Frequency of glutathione-S-transferase null-M1 and null-T1 genotypes among the Turabah population in Saudi Arabia

Copy Number Variation in the GSTM1 and GSTT1 Genes and the Risk of Liver Cirrhosis in Eastern Ethiopia

Background

Polymorphisms in glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) can cause an entire gene deletion. The current methodology can accurately identify GSTM1 and GSTT1 copy number variants (CNVs), which may shed light on the true contribution of each gene copy to the cellular detoxification process and disease risk. Because liver cirrhosis is becoming a critical worldwide health issue, this study determined the CNVs of GSTM1 and GSTT1 and their relationship to the risk of liver cirrhosis.

Methods

In this study, we compared 106 patients with liver cirrhosis to 104 healthy controls. Real-time PCR was used to identify the CNVs of GSTM1 and GSTT1. Logistic and linear regression models were used to estimate the relationship between liver cirrhosis and clinical chemistry variables with the CNVs, respectively.

Results

In 3.3% of the study participants, >2 copies of the GSTM1 or GSTT1 genes were detected. GSTT1 carriers had a significantly lower risk of liver cirrhosis (p<0.05) compared with individuals who had homozygous deletion (adjusted odds ratio (AOR) = 0.47; 95% CI: 0.25, 0.86). This risk reduction was significant (p<0.05) in patients with a single copy of the GSTT1 gene (AOR = 0.48; 95% CI: 0.25, 0.91). Those with ≥2 copies of combined GSTM1 and GSTT1 also had a significantly (p<0.05) lower risk of developing liver cirrhosis compared with double null genotypes (AOR = 0.38; 95% CI: 0.16, 0.91, p trend <0.001). Moreover, ≥2 copies of combined GSTM1 and GSTT1 genes were associated with a substantial decrease in alanine amino transferase (ALT) and aspartate aminotransferase (AST) levels, respectively.

Conclusion

A single copy number of GSTT1, and ≥2 copies of combined GSTM1 and GSTT1 genes were associated with a reduced risk of liver cirrhosis in Ethiopians. These findings underscore the importance of gene-environment interactions in the multifactorial development of liver cirrhosis.

Impact of Glutathione S-Transferase Polymorphisms on Busulfan Pharmacokinetics and Outcomes of Hematopoietic Stem Cell Transplantation

BACKGROUND

Busulfan (Bu) is an alkylating drug used in many preparative regimens before hematopoietic stem cell transplantation (HSCT). It is conjugated in the liver mainly by glutathione S-transferase isoenzyme A1-1 ( GSTA1 ). Genetic polymorphisms in these isoenzymes may affect the pharmacokinetics of Bu and the clinical outcomes of HSCT. This study aimed to assess the impact of glutathione S-transferase ( GST ) genetic polymorphisms on the clearance of Bu and the clinical outcomes of patients undergoing HSCT.

METHODS

This single-center retrospective study included patients who received IV Bu before HSCT at Sultan Qaboos University Hospital (SQUH), Oman from January 2003 to October 2016. Genotyping for polymorphisms was performed for GSTM1 , GSTT1 , GSTA1 , and GSTP1 . Each GST polymorphism was analyzed for its impact on Bu clearance and HSCT outcomes.

RESULTS

A total of 135 patients were included. The mean Bu clearance was 3.7 ± 0.98 mL/min/kg. Patients with GSTA1 A-513G heterozygosity (AG) were found to have a higher incidence of graft loss ( P = 0.006). Homozygous double null of GSTM1 and GSTT1 was associated with a higher incidence of acute graft versus host disease ( P = 0.04). Double non-null GSTM1 and GSTT1 and non-null GSTM1 increased the risk of mortality ( P = 0.034 and 0.021, respectively).

CONCLUSIONS

GST genotyping before HSCT may predict HSCT outcomes. The results of this preliminary retrospective study need to be confirmed in a larger prospective study.

