Related Experiment Videos
Adenovirus-mediated TNF-alpha gene transfer induces significant tumor regression in mice
1Saskatoon Cancer Center, Department of Microbiology, University of Saskatchewan, Canada.
Abstract:
Recombinant adenovirus vectors are highly efficient at in vitro and in vivo gene delivery. The in vitro infection of a mouse colon adenocarcinoma cell line MCA-26 with the adenovirus AdV-LacZ can reach a maximal 75% of infectivity at an MOI of 1000. Intratumoral injection of AdV-LacZ (2X10(9) pfu) resulted in substantial gene transfer in nearly 70% of MCA-26 tumors. After the in vitro infection of AdV-TNF-alpha, infected MCA-26 cells showed significant secretion of TNF-alpha (45 ng/ml/10(6) cells) in tissue culture. The secretion peaks at day 2 and is diminished at day 4 following the viral infection. Infected MCA-26 tumor cells secreting TNF-alpha significantly reduced their tumorigenicity in syngeneic BALB/c mice. In mice bearing small tumors, intratumoral injection of 2X10(9) pfu of AdV-TNF-alpha virus with a repeated booster treatment resulted in complete regression of three tumors and significant diminution of the other two with a mean tumor-weight of 0.16 g; this is in contrast to 0.85 and 1.62 g for tumors injected with the control AdV-pLpA and PBS respectively (p < 0.01). Mice with complete tumor regression further developed protective immunity against the second challenge of MCA-26 inoculation. In mice bearing large tumors, this treatment also caused significant inhibition of tumor growth with a mean tumor weight of 0.65 g vis-a-vis 3.05 g for tumors injected with the control AdV-pLpA. On the contrary, in mice bearing large tumors, the treatment of tumors with pCI-TNF-alpha delivered by the gene gun did not induce significant tumor inhibition. These results indicate that the adenoviral delivery of TNF-alpha gene is more efficient than the particle-mediated gene gun device, and that adenovirus-mediated cytokine gene therapy may be a useful approach in the clinical management of human solid tumors.
Insights
Adenovirus vectors efficiently deliver genes for cancer therapy. Adenovirus-mediated delivery of the tumor necrosis factor-alpha (TNF-alpha) gene significantly inhibited tumor growth and induced protective immunity in mice.
Area of Science:
- Oncology
- Gene Therapy
- Virology
Background:
- Recombinant adenovirus vectors demonstrate high efficiency in both in vitro and in vivo gene delivery.
- Adenovirus vectors are being explored for their potential in cancer treatment through gene delivery.
Purpose of the Study:
- To evaluate the efficacy of adenovirus-mediated delivery of the tumor necrosis factor-alpha (TNF-alpha) gene for cancer therapy.
- To compare adenoviral gene delivery with particle-mediated gene gun delivery for TNF-alpha gene therapy.
Main Methods:
- Infection of mouse colon adenocarcinoma cell line (MCA-26) with recombinant adenovirus vectors (AdV-LacZ and AdV-TNF-alpha).
- Intratumoral injection of AdV-TNF-alpha into syngeneic BALB/c mice bearing MCA-26 tumors.
- Comparison of adenoviral gene delivery with gene gun delivery of TNF-alpha.
Main Results:
- AdV-LacZ achieved 75% infectivity in vitro and gene transfer in 70% of tumors in vivo.
- Infected MCA-26 cells secreted significant levels of TNF-alpha, peaking at day 2.
- AdV-TNF-alpha treatment led to complete tumor regression in some mice and significant tumor growth inhibition in others, outperforming control treatments and gene gun delivery.
Conclusions:
- Adenovirus-mediated delivery of the TNF-alpha gene is an effective strategy for inhibiting tumor growth and inducing anti-tumor immunity.
- Adenoviral gene delivery is more efficient than particle-mediated gene gun delivery for TNF-alpha gene therapy.
- Adenovirus-mediated cytokine gene therapy holds promise for the clinical management of human solid tumors.