e23093 Background: Gastric cancer is primarily managed endoscopically by white light gastroscope with suboptimal diagnostic accuracy. Emerging optical imaging technologies possess great potential for improving diagnostic accuracy but currently lack imaging agents for molecular specificity. In this study, a novel ligand of transferrin receptor 1 (TfR1), human H-ferritin (HFn), was labeled with fluorescent agents to enable in vivo real-time imaging by confocal laser endomicroscopy (CLE). Methods: In vivo fluorescence imaging was performed in tumor-bearing mice from human gastric cancer cell lines using fluorescently labeled HFn nanoprobe. The HFn-FITC as molecular imaging agent was applied to the gastric cancer with confocal laser endomicroscopy (CLE) in fresh endoscopic submucosal dissection (ESD) of early gastric cancer. Results: Intravital imaging of gastric xenograft tumors revealed a specific tumor targeting effects of HFn-IRDye800CW, whereas no specific signal was observed in mice injected with free dye. An ex vivo experiment on human specimens using a rigid confocal probe showed positive fluorescent staining in ESD samples diagnosed as early gastric cancers. Our CLE evaluation correlated well with immunohistochemical findings. Conclusions: CLE can be used for in vivo, molecular analysis of early gastric cancer and to identify TfR1 expression in xenografts and human tissue samples. HFn-targeted molecular imaging could improve early detection of gastric cancer.
Sa1965 DEVELOPMENT AND VALIDATION OF A NEW CLASSIFICATION FOR IN VIVO DIAGNOSIS OF DUODENAL EPITHELIAL TUMORS WITH CONFOCAL LASER ENDOMICROSCOPY
