Abstract: 【Abstract】 Objective To observe the inhibition of lentiviral vector-mediated RNA interference on the expression of Friend leukemia integration-1 gene in mouse erythroleukemia cell line（ CB3 ） and provide powerful technical support for follow-up experiments. Methods Small interfering RNA that is directed towards FLI-1 gene was designed and RNAi mediated with lentivirus-based vectors was constructed. Those colonies with positive PCR result were sequenced. After the packaging and the titer assaying, the lentivirus were used to infect the CB3 cells. Then, the expression of GFP was observed, and the inhibition of the expression of FLI-1 was analyzed via both RT-PCR and Western Blot approaches. Results The lentivirus RNAi vectors with target gene were successfully constructed and the titer of concentrated virus was 1.5E+9TU/ml.Compared to the negative and non-infected controls, the expression of FLI-1 gene was significantly inhibited after the CB3 cells were infected by lentivirus（P<0.001）. Conclusions The lentivirus RNAi vectors toward FLI-1 could be used to infect the CB3 cell line. After delivering this sort of vectors into the CB3 cells, the experession of FLI-1 was inhibited dramatically. Current research has provided a stable infection tool for CB3 cell line and this will facilitate the follow-up experiments.

Key words: Fli-1, RNA interference, lentivirus-based vectors