The Relation between Polymorphisms in Exon 5 and Exon 6 of GSTP1 Gene and the Risk of Lung Cancer in Iranian People

Association of GSTM1 and GSTT1 Null Deletions and GSTP1 rs1695 Polymorphism with the Risk of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

Context: Hepatocellular carcinoma (HCC), as the most common type of primary liver cancer (accounting for 70% - 90% of all liver cancers), is the seventh most common malignancy worldwide. Glutathione S-transferases (GSTs) are a specific group of enzymes that are responsible for the detoxification of carcinogens. According to the available literature, genetic variations in this group of enzymes may be associated with the risk of HCC. In this study, we aimed to assess the association of GSTM1 and GSTT1 null deletions and GSTP1 rs1695 polymorphism with the risk of HCC. Methods: We systematically searched electronic databases, including PubMed, Scopus, and Web of Science, using appropriate keywords to gather relevant data until March 2019. Studies that met the inclusion criteria were included in the meta-analysis, using either fixed- or random-effects models based on the presence of heterogeneity. Results: This meta-analysis pooled 19 studies for GSTM1 null deletions, 14 studies for GSTT1 null deletions, and five studies for GSTP1 rs1695 polymorphism. In terms of heterogeneity, the pooled odds ratio (OR) was calculated in a random-effects model for both Asian and non-Asian populations. HCC was found to be associated with GSTM1 null deletions (OR = 1.26, 95% CI: 1.00 - 1.58, P = 0.05) and GSTT1 null deletions (OR = 1.39, 95% CI: 1.10 - 1.74, P = 0.005); however, no significant association was found between HCC and GSTP1 rs1695 polymorphism (OR = 1.14, 95% CI: 0.86 - 1.50, P = 0.36). Conclusions: We found that GSTM1 and GSTT1 null deletions increased the risk of HCC; however, the GSTP1 rs1695 polymorphism did not have a similar effect.

CORRELATION ANALYSIS OF GSTP1 GENE POLYMORPHISM WITH MORBIDITY OF PRIMARY METASTATIC COLORECTAL CANCER

Colorectal cancer (CRC) is one of the most common malignancies. Susceptibility to malignant processes is mediated by genetically driven differences in the effectiveness of detoxification of potential carcinogens. One of the factors that may influence the risk of CRC is the glutathione-S-transferase (GST) gene family that encodes glutathione transferase enzymes. The GSTP1 gene is expressed both in normal and pathological conditions. Determining its specific alleles may be a marker of CRC. The aim of the research – to study GSTP1 gene polymorphism, which is likely to be more common among patients with primary metastatic colorectal cancer compared with healthy population. Materials and methods. The study involved 12 patients with primary metastatic colorectal cancer aged 43 to 72 years, the control group was represented by a sample of 31 people without cancer. Results. The incidence of advanced CRC in the presence of GSPT1 Val / Val (aa) polymorphism is statistically significantly higher than in the presence of Ile / Ile (AA) and Ile / Val (Aa) GSPT1 polymorphism. Conclusions. Among people with GSTP1 Val / Val (aa) polymorphism, primary CRC is 4.4 times more likely than among people with GSPT1 Ile / Ile (AA) and Ile / Val (Aa) polymorphisms, which are statistically significant (P < 0.05). The obtained results indicate the possibility of conducting a genetic study of GSTP1 polymorphism to form groups of potential risk of CRC.

Glutathione S-Transferase P1 Polymorphism on Exon 6 and Risk of Hepatocellular Carcinoma in Thai Male Patients

INTRODUCTION

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the fourth leading cause of cancer-related deaths worldwide. HCC cases are two to four times more common in males than in females, and the highest incidence is found in Asia and Sub-Saharan Africa. This gender disparity is the result of different behavioral risk factors, such as smoking and drinking alcohol. Glutathione S-Transferase P1 (GSTP1) is an enzyme that is involved in the detoxification of carcinogenic electrophiles. GSTP1 codon 105 in exon 5 and codon 114 in exon 6 polymorphisms result in decreased enzyme detoxification activity, which is the cause of many cancers.

OBJECTIVES

This study aims to investigate the associations between GSTP1 polymorphism, HCC patients, and the risk factors for HCC. It is hoped that this research will provide useful knowledge on the effects of genetic GSTP1 polymorphism in Thai HCC patients.

METHODS

DNA from 44 Thai HCC patients and 52 healthy controls was analyzed for GSTP1 exon 5 and exon 6 polymorphisms by PCR-RFLP. The associations between GSTP1 polymorphism, the control group, and clinicopathological parameters were determined.

RESULTS

The results show that GSTP1 exon 6 polymorphism genotypes (C/T) were correlated with an increased risk of HCC susceptibility (OR = 4.40). Moreover, exon 6 polymorphism genotypes (C/T) were associated with the gender of patients (p = 0.015), but no relationships were found between GSTP1 exon 5 polymorphism and the clinicopathological data of patients.

CONCLUSIONS

The results suggest that the GSTP1 exon 6 polymorphism genotype was associated with an increase in the risk of HCC in male patients and that it tended to be related to cancer differentiation. No association was found between GSTP1 exon 5 polymorphism and the risk of HCC.