ABSTRACT
BACKGROUND: Dysfunctional regulation at immune checkpoints may lead to escape of the tumor cells and gives a scope to set in the unresolved Breast cancer (BC). The major anti-tumor retort is cell-mediated response which involves T lymphocytes. CTLA-4 (Cytotoxic T lymphocyte associated protein-4) with immune suppressive function and tolerance is associated with various autoimmune diseases and cancers including BC. The present study deals with CTLA-4 gene selected polymorphisms (rs11571317 C/T and rs3087243G/A) to explore their relation with breast cancer susceptibility and progression in BC patients. METHODS: For the present case-control study, we recruited a total of 570 women which include breast cancer patients and healthy control women from south India. Blood samples were collected, genomic DNA was isolated and genotyped by using PCR-RFLP method, and the data were analysed through suitable statistics. RESULTS: We observed a significant association of rs11571317 with BC in our study group, where CC genotype showed a three-fold increased risk towards BC and CT genotype to be protective. In-silico analyses strengthened our observation revealing the abolition of SP1 binding site in the CTLA-4 promoter by the mutant allele T. The CTLA-4 rs3087243 polymorphism showed an association not with the susceptibility but towards the tumor progression, where GG genotype was coupled with reduced tumor growth (OR = 0.01) and GA (OR = 6.2), AA (OR = 3.4) with increased tumor growth. The T-G haplotype was found to confer protection against breast cancer risk while C-A (OR = 3.6) and T-A (OR = 15.8) haplotypes were associated with disease progression. In-silico analysis for rs3087243 revealed change in threshold values between reference and variant sequences. CONCLUSION: The study suggests varied roles of different polymorphisms of CTLA-4 in the aetiopathogenesis of BC. Understanding the mechanism may help in the CTLA-4 based immunotherapy for BC.
ABSTRACT
Breast cancer is the most common female neoplasm that drives the transformation of normal mammary epithelial cells into highly malignant derivatives. Forkhead Box Protein3 (Foxp3), a tumor suppressor/immunomodulatory gene, which controls the function of Treg cells and oncogenes is down regulated in breast cancer. The main aim of the present study is to evaluate the potential influence of Foxp3-3279 C>A polymorphism (rs3761548) and -2383 C>T polymorphism (rs3761549) in 202 breast cancer patients and 130 normal healthy women of Indian origin. The genotypes were determined using ARMS-PCR for rs3761548 and PCR-RFLP method for rs3761549 using specific primers. The results revealed lack of association of these two polymorphisms with breast cancer susceptibility. However, with respect to AA genotype of rs3761548, we found highly significant association with the advanced stage (T3-4) of the tumor (OR = 3.90; 95% confidence interval (CI) = 1.56-9.70; p = 0.03). Stratified data also revealed an association of homozygous mutant genotype with advanced stage of tumor in premenopausal women (OR = 4.56; 95% CI = 1.07-19.38; p = 0.04) with disease duration of <6 months (OR = .10; 95% CI = 1.80-20.50; p = 0.002) suggestive of modulating effect of rs3761548 in tumor progression. We conclude that Foxp3 rs37161548 has a potential to be a polymorphic marker for tumor progression in premenopausal breast cancer patients in Indian women.
