Molecular Evaluation of HIF-1α Gene Variation and Determination of Its Frequency and Association with Breast Cancer Susceptibility in Saudi Arabia.

Abstract

Hypoxia-inducible factor 1 (HIF-1α) is responsible in regulating oxygen homeostasis in tissues and is a central effector of the hypoxic response besides its protein overexpression has been shown to have prognostic relevance in several cancers including breast cancer. Several reports indicated that HIF-1α gene variation C1772T (Pro582Ser) is associated with increased breast susceptibility but results remained controversial. Therefore, we performed the molecular evaluation of HIF-1α gene variation and determined its frequency and association with Breast Cancer susceptibility in Saudi Arabia. This study was conducted on histologically confirmed Breast cancer patients and gender matched healthy women. HIF-1α C1772T (Pro582Ser) 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. A significant difference was observed in genotype distribution of HIF-1α gene variation C1772T (Pro582Ser) between breast cancer cases and gender matched healthy controls (P=0.010). 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 = 2.20, 95% CI = (1.28 -3.77), P = 0.004) in codominant inheritance model. The significant association was reported for HIF1A for genotypes CC vs (CT+ TT) OR = 1.98, 95% CI = (1.17-3.34), P = 0.010) in dominant inheritance model tested. In case of recessive inheritance model, a non-significant association of HIF-1 alpha gene variants was reported for (CC+ CT) vs TT) OR = 1.03, 95% CI = (0. 064-16.79), P = 0.97). During the allelic comparison, a non-significant association was reported between A vs C allele among Breast cancer patients. A significant association of HIF- 1α polymorphism was reported with stage as well as distant metastasis of the disease. A significant difference was observed in genotype distribution of HIF-1α gene variation C1772T (Pro>Ser) between breast cancer cases and gene matched healthy controls (P=0.010). HIF-1α- CT heterozygosity and CC genotype increased the susceptibility .The HIF-1α polymorphism was reported to be significantly associated with the distant metastasis of Breast cancer. Further studies with larger data set and well-designed models are required to validate our findings.