Abstract
As an antitumor agent, interleukin-12 (IL-12) has been revealed to be a key regulator of the immune response, particularly that involving CTL and natural killer (NK) cells. We report herein the antiangiogenesis effect of IL-12 on human as well as murine tumors in NK-depleted severe-combined immunodeficient mice using fibroblasts genetically engineered to secrete this cytokine. Although the in vitro growth of tumor cells was not affected by the presence of IL-12, coinoculation of IL-12-secreting fibroblasts strongly inhibited tumor growth in immunodeficient mice. The neovascularization surrounding the tumor was remarkably inhibited in the area in which the IL- 12-secreting fibroblasts were implanted, resulting in the suppression of tumor growth. Lectin staining in tumor sample sections also showed a significant reduction in the number of vessels. The RNA expression of IFN-γ and its inducible antiangiogenic chemokine IFN γ-inducible protein 10 was stimulated in endothelial cells cultured with IL-12. It was also found that IL-12 down-regulated the expression of the endothelial cell mitogens vascular endothelial growth factor and basic fibroblast growth factor. The antitumor effects of IL-12 were accompanied by interesting histological changes consisting of a high degree of keratinization and apoptosis and a decrease in the proliferation rate of human tumors and extensive necrosis in the murine ones.
Original language | English |
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Pages (from-to) | 1111-1116 |
Number of pages | 6 |
Journal | Cancer Research |
Volume | 60 |
Issue number | 4 |
Publication status | Published - 2000 Feb 15 |
ASJC Scopus subject areas
- Oncology
- Cancer Research