAFLD) in a case-control study among Iranian adults.

METHODS

Totally 225 newly diagnosed NAFLD patients and 450 controls, aged 20-60 years, were recruited in this study. Participants' dietary intakes were collected using a valid and reliable 168-item semi-quantitative food frequency questionnaire (FFQ). The logistic regression test was used for assessing the association between total, raw, and boiled dietary spinach with the odds of NAFLD.

RESULTS

The mean (SD) age and BMI of participants (53% male) were 38.1 (8.8) years and 26.8 (4.3) kg/m², respectively. In the final adjusted model for potential confounders, the odds (95% CI) of NAFLD in individuals in the highest tertile of daily total and raw spinach intake was [0.36 (0.19-0.71), P_trend = 0.001] and [0.47 (0.24-0.89), P_trend = 0.008], respectively compared with those in the lowest tertile. Furthermore, in the adjusted analyses, an inverse association was observed between the highest yearly intake versus no raw spinach consumption and odds of NAFLD [(OR 0.41; 95% CI 0.18-0.96), P for trend = 0.013]. However, there was no significant association between higher boiled spinach intake and odds of NAFLD.

CONCLUSIONS

The present study found an inverse association between total and raw spinach intake with the odds of NAFLD.

Deciphering the Variants Located in the MIR196A2, MIR146A, and MIR423 with Type-2 Diabetes Mellitus in Pakistani Population

MicroRNAs (miRNAs) are small non-coding RNA molecules that control the post-transcriptional gene expression. They play a pivotal role in the regulation of important physiological processes. Variations in miRNA genes coding for mature miRNA sequences have been implicated in several diseases. However, the association of variants in miRNAs genes with Type 2 Diabetes Mellitus (T2DM) in the Pakistani population is rarely reported. Therefore, the current study was designed to investigate the association of rs11614913 T/C (MIR196A2), rs2910164 G/C (MIR146A), and rs6505162 C/A (MIR423) in clinicopathological proven T2DM patients and gender-matched healthy controls. The tetra-primer amplification refractory mutation system-polymerase chain (ARMS-PCR) reaction method was used to determine the genotypes and to establish the association of each variant with T2DM through inherited models. In conclusion, the present study showed that variants rs11614913 T/C and rs2910164 G/C were linked with the risk of T2DM. The data suggested that rs11614913 T/C and rs2910164 G/C could be considered as novel risk factors in the pathogenesis of T2DM in the Pakistani population.

Identifying potential biomarkers of nonalcoholic fatty liver disease via genome-wide analysis of copy number variation

BACKGROUND

The prevalence of Non-alcoholic fatty liver disease (NAFLD) is increasing and emerging as a global health burden. In addition to environmental factors, numerous studies have shown that genetic factors play an important role in the development of NAFLD. Copy number variation (CNV) as a genetic variation plays an important role in the evaluation of disease susceptibility and genetic differences. The aim of the present study was to assess the contribution of CNV to the evaluation of NAFLD in a Chinese population.

METHODS

Genome-wide analysis of CNV was performed using high-density comparative genomic hybridisation microarrays (ACGH). To validate the CNV regions, TaqMan real-time quantitative PCR (qPCR) was utilized.

RESULTS

A total of 441 CNVs were identified, including 381 autosomal CNVs and 60 sex chromosome CNVs. By merging overlapping CNVs, a genomic CNV map of NAFLD patients was constructed. A total of 338 autosomal CNVRs were identified, including 275 CNVRs with consistent trends (197 losses and 78 gains) and 63 CNVRs with inconsistent trends. The length of the 338 CNVRs ranged from 5.7 kb to 2.23 Mb, with an average size of 117.44 kb. These CNVRs spanned 39.70 Mb of the genome and accounted for ~ 1.32% of the genome sequence. Through Gene Ontology and genetic pathway analysis, we found evidence that CNVs involving nine genes may be associated with the pathogenesis of NAFLD progression. One of the genes (NLRP4 gene) was selected and verified by quantitative PCR (qPCR) method with large sample size. We found the copy number deletion of NLRP4 was related to the risk of NAFLD.

CONCLUSIONS

This study indicate the copy number variation is associated with NAFLD. The copy number deletion of NLRP4 was related to the risk of NAFLD. These results could prove valuable for predicting patients at risk of developing NAFLD.

Association of xenobiotic-metabolizing enzymes (GSTM1 and GSTT 1), and pro-inflammatory cytokines (TNF-α and IL-6) genetic polymorphisms with non-alcoholic fatty liver disease

Previous studies have revealed that genetic polymorphisms of the Glutathione S-transferase M1 and T1 (GSTM1 and GSTT1), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) are associated with the presence of non-alcoholic fatty liver disease (NAFLD) in many populations. This study was conducted to investigate the association of the GSTM1, GSTT1, TNF-α rs1800629, and IL-6 rs1800795 with NAFLD in the general Iranian population. A case-control analysis included 242 NAFLD patients and 324 healthy controls from Iranian adults. After the physical examination, the genotypes were determined by polymerase chain reaction(PCR). The GSTM1 null, GSTT1 null, TNF-α AG/AA, and IL-6 CG/CC genotypes were deemed to be high-risk. The null allele of GSTM1 and A allele of TNF-α were more frequent in NAFLD patients even after Bonferroni's correction (P values<0.005, adjusted odds ratio (OR), 1.66 and 2.02; 95% confidence intervals (CI), (1.18-2.32) and (1.34-3.34), respectively. The IL-6 CC/CG genotype association with NAFLD was not significant after correction (P value = 0.04) Polymorphisms of xenobiotic and pro-inflammatory genes are associated with NAFLD in the Iranian population and seem to be a useful tool for NAFLD prevention and care.

