Use of anti-angiogenic compounds for cancer treatment is currently under investigation in clinical trials. Three basic approaches exist for assaying the angiogenic effect of compounds. Two are in vitro assays which require subsequent in vivo validation. The remaining approach is an in vivo assay but the assay is experimentally elaborate and expensive, making it less useful for drug screening. Because of the complex nature of angiogenesis and limitations of current assays, a rapid, quantitative and physiologically informative assay for drug screening is urgently needed. Using zebrafish embryos, this Phase I SBIR aims to develop several assays which permit quantification of angiogenic response to drugs and its classification at the molecular and histological levels. Since anti-angiogenic compounds may affect the immune system, an assay will also be developed to assess hematopoietic response at the cellular level in order to determine the usefulness of potential drug candidates for cancer therapy. PROPOSED COMMERCIAL APPLICATIONS: By providing a rapid, high throughput method for screening drugs, the zebrafish assay will help to streamline the drug development process for cancer.