[Expression of VHL, VEGF and HIF-1α in endolymphatic sac tumors]

Objective: To investigate the expression of von Hippel-Lindau (VHL), vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α (HIF-1α) in endolymphatic sac tumor (ELST) and its clinical significance, and to analyze its association with VHL gene mutation. Methods: Twenty-four cases of ELST, which were surgically resected and diagnosed by pathological examination in Beijing Tongren Hospital Affiliated to Capital Medical University, Beijing, China during 2012-2020, were recruited as the ELST group, and 24 cases of otitis media diagnosed in the same hospital were selected as the control group. The expression of VHL, VEGF, and HIF-1α was assessed using EnVision immunohistochemical staining and compared between the ELST and control groups. Sanger sequencing was performed to detect the VHL mutation status in 24 ELSTs. The correlations among VHL, VEGF and HIF-1α expression were analyzed. The associations of VHL, VEGF and HIF-1α expression with age of onset, gender, tumor size, bone invasion and clinical stage in ELST were also analyzed. Results: The expression rate of VHL in the ELST group was significantly lower than that in the control group (P<0.05), but the expression rates of VEGF and HIF-1α in the ELST group were significantly higher than those in the control group (P<0.05). VHL expression was inversely correlated with VEGF and HIF-1α expression. The expression of VEGF and HIF-1α was associated with bone invasion and clinical stage (P<0.05), but the expression of VHL, VEGF and HIF-1α had no significant associations with the age of onset, gender, or tumor size of ELST (P>0.05). Conclusions: The expression of VHL is decreased while that of VEGF and HIF-1α increased in ELST. Expression of VHL is inversely correlated with that of VEGF and HIF-1α. The expression of VEGF and HIF-1α is correlated with bone invasion and clinical stage. Thus, VEGF and HIF-1α may be therapeutic targets of ELST.