Background. The present study investigated whether treatment with anginex, a novel antiangiogenic peptide, could block re-vascularization after radiation treatment. Methods. A squamous cell (SCCVII) xenograft tumor mouse model was employed to assess the effects of anginex given post-radiation on tumor growth, microvessel density (MVD), and oxygen levels. The oxygen status was determined by the partial pressure of O2. Results. Tumors in untreated mice increased threefold in 7.0 days, anginex-treated tumors (10 mg/kg intraperitoneal, twice) required 7.3 ± 0.9 days, and tumors exposed to 8-Gy radiation increased threefold over 11 days. Combination treatment of anginex and radiation caused the tumors to grow threefold in 16.1 ± 1.6 days, a delay which was significant and deemed supra-additive. Oxygen levels in tumors treated by stand-alone or combination therapies were significantly reduced; for example from 19.5 ± 4.9 mmHg in controls to 9.7 ± 1.9 mmHg in combination-treated, size-matched tumors. In addition, immunohistochemistry showed a decrease in MVD in the tumors treated with anginex, radiation, or the combination. These results suggest that a combination of anginex and radiation can greatly affect the amount of functional vasculature in tumors and prolong radiation-induced tumor regression. Conclusion. Antiangiogenesis therapy with anginex, in addition to radiotherapy, will be useful by blocking angiogenesis-dependent regrowth of vessels.
- Radiation therapy