%0 Journal Article %A Maral Pourghiasian %A James Inkster %A Navjit Hundal %A Felix Mesak %A Brigitte Guerin %A Samia Ait-Mohand %A Thomas Ruth %A Michael Adam %A Kuo-Shyan Lin %A Francois Benard %T 18F-BVD-15 for NPY Y1 receptor imaging in breast cancer and neuroblastoma models by PET %D 2011 %J Journal of Nuclear Medicine %P 1682-1682 %V 52 %N supplement 1 %X 1682 Objectives Neuropeptide Y1 receptors (NPY1R) are overexpressed in breast cancers and neuroblastomas. The purpose of this study was to evaluate an NPY1R antagonist labeled with F-18, using breast and neuroblastoma tumor-bearing mice. Methods 18F- and 19F-ALK-BVD-15 were prepared via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) conjugation of an azide-substituted peptide (Ile-Asn-Pro-Lys(-CO-CH2-N3)-Tyr-Arg-Leu-Arg-Tyr-NH2) with alkyne-bearing prosthetic 18/19FFPy5yne. In vitro competitive binding assays were performed on human breast cancer (MCF-7) and neuroblastoma (SK-N-MC) cells. Immunohistochemistry was used to document the presence of NPY1R receptors in the tumors implanted in vivo. Biodistribution studies were performed on nude mice bearing MCF-7 or SK-N-MC tumors, while imaging studies were performed using microPET/CT. Tissues of interest were collected 1 hour post-injection and the percentage injected dose per gram of tissue (%ID/g) was measured. Results Competitive binding assays showed good in vitro binding for 19F-ALK-BVD with a Ki of 31±18 nM for MCF-7 cells and 14.8±5.8 nM for SK-N-MC cells. The receptor density was significantly higher in SK-N-MC cells. 18F-ALK-BVD had a suitable biodistribution but no significant uptake in tumors was observed in MCF-7 tumor-bearing mice (%ID/g: 0.10±0.04). Uptake of tumor was higher (0.7±0.2) in SK-N-MC tumor-bearing mice and with higher intensity at the rim of the tumors by imaging. Both tumor models showed evidence of NPY1R expression ex vivo by immunohistochemistry. Conclusions In vitro binding assays showed a good binding affinity of 19F-ALK-BVD to SK-N-MC cells and a higher number of receptors compared to MCF-7 cells. 18F-ALK-BVD had a suitable biodistribution but low receptor-mediated tumor uptake was seen in NPY1R positive tumors. In vitro and in vivo results suggest that neuroblastoma tumors could be a better model for NPY1 receptor imaging. Research Support Canadian Institutes for Health Researc %U