Molekulare Bildgebung des Mammakarzinoms in einem transgenen Mausmodell

Background: Purpose of the study was to detect early breast cancer and its precursors by in vivo optical molecular imaging in an animal model. Material and methods: Females of the transgene mouse strain WAP-TNP8 develop non-invasive and consequently invasive tumours of the mammary glands due to specific expression of the viral SV40 large tumour antigen induced by lactation. The molecular target for imaging was extradomain-b fibronectin (EDB-FN), which is associated with tumour angiogenesis. The optical probe was designed as a compound of an anti-EDB-FN antibody fragment and a near-infrared fluorescent dye. 30h after intravenous injection of the contrast agent, optical imaging was performed using a pulsed Laser system for excitation and an intensified CCD-camera to record fluorescence images. After optical molecular imaging all animals were sacrified and the tumours were examined histologically. Results: Initiated transgene female animals developed palpable masses of the mammary gland within 6 months (median 4 months). Imaging was performed in 5 animals with a total of 9 tumours (diameter 2–7mm, median 4mm). Applying optical molecular imaging 8 of 9 tumours were detected. The urogenital tract was contrasted unspecifically. Histological examination proved invasive epithelial tumours of the mammary gland in all cases. Conclusion: Breast cancer can be detected in vivo by near-infrared fluorescence molecular imaging targeting neoangiogenesis in a transgene mouse-model.