Impact of Co-transfection with Livin and survivin shRNA expression vectors on biological behavior of HepG2 cells

Transfection with Livin and Survivin shRNA inhibits the growth and proliferation of non‑small cell lung cancer cells

Lung cancer is reported to be a major public health issue worldwide and the overall prognosis of patients remains poor. The expression levels of Livin and Survivin, of the inhibitors of apoptosis (IAP) family, are associated with prognostic significance in the majority of solid tumors. Therefore, in the presents study, short hairpin (sh)RNA expression vectors inhibiting the Livin and Survivin genes were constructed to examine the effects of the transfection of Livin shRNA and/or Survivin shRNA on the biological functions of tumor cells. The transfection efficiency was measured using fluorescence reverse transcription‑quantitative polymerase chain reaction and western blot analyses. The cell growth inhibition ratio was measured using a CCK assay. Cell apoptosis following transfection and in tumor tissues were measured using a TUNEL assay, and a cancer xenograft model was used to investigate the effect of Livin shRNA and/or Survivin shRNA on tumor growth. The results indicated that the mRNA and protein expression levels were suppressed following the transfection of Livin and Survivin shRNA into tumor cells (P<0.05, compared with control group). The growth of tumor cells in vivo and in vitro was significantly inhibited following transfection with Livin and Survivin shRNA, compared with that in the other groups (P<0.05). Taken together, the transfection of cells with Livin and Survivin inhibited tumor growth in vivo and in vitro, with the co‑transfection of Livin and Survivin shRNA showing increased efficiency, compared with transfection of either the Livin vector or Survivin vector alone. The combined inhibition of Livin and Survivin may be a promising multitargeted gene therapeutic strategy in cancer treatment.

A novel inducible lentiviral system for multi-gene expression with human HSP70 promoter and tetracycline-induced promoter

Despite lentiviral system's predominance, its ultimate potential for gene therapy has not been fully exploited. Currently, most lentivirus vectors are non-inducible expression system or single-gene-induced system, which limits the extensive application in gene therapy. In this study, we designed a novel lentiviral vector containing HSP70 promoter and TRE promoter. Compared to traditional lentiviral vectors and inducible vectors, our controllable system has many advantages. Firstly, it contains multiple gene or shRNA targets. Secondly, genes expression is on/off in response to heat shock and DOX induction in time of need respectively with high effectivity and sensitivity. Thirdly, TRE promoter and HSP70 promoter can work with no interference from each other in the same inducible lentiviral vector. In addition, our study also shows that our novel vector has a higher downstream gene expression efficiency than co-transfection method and can co-position multi-genes in single cell effectively. Finally, we propose four derived models based on our vector at the end, which may be useful in biological research and clinical research in the future. Therefore, we believe that this novel lentiviral system could be promising in gene therapy for tumor.

Effect of Co-transfection of Anti-myostatin shRNA Constructs in Caprine Fetal Fibroblast Cells

Knockdown of myostatin gene (MSTN), transforming growth factor-β superfamily, and a negative regulator of the skeletal muscle growth, by RNA interference (RNAi), has been reported to increase muscle mass in mammals. The current study was aimed to cotransfect two anti-MSTN short hairpin RNA (shRNA) constructs in caprine fetal fibroblast cells for transient silencing of MSTN gene. In the present investigation, approximately 89% MSTN silencing was achieved in transiently transfected caprine fetal fibroblast cells by cotransfection of two best out of four anti-MSTN shRNA constructs. Simultaneously, we also monitored the induction of IFN responsive genes (IFN), pro-apoptotic gene (caspase3) and anti-apoptotic gene (MCL-1) due to cotransfection of different anti-MSTN shRNA constructs. We observed induction of 0.66-19.12, 1.04-4.14, 0.50-3.43, and 0.42-1.98 for folds IFN-β, OAS1, caspase3, and MCL-1 genes, respectively (p < 0.05). This RNAi based cotransfection method could provide an alternative strategy of gene knockout and develop stable caprine fetal fibroblast cells. Furthermore, these stable cells can be used as a cell donor for the development of transgenic cloned embryos by somatic cell nuclear transfer (SCNT) technique.