Murine portal vein catheterization to analyze liver-directed therapies

• Published in: The Journal of surgical research Vol. 185; no. 2; pp. 690 - 696
• Main Authors: Valentino, Joseph D., MD, Rychahou, Piotr G., MD, Mustain, W. Conan, MD, Elliott, Victoria A., BS, Evers, B. Mark, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2013
• Subjects: Animal model; Animals; Antigens, Neoplasm - genetics; Catheterization; Catheterization, Central Venous - methods; Cell Adhesion Molecules - genetics; Cell Line, Tumor; Colonic Neoplasms - secondary; Colonic Neoplasms - therapy; Colorectal cancer; Disease Models, Animal; Epithelial Cell Adhesion Molecule; Genetic Therapy - methods; Liver - blood supply; Liver - pathology; Liver metastasis; Liver Neoplasms, Experimental - secondary; Liver Neoplasms, Experimental - therapy; Mice; Mice, Inbred BALB C; Microspheres; Neoplasm Transplantation; Polystyrenes - pharmacokinetics; Portal Vein; RNA, Small Interfering - pharmacology; siRNA; Surgery; Animal model; siRNA; Portal vein; Catheterization; Liver metastasis; Colorectal cancer
• ISSN: 0022-4804; 1095-8673
• DOI: 10.1016/j.jss.2013.06.051

Abstract Background Small interfering RNA (siRNA) provides a highly selective method to target mutated pathways; however, its use is complicated by specific delivery to tumor cells. The aims of the present study were to develop a novel murine model of portal vein catheterization for the chronic delivery of therapeutic agents to liver metastases, determine the benefits of local delivery of siRNA to liver metastases, and determine the utility of epithelial cell adhesion molecule (EpCAM) as a selective target for siRNA delivery to colorectal cancer (CRC) metastases. Materials and methods First, portal vein catheterization was performed through a midline laparotomy in 2 mo-old Balb/C mice. Second, the portal venous flow distribution and catheter patency were evaluated using fluorescent-labeled microspheres. Metastatic studies were performed by splenic injection of CT26 murine colon cancer cells. Uptake of DY-547-labeled siRNA was assessed by IVIS imaging, with delivery to the metastases confirmed using fluorescent microscopy. Finally, EpCAM expression was evaluated using immunohistochemical staining of human tissue microarrays. Results Successful portal vein catheterization was confirmed by saline injection and ultrasound. Fluorescent imaging of microspheres confirmed excellent distribution and catheter patency. Portal venous injection of DY547-labeled siRNA demonstrated a high level of fluorescence throughout the liver, with siRNA also identified within the liver metastases. Also, all primary CRCs and liver metastases stained strongly for EpCAM, with no expression in normal hepatocytes. Conclusions Liver-directed therapy can provide the selective delivery of siRNA to CRC metastases. EpCAM expression in CRC, but not normal liver, could further selectively target hepatic metastases of epithelial origin.