BACKGROUNDTo investigate the biological effects of anti VEGF₁₆₅ ribozyme on human lung adenocarcinoma cell.

METHODSHammerhead ribozyme (VRz) against VEGF₁₆₅ gene transcripts (site 212) and its paired mutant ribozyme (mVRz) were designed and synthesized, and the cleavage activity of the ribozymes on target RNA in a cell-free system was observed. The replication-incompetent adenovirus-mediated eukaryotic expression vectors (rpAdVRz) containing VRz and mVRz gene were constructed and identified. Then the human lung adenocarcinoma cells (A549) were infected with recombinant adenovirus. The biological characteristics of A549 cell before and after infection in vitro were inspected by Northern blot, laser confocal imaging system analysis, flow cytometry and transmission electron microscopy.

RESULTSVRz specifically and efficiently cleaved the VEGF₁₆₅ mRNA. The rpAdVRz was successfully constructed and infected A549 cell. The level of VEGF₁₆₅ expression decreased 87% in rpAdVRz infected cells compared with the other groups, but their biological characteristics were not influenced by the expression of the exogenous gene.

CONCLUSIONSThe adenovirus mediated hammerhead ribozyme against VEGF₁₆₅ can significantly decrease the expression of VEGF₁₆₅. This provides an experimental basis for human lung cancer gene therapy with antiangiogenesis method.