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.

Abstract

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). 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. 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. 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.