Genetic factors contributing to extensive variability of sex-specific hepatic gene expression in Diversity Outbred mice

Sex-specific transcription characterizes hundreds of genes in mouse liver, many implicated in sex-differential drug and lipid metabolism and disease susceptibility. While the regulation of liver sex differences by growth hormone-activated STAT5 is well established, little is known about autosomal genetic factors regulating the sex-specific liver transcriptome. Here we show, using genotyping and expression data from a large population of Diversity Outbred mice, that genetic factors work in tandem with growth hormone to control the individual variability of hundreds of sex-biased genes, including many long non-coding RNA genes. Significant associations between single nucleotide polymorphisms and sex-specific gene expression were identified as expression quantitative trait loci (eQTLs), many of which showed strong sex-dependent associations. Remarkably, autosomal genetic modifiers of sex-specific genes were found to account for more than 200 instances of gain or loss of sex-specificity across eight Diversity Outbred mouse founder strains. Sex-biased STAT5 binding sites and open chromatin regions with strain-specific variants were significantly enriched at eQTL regions regulating correspondingly sex-specific genes, supporting the proposed functional regulatory nature of the eQTL regions identified. Binding of the male-biased, growth hormone-regulated repressor BCL6 was most highly enriched at trans-eQTL regions controlling female-specific genes. Co-regulated gene clusters defined by overlapping eQTLs included sets of highly correlated genes from different chromosomes, further supporting trans-eQTL action. These findings elucidate how an unexpectedly large number of autosomal factors work in tandem with growth hormone signaling pathways to regulate the individual variability associated with sex differences in liver metabolism and disease.

Metabolomic-proteomic combination analysis reveals the targets and molecular pathways associated with hydrogen sulfide alleviating NAFLD

AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease worldwide. Exogenous H₂S has been shown to effectively mitigate NAFLD, although little is known about the underlying targets and molecular mechanisms.

METHODS

C57BL/6 mice were fed with normal fat diet (NFD) or high fat diet (HFD) for a total 16 weeks, and HFD-fed mice were treated with saline or NaHS beginning in 12th week. The combination analysis of metabolomics and proteomics of liver tissues was firstly performed to discover the candidate targets and potential molecular pathways involved in H₂S mitigating the NAFLD.

KEY FINDINGS

Compared with NaCl, H₂S relieved NAFLD by reducing liver weight, body weight and lipid accumulation in liver, and improving liver pathology and serum biochemical parameters. There were 40 overlapping metabolites in the intersection analysis between comparative analysis of HFD + NaCl vs NFD and HFD + NaHS vs HFD + NaCl based on liver metabolomics. Moreover, a total of 58 proteins were obtained whose changes were reversed after treatment with H₂S. A combined analysis of liver metabolomics and proteomics was then conducted, revealing 8 shared molecular pathways, as well as the enrichment of unsaturated fatty acids. In addition, Plin2 may also be a potential target of H₂S via the regulation of lipid droplet degradation in alleviating NAFLD.

SIGNIFICANCE

We performed the first study combining metabolomics and proteomics to explore the mechanisms behind the alleviation of NAFLD by H₂S. Our results not only provide evidence that H₂S alleviates NAFLD but also reveals its possible molecular mechanisms and targets.

Association of Genetic Polymorphisms in GSTP1, GSTM1, and GSTT1 Genes with Vesicoureteral Reflux Susceptibility in the Children of Southeast Iran

Background:

Vesicoureteral reflux (VUR) disease is the most common type of urinary tract anomalies in children. Genetic risk factors may be associated with the etiology of VUR. The role of the Glutathione S-transferases (GSTs) as multifunctional enzymes is cellular oxidative stress handling. This is the first study aimed at evaluating the relative risk of GSTP1, GSTM1, and GSTT1 polymorphisms in VUR susceptibility in children and provides new important insights into the genetics of affected children.

Methods:

The study was done in 2013 in Sistan and Baluchestan University, eastern Iran. Genotyping of three GSTP1, GSTM1, and GSTT1 genes were determined using the multiplex polymerase chain reaction assay in 216 reactions for 72 VUR children and 312 reactions for 104 healthy controls.

Results:

The presence of GSTT1 deletion was associated with high risk of VUR in children, whereas GSTP1 and GSTM1 genotypes did not show the same effect. Furthermore, the combination of GSTT1/GSTM1 and GSTT1/ GSTP1 genotypes showed a significant influence on lower risk of VUR in children.

Conclusion:

Deletion of GSTT1 functional gene is a genetic risk factor causing VUR in children. Interestingly, the combination of GSTM1 and GSTP1 null genotypes with GSTT1 has shown a protective role against risk of GSTT1 deletion.

Glutathione S-transferase T1 and M1 null genotype distribution among non-alcoholic fatty liver disease patients and its association with cytokine and adipokine profiles

Aim of the study

Among the key genes involved in the development of non-alcoholic fatty liver disease (NAFLD) are genes encoding the synthesis of glutathione S-transferase (GST).

Material and methods

Deletion polymorphism of GSTT1 and GSTM1 genes was investigated in 104 NAFLD patients and 45 healthy individuals. Biochemical blood analysis, tumor necrosis factor-α (TNF-α), interleukin-10, leptin and adiponectin plasma levels were studied.

