Abstract
RNA interference (RNAi) is a process to knock down gene expression by injecting a small segment of double stranded RNA of the corresponding gene. Recent advances have allowed us to use this technique to silence a gene in the mammalian system. We applied RNAi to silence Ligase IV gene, a key molecule associated with nonhomologous end joining (NHEJ). HFL III normal human fibroblasts were transfected with Ligase IV siRNA using Hemagglutinating virus of Japan envelop (HVJ-E), and its protein expression and radiobiological characteristics were investigated. We have observed a reduction in Ligase IV protein expression associated with a decrease in X-ray survival in cells with Ligase IV si RNA when compared to cells treated with HVJ-E alone. These results indicate that the siRNA strategy can be applied in this repair gene. Further application and optimization of this technique are underway and will be reported. [J Radiat Res 44:404 (2003)]
