Co-suppression of VEGF-A and VEGF-C inhibits development of experimental hemangioma

Vascular endothelial growth factor A (VEGF-A) plays a critical role in the development and progression of Infantile hemangioma (IH), the most common vascular tumor occurring during infancy. However, a role of VEGF-C in IH remains unclear. Here, we addressed this question. The expression of VEGF family members in hemangiomas at involuting-phase and at proliferating-phase was compared, by RT-qPCR and by ELISA. VEGF-A and VEGF-C were suppressed by specific short-hairpin interfering RNA (shRNA), respectively. Cell growth was determined in an MTT assay. Cell proliferation was assessed by BrdU incorporation and analysis of cell-cycle regulators by Western blotting. Cell apoptosis was assessed by Annexin V assay and analysis of apoptosis-associated proteins by Western blotting. The effects of VEGF-A suppression, or VEGF-C suppression, or both, on hemangioma growth were analyzed in vivo by bioluminescence assay and by weight of the implanted tumor. Significantly higher levels of VEGF-A and VEGF-C were detected in the proliferating-phase of the hemangiomas than in the involuting-phase of the hemangiomas. Suppression of either VEGF-A or VEGF-C decreased hemangioma cell growth, likely through inhibition of proliferation and enhancement of the apoptosis, while suppression of both VEGF-A and VEGF-C had a more pronounced effect than suppression of either VEGF-A or VEGF-C alone. VEGF-A and VEGF-C seemed to regulate proliferation and apoptosis through different proteins. Suppression of both VEGF-A and VEGF-C had a more pronounced effect than suppression of either one on the growth of the implanted hemangiomas In vivo. Thus, co-suppression of VEGF-A and VEGF-C has better inhibitory effects on the growth of hemangioma.