Results

The distribution of deletion vs. non-deletion genotypes of the GSTT1 gene in NAFLD patients was 18 (17.3%) vs. 86 (82.7%) patients and in healthy people it was 6 (13.3%) vs. 39 (86.7%) individuals. The genotype distribution of the GSTM1 gene was as follows: 52 (50.0%) NAFLD patients had null genotype vs. 52 patients (50.0%) with non-deletion genotype; in the control group - 23 (51.1%) vs. 22 (48.9%) individuals. Deletion of the GSTT1 gene in NAFLD patients was associated with twice as high (p = 0.01) TNF-α level in the blood as compared to patients with normal genotype. Higher concentration of leptin in blood by 37.1% (p = 0.04) was observed in patients with null genotype of the GSTM1 gene, as compared to those with normal genotype.

Conclusions

Deletion polymorphism of GSTT1 and GSTM1 genes distribution among NAFLD patients did not differ as compared to healthy individuals. Null-genotype GSTT1 gene carriers were characterized by higher TNF-α concentration and null-genotype GSTM1 gene carriers were characterized by elevated leptin level as compared to normal genotype carriers.

Transcriptome responses in blood reveal distinct biological pathways associated with arsenic exposure through drinking water in rural settings of Punjab, Pakistan

BACKGROUND

Groundwater Arsenic (As) contamination is a global public health concern responsible for various health implications and a neglected area of environmental health research in Pakistan. Because of interindividual differences in genetic predisposition, As-related health issues may not be equally distributed among the As-exposed population. However, till date, no studies have been conducted including multiple SNPs involved in As metabolism and disease risk using a linear mixed effect model approach to analyze peripheral blood transcriptomics results.

OBJECTIVES

In order to detect early responses on the gene expression level and to evaluate the impact of selected SNPs inferring disease risks associated with As exposure, we designed a systematic study to investigate blood transcriptomics profiles of 57 differentially exposed rural subjects living in drinking water As-contaminated settings of Lahore and Kasur districts in Punjab Province in southeast Pakistan. Exposure among the subjects was correlated with individual transcriptome responses applying urinary As profiles as the main biomarker for risk stratification.

METHODS

We performed whole genome gene expression analysis in blood of subjects using microarrays. Linear effect mixed models were applied for evaluating the combined impact of SNPs hypothetically increasing the risk for As exposure-induced health effects (GSTM1, GSTT1, As3MT, DNMT1, MTHFR, ERCC2 and EGFR).

RESULTS

Our findings confirmed important signaling, growth factor, cancer and other disease related pathways known to be associated with increased As exposure levels. In addition, upon implementing our integrative SNPs-based genetic risk factor, pathways associated with an increased risk of NAFLD and diabetes appeared significantly enhanced by down-regulation of genes NDUFV3, IKBKB, IL6R, ADIPOR1, PPARA, OGT and FOXO1.

CONCLUSION

We report the first comprehensive study applying state-of-the-art bioinformatics approaches to address multiple SNP-based inter-individual variability in adverse molecular responses among subjects exposed to drinking water As contamination in Pakistan thereby providing strong evidence of various gene expression targets associated with development of known As-related diseases.

Polymorphism of Glutathione S-transferase Genes and the Risk of Toxic Liver Damage in Petrochemical Workers

BACKGROUND

Exposure to numerous chemicals, including industrial ones, may result in liver damage. The body susceptibility to the environmental hazards largely depends on the activity of the enzymes in the xenobiotic detoxification system. Function abnormalities of such enzymes due to genetic variations would increase the risk of developing various diseases.

OBJECTIVE

To elucidate the relationship between polymorphism in glutathione S-transferase genes (GSTM1, GSTT1 and GSTP1) and the risk of toxic liver damage in a group of petrochemical workers.

METHODS

This study was conducted on 72 workers with toxic liver injury, 156 healthy workers, and 322 healthy individuals without history of occupational exposure to chemicals. Genotyping of the GSTP1 rs1695 gene polymorphism was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Polymerase chain reaction (PCR) was used to perform genotyping of the GSTM1 and GSTT1 genes polymorphism.

RESULTS

There was a significant difference in genotype frequencies of the GSTP1 rs1695 gene polymorphism among the groups studied. The distribution of Val/Val genotype of the GSTP1 rs1695 gene polymorphism had a higher incidence in healthy workers compared with patients with toxic liver damage (p=0.036). No significant association was found between the GSTM1 and GSTT1 polymorphisms and toxic liver damage.

CONCLUSION

The GSTP1 rs1695 gene polymorphism can play a protective role in the development of toxic liver damage in petrochemical workers.

Leukocyte Telomere Length Shortening, hTERT Genetic Polymorphisms and Risk of Childhood Acute Lymphoblastic Leukemia

Background: Telomeres are involved in chromosomal stability, cellular immortality and tumorigenesis. Human telomerase reverse transcriptase (TERT) is essential for the maintenance of telomere DNA length. Recently, a variable tandem-repeats polymorphism, MNS16A, located in the downstream region of the TERT gene, was reported to have an effect on TERT expression and telomerase activity. Previous studies have linked both relative telomere length (RTL) and TERT variants with cancer. Therefore, we evaluated associations between RTL, TERT gene polymorphisms (hTERT, rs2735940 C/T and MNS16A Ins/Del) and risk of childhood acute lymphoblastic leukemia (ALL) in an Iranian population. Methods: RTL was determined by a multiplex quantitative PCR-based method, and variants of the hTERT, rs2735940 C/T and MNS16A Ins/Del, were genotyped by amplification refractory mutation system PCR (ARMS-PCR), and PCR, respectively. Results: Our results indicated that RTL was shorter in ALL patients (1.53±0.12) compared to the control group (2.04±0.19) (P=0.029). However, no associations between hTERT gene variants or haplotypes and the risk of childhood ALL were observed (P>0.05). Also hTERT polymorphisms were not associated with RTL or patient clinicopathological characteristics, including age (P=0.304), sex (P=0.061) organomegally (P=0.212) CSF involvement (P=0.966) or response to treatment (P=0.58). Conclusions: We found that telomere attrition may be related to the pathogenesis of childhood ALL, irrespective to TERT variants.

