Prospective Case-Control Study to Evaluate the Role of Glutathione S Transferases (GSTT1 and GSTM1) Gene Deletion in Breast Carcinoma and Its Prognostic Significance

Investigating the Role of Glutathione S- Transferase Genes, Histopathological and Molecular Subtypes, Gene-Gene Interaction and Its Susceptibility to Breast Carcinoma in Ethnic North- Indian Population

BACKGROUND

Breast Cancer (BC) is a genetically and clinically heterogeneous disease including complex interactions between gene-gene and gene-environment components. This study aimed, to explore whether the Glutathione S- transferase (GSTs) gene polymorphism has role in BC susceptibility. We further evaluated the frequency of four subtypes of BC based on molecular classification followed by microscopic histological analysis to study the grades of invasive ductal carcinoma (IDC).

MATERIALS AND METHOD

Polymorphism in GST genes in North-Indian BC patients was assessed by multiplex-PCR and PCR-RFLP methods. 105 BC patients and 145 healthy controls were enrolled for this study. Data was analyzed by calculating the odds ratio (OR) and 95% CI from logistic regression analyses.

RESULTS

Our findings revealed that GSTM1 null genotype (OR = 2.231; 95% CI = 1.332-3.737; p-value= 0.002) is significantly associated to BC risk in ethnic North- Indian population. However, the risk for BC susceptibility in North-Indians does not appear to be associated with GSTT1 null genotype. The GSTP1 (Val/Val) genotype (OR=1.545; CI=0.663-3.605; p-value= 0.314) was also found to be susceptible for BC risk. Combination of three high risk GST genotypes association exhibiting gene-gene interaction further confirmed the increased risk to BC in this region.

CONCLUSIONS

The results of present study indicated that polymorphism in GSTM1 and rs1695 of GSTP1 genes may influence BC development among North-Indian women. Thus, the screening of GSTM1 and GSTP1 gene should be recommended for the earlier investigation for BC as a precautionary measure.

Absence of Glutathione S-Transferase Theta 1 Gene Is Significantly Associated With Breast Cancer Susceptibility in Pakistani Population and Poor Overall Survival in Breast Cancer Patients: A Case-Control and Case Series Analysis

Purpose

Deletion of Glutathione S-Transferase Theta 1 (GSTT1) encoding gene is implicated in breast cancer susceptibility, clinical outcomes, and survival. Contradictory results have been reported in different studies. The present investigation based on a representative Pakistani population evaluated the GSTT1-absent genotype in breast cancer risk and prognosis.

Methods

A prospective study comprising case-control analysis and case series analysis components was designed. Peripheral blood samples were collected from enrolled participants. After DNA extraction, GSTT1 genotyping was carried out by a multiplex PCR with β-globin as an amplification control. Association evaluation of GSTT1 genotypes with breast cancer risk, specific tumor characteristics, and survival were the primary endpoints.

Results

A total of 264 participants were enrolled in the molecular investigation (3 institutions). The study included 121 primary breast cancer patients as cases and 143 age-matched female subjects, with no history of any cancer, as controls. A significant genetic association between GSTT1-absent genotype and breast cancer susceptibility (p-value: 0.03; OR: 2.13; 95% CI: 1.08-4.29) was reported. The case-series analysis showed lack of association of GSTT1 genotypes with menopause (p-value: 0.86), tumor stage (p-value: 0.12), grade (p-value: 0.32), and size (p-value: 0.07). The survival analysis revealed that GSTT1-absent genotype cases had a statistically significant shorter overall survival (OS) than those with the GSTT1-present genotype cases (mean OS: 23 months vs 33 months). The HR (95% CI) for OS in patients carrying GSTT1-absent genotype was 8.13 (2.91-22.96) when compared with the GSTT1-present genotype.

Conclusions

The present study is the first report of an independent significant genetic association between GSTT1-absent genotype and breast cancer susceptibility in a Pakistani population. It is also the foremost report of the association of this genotype with OS in breast cancer cases. Upon further validation, GSTT1 variation may serve as a marker for devising better population-specific strategies. The information may have translational implications in the screening and treatment of breast cancers.

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.

The signature of pharmaceutical sensitivity based on ctDNA mutation in eleven cancers

IMPACT STATEMENT

Gene mutations are closely related to cancers and drug sensitivity and noninvasive liquid biopsy was used to detect mutations of ctDNA in plasma. In this study, we performed exon sequencing of 416 cancer-related genes for cancer primary tissue and plasma samples of 20 patients in 11 cancers and obtained the comprehensive mutation landscape. We found that liquid biopsy is reliable in place of tissue biopsy. And 31 potential unique mutation prognostic markers were screened in 7 cancer types. Moreover, the drug-mutation network (DMN) was constructed and 9 gene mutations (B-Mut-9) were confirmed that can be served as drug biomarkers in blood. Our study showed that the variation in ctDNA can be used as the biomarkers for cancer prognosis and drug efficacy prediction. This can provide a reference for clinical noninvasive testing.

Glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) variants and breast cancer risk in Burkina Faso

Background and objective

Breast cancer remains the most common cause of cancer mortality in women. The aim of this study was to investigate associations between genetic variability in GSTM1 and GSTT1 and susceptibility to breast cancer.

Methods

Genomic DNA was extracted from blood samples for 80 cases of histologically diagnosed breast cancer and 100 control subjects. Genotyping analyses were performed by PCR-based methods. Associations between specific genotypes and the development of breast cancer were examined using logistic regression to calculate odds ratios [1] and 95% confidence intervals (95%CI).

Results

No correlation was found between GSTM1-null and breast cancer (OR = 1.83; 95%CI 0.90-3.71; p = 0.10), while GSTT1-null (OR = 2.42; 95%CI 1.17-5.02; p= 0.01) was associated with increased breast cancer risk. The GSTM1/GSTT1 double null was not associated with an increased risk of developing breast cancer (OR = 2.52; 95%CI 0.75-8.45; p = 0.20). Furthermore, analysis found no association between GSTM1-null (OR =1.12; 95%CI 0.08-15.50; p = 1.00) or GSTT1-null (OR = 1.71; 95%CI 0.13-22.51; p = 1.00) and the disease stage of familial breast cancer patients or sporadic breast cancer patients (GSTM1 (OR = 0.40; 95%CI 0.12-1.32; p = 0.20) and GSTT1 (OR = 1.41; 95%CI 0.39-5.12; p = 0.75)). Also, body mass index (BMI) was not associated with increased or decreased breast cancer risk in either GSTM1-null (OR = 0.60; 95%CI 0.21-1.68; p = 0.44) or GSTT1-null (OR = 0.60; 95%CI 0.21-1.68; p =0.45).

Conclusion

Our results suggest that only GSTT1-null is associated with increased susceptibility to breast cancer development.

Honey and cancer: A mechanistic review

BACKGROUND

Globally, cancer ranks among the most common causes of death. Multiple experimental and clinical studies have investigated anticancer effects of honey with promising results. This study focused on potential background mechanisms of this effect.

METHODS

The current literature was reviewed for potential anticancer pathways which are suggested for honey and its ingredients.

RESULTS

Flavonoids (kaempferol, catechin, and quercetin) and phenolic acids (caffeic acid and gallic acid) are the most important ingredients of honey with known anti-cancer activity. The main suggested mechanisms for anti-cancer activity of honey and its ingredients are antioxidant, apoptotic, tumor necrosis factor inhibiting, antiproliferative, immunomodulatory, anti-inflammatory and estrogenic effects.

CONCLUSION

This review collates the current scientific understanding on the mechanism of anti-cancer activity of honey.