Abstract 1641: Color-coded imaging of interaction between RFP-expressing blood vessels and αv integrin-GFP expressing osteosarcoma cells.

Abstract We report here imaging the interaction between αv integrin tagged to GFP in human osteosarcoma cells and blood vessels growing on Gelfoam@ implanted subcutaneously in mice. 143B osteosarcoma cells expressing αv integrin-GFP were generated by transfection of an αv integrin-GFP vector. Gelfoam@ (5×5 mm) was treated with basic fibroblast growth factor (bFGF) and transplanted subcutaneously in RFP transgenic nude mice. Skin-flap imaging windows were made at days 7, 14, 21, 28 after transplantation of Gelfoam@. Angiogenesis was observed in the Gelfoam@ using fluorescence imaging via the skin flap windows. Frozen sections were made at day 28 after Gelfoam@ transplantation. RFP-expressing blood vessels were imaged growing into the Gelfoam@. Immunohistochemical (IHC) staining showed that CD31 and RFP fluorescence co-localized in the newly formed RFP-expressing blood vessels in the Gelfoam@. To observe the interaction of tumor cells and RFP blood vessels, 143B cells (5×105),expressing αv integrin-GFP, were injected into the Gelfoam@ 7 days after transplantation. Seven days after cancer-cell injection, the cancer cells were observed in the Gelfoam@ by confocal microscopy via skin-flap windows. 143B cells expressing αv integrin-GFP proliferated into the Gelfoam@ as observed by skin-flap-window imaging. Strong expression of αv integrin-GFP cells was observed near RFP vessels in the Gelfoam@ in the RFP mice 28 days after cancer cell injection. The results show that Gelfoam@ is a useful tool to observe angiogensis in vivo and the interactions of αv integrin-GFP with blood vessels which will allow further understanding of its role in angiogenesis and tumor progression. Citation Format: Fuminori Uehara, Yasunori Tome, Hiroki Maehara, Fuminori Kanaya, Robert M. Hoffman. Color-coded imaging of interaction between RFP-expressing blood vessels and αv integrin-GFP expressing osteosarcoma cells. [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 1641. doi:10.1158/1538-7445.AM2013-1641