[The relationship between the expression of HIF-1alpha and the angiogenesis in infancy hemangioma]

To investigate the expression of HIF-1alpha and its roles on the vascular endothelial cell growth factor (VEGF) and microvessel density (MVD ) in hemangioma.

Immunohistochemical streptavidin/peroxidase(SP) stain was applied to examine the expression of HIF-1alpha, VEGF and CD34. The amount of microvessel was counted, which the endothelial cell expressed CD34.

The nuclei and cytoplasm of the endothelial cell showed positive staining for HIF-1alpha in hemangioma. In 28 cases, positive rate for HIF-1alpha was 64%, for VEGF was 71.4%. In the proliferating phase, positive rate for HIF-1alpha was 87.5%, for VEGF was 93.7%. However, the positive rate for HIF-1alpha, in the involuting phase, was 33.3%, and for VEGF was 41.7%. There was a very significantly different between two phases (P < 0.01). In the proliferating phase, MVD was 73.4 +/- 14.63 . In the involuting phase, MVD was 30.2 +/- 9.1 (P < 0.01). The correlation between the HIF-1alpha and VEGF was positive (P < 0.01). There was a positive correlation between the HIF-1alpha and MVD (P < 0.01).

There might be a special hypoxia microenvironment in endothelial cell of the hemangioma in proliferating phase , which could up-regulate the expression of the HIF-1alpha protein. The HIF-1alpha protein could also up-regulate the VEGF protein and then result in the angiogenesis.