PIK3CA Polymorphism (rs17849079 C/T) and Expression in Breast cancer Patients

The phosphatidylinositol-3-kinase (PI3K) pathway is an important signaling pathway in cells and is involved in essential cellular functions and plays a main role in development and progression of breast cancer. The present study aimed to assess the frequency of PIK3CA rs17849079 polymorphism in breast cancer patients and its relationship with the PIK3CA gene expression. Methods: A total of 50 healthy controls and 50 breast cancer patients were included in this study. Genomic DNA was extracted from peripheral blood leukocytes and genotyping was performed using a TaqMan® SNP ready-made genotyping assay. RNA was extracted from breast carcinoma tissues and adjacent normal tissues. The Quantitative Real Time PCR was used to quantify expressions of PIK3CA. Chi-square test, odds ratios (ORs) and 95% CIs were used to determine associations. Results: The frequency of SNP rs17849079 was significantly higher in the BC cases (16%) than controls group (2%), (P = 0.019, OR = 12.25, 95%, CI = 1.50 – 99.8). The study results showed no significant association between SNP rs17849079 and PIK3CA expression. Conclusion: Significant association was observed between the PIK3CA rs17849079 polymorphism and breast cancer risk. PIK3CA gene expression is found to be significantly higher in carcinoma tissues than in normal tissues.