Related Experiment Video For Colitis-associated colon cancer
Updated: May 21, 2026
Murine Endoscopy for In Vivo Multimodal Imaging of Carcinogenesis and Assessment of Intestinal Wound Healing and Inflammation
Published on: August 26, 2014
Fluorescence endoscopic detection of murine colitis-associated colon cancer by topically applied enzymatically
Makoto Mitsunaga1, Nobuyuki Kosaka, Peter L Choyke
1Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10, Room B3B69, MSC1088, Bethesda, MD 20892-1088, USA.
Objectives:
Screening colonoscopy to monitor for early colitis-associated colon cancer (CAC) is difficult due to the aberrant mucosal patterns associated with long-standing colitis. The aim of this study was to develop a rapid fluorescent detection method for use during colonoscopy for improving the detection of CAC utilising a topically applied enzymatically activatable probe (gGlu-HMRG) which fluoresces in the presence of γ-glutamyltranspeptidase (GGT), an enzyme associated with cancer.
Methods:
Expression of GGT in colon cell lines was examined with fluorescence microscopy and flow cytometry. A mouse model (azoxymethane/dextran sulphate sodium) of CAC was used and mice were examined with white light and fluorescence colonoscopy before and after topical gGlu-HMRG administration.
Results:
Expression of GGT, although variable, was higher in human colon cancer cells than normal human colon cells. Using fluorescence colonoscopy in mice, gGlu-HMRG fluorescent lesions were detected 5 min after topical administration and fluorescence persisted for at least 30 min. Fluorescence guided biopsy revealed all fluorescent lesions that contained cancer or dysplasia (n=16), whereas three out of 12 non-fluorescent lesions contained low grade dysplasia and others did not contain neoplastic histology. Microscopic inflammatory infiltration also had variable fluorescence but in general was much lower (∼10-fold) in signal than cancer. Repeat fluorescence endoscopy allowed individual tumours to be monitored.
Conclusion:
These results suggest that gGlu-HMRG can improve endoscopic detection of CAC with a higher target to background ratio than conventional white light colonoscopy. This could be of benefit to patients with long-standing colitis who must undergo repeated screening colonoscopies.
