Overexpression of Annexin A1 is associated with the formation of capillaries in infantile hemangioma.

Infantile hemangioma is a common benign tumor in infants. However, the molecular mechanism that controls the proliferation and differentiation of hemangioma is not well understood. Annexin A1 (ANX A1) is a phospholipid-binding protein involved in a variety of biological processes, including inflammation, cell proliferation and apoptosis. To explore the significance of ANX A1 in the process of proliferation or differentiation of hemangioma, proliferating and involuting hemangioma tissues were collected to detect the expression of ANX A1 using immunohistochemistry and western blotting. Normal skin tissues were used as the negative control. The results revealed that ANX A1 was upregulated in the proliferative phase of hemangioma, and its expression was decreased when the hemangioma entered the involuting phase. Additionally, in the proliferative phase, the strongest staining of ANX A1 was observed in newly born capillaries, and the staining of ANX A1 became weaker in enlarged vessels, indicating that ANX A1 plays an important role in promoting the formation of capillaries. The expression of hypoxia-inducible factor (HIF)-1α was positively associated with the expression trend of ANX A1, suggesting that the overexpression of ANX A1 may be associated with the increase of HIF-1α. In summary, the results of the present study revealed that the expression of ANX A1 was increased in proliferating hemangioma tissue, and that high expression of ANX A1 may be closely associated with the formation of capillaries in infantile hemangioma.