A new model of rectal cancer with regional lymph node metastasis allowing in vivo evaluation by imaging biomarkers

• Published in: Biomedicine & pharmacotherapy Vol. 65; no. 6; pp. 401 - 406
• Main Authors: Minicozzi, A.M., Conti, G., Merigo, G., Marzola, P., Boschi, F., Calderan, L., Pacca, R., Sbarbati, A., Cordiano, C.
• Format: Journal Article
• Language: English
• Published: France Elsevier SAS 01.09.2011
• Subjects: Animals; Disease Models, Animal; Early Detection of Cancer - methods; HT29 Cells; Humans; In vivo imaging; Internal Medicine; Luciferases - biosynthesis; Luciferases - genetics; Luminescent Agents; Lymph node metastasis; Lymph Nodes - metabolism; Lymph Nodes - pathology; Lymphatic Metastasis - diagnosis; Lymphatic Metastasis - pathology; Magnetic Resonance Imaging; Male; Medical Education; Mice; Mice, Nude; Molecular Imaging; Neoplasm Proteins - biosynthesis; Neoplasm Proteins - genetics; Neoplasm Transplantation - methods; Pilot Projects; Recombinant Proteins - biosynthesis; Recombinant Proteins - genetics; Rectal Neoplasms - diagnosis; Rectal Neoplasms - genetics; Rectal Neoplasms - metabolism; Rectal Neoplasms - pathology; Rectum - metabolism; Rectum - pathology; Reproducibility of Results; TARCI; Tumor Burden; Lymph node metastasis; TARCI; In vivo imaging
• ISSN: 0753-3322; 1950-6007; 1950-6007
• DOI: 10.1016/j.biopha.2011.04.027

The work is aimed to develop a murine model of rectal cancer, which could be used to monitor lymph node metastasis development by magnetic resonance imaging (MRI) and optical imaging (OI) techniques. Ht-29 cancer cells were directly injected into the submucosal layer of the rectum of athymic nude mice using trans-anal rectal cancer cell injection (TARCI). Thirty-six mice were inoculated with 10 × 10 5 cells and five mice were treated with sterile phosphate buffer solution. One to 4 weeks after cell injection, tumor growth was evaluated in vivo using T2-weighted MRI at 4.7T. A further group of animal ( n = 6) treated with ht-29_luc cells, with the same protocol, was monitored by optical imaging. In both groups, the presence of the primary tumor and of lymph nodes metastasis was confirmed by histology. In all animals, primary tumors were detectable by MRI, 1 week from TARCI. After 4 weeks primary tumors showed a mean longitudinal diameter of about 2 cm. All animals developed regional lymph node metastases. Others organs (e.g. lung or liver) were not affected. In fat-suppressed, T2-weighted MRI, lymph nodes appeared as small areas characterized by hyper-intense signal compared to muscle. OI permitted evaluation of the primary tumor growth in perineal region. TARCI of ht-29 cells into the rectum of nude mice is a feasible way to obtain a easily reproducible model of regional lymph node metastases could be monitored by magnetic resonance and optical imaging techniques.