Impact of xenobiotic-metabolizing gene polymorphisms on breast cancer risk in South Indian women

Association of xenobiotic-metabolizing genes polymorphisms with cervical cancer risk in the Tunisian population

BACKGROUND

Host genetic characteristics and environmental factors interactions may play a crucial role in cervical carcinogenesis. We investigated the impact of functional genetic variants of four xenobiotic-metabolizing genes (AhR, CYP1A1, GSTM1, and GSTT1) on cervical cancer development in Tunisian women.

METHODS

The AhR gene polymorphism was analyzed using the tetra-primer ARMS-PCR, whereas the CYP1A1 polymorphism genotypes were identified by PCR-RFLP. A multiplex ligation-dependent polymerase chain reaction approach was applied for the analysis of GSTM1 and GSTT1 polymorphisms.

RESULTS

The homozygous A/A genotype of the AhR gene (rs2066853) and the heterozygous T/C genotype of the CYP1A1 SNP (CYP1A1-MspI) appeared to be associated with an increased risk of cervical tumorigenesis (OR^a = 2.81; OR^a = 5.52, respectively). Furthermore, a significantly increased risk of cervical cancer was associated with the GSTT1 null genotype (OR^a = 2.65). However, the null GSTM1 genotype showed any significant association with the risk of cervical cancer compared to the wild genotype (OR^a = 1.18; p = 0.784). Considering the combined effect, we noted a significantly higher association with cancer risk for individuals with at least two high-risk genotypes of CYP1A1/GSTT1 (OR^a = 4.2), individuals with at least two high-risk genotypes of CYP1A1/GSTT1/AhR (OR^a = 11.3) and individuals with at least two high-risk genotypes of CYP1A1/GSTM1/GSTT1/AhR exploitation low-risk genotype as a reference.

CONCLUSION

This study indicated that the single-gene contribution and the combined effect of xenobiotic-metabolizing gene polymorphisms (AhR, CYP1A1-MspI, GSTM1, and GSTT1) may have a considerable association with increased cervical cancer risk.

Association of GSTT1, GSTM1 and GSTP1 (Ile105Val) mRNA Expression with Cardiometabolic Risk Parameters in Women with Breast Cancer and Comorbidities

Breast cancer (BC) and cardiometabolic diseases share a multifactorial and modifiable etiology, modulated by complex molecular pathways. Glutathione S-transferase (GST) plays a critical role, providing protection against xenobiotics and regulating levels of enzymes and proteins in the cell. GST variants have a significant impact on susceptibility to diseases whose pathogenesis involves oxidative stress, as is the case in many inflammatory diseases such as BC and cardiometabolic pathologies. However, the expression of these polymorphic variants has not been studied in BC. This study aimed to evaluate the presence of GST mRNA isoforms and their association with clinical and cardiometabolic parameters in women with BC. This was a case-control study, and a total of 57 participants were recruited. Concentrations of glucose and lipids in blood were measured in all the participants. GST variants (GSTT1, GSTM1 and GSTP1 Ile105Val polymorphism) were evaluated in all the participants by real-time PCR analysis. There was a significant association (p < 0.05) between the frequency of GSTP1 and LDL-c in the BC group. However, the control group showed significant associations between blood pressure with GSTT1 and GSTP1 variants with total cholesterol (TC), LDL-c, VLDL-c and triacylglycerols (TG). Therefore, GSTT1 and GSTP1 variants could be emerging biomarkers to discriminate between BC cases related or not to cardiometabolic disease factors.

Evaluation of molecular markers GSTM1 and GSTT1 and clinical factors in breast cancer: case-control study and literature review

The study was conducted to evaluate the frequency of polymorphisms in GSTM1 and GSTT1 genes in patients with breast cancer compared with individuals without history of cancer, and the association of these polymorphisms with clinical/epidemiological parameters.There were evaluated 752 women (219 patients and 533 controls). Molecular analysis was performed by the Polymerase Chain Reaction (PCR). Statistical analysis was used multiple logistic regression and descriptive statistics.Age ≥50 years (OR =3.22, 95% CI =2.30 - 4.51, p <0.001) and alcohol consumption (OR =1.60, 95% CI =1.13 - 2.27, p = 0.008) were associated to the development of breast cancer, while smoking and null genotypes GSTM1 and GSTT1 presented no association. GSTM1 and GSTT1 polymorphisms presented no relationship with the clinical and histopathological parameters or molecular subtypes of breast cancer. Ninety-two percent of tumors were invasive ductal, 66% were grade II, 65% were larger than 2 cm, the stages II (35.3%) and III (31.2%) were the most prevalent, and 47.7% were molecular subtype luminal B.Individuals aged ≥50 years and alcohol consumers have more chance to developing breast cancer. GSTM1 and GSTT1 polymorphisms are not associated to the risk of breast cancer.