Elevated Nrf-2 responses are insufficient to mitigate protein carbonylation in hepatospecific PTEN deletion mice

Objective

In the liver, a contributing factor in the pathogenesis of non-alcoholic fatty liver disease (NASH) is oxidative stress, which leads to the accumulation of highly reactive electrophilic α/β unsaturated aldehydes. The objective of this study was to determine the impact of NASH on protein carbonylation and antioxidant responses in a murine model.

Methods

Liver-specific phosphatase and tensin homolog (PTEN)-deletion mice (PTEN^LKO) or control littermates were fed a standard chow diet for 45–55 weeks followed by analysis for liver injury, oxidative stress and inflammation.

Results

Histology and Picrosirius red-staining of collagen deposition within the extracellular matrix revealed extensive steatosis and fibrosis in the PTEN^LKO mice but no steatosis or fibrosis in controls. Increased steatosis and fibrosis corresponded with significant increases in inflammation. PTEN-deficient livers showed significantly increased cell-specific oxidative damage, as detected by 4-hydroxy-2-nonenal (4-HNE) and acrolein staining. Elevated staining correlated with an increase in nuclear DNA repair foci (γH2A.X) and cellular proliferation index (Ki67) within zones 1 and 3, indicating oxidative damage was zonally restricted and was associated with increased DNA damage and cell proliferation. Immunoblots showed that total levels of antioxidant response proteins induced by nuclear factor erythroid-2-like-2 (Nrf2), including GSTμ, GSTπ and CBR1/3, but not HO-1, were elevated in PTEN^LKO as compared to controls, and IHC showed this response also occurred only in zones 1 and 3. Furthermore, an analysis of autophagy markers revealed significant elevation of p62 and LC3II expression. Mass spectrometric (MS) analysis identified significantly more carbonylated proteins in whole cell extracts prepared from PTEN^LKO mice (966) as compared to controls (809). Pathway analyses of identified proteins did not uncover specific pathways that were preferentially carbonylated in PTEN^LKO livers but, did reveal specific strongly increased carbonylation of thioredoxin reductase and of glutathione-S-transferases (GST) M6, O1, and O2.

Conclusions

Results show that disruption of PTEN resulted in steatohepatitis, fibrosis and caused hepatic induction of the Nrf2-dependent antioxidant system at least in part due to elevation of p62. This response was both cell-type and zone specific. However, these responses were insufficient to mitigate the accumulation of products of lipid peroxidation.

Differential carbonylation of proteins in end-stage human fatty and nonfatty NASH

OBJECTIVE

In the liver, a contributing factor in the pathogenesis of non-alcoholic fatty liver disease is oxidative stress leading to the accumulation of highly reactive electrophilic α/β unsaturated aldehydes. The objective of this study was to determine if significant differences were evident when evaluating carbonylation in human end-stage fatty nonalcoholic steatohepatitis (fNASH) compared to end-stage nonfatty NASH (nfNASH).

METHODS

Using hepatic tissue obtained from healthy humans and patients diagnosed with end stage nfNASH or fNASH, overall carbonylation was assessed by immunohistochemistry (IHC) and LC-MS/MS followed by bioinformatics.

RESULTS

Picrosirius red staining revealed extensive fibrosis in both fNASH and nfNASH which corresponded with increased reactive aldehyde staining. Although significantly elevated when compared to normal hepatic tissue, no significant differences in overall carbonylation and fibrosis were evident when comparing fNASH with nfNASH. Examining proteins that are critical for anti-oxidant defense revealed elevated expression of thioredoxin, thioredoxin interacting protein, glutathione S-transferase p1 and mitochondrial superoxide dismutase in human NASH. As important, using immunohistochemistry, significant colocalization of the aforementioned proteins occurred in cytokeratin 7 positive cells indicating that they are part of the ductular reaction. Expression of catalase and Hsp70 decreased in both groups when compared to normal human liver. Mass spectrometric analysis revealed a total of 778 carbonylated proteins. Of these, 194 were common to all groups, 124 unique to tissue prepared from healthy individuals, 357 proteins exclusive to NASH, 124 proteins distinct to samples from patients with fNASH and 178 unique to nfNASH. Using functional enrichment analysis of hepatic carbonylated proteins revealed a propensity for increased carbonylation of proteins regulating cholesterol and Huntington's disease related pathways occurred in nfNASH. Examining fNASH, increased carbonylation was evident in proteins regulating Rho cytoskeletal pathways, nicotinic acetylcholine receptor signaling and chemokine/cytokine inflammatory pathways. Using LC-MS/MS analysis and trypsin digests, sites of carbonylation were identified on peptides isolated from vimentin, endoplasmin and serum albumin in nfNASH and fNASH respectively.

CONCLUSIONS

These results indicate that cellular factors regulating mechanisms of protein carbonylation may be different depending on pathological diagnosis of NASH. Furthermore these studies are the first to use LC-MS/MS analysis of carbonylated proteins in human NAFLD and explore possible mechanistic links with end stage cirrhosis due to fatty liver disease and the generation of reactive aldehydes.

