Relative quantitative expression of hypoxia-inducible factor 1 alpha messenger ribonucleic acid in recurrent craniopharyngiomas

Abstract

Craniopharyngioma is a benign tumor, but recurrences are common and prognosis is poor. The pathologic mechanism underlying the high recurrence is still unknown. We hypothesized that there are hypoxic microenvironments within craniopharyngiomas and hypoxia inducible factor-1 alpha (HIF-1α) and its related genes are largely expressed in recurrent craniopharyngiomas. A total of 19 patients with craniopharyngiomas have been identified. The relative quantitative expressions of HIF-1α, vascular endothelial growth factor (VEGF) and carbonic adhydrase 9 (CA9) messenger ribonucleic acid (mRNA) of craniopharyngioma tissues were detected by real time reverse transcription polymerase chain reaction. HIF-1α and VEGF mRNA was significantly up-regulated in recurrent craniopharyngiomas. Mean expression levels (recurrent craniopharyngiomas compared with non-recurrent craniopharyngiomas, as normalized to expression of β-actin) were 3.09 versus 0.75 (P = 0.001) for HIF-1α, 1.07 versus 0.32 (P = 0.000) for VEGF, 1.21 versus 1.93 (P = 0.503) for CA9. In craniopharyngiomas, the expression of VEGF showed a significant correlation with HIF-1α (r = 0.836, P = 0.000). There were hypoxic microenvironments within craniopharyngiomas. Therefore, preventing the tumor cells from adapting to the hypoxic conditions may be an effective way to obviate the relapse of craniopharyngioma.