Genetic polymorphism of lysyl oxidase, glutathione S-transferase M1, glutathione-S-transferase T1, and glutathione S-transferase P1 genes as risk factors for lung cancer in Egyptian patients

Lung cancer is a lethal malignancy and is affected by genetic polymorphisms that contribute to an individual's susceptibility to developing the disease. Several studies on lung cancer showed conflicting results. The aim of this study is to investigate whether individual or combined modifying effects of LOX G/A, GSTM1 active/null, GSTT1 active/null and GSTP1 Ile/Val polymorphisms are related to the risk of lung cancer in relation to smoking in the Egyptian population. This study is a hospital-based case control study that included 200 patients and 200 control subjects. Genotyping of the 4 studied genes was determined by Multiplex PCR for GSTM1 and GSTT1 and Taq man SNP assay for GSTP1 and LOX genes. The LOX G/A and GSTP1 Ile/Val in both homozygous and heterozygous variants, and the GSTM1 and GSTT1 null genotype showed significant association with lung cancer. Combination between gene polymorphism and smoking increased the risk of developing cancer by 2.7 fold in the LOX GA+AA variant, 1.9 fold in the GSTM1 null variant, 4.8 fold in the GSTT1 null variant and 4.3 fold in the GSTP1 Ile/Val+Val/Val variant. The genetic combination (LOX GA+AA/GSTT1 active, LOX GG/GSTT1 null, LOX GA+AA/GSTT1 null, LOX GA+AA/GSTP1 Ile/Ile, LOX GG/GSTP1 Ile/Val+Val/Val and LOX GA+AA/GSTP1 Ile/Val+Val/Val) led to a higher lung cancer risk, compared to the reference group. The LOX GA/AA, GSTM1 null, GSTT1 null and GSTP1 Ile/Val, Val/Val genotypes contributed to increased lung cancer susceptibility. To the best of our knowledge, this is the first study of LOX genotyping in the Egyptian population. The combination of genotypes increased the risk of cancer, indicating the importance of gene-gene interaction and giving a targeted preventive approach.

Association of glutathione S-transferase GSTM1 and GSTT1 deletion polymorphisms with obesity and their relationship with body mass index, lipoprotein and hypertension among young age Saudis

Objectives

Persistent oxidative stress is one of the several risk factors that may be associated with the etiology of obesity. The present study is aimed to investigate association between GSTM1 and GSTT1 polymorphisms with obesity and their relationship with plasma lipoproteins, body mass index (BMI) and hypertension.

Design

The GSTM1 and GSTT1 deletion polymorphisms were analyzed by multiplex polymerase chain reaction. The lipoproteins were measured in plasma using commercially available kit and the weight, height, systolic (SBP) and diastolic (DBP) blood pressures by standard procedure of measurements.

Setting

Prince Sultan Military Medical City, Riyadh Saudi Arabia.

Participants

A total of 420 overweight/obese cases and 234 normal weight controls belong to young age Saudis.

Main outcomes measures

GSTM1/GSTT1 polymorphisms may be associated with obesity.

Results

Weight, BMI, low-density lipoprotein (LDL) and SBP were significantly higher while high-density lipoprotein (HDL) was significantly lower in cases in comparison to controls. Frequency of GSTM1+/GSTT1− (OR = 2.70, 95% CI = 1.52–4.81, p = <0.001) and GSTM1−/GSTT1− (OR = 2.43, 95% CI = 1.15–5.15, p = 0.018) was significantly higher in cases as compared to controls. BMI and weight were significantly higher in GSTM1+/GSTT1− and GSTM1−/GSTT1− genotypes, and LDL, DBP and SBP significantly higher in GSTM1−/GSTT1− null genotype while HDL was significantly lower in GSTM1−/GSTT1+ and GSTM1−/GSTT1− genotypes in comparison to GSTM1+/GSTT1+ genotype.

Conclusions

The GSTM1+/GSTT1− and GSTM1−/GSTT1− null genotypes were significantly associated with obesity and have shown relationship with obesity risk factors in cases. Hence, these genes may be associative genetic risk factor for obesity among young age Saudis.