Abstract
AIM: To investigate the effect of antisense RNA to vascular endothelial growth factor165 (VEGF165) on human esophageal squamous cell carcinoma cell line EC109 and the feasibility of gene therapy for esophageal carcinoma. METHODS: By using subclone technique, the full length of VEGF165 amino acid cDNA, which was cut from pGEM-3Zf+,was cloned inversely into the eukaryotic expression vector pCEP4. The recombinant plasmid pCEP-AVEGF165 was transfected into EC109 cell with lipofectamine. After a stable transfection, dot blot, enzyme-linked immunosorbent assay (ELISA),laser confocal imaging system analysis, transmission electron microscopy and flow cytometry were performed to determine the biological characteristics of EC109 cell line before and after transfection in vitro and whether there was a reversion in the tumorigenic properties of the EC109 cell in vitro. RESULTS: The eukaryotic expression vector pCEP-AVEGF165 was successfully constructed and transfected into EC109 cells. The expression of VEGF165 was significantly decreased in the transfected cells while the biological characteristics of the cells were not influenced by the expression of antisense gene. The tumorigenic and angiogenic capabilities were greatly reduced in nude mice, as demonstrated by reduced tumor end volume (820+/-112.5)mm(3) vs (7930+/-1035)mm(3) and (7850+/-950)mm(3), P<0.01) and microvessel density (average number: (8.5+/-1.2)mm(-2) vs (44.3+/-9.4)mm(-2) and (46.4+/-12.6)mm(-2), P<0.01) in comparison between experimental groups empty vector transfected group and control group. CONCLUSION: The angiogenesis and tumorigenicity of human esophageal squamous cell carcinoma were effectively inhibited by VEGF165 antisense RNA. Antisense RNA to VEGF165 can potentially be used as an adjuvant therapy for solid tumors.