Lentivirus-mediated Gene Transfer of Human sTRAIL Induced Apoptosis in SGC-7901 Cells

Objecitve To construct self-inactivating (SIN) lentiviral vector carrying human soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL) gene and to observe the effects of sTRAIL gene on apoptosis in SGC-7901 cells, so as to assess the value of sTRAIL in gene therapy for gastric cancer. Methods The bicistronic SIN lentiviral transfer plasmid containing sTRAIL gene and internal ribosomal entry site-green fluorescent protein gene (IRES-GFP) was constructed. Recombinant lentivirus containing sTRAIL were packaged using liposome by lentiviral packing system. Several cell lines including HL-7702, HLF-1 and SGC-7901 cells were infected with the viral supernatant. Flow cytometry was used to measure apoptosis of cells and recombinant sTRAIL protein was assayed by ELISA at 24 h after infection. Results The lentiviral transfer plasmid pXZ208-sTRAIL was constructed, and the virus titres were above 10⁶ IU/mL in the supernatant. SGC-7901 cells were efficiently infected by recombinant virus. The apoptosis rate of SGC-7901 cells was increased with the virus multiplicity of infection (MOI) increasing. When the MOI was ≥ 0.5, a dose-dependent apoptosis rate was observed. At MOI of 6.0, the highest apoptosis rate (29.12±2.87)% was observed, while the expression of sTRAIL in the supernatant was only (34.08±3.43) ng/mL. However, no significant apoptosis was observed in HL-7702 cells and HLF-1 cells. Conclusion Recombinant lentivirus carrying human sTRAIL gene can efficiently infected SGC-7901 cells, which induced apoptosis in SGC-7901 cells in vitro by secreting bioactive sTRAIL protein. However, this effect is not seen in normal cells.