Abstract Malignant gliomas like glioblastoma multiforme are the most lethal form of adult brain tumor. Patients with this disease survive for only 12-15 months after diagnosis. Angiogenesis, a process of formation of new blood vessels is a pathological hallmark of glioblastoma and plays an important role in tumor growth and survival. Although angiogenesis holds promise as a drug target, recent studies have highlighted that glioblastoma acquires aggressive invasive characteristics when treated with anti-angiogenic monotherapy. Therefore, there is an urgent demand for therapies which effectively target angiogenesis and limit invasion in glioblastoma. Previously, our laboratory has found that biochanin A, a dietary isoflavone inhibits invasion in human glioblastoma cells. In this study, we determined the effects of biochanin A on brain tumor angiogenesis using rat brain tumor cells (C6) and endothelial (bEnd.3) cells. Our cell survival data indicate a dose dependent decrease in cell survival of both C6 and bEnd.3 cells treated with biochanin A (5μM-70μM) for 72 hours. Biochanin A also inhibited ERK and AKT pathway in these cells. Zymography invasion assay demonstrated a decrease in enzymatic activity of MMP's in biochanin A treated C6 and bEnd.3 cells. Apart from these signaling molecules, angiogenesis is also driven by hypoxia through upregulation of hypoxia inducible factor (HIF-1α) which releases vascular endothelial growth factor (VEGF), a key player of angiogenesis. We found that biochanin A at 35 μM inhibited protein expressions of both HIF-1α and VEGF in C6 cells treated with cobalt chloride, a chemical inducer of hypoxia. Biochanin A was also effective in inhibiting angiogenesis in an ex vivo chick chorioallantoic membrane model. These findings indicate that we may use biochanin A as a dual targeted agent that inhibits two processes, invasion and angiogenesis at similar concentrations. Thus, our study will allow the formulation of new and improved therapies for glioblastoma and ultimately enhance patient survival. (This study was supported by NIH INBRE grant #P20R16454, University Research Committee grant and Mountain States Tumor and Medical Research Institute grant). Citation Format: Aditi Jain, James C.K. Lai, Alok Bhushan. Biochanin A, a natural isoflavone inhibits angiogenesis in glioma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5095. doi:10.1158/1538-7445.AM2013-5095