Molecular evaluation of HIF-1α gene variation and determination of its frequency, and association with Breast Cancer susceptibility in Saudi Arabia.

AIM Hypoxia-inducible factor 1 (HIF-1) is responsible in regulating oxygen homeostasis in tissues. HypoxiaInducible Factor α (HIF1-α) is a central effector of the hypoxic response. HIF-1α protein overexpression has been shown to have prognostic relevance in breast cancer. HIF-1α polymorphism is associated with increased breast susceptibility reported by several case controls studies but results remained controversial. Therefore, we studied the relationship between the HIF1α gene polymorphism with the breast cancer risk in Saudi Arabia. Methods: This study was consisted of 114 histologically confirmed Breast cancer patients and 117 sex -matched healthy women. HIF-1α genotyping was done by Amplification refractory mutation system PCR method. The HIF-1α gene genotypes were correlated with different clinicopathological characteristics of breast cancer patients. Results: A significant difference was observed in genotype distribution of HIF-1α gene variation C1772T between breast cancer cases and sex matched healthy controls (p=0.001). Our findings showed that the HIF- 1α variant was associated with an increased risk of Breast cancer for HIF-1α CC vs CT genotype OR = 0. 38, 95% CI = (0. 22 -0. 65), P = 0.005) in codominant inheritance model. The significant association was reported for HIF1A for genotypes CC vs (CT+ TT) OR = 0. 39, 95% CI = (0. 231 -0. 67), P = 0.007) in dominant inheritance model tested. In case of recessive inheritance model, a significant association of HIF-1 alpha gene variants was reported for CC VS -(CC+ CT) vs TT) OR = 3.10, 95% CI = (0. 12- 77.03), P = 0.56). During the allelic comparison, A allele significantly increased the risk of Breast cancer with odd ratio (OR = 0. 66, 95% CI = 0. 53 -1. 21, P = 0.04) and risk ratio RR= 0. 51 (0. 32 -0. 80) P= 0.004). A significant association of HIF1α polymorphism was reported with stage as well as distant metastasis of the disease. Conclusion: A significant association of HIF- 1α-CT heterozygosity and T allele significantly increased the susceptibility and is associated with the metastasis of Breast cancer. Further studies with larger data set and well-designed models are required to validate our findings.