Treatment of hemangioma by transfection of antisense VEGF gene

Summary  The effect of transfection of antisense vascular endothelial growth factor (VEGF) gene on the growth of hemangioma was studied. A total of 49 cases of capillary hemangiomas of the skin were collected. Immunohistochemical method was used to detect the expression of PCNA in hemangioma tissues. According to the finding, 49 cases of hemangiomas fell into proliferating phase (27 cases) and involuting phase (22 cases) respectively. Another 5 cases of normal skin tissues adjacent to the tumor tissues served as control. Immunohistochemical staining was performed to detect the expression of VEGF in the tumor tissues and the normal tissues. The average absorbance (A) values and the average positive area rate of VEGF were measured by image analysis system (HPIAS-2000). Endothelial cells from the tumor tissues in proliferating phase were cultured. Eukaryotic expression vector was constructed by sub-cloning, and transfected into human hemangioma endothelial cells by using cation liposome as vector. The expression of VEGF mRNA and protein was detected by RT-PCR and indirect immunofluorescence assay (IFA), respectively, and the biological characteristics of the transfected endothelial cells were examined by MTT assay and flow cytometry (FCM) after transfection. Immunohistochemical results showed that the expression of VEGF in proliferating endothelial cells was remarkably higher than those in involuting endothelial cells and normal endothelial cells (P<0.01), but there was no significant difference in the expression of VEGF between involuting endothelial cells and normal ones (P>0.01). Electrophoresis and sequencing indicated that the eukaryotic expression vector containing antisense VEGF gene, i.e. pcDNA3.1-VEGF, was successfully constructed. After VEGF antisense RNA recombinant was transfected into hemangioma endothelial cells, RT-PCR revealed that the expression of VEGF mRNA in pcDNA-VEGF (V) group and blank group was obviously higher than that in pcDNA-VEGF (A) group, and that the expression of endogenous VEGF mRNA in pcDNA-VEGF (A) group was significantly inhibited. Immunohistochemical result demonstrated that, compared with blank group, there was statistically significant difference between pcDNA-VEGF (A) and pcDNA-VEGF (V) groups (P<0.01), but there was no significant difference between pcDNA-VEGF (V) group and blank group (P>0.05). The activity of endothelial cell proliferation was reduced significantly after transfection, and obvious apoptosis occurred in hemangioma endothelial cells after transfection of antisense VEGF. It was suggested that VEGF plays an important role in the pathological change of hemangiomas by promoting endothelial cell proliferation and angiogenesis. Antisense VEGF gene transfection could effectively inhibit the growth of hemanioma endothelial cells. This project was supported by grants from the National Natural Sciences Foundation of China (No. 30872688), Hubei Province Sci-tech Bureau Department (No. 2003ABA164, 2004ABA155 and 2004AA301c107), and Hubei Province Hygiene Department (No. JXIB075).