Polymorphisms in the hypoxia inducible factor-1α gene (HIF1A) are associated with the renal cell carcinoma phenotype

Hypoxia inducible factor 1 (HIF-1) is a key regulator of the genes involved in the cellular response to hypoxia. HIF consists of α and β subunits, with the α subunit being degraded under normoxic conditions and stabilized under hypoxia. We investigated C1772T and G1790A polymorphisms in exon 12 of the HIF gene, which result in an amino acid change from proline 582 to serine and from alanine 588 to threonine, respectively. These polymorphisms are found within the oxygen-dependent degradation domain of the HIF-1α protein and may be important in the oxygen regulation of the protein via hydroxylation of the proline residue at position 564 (P564) by HIF-α prolyl hydroxylase (HIF-PH). The frequency of these polymorphisms was studied in 160 nontumor DNA samples from patients with renal cell carcinoma (RCC). There was a highly significant increase in the frequency of both the G/A1790 (45.9 vs. 13.5%, P < 0.00001) and C/C1772 (10 vs. 0.7%, P = 0.0004) genotypes in patients with RCC compared with normal healthy controls. A decrease was seen for the GG (44.5 vs. 83%, P < 0.00001) and CT (33.8 vs. 55.5%, P = 0.0001) genotypes in patients compared with controls. There was a marked increase in the T-A haplotype (22.8 vs. 9.5%, P = 0.00008) and an increase in the C-A haplotype (4.9 vs. 1.1%, P = 0.02) in patients compared with controls, and a decrease in the T-G haplotype (53.4 vs. 65.1%, P = 0.01). No statistical difference was found for the other haplotypes. These findings show that polymorphisms of the HIF1A gene may confer susceptibility to RCC.