Oxidative Stress as a Critical Factor in Nonalcoholic Fatty Liver Disease Pathogenesis

SIGNIFICANCE

Nonalcoholic fatty liver disease (NAFLD), characterized by liver triacylglycerol build-up, has been growing in the global world in concert with the raised prevalence of cardiometabolic disorders, including obesity, diabetes, and hyperlipemia. Redox imbalance has been suggested to be highly relevant to NAFLD pathogenesis. Recent Advances: As a major health problem, NAFLD progresses to the more severe nonalcoholic steatohepatitis (NASH) condition and predisposes susceptible individuals to liver and cardiovascular disease. Although NAFLD represents the predominant cause of chronic liver disorders, the mechanisms of its development and progression remain incompletely understood, even if various scientific groups ascribed them to the occurrence of insulin resistance, dyslipidemia, inflammation, and apoptosis. Nevertheless, oxidative stress (OxS) more and more appears as the most important pathological event during NAFLD development and the hallmark between simple steatosis and NASH manifestation.

CRITICAL ISSUES

The purpose of this article is to summarize recent developments in the understanding of NAFLD, essentially focusing on OxS as a major pathogenetic mechanism. Various attempts to translate reactive oxygen species (ROS) scavenging by antioxidants into experimental and clinical studies have yielded mostly encouraging results.

FUTURE DIRECTIONS

Although augmented concentrations of ROS and faulty antioxidant defense have been associated to NAFLD and related complications, mechanisms of action and proofs of principle should be highlighted to support the causative role of OxS and to translate its concept into the clinic. Antioxid. Redox Signal. 26, 519-541.

Quercetin protects liver injury induced by bile duct ligation via attenuation of Rac1 and NADPH oxidase1 expression in rats

BACKGROUND

Bile duct ligation (BDL) and subsequent cholestasis are correlated with oxidative stress, hepatocellular injury and fibrosis. Quercetin is a flavonoid with antifibrotic, and hepatoprotective properties. However, the molecular mechanism underlying quercetin-mediated hepatoprotection is not fully understood. The current study was to evaluate mechanisms of hepatoprotective effect of quercetin in BDL rat model.

METHODS

We divided male Wistar rats into 4 groups (n=8 for each): sham, sham+quercetin (30 mg/kg per day), BDL, and BDL+quercetin (30 mg/kg per day). Four weeks later, the rats were sacrificed, the blood was collected for liver enzyme measurements and liver for the measurement of Rac1, Rac1-GTP and NOX1 mRNA and protein levels by quantitative PCR and Western blotting, respectively.

RESULTS

Quercetin significantly alleviated liver injury in BDL rats as evidenced by histology and reduced liver enzymes. Furthermore, the mRNA and protein expression of Rac1, Rac1-GTP and NOX1 were significantly increased in BDL rats compared with those in the sham group (P<0.05); quercetin treatment reversed these variables back toward normal (P<0.05). Another interesting finding was that the antioxidant markers e.g. superoxide dismutase and catalase were elevated in quercetin-treated BDL rats compared to BDL rats (P<0.05).

CONCLUSION

Quercetin demonstrated hepatoprotective activity against BDL-induced liver injury through increasing antioxidant capacity of the liver tissue, while preventing the production of Rac1, Rac1-GTP and NOX1 proteins.

Association between LAPTM4B gene polymorphism and prostate cancer susceptibility in an Iranian population

Lysosome associated protein transmembrane 4 β (LAPTM4B) is an oncogene associated with many human cancers. In the present study we aimed to examine the possible association between LAPTM4B polymorphism and risk of prostate cancer (PCa) in an Iranian population. This case control study was performed on 168 patients with PCa and 176 controls with benign prostatic hyperplasia (BPH). Genomic DNA was extracted from whole blood and LAPTM4B genotypes were identified by polymerase chain reaction. The distributions of LAPTM4B genotypes were significantly different between PCa patients (60.7% for *1/1, 32.8% for *1/2, and 6.5% for *2/2) and controls (44.9% for *1/1, 49.4% for *1/2, and 5.7% for *2/2). Both the *1/2 and *1/2+*2/2 genotypes significantly decreased the risk of PCa compared with the *1/1 genotype (OR = 49, 95% CI = 0.31-0.77, p = 0.002 and OR = 0.53, 95% CI = 0.34-0.81, p = 0.004, respectively). The minor allele (LAPTM4B*2) was associated with a decreased risk of PCa compared with the LAPTM4B*1 allele (OR = 0.68, 95% CI = 0.48-0.96, p = 0.031). Moreover, LAPTM4B polymorphism was not associated with clinicopathological characteristics of PCa patients. The results of this study showed that LAPTM4B*2 was associated with a decreased risk of PCa but the clinicopathological characteristics of PCa were not linked to LAPTM4B polymorphism. Further studies with larger sample sizes and different ethnicities are needed to confirm our findings.

Association between Programmed Cell Death 6 Interacting Protein Insertion/Deletion Polymorphism and the Risk of Breast Cancer in a Sample of Iranian Population

It has been suggested that genetic factors contribute to patients' vulnerability to breast cancer (BC). The programmed cell death 6 interacting protein (PDCD6IP) encodes for a protein that is known to bind to the products of the PDCD6 gene, which is involved in the apoptosis pathway. The aim of this case-control study is to investigate the relationship between the PDCD6IP 15 bp insertion/deletion (I/D) polymorphism (rs28381975) and BC risk in an Iranian population. A total of 491 females, including 266 BC patients and 225 control subjects without cancer, were enrolled into the study. Our findings revealed that the PDCD6IP 15 bp I/D polymorphism decreased the risk of BC in codominant (OR = 0.44, 95% CI = 0.31-0.65, p < 0.0001, I/D versus DD; OR = 0.39, 95% CI = 0.17-0.88, p = 0.030, I/I versus DD) and dominant (OR = 0.44, 95% CI = 0.30-0.63, p < 0.0001, D/I + I/I versus D/D) tested inheritance models. Also, the PDCD6IP I allele significantly decreased the risk of BC (OR = 0.59, 95% CI = 0.45-0.78, p < 0.001) compared to the D allele.

