mRNA expression of HIF-1α and VEGF genes in nasopharyngeal squamous cell line cells during hypoxia-reoxygenation

Objective To investigate the change in mRNA expression of hypoxia inducible factor 1α HIF 1α and vascular endothelial growth factor (VEGF) genes in the highly differentiated nasopharyngeal squamous carcinoma (CNE) cell line during hypoxia reoxygenation.Methods CNE cells were cultured in normoxic, continuous 8 hour hypoxia ,16 hour hypoxia and 16 hour hypoxia 4 hour reoxygenation conditions respectively. Expressions of HIF 1α and VEGF genes were assessed by the reverse transcription polymerase chain reaction (RT PCR) technique. Results The mRNA expression of HIF 1α gene was kept constant in the different culture conditions,whereas the mRNA expression of VEGF gene increased significantly after 8 or 16 hour hypoxia and decreased after reoxygenation for 4 hours. Conclusions Hypoxia is able to induce the mRNA expression of VEGF gene in the CNE cell, but is unable to do so in HIF 1α mRNA expression. These findings suggest that VEGF upregulation induced by hypoxia be independent HIF 1a transcription.