A systemic review of glutathione S-transferase P1 Ile105Val polymorphism and colorectal cancer risk

Deletion and Single Nucleotide Polymorphisms in Common Glutathione-S Transferases Contribute to Colorectal Cancer Development

Glutathione-S transferases (GSTs) are xenobiotic-conjugation enzymes involved in the detoxification process of heterocyclic aromatic amines and polycyclic aromatic hydrocarbons, widely recognized risk factors of colorectal cancer (CRC) development. Polymorphism in GSTs often leads to alteration or complete lack of enzyme activity, which might have an effect on CRC carcinogenesis. Aim of this study was to investigate GST gene variants as risk factors in patients with CRC. A total of 523 CRC patients administered for surgical resection and 400 matched controls were included. Deletion polymorphism of GSTs M1 and T1 was investigated by polymerase chain reaction. Single nucleotide polymorphism of GST A1 and P1 was investigated by restriction fragment length polymorphism method. The association between GST genotype and risk of CRC development was found in carriers of GSTT1-null and GSTP1-variant genotypes individually (p = 0.050 and p = 0.016, respectively). Furthermore, statistically significant association was found when combination of GSTP1-variant genotype with any of other three common GST genotypes was analyzed with respect to CRC susceptibility. Additionally, patients with combined GSTM1-null/GSTT1-null/GSTA1 low-activity/GSTP1-variant genotype showed 2.71-fold increased risk of developing CRC (p = 0.037). This study supports hypothesis that GST polymorphisms might have an important role in the process of the CRC development. Additionally, GSTM1-null/ GSTT1-null/ GSTA1 low-activity/ GSTP1-variant genotype could be combination of GST genotypes whose carriers are more prone to CRC development.

Glutathione S-Transferase M1 and T1 Gene Polymorphisms in Patients with Chronic Plaque-Type Psoriasis: A Case-Control Study

OBJECTIVE

To determine the role of glutathione S-transferase (GST) isoenzyme polymorphisms as susceptibility factors in patients with psoriasis in a Turkish cohort.

SUBJECTS AND METHODS

In this case-control study, 105 patients with plaque-type psoriasis and 102 healthy controls were recruited from the dermatology outpatient clinics of two university hospitals. Genomic DNA was extracted from whole blood using a DZ DNA isolation kit. Multiplex PCR was used to determine GSTM1 and GSTT1 polymorphisms in the isolated DNAs.

RESULTS

Of the 150 patients with psoriasis, 83 (79%) were identified with the GSTT1 genotype and 22 (21%) with the null genotype. Of the 102 patients in the control group, 69 (67.6%) subjects were identified with the GSTT1 genotype and 33 (32.4%) with the null genotype. There was no significant difference between the patient and control groups (p = 0.063). Regarding the GSTM1 polymorphism, 54 (51.4%) patients were identified with this genotype and 51 (48.6%) with the null genotype; in the control group, 50 (49%) were identified with this genotype and 52 (51%) with the null genotype. Again there was no statistically significant difference between the groups (p = 0.957).

CONCLUSION

In this Turkish cohort of patients with psoriasis, neither GSTT1 nor GSTM1 polymorphisms were associated with disease susceptibility. Larger studies with a wider range of GST isoenzyme are needed.

The effect of GSTT1, GSTM1 and GSTP1 gene polymorphisms on the susceptibility of age-related cataract in Chinese Han population

OBJECTIVE

Age-related cataract (ARC) is one of the most common eye diseases in the elderly worldwide, especially in China. The genetic polymorphisms of many glutathione S-transferases coding genes are likely to be closely related to the development of ARC, especially the GSTT1, the GSTM1 and the GSTP1. This investigation is aimed to determine the possible associations of GSTT1, GSTM1 and GSTP1 polymorphisms with the susceptibility of ARC in Chinese Han Population.

METHODS

A case-control study including ARC cases (n = 312) and controls (n = 256) in Chinese Han Population was performed. GSTT1 and GSTM1 polymorphisms were detected by duplex polymerase chain reaction (PCR), and two SNPs (rs1695, A/G and rs1138272, C/T) in GSTP1 gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, all the results were verified by sequencing method.

RESULTS

The GSTT1 null genotype carriers had a much higher risk of ARC compared with non-null genotype (χ(2) = 14.091, P<0.001), and the allele G carriers also had a increased risk over the allele A carriers in the SNP (rs1695, A/G) in GSTP1 gene (χ(2) = 7.696, P = 0.006), while the GSTM1 polymorphism and the SNP (rs1138272, C/T) in GSTP1 gene seem had no association with the susceptibility of ARC in Chinese Han Population.

CONCLUSIONS

These preliminary results indicated carriage of null GSTT1 and GSTP1 Val/Val genotypes may contribute to genetic susceptibility to ARC in Chinese Han Population, and these genetic polymorphisms might be used as molecular markers for detecting ARC susceptibility.