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Updated: Aug 20, 2026
A Preclinical Murine Model of Hepatic Metastases
Published on: September 27, 2014
IL-12 cDNA direct injection: antimetastatic effect from a single injection in a murine hepatic metastases model
Sharon M Weber1, Chen Qi, Zane Neal
1Department of Surgery, University of Wisconsin Hospital, Madison 53792, USA. webers@surgery.wisc.edu
Background:
Interleukin 12 (IL-12) gene therapy is an effective antitumor agent in local and metastatic murine tumor models. We sought to evaluate the antimetastatic effect of IL-12 cDNA in a liver metastases model.
Materials And Methods:
A liver metastases model was induced by creating a "primary" splenic tumor through inoculation of 1 x 10(5) TS/A adenocarcinoma cells directly into the inferior pole of the spleen in female BALB/c mice. On day 4, 50 microg of IL-12 cDNA or control plasmid DNA was injected into splenic tumor, followed by splenectomy on day 8. Mice were sacrificed on day 25 to assess liver tumor burden. IL-12 mRNA and mIL-12 and IFN-gamma protein levels were assessed after IL-12 injection. Peripheral blood CD4+, CD8+, and NK cells were quantified on day 14 using FACS. To determine the significance of site of cytokine DNA injection, IL-12 cDNA was injected on day 4 into splenic tumor or into the non-involved spleen after isolation of the inferior and superior portions of the spleen, respectively, with surgical clips. Splenectomy was performed on day 8 and sacrifice was performed on day 25.
Results:
IL-12 mRNA was detected in the liver 8 h after injection, with a peak at 24 h. After splenic injection, protein levels of IL-12 and IFN-gamma were detectable in the liver and spleen 24 h after treatment. IL-12 and IFN-gamma were not detectable in control animals. In the peripheral blood, there was a marked increase in NK cells (13% of total lymphocytes versus 4%, control) and in the CD4+/CD8+ ratio (5.5 versus 1.9). At day 25, there was a marked antimetastatic effect after IL-12 injection into either splenic tumor [liver:body weight, 6.2 versus 10.9 (control), P = 0.007] or non-involved spleen (6.8 g versus 10.7 g, P = 0.005). There was no difference in the antimetastatic effect between animals injected into splenic tumor or non-involved spleen (P = 0.3).
Conclusion:
Injection with a single dose of IL-12 cDNA into splenic tumor or non-involved spleen resulted in a profound antimetastatic effect. Splenic IL-12 injection results in mRNA expression in the liver, protein expression in the liver and spleen, and a marked increase in NK cells and the CD4+/CD8+ ratio in peripheral blood.
Insights
Interleukin 12 (IL-12) gene therapy demonstrated a significant antimetastatic effect in a liver metastases model. Splenic IL-12 cDNA injection increased natural killer (NK) cells and the CD4+/CD8+ ratio, reducing liver tumor burden.
Area of Science:
- Immunotherapy
- Gene Therapy
- Oncology
Background:
- Interleukin 12 (IL-12) gene therapy shows promise as an antitumor agent.
- Previous studies highlight its efficacy in murine tumor models.
- This study investigates IL-12's antimetastatic potential in a liver metastasis model.
Purpose of the Study:
- To evaluate the antimetastatic effect of IL-12 cDNA in a murine liver metastases model.
- To assess the impact of IL-12 gene therapy on immune cell populations.
- To determine the optimal site for IL-12 cDNA injection.
Main Methods:
- A liver metastases model was established using TS/A adenocarcinoma cells in BALB/c mice.
- IL-12 cDNA or control plasmid was injected into the splenic tumor or non-involved spleen.
- Splenectomy was performed, and liver tumor burden was assessed.
- mRNA and protein levels of IL-12 and IFN-gamma were measured.
- Peripheral blood immune cells (CD4+, CD8+, NK cells) were quantified via FACS.
Main Results:
- IL-12 gene therapy led to significant reduction in liver tumor burden.
- IL-12 and IFN-gamma expression was detected in the liver and spleen post-injection.
- A notable increase in NK cells and the CD4+/CD8+ ratio was observed in peripheral blood.
- Injection into either splenic tumor or non-involved spleen yielded comparable antimetastatic effects.
Conclusions:
- A single dose of IL-12 cDNA administered to the spleen induces a potent antimetastatic response.
- Splenic IL-12 gene therapy promotes systemic immune changes, including increased NK cell activity.
- This approach offers a promising strategy for controlling liver metastases.
