ABSTRACT
Objective To observe recombinant plasmids were constructed with the macrophage colony-stimulating factor ( GM-SCF) , interleukin -21 (IL-21) and retinoic acid early transcription factor-1 (Rae-1), and observe the inhibitory effects in subcutaneous liver cancer model in mice with the recombinant plasmids.Methods The recombinant plasmids of GM-SCF, IL-21 and Rae-1 were constructed with RT-PCR method, mouse model was constructed, the model mice were randomly divided into six groups including control, IRES/GFP, IRES/IL21, IRES/GM-SCF, IRES/GM-SCF-IL21 and IRES/combination with 10 mice included in each group, each groups (15 mice) were treated with the corresponding gene therapy.The survival rate were observed after 60 days.The blood levels of interferon -γ(IFN-γ) and interleukin -2 (IL-2) were detected in each group.Results The pGM-CSF-GFP-IRES-Rae-1-IL-21 has been successfully constructed.All mice had demised 14 and 16 days after treatment in the control and IRES/GFP groups, respectively.There were 2, 1, 11 mice remaining after 60 days of treatment in the IRES/GM-SCF, IRES/IL21 and IRES/GM-SCF-IL21 groups respectively.The survival rate of mice at 60 days of treatment was 73.33%, 13.33%, and 6.67% for groups IRES/GM-SCF-IL21, IRES/GM-SCF and IRES/IL21, respectively.The survival rate of the mice was significantly higher in IRES/GM-SCF-IL21 than the other groups.The levels of IL-2 and INF-γof mice 1-6 days after treatment gradually increased in the IRES/combination groups, including IRES/GM-SCF-IL21, IRES/GM-SCF and IRES/IL21.They were highest in the IRES/combination group and lowest (P<0.01) in the IRES/GM-SCF and IRES/IL21 groups, with the IRES/GM-SCF-IL21 group showing intermediate levels.By 6-10 days after treatment, IL-2 and INF-γlevels had stably increased in the IRES/combination groups, but had gradually decreased in the IRES/GM-SCF-IL21, IRES/GM-SCF and IRES/IL21 groups.At the end of treatment, IL-2 and INF-γlevels were significantly (P<0.01) higher in the IRES/GM-SCF-IL21 than were found in either the IRES/GM-SCF group or IRES/IL21 group, which were also significantly (P<0.01) higher than either the IRES/GFP or control groups.The levels of IL-2 and INF-γwere highest in the IRES/combination group ( P<0.01) and not significantly different among the IRES/GM-SCF, IRES/IL21, IRES/GFP, and control groups.Conclusion The inhibitory effects in subcutaneous liver cancer model in mice were obvious significantly, and its mechanism maybe be related to the activation of the body's immune.