Targeting Colon Cancer Cells with Fluorescent Magnetic Nanoparticles Conjugated to Anti-epidermal Growth Factor Receptor Antibodies
Chang Wook Kim, M.D., Young Seok Cho, M.D., Tae Jong Yoon, Ph.D.*, Hyung Keun Kim, M.D., Sung Soo Kim, M.D., Ki Yuk Chang, M.D., Hiun Suk Chae, M.D., Myung Gyu Choi, M.D. and Kyu Yong Choi, M.D.
Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea, *Center for Molecular Imaging Research, Harvard Medical School, Massachusetts General Hospital, USA
Abstract
Background/Aims: The aim of this study was to evaluate targeting the epidermal growth factor receptors (EGFRs) of colon cancer cells with fluorescent magnetic nanoparticles (FMNP) conjugated to anti-EGFR antibodies. Methods: The expression of EGFRs was evaluated in the HT-29 colon cancer cell lines and the control H-520 lung cancer cells by performing Western blot analysis. We synthesized silica-overcoated iron oxide nanoparticles that contained rhodamine B isothiocyanate (RITC) within a silica shell of a controllable thickness. This FMNP was conjugated to anti-EGFR mouse monoclonal antibody. The cells were treated with this probe conjugate for 4 hours and then the targeting was assessed via confocal microscopy. The fluorescence properties were evaluated for their binding to the expressed EGFRs with using a FACScan flow cytometer. Results: EGFR was expressed in the HT-29 cells, as assessed by Western blot analysis. Red fluorescence was only detected in the membrane regions of the HT-29 cells on the confocal microscope imaging. On the FACS analysis, there was a significant shift of fluorescence intensity for the HT-29 cells. Conclusions: Our data show the feasibility of targeting colon cancer cells with FMNP conjugated with anti-EGFR antibodies in vitro. (Korean J Gastrointest Endosc 2008;36:1-6)