[Stable interference on P210(bcr/abl) gene expression by lentiviral vector-delivered shRNA in vitro and in vivo].

P210(bcr/abl) fusion gene is indispensable for generation and progression of chronic myeloid leukemia (CML). Small molecule inhibitors, such as imatinib, are effective for P210(bcr/abl) gene mediated CML, but drug resistance may occur. The unique fusion junction of P210(bcr/abl) gene is an attractive target for therapeutic intervention using RNA interference (RNAi). This study was purposed to constructed the BaF3 cell line by viral vector which can stably express P210(bcr/abl) shRNA and P210(bcr/abl) mRNA at the same time, and investigate the effect of lentiviral-victor-delivered shRNA on P210(bcr/abl) gene expression. The infective rate of lentiviral vector on BaF3 cells with P210(bcr/abl) gene was assayed by fluorescent microscopy; the cell proliferation ability was determined by trypan blue exclusion; the P210(bcr/abl) mRNA and protein expressions were detected by RT-PCR and Western blot respectively. The results found that stable expression of the P210(bcr/abl) shRNA resulted in obvious inhibition of P210(bcr/abl) mRNA and protein expression and increased sensitivity of these P210(bcr/abl) gene transformed Ba/F3 cells to imatinib. The IC(50) to imatinib in these cells decreased < 50% as compared with Ba/F3-P210(bcr/abl) cells which did not express P210(bcr/abl) mRNA. The survival time of the lethal dose irradiated mice induced by intravenous injection of these Ba/F3 cells was longer than the other group induced by Ba/F3-P210(bcr/abl). It is concluded that stable expression of shRNA targeting the P210(bcr/abl) gene fusion junction may potentiate the effects of conventional therapy for CML.