Abstract 5369: AN019 in combination with ionizing radiation retards intracranial tumor growth and inhibits angiogenic induction in vitro and in vivo

Abstract

Abstract Successful treatment of malignant glioma is hampered by the development of resistance to alkylating agents such as Temozolomide (TMZ). The addition of radiation to a TMZ treatment regime has shown promising results with reported survivability of up to 5 years. One of the side effects of Temozolomide is the increased activation of angiogenic factors which may work contrary to the desired result. In this report we demonstrate the development of a novel compound AN019, showing specific VEGF suppression accompanied with anti-angiogenic and anti-proliferative properties in gliomas. We used U87, a glioma cell line, and EGFRvIII over-expressing glioma xenograft 4910 cells for this study. Deduced IC50 values indicated that AN019 had greater anti-proliferative effect than Temozolomide (U87: AN019=103µM, TMZ=768µM; 4910: AN019=169µM, TMZ=582µM). Matrigel invasion assay indicated that AN019 retarded the invasive potential of both U87 and 4910 glioma cells over TMZ treated cells which was enhanced after radiation treatment. In-vitro angiogenic and migration assays showed an almost complete inhibition of angiogenic induction and migration in U87 and 4910 cells after AN019 treatment when compared to TMZ. Cell cycle analysis revealed that 100µg/ml concentration of AN019 was sufficient to achieve >70% apoptosis in both U87 and 4910 cells, whereas 150µg/ml of TMZ was required to achieve the same response. Western blot and ELISA for the expression of VEGF levels indicated that lower concentrations of AN019 (U87=86±3µg/ml and 12±1µg/ml with radiation; 4910=100±1µg/ml and 6µg/ml with radiation) were required for 50% inhibition of VEGF expression. TMZ treatment required a higher concentration to achieve similar 50% inhibition of VEGF expression (U87=80±10µg/ml and 12±3µg/ml with radiation; 4910=100±3µg/ml and 27±3µg/ml with radiation). Animal studies showed that oral doses of AN019 (20mg/kg) regressed tumors in all animals and 70% of the animals showed complete absence of intracranial tumors, whereas TMZ (100mg/kg) treated animals also showed regression of tumors with a 30% cure rate. Overall, our results demonstrate that AN019 has anti-angiogenic, anti-proliferative and anti-tumorogenic properties which may have clinical implications. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5369.