A high HIF-1α expression genotype is associated with poor prognosis of upper aerodigestive tract carcinoma patients

Summary 

The aim of the present study was to evaluate the role of HIF-1α genetic polymorphisms and protein expression in the development of metastasis in upper aerodigestive tract cancer (UADTC) patients. The expression of pro-angiogenic markers was also evaluated. Protein expression was analysed using immunohistochemistry, and RFLP analysis was used to investigate HIF-1α C1779T and G1790A polymorphisms in 52 patients with UADTC. Primary lesions were divided into 2 groups according to the absence or presence of metastasis. Lymph node samples were divided into 3 groups: metastatic lymph nodes, non-metastatic lymph nodes (both derived from patients with metastatic disease), and control lymph nodes, which were obtained from patients without any metastasis. The allele T was more frequently found in patients with metastatic disease. HIF-1α protein expression in the lymph nodes was increased in the presence of the T allele. Metastatic lymph nodes showed lower levels of HIF-1α, VEGFR1, and MMP-9 proteins compared to lymph nodes without metastasis, while VEGFR2 protein levels were increased. In agreement, HIF-1α expression was correlated with MMP-9. Cox regression analysis demonstrated that higher HIF-1α and MMP-9 protein expression levels and GA and GG genotypes were associated with poor survival. Our findings show that the C1772T and G1790A polymorphisms of the HIF-1α gene are associated with increased expression of the HIF-1α protein in UADTC. The present data indicate that non-metastatic tissues express higher levels of HIF-1α, VEGFR1, and MMP-9, while in metastatic lymph nodes, VEGFR2 protein expression is elevated. The present study also shows that the HIF-1α G1790A polymorphism and its protein expression have an impact on the prognosis of UADTC patients.

Keywords: Metastasis, Angiogenesis, Hypoxia, HIF, Polymorphism, VEGFR1, Upper aerodigestive tract cancer