Association between hTERT polymorphisms and the risk of breast cancer in a sample of Southeast Iranian population

BACKGROUND

Breast cancer (BC) is considered to be one of the most important causes of death worldwide, and it affects the Iranian female population a decade earlier than female in other parts of the world. Human telomerase reverse transcriptase (hTERT) is a main subunit of the telomerase complex. MNS16A is located downstream of the hTERT gene and is recognized as the regulator of hTERT promoter activity. The aim of the present study was to access the possible impact of hTERT variants on BC risk in an Iranian population in southeast Iran.

METHODS

A total of 491 subjects including 266 BC patients and 225 healthy women participated in the study. Polymerase chain reaction (PCR) was used to genotype the MNS16A variable number of tandem repeats and 177 bp ins/del polymorphisms in the hTERT gene. PCR-RFLP and ARMS-PCR were used to genotype hTERT rs2736098 and 2735940, respectively. The association between genotypes and BC was assessed by computing the odds ratio (OR) and 95% confidence intervals (95% CI) from logistic regression analyses. A p-value of <0.05 was considered statistically significant.

RESULTS

The MNS16A genotype frequency distribution in BC patients was: LL, 43.2%; LS, 51.1%; and SS, 5.7%, and in controls: LL, 29.5%; LS, 68.3%; and SS, 2.2%. The LS genotype decreased the risk of BC compared with LL (OR=0.51, 95% CI=0.35-0.75, p<0.001). The hTERT 177 bp ins/del polymorphism was not polymorphic in our population. All subjects had the ins/ins genotype. Our findings indicate that the MNS16A genotype and hTERT rs2736098 variant were associated with BC risk in the study. We also showed that the rs2736098 A/G polymorphism increased the risk of BC (OR=1.80, 95% CI=1.12-2.88, p=0.017, AG vs AA; OR=1.80, 95% CI=1.06-3.06, p=0.033, GG vs AA; OR=1.87, 95% CI=1.19-2.94, p=0.006, AG+GG vs AA). No significant association was found between the rs2735940 C/T variant and BC.

CONCLUSION

Our findings indicate that the MNS16A genotype and the hTERT rs2736098 variant influence the risk of BC in an Iranian population in southeast Iran.

Glutathione S-transferase M1 and glutathione S-transferase T1 genotype in chronic pancreatitis: a meta-analysis

OBJECTIVE

A meta-analysis to determine the association between chronic pancreatitis and glutathione-S transferase (GST) mu 1 (GSTM1) and theta 1 (GSTT1) deletions.

METHODS

Case-control studies concerning the relationship between chronic pancreatitis and GSTM1 or GSTT1 deletions were identified (up to October 2013). Meta-analyses of the association between GSTM1 and GSTT1 genotype and chronic pancreatitis or alcoholic chronic pancreatitis (ACP) were performed.

RESULTS

Seven studies were included in the meta-analysis (650 patients/1382 controls for GSTM1 and 536 patients/1304 controls for GSTT1). There were no significant relationships between GSTM1/GSTT1 and chronic pancreatitis or GSTT1 and ACP. There was a significant association between GSTM1 null genotype and ACP (odds ratio 1.16, 95% confidence intervals 1.03, 1.30).

CONCLUSION

The GSTM1 null genotype was significantly associated with ACP risk.

Association between CCNE1 polymorphisms and the risk of breast cancer in a sample of southeast Iranian population

Cyclin E1 (CCNE1) is a key proto-oncogene. The present study aimed to investigate the effects of single nucleotide polymorphisms in CCNE1 on the risk of breast cancer (BC) in an Iranian population in southeast of Iran. A total of 491 subjects including 266 BC patients and 225 healthy control women were participated in the study. Genotyping of CCNE1 rs3218073 and 72010703 polymorphisms was done using allele-specific polymerase chain reaction (AS-PCR) and rs1406 by PCR-RFLP method.Our findings showed that rs1406 C/A polymorphism increased the risk of BC in codominant (OR 1.60, 95% CI 1.05-2.43, p=0.032 CA vs CC; OR 2.35, 95% CI 1.23-4.49, p=0.011 AA vs CC) and dominant (OR 1.69, 95% CI 1.22-2.56, p=0.012 CA+AA vs CC) inheritance models. The rs1406 A allele increased the risk of BC (OR 1.37, 95% CI 1.06-1.76, p=0.019) in comparison with C allele. On the other hand, CCNE1 rs72010703 (4-bp I/D) and rs3218073 polymorphisms did not show any significant association with BC. This study indicates that CCNE1 rs1406 polymorphism may contribute to BC risk.

Association between LAPTM4B gene polymorphism and breast cancer susceptibility in an Iranian population

Lysosome associated protein transmembrane 4beta (LAPTM4B) contribute to the risk of numerous cancers. The present study focused on the possible association between LAPTM4B polymorphism and the risk of breast cancer (BC) in an Iranian population in southeast Iran. This case control study includes 311 BC patients and 225 healthy women. Genomic DNA was extracted from the whole blood by salting out method and LAPTM4B genotype was investigated using polymerase chain reaction. Our findings showed that LAPTM4B genotype was not associated with the risk of BC in any inheritance model tested. The minor allele frequency in case and control group was 0.297 and 0.278, respectively. The minor allele (LAPTM4B*2) was not associated with BC risk in comparison with LAPTM4B*1 allele (odds ratio 1.10, 95 % confidence intervals 0.84-1.44, p = 0.495). Moreover, LAPTM4B polymorphism was not associated with clinical and pathological characteristics in the patient group. In conclusion, the findings of our study suggested that the polymorphism of LAPTM4B gene was not associated with susceptibility to BC and clinicopathological characteristics in an Iranian population.

