A murine tumor resection model of endogenously induced intrahepatic cholangiocarcinoma (ICC) with a single, primary tumor and extrahepatic metastases

Intrahepatic cholangiocarcinoma (ICC) is a tumor with worldwide increasing incidence and dismal prognosis. Although surgical resection (R0) of the primary tumor is the only potential curative treatment, most of the patients die because of frequent tumor recurrence and outgrowth of metastases after surgery. Mouse tumor resection models are urgently needed to reflect the clinical relevant situation and investigate novel therapies in the context of ICC. In this study, we wanted to establish a corresponding endogenously induced murine tumor model of resectable, single locus ICC formation. We investigated tumor development at a defined intrahepatic locus by injection of Sleeping Beauty-based, oncogenic transposon plasmids into the liver lobe followed by subsequent electroporation. The plasmids included the constitutively activate KRasG12V oncogene together with a plasmid for Cre-recombinase and were applied in p53-fl/fl mice to induce the p53-knockout. This setup was chosen since molecular pathogenesis of ICC frequently involves both KRas-activation and p53-aberrations Mice developed a single intrahepatic tumor lesion within 3–7 weeks following electroporation. Develoment of ICC was verified by histological analysis. Molecular analysis after electroporation of defined lineage-specific fluorescent reporter plasmids provided evidence for hepatocytes as origin of ICC formation. At the time of primary tumor growth no formation of metastases in the lung could be detected. But formation of satellites close to the primary tumor and vascular invasion could be observed as an indicator of early metastasis. After R0-resection of the primary tumor we were able to prolong median survival with the observation of local disease recurrence, peritoneal carcinomatosis and lung metastases. This resection model of the endogenous, intrahepatic tumor induction allows preclinical testings of adjuvant therapies. In conclusion, we have successfully developed a murine model of endogenously induced ICC with a single, resectable, primary tumor. This model has favorable characteristic for the study of recurrence patterns after resection and the mechanisms of metastasis. It also holds promise for preclinical evaluation of novel multimodal or adjuvant therapies to prevent recurrence and outgrowth of metastases after R0-resection.