Interactions between oral contraceptive status and GSTM1 and GSTT1 deletions on insulin-like growth factor-1 (IGF-1) plasma levels in young healthy women

Association of glutathione S-transferase 1 (GSTP1) polymorphisms with Breast Cancer susceptibility

Hereditary and environmental variables have a role in the development of breast cancer. This study aimed to examine the links between genetic Variations in the GSTP1 gene and Predisposition to breast cancer in an Iraqi population. The research included 40 Iraqi female breast cancer patients and 20 healthy volunteers. GSTP1-1695 A/G gene polymorphisms were investigated using polymerase chain reaction in Real-time (RT-PCR). The results showed the GSTP1 frequency of the wild GG genotypes was showed significantly (P<0.01) higher in healthy women in comparison with Breast cancer women (GG, 80% vs. 32.5%, respectively; furthermore, heterozygous AG genotypes were significantly higher in Breast cancer women in comparison with healthy women 42.5% vs. 20%, respectively at (P<0.01). While the mutant AA genotype (25%) in patient women appeared significantly (P<0.01) higher compared to healthy women (0.0%). Finally, we discovered a connection between GSTP1 polymorphisms and a higher chance of developing breast cancer in an Iraqi female population sample. Keywords: glutathione S-transferase1, breast cancer, polymorphism.

GSTM1 and GSTT1 copy number variants and the risk to Thai females of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a common malignancy found throughout the world that most often occurs in males. The cancer is associated with many risk factors such as viral infection, cirrhosis, alcohol, smoking, and fungal toxins. GSTM1 and GSTT1 are detoxification enzymes activated by the cleansing of carcinogenic compounds. Low DNA copy numbers of Glutathione S-transferases M1 and T1 result in a loss of enzyme activity, which causes carcinogenesis factors. DNA copy number variants (CNVs) were determined to compare the differences between the frequencies of GSTM1 and GSTT1 in a control group and patients. Then, the association of these genes with the pathological/survival status of HCC patients was investigated.

Methods

Forty-nine Thai HCC patients' DNA and the genomic DNA of 66 healthy controls were investigated for GSTM1 and GSTT1 CNVs by real-time polymerase chain reaction (PCR). Then, the correlations between GSTM1 and GSTT1 patients' CNVs, the control group, and clinico-pathological parameters were determined.

Results

The results show that were no differences between the CNVs of GSTM1 and GSTT1 in the controls and patients (P≥0.05). Only GSTT1 genotypes 0/0 correlated to an increase in the risk of hepatocellular carcinogenesis (OR value was 1.88). GSTM1 CNVs were associated with the gender of patients (P=0.002). However, no correlations were found between GSTT1 CNVs and any of the clinico-pathological parameters.

Conclusions

The results suggest that only GSTT1 CNVs are associated with increased risk factors of HCC in Thais. GSTM1 copy numbers had a dominant correlation with female HCC patients.

Genetic polymorphisms of insulin-like growth factor 1 and insulin-like growth factor binding protein 3, xenoestrogen, phytoestrogen, and premenopausal breast cancer

BACKGROUND

Previous studies suggest a combined effect of insulin-like growth factor 1 (igf-1) and igf binding protein 3 (igfbp-3) gene polymorphisms, xenoestrogen, and phytoestrogen on the igf-1 signalling pathway and serum concentrations in the igf system, which are associated with premenopausal breast cancer (bca) risk.

METHODS

Between 2010 and 2012, our study recruited 140 premenopausal bca patients and 160 community-based premenopausal control subjects. Participants were surveyed about oral contraceptive (oc) use, dietary habits, and other bca risk factors. TaqMan assays were used to determine igf-1 rs1520220 and igfbp-3 rs2854744 genotypes. Daily intakes of energy-adjusted soy isoflavones (easis) were calculated by the residual method. Multivariate logistic regression was applied to estimate the adjusted odds ratios (ors) and 95% confidence intervals (cis) of the igf-1 rs1520220 and igfbp-3 rs2854744 genotypes, oc use, and intake of easis. Stratified analyses were performed to detect the gene-environment combined effect, and multivariate logistic regression was used to estimate interaction coefficients (iors) by the multiplicative model, with 95% cis. The delta method was used to calculate interaction coefficients by the additive model [relative excess risk of interaction (reri), attributable proportions of interaction (apis)] and 95% cis.

RESULTS

The igf-1 and igfbp-3 genotypes, oc use, and easis were not found to be associated with bca risk (p > 0.05). Stratified analysis showed that the risk of bca was markedly increased in women carrying the igfbp-3C allele and using ocs compared with women either carrying the igfbp-3C allele or using ocs (or: 3.02; 95% ci: 1.04 to 8.79). The interaction coefficients ior, reri, and api were 4.89 (95% ci: 1.09 to 21.90), 2.42 (95% ci: -0.76 to 5.61), and 0.80 (95% ci: 0.46 to 1.67) respectively.

CONCLUSIONS

The igfbp-3 rs2854744 polymorphism and oc use might synergistically increase premenopausal bca risk.

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.