Investigation of FGF1 and FGFR gene polymorphisms in a group of Iranian patients with nonsyndromic cleft lip with or without cleft palate

OBJECTIVE

Nonsyndromic cleft lip with or without cleft palate (NS-CL/P) is one of the most common craniofacial malformations determined by the interaction between multiple genes and environmental risk factors. Genes coding for fibroblast growth factors and their receptors (FGF/FGFR genes) are considered as excellent candidate genes, which their proteins play important roles in craniofacial and palatal development. The aim of the current study was to assess the possible association between FGF1 rs34010 C>A and FGFR1 rs13317 A>G gene polymorphisms and susceptibility to NS-CL/P in an Iranian population.

DESIGN

This case-control retrospective study was performed on a total of 200 subjects including 100 NS-CL/P patients and 100 healthy unrelated controls. Tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) was used to detect FGF1 rs34010 C>A and FGFR1 rs13317 A>G SNPs.

RESULTS

Our data demonstrated that the FGF1 rs34010, CA and CA+AA genotypes were associated with a reduced risk of NS-CL/P the in codominant (CA vs. CC: OR=0.29, 95%CI=0.16-0.55, P=0.001) and dominant (CA+AA vs. CC: OR=0.36, 95%CI=0.19-0.69, P=0.001) tested inheritance models, respectively. Additionally, the analysis of FGF1/FGFR1 genotype combinations revealed that rs34010CA/rs13317AA and rs34010CA/rs13317AG combinations were associated with a lower risk of NS-CL/P (OR=0.357, P=0.008 for the rs34010CA/rs13317AA; OR=0.226, P=0.004 for the rs34010CA/rs13317AG).

CONCLUSIONS

Our findings suggest that the FGF1 rs34010 C/A polymorphism was associated with a decreased risk of NS-CL/P, and might act as a protective factor against NS-CL/P predisposition.

A case-control study on the effect of metabolic gene polymorphisms, nutrition, and their interaction on the risk of non-alcoholic fatty liver disease

The oxidative stress is a key issue in the etiology of non-alcoholic fatty liver disease (NAFLD). The aim of our study was to evaluate the effect of metabolic gene polymorphisms involved in the oxidative stress (GSTT1, GSTM1, SULT1A1, CYP2E1, and 1A1), lifestyle and nutrition aspects, and their interaction, on the risk of NAFLD. We enrolled 294 cases and 359 controls, and collected demographics, anthropometric, lifestyle, and nutrition data. A subgroup of NAFLD provided additional data on nutrients and on physical activity engagement. Each patient provided a blood sample for DNA extraction and genotyping. Clinical and laboratory data were collected from cases. Multivariable analysis shows a significant protective effect of age, gender, and moderate drinking habits on the risk of NAFLD, while an increased risk for greater consumption of fruit and grilled meat or fish. Significant interactions were reported between alcohol consumption, fruit intake, grilled meat and fish, and selected genetic variants. From the subgroup analysis, a moderate/high consumption of fat and/or grilled meat/fish, and a high consumption of white meat increase the risk of NAFLD. Engaging any physical activity at least 1 time/week halves the risk of NAFLD. Besides confirming the beneficial effect of moderate alcohol intake and regular physical activity, and the increased risk associated with high fruit and fat intake, for the first time, we report a detrimental effect of grilled food on NAFLD risk. An effect modification by selected gene variants increases the risk in combination with fruit and grilled food intake.

Association between CDH1 and MSX1 Gene Polymorphisms and the Risk of Nonsyndromic Cleft Lip and/or Cleft Palate in a Southeast Iranian Population

Objective

Orofacial clefts such as cleft palate (CP) and cleft lip (CL) and/or cleft palate (CL/P) are the most common congenital anomalies of the head and neck. The aims of the present study were to evaluate the possible association between CDH1 (rs11642413 and rs16260) and MSX1 (rs12532 and rs3775261) gene polymorphisms and nonsyndromic cleft lip and/or cleft palate (NS-CL/P) in a sample of the Iranian population.

Design and Setting

This case-control study was performed on 100 subjects with NS-CL/P and 100 healthy unrelated control subjects. Tetra amplification refractory mutation system-polymerase chain reaction and multiplex polymerase chain reaction were used to detect the single-nucleotide polymorphisms.

Results

There was a significant difference between NS-CL/P subjects and control subjects regarding CDH1 rs16260 C > A polymorphism, and the rs16260 AC as well as the rs16260 AA genotypes were associated with NS-CL/P susceptibility (odds ratio [OR] = 3.02, 95% confidence interval [CI] =1.51 −6.00, P=.001; and OR = 8.05, 95% CI = 1.72–37.75, P=.002, respectively). No significant difference was found between the groups regarding CDH1 rs11642413 polymorphism. Although MSX1 rs3775261 polymorphism was not a risk factor for the disease, the rs12532 AG and rs12532 GG genotypes were associated with NS-CL/P risk (OR = 2.82, 95% CI = 1.55–5.15, P=.001; and OR = 8.42, 95% CI = 2.26–31.29, P=.004, respectively).

Conclusion

Our data suggest that CDH1 and MSX1 gene polymorphisms are risk factors for susceptibility to NS-CL/P in a sample of the Iranian population. Larger studies are required to validate our findings.

