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[Killing effect of double suicide genes mediated by lentivirus on lymphoma cells].

BACKGROUND & OBJECTIVE
The lentiviral vectors can integrate interest genes into genome of the target cells that allow for stable transgenic expression even in non-dividing cells without evoking an immune response of the host. All the features have promised them to be used in vivo gene therapy. This study was designed to explore the killing effect of double suicide genes mediated by lentivirus on lymphoma cells (Raji).


METHODS
The three plasmids expressed lentivirus, packaging plasmid pCMV 8.2, envelope plasmid pCMV.VSVG and target plasmid (pHR'CS. GFP as control group, pHR'CS.CDglytk as experiment group) were packaged into 293T cells using lipofectine method. Supernatant was harvested and concentrated. The Raji cells were infected with the concentrated virus. The gene integration and expression were confirmed by fluorescence microscopy and RT-PCR. After prodrug GCV or/and 5-FC administration, MTT method was used to detect the growth inhibition rate (GIR) of Raji cells for evaluating the killing effect of CD and HSV-tk double suicide genes on Raji cells.


RESULTS
The three plasmids were effectively transferred into 293T cells. Green fluorescence on the cell was observed through fluorescence microscopy and a lot of virus particles were observed through transmission electronic microscopy. Double suicide genes mediated by lentivirus were effectively and stably expressed in Raji cells. The GIR of Raji cells using GCV or 5-FC was 51% or 50%, respectively, and it was apparently higher than that of untransfected cells(P< 0.01). When using GCV and 5-FC together, the GIR was 73%, which was apparently higher than that of group using GCV or 5-FC alone (P< 0.01).


CONCLUSION
Double suicide genes mediated by lentiviral vector could transfect lymphoma cells effectively and stably. The double suicide gene system enhanced killing effect remarkably on lymphoma cells than CD/5FC or HSV-tk/GCV system alone.