Prostate cancer (PCa) is the second most common cancer in US men. Metastasis is the final step of tumor progression and remains the primary cause of PCa death. Hence preclinical, orthotopic models of PCa metastasis are necessary to develop new therapeutics against metastatic disease. Yet unlike irrelevant subcutaneous tumor models, the deployment of orthotopic models of cancer metastasis in drug research and development is limited by the inability to longitudinally monitor cancer progression/regression in response to administration of experimental pharmaceuticals. Recently, a nearinfrared fluorescent protein (iRFP) was created for deeper imaging [1]. Imaging prostate tumor growth and lymph node metastasis in nude mice therefore becomes possible using this new fluorescent gene reporter. In this study, we first developed an intensified CCD (ICCD)-based iRFP fluorescence imaging device. Then human PCa PC3 cell lines expressing iRFP gene reporter were orthotopically implanted in male Nu/Nu mice at 8-10 weeks old. After 6-10 weeks, in vivo, in situ and ex vivo fluorescence imaging was performed. In vivo iRFP fluorescence imaging showed that the detected fluorescence concentrated at the prostate and became stronger over time, indicating the growth of implanted PCa. Fluorescence was non-invasively detected at locations of prostate-draining lymph nodes as early as 5 weeks post implantation, indicating the metastasis to lymph nodes. In situ and ex vivo fluorescence imaging demonstrated that the detected signals from PCa and lymph nodes were correlated with cancer positive status of tissues as assessed through standard pathology.

Date Published: 8 March 2013
PDF: 6 pages
Proc. SPIE 8565, Photonic Therapeutics and Diagnostics IX, 85651E (8 March 2013); doi: 10.1117/12.2002092

Published in SPIE Proceedings Vol. 8565:
Photonic Therapeutics and Diagnostics IX
Andreas Mandelis; Brian Jet-Fei Wong; Anita Mahadevan-Jansen; Henry Hirschberg M.D.; Hyun Wook Kang; Nikiforos Kollias; Melissa J. Suter; Kenton W. Gregory M.D.; Guillermo J. Tearney M.D.; Stephen Lam; Bernard Choi; Steen J. Madsen; Bodo E. Knudsen M.D.; E. Duco Jansen; Justus F. Ilgner M.D.; Haishan Zeng; Matthew Brenner; Laura Marcu, Editor(s)