Association of Adiponectin rs1501299 and rs266729 Gene Polymorphisms With Nonalcoholic Fatty Liver Disease

BACKGROUND

Genetic and environmental factors are important for the development of nonalcoholic fatty liver disease (NAFLD). Adiponectin is a white and brown adipose tissue hormone, and have been found to play essential roles in the regulation of energy homoeostasis. Recent reports have identified a possible role of adiponectin in NAFLD via PPARγ pathway.

OBJECTIVES

The present study was designed to find out the impact of adiponectin rs1501299 (276G/T) and rs266729 (-11377C/G) gene polymorphisms in NAFLD.

PATIENTS AND METHODS

Eighty-three patients with diagnosis of NAFLD, and 93 healthy subjects were included in the study. Tetra ARMS-PCR was designed to detect single nucleotide polymorphisms.

RESULTS

A significant difference was found between NAFLD and control group regarding the rs266729 polymorphism (χ2 = 7.35, P = 0.025). The rs266729 polymorphism increased the risk of NAFLD in codominant (CC vs. CG: OR = 2.18, 95% CI = 1.16 - 4.12, P = 0.016) and dominant (CC vs. CG/GG: OR = 2.31, 95% CI = 1.25 - 4.27; P = 0.008) inheritance tested models. The G allele increased the risk of NAFLD (OR = 1.63, 95% CI = 1.03 - 2.57, P = 0.037) in comparison with C allele. No significant difference was found between the groups concerning adiponectin rs1501299 gene polymorphism (χ2 = 0.70, P = 0.697).

CONCLUSIONS

adiponectin rs266729 polymorphism might be a candidate gene, which determines the susceptibility to NAFLD. Larger studies are necessary to confirm these findings in various populations.

Interactive effects of smoking and glutathione S-transferase polymorphisms on the development of non-alcoholic fatty liver disease

Glutathione S-transferases (GSTs) protect cells against exogenous and endogenous oxidative stress. GST polymorphisms are associated with the development of cardiovascular disease (CVD) and diabetes mellitus (DM), especially in current-smokers. Non-alcoholic fatty liver disease (NAFLD) is a predictor of future CVD or DM, because oxidative stress contributes to their pathogenesis. This study investigated whether the combination of smoking status and GST genotypes could affect the risk for NAFLD. A cross-sectional analysis was conducted among 713 Japanese participants (458 males and 255 females) during a health screening program. The GSTM1 null, GSTT1 null, GSTP1 A/B or B/B and GSTA1 A/B or B/B genotypes were determined and deemed to be high-risk genotypes. The prevalence of NAFLD was 18.7%. Among never-smokers, carriers of one, and those of two or more high-risk GSTM1, GSTP1 or GSTA1 genotypes were at a higher risk for NAFLD than those who were not carriers [odds ratio (95% confidence interval): 2.6 (1.1-5.9) and 3.3 (1.3-8.1), respectively], and the risk was further increased among current-smokers [4.6 (1.6-13.0) and 5.4 (1.2-23.7), respectively]. This is the first report to show that the combination of current-smoking and harboring high-risk GSTM1, GSTP1 and/or GSTA1 genotypes is interactively associated with the risk of NAFLD.

Association between polymorphisms of glutathione S-transferase genes (GSTM1, GSTP1 and GSTT1) and breast cancer risk in a sample Iranian population

Aim: Genetic and environmental factors are risk factors for breast cancer. Our aim was to investigate the associations between genetic polymorphism of GST genes (GSTM1, GSTT1 and GSTP1) and susceptibility to breast cancer in an Iranian population. Materials & methods: This case–control study was carried out on 134 patients with breast cancer and 152 healthy, cancer-free women. GSTP1 polymorphism was determined using tetra-primer amplification refractory mutation system PCR assay and GSTM1 and GSTT1 were genotyped by a multiplex PCR. Results: We found that the GSTM1 null genotype is a risk factor for predisposition to breast cancer (odds ratio [OR] = 2.01; 95% CI = 1.78–3.45; p = 0.010). No significant difference was found between the groups regarding GSTT1 null genotype (p > 0.05). The GSTP1 Ile/Val and Val/Val genotypes were associated with breast cancer risk (OR = 3.29; 95% CI = 1.84–5.91; p < 0.0001 and OR = 20.68; 95% CI = 5.66–75.60; p < 0.0001, respectively). Conclusion: In summary, GSTM1 and GSTP1, but not GSTT1 genetic polymorphisms are associated with increased risk of breast cancer in our population.

Bi-directional PCR allele-specific amplification (bi-PASA) for detection of caspase-8 -652 6N ins/del promoter polymorphism (rs3834129) in breast cancer

Caspase-8 (CASP8) plays a critical role in regulating apoptosis, and its functional polymorphisms may modify cancer risk. We investigated the possible association between CASP8 -652 6N ins/del (rs3834129) and the risk of breast cancer in a sample of Iranian population. This case-control study was done on 236 breast cancer patients and 203 cancer free healthy female. We designed a rapid and simple bi-directional PCR allele-specific amplification (bi-PASA) for detection of CASP8 -652 6N ins/del polymorphism. The results showed that the CASP8 -652 6N del/dl genotype was inversely associated with breast cancer risk (OR=0.33, 95% CI=0.17-0.65, p=0.001). The frequencies of the del allele in cases and controls were 29.1% and 38.6%, respectively. An inverse association between CASP8 6N del variant and the risk of breast cancer (OR=0.66, 95% CI=0.66-0.87, p=0.002) was found. In conclusion, the result suggests that the CASP8 -652 6N del polymorphism plays a protective role in susceptibility to breast cancer in our population. Further studies in other populations with larger samples are needed to confirm these findings.