Expression of Hypoxia-Inducible Factor-1alpha and Correlation between Hypoxia-Inducible Factor-1alpha and Vascular Endothelial Growth Factor in Nasal Polyps / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: The function of hypoxia-inducible factors (HIFs) in the hypoxic environment is to orchestrate adaptational adjustments of vascular homeostasis through the activation of several dozens of target genes including vascular en-dothelial growth factors (VEGF). It has been suggested that VEGF is involved in the pathogenesis of nasal polyp. The purpose of this study is to determine and correlate concentrations of HIF-1alpha and VEGF in nasal polyps. MATERIALS AND METHOD: Twenty-five nasal polyps were collected at the time of endoscopic sinus surgery. The production of HIF-1alpha and VEGF messenger RNA (mRNA) was measured by reverse transcriptase polymerase chain reaction (RT-PCR) and HIF-1alpha and VEGF proteins were determined by immunohistochemical staining. RESULTS: The expressions of HIF-1, VEGF mRNA and proteins were detected in nasal polyps. RT-PCR demonstrated that the level of mRNA expression of HIF-1alpha and VEGF were 1.12+/-0.33 and 1.11+/-0.42, respectively. A positive correlation was observed between HIF-1alpha and VEGF mRNA (correlation coefficient [r]=0.49, p<0.05). The immunohistochemical studies revealed that HIF-1alpha was predominantly expressed in surface epithelial cells, submucosal glandular cells, endothelial cells and inflammatory cells in the stroma and VEGF was more strongly and diffusely expressed in subglandular epithelial cells, vascular endothelial cells, and inflammatory cells than in surface epithelial cells. The expressions of HIF-1alpha and VEGF proteins were 3.24+/-1.80 and 3.52+/-1.89, respectively. A positive correlation was observed between HIF-1alpha and VEGF proteins (r=0.76, p<0.05). CONCLUSION: We suggest that HIF-1alpha has a role in inducing VEGF in nasal polyps, and hypoxia is an important factor in the growth of nasal polyps.