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DOI: 10.1055/s-0038-1677211
Novel short-termed mouse model of intrahepatic cholangiocarcinoma (ICC) by orthotopic transplantation of ICC cell line in C57/B6 mice
Publikationsverlauf
Publikationsdatum:
04. Januar 2019 (online)
Background and Aims:
Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive cancer that ranks the second most common liver cancer in the world. It is associated with very poor prognosis and limited treatment options. Well-defined animal models recapitulating human disease to dissect molecular mechanisms and identify and evaluate new therapeutic strategies in preclinical settings are sparse. of rise and progression of cholangiocarcinoma animal models are needed. Here we present an murine orthotopic transplant model on B6 background resulting in ICCs with high molecular homology to human ICC within two to four weeks.
Method:
2*106 Hep55.1C cells were injected in the left liver lobe of 6 – 8 weeks old C57/B6 male mice and tumor growth was followed by weekly ultrasound. After two and four weeks mice were sacrificed and gene expression of tumor and surrounding tissue was analyzed mRNA sequencing and qPCR. Immunohistological stainings were performed to determine protein expression of cholangiocyte and hepatocyte markers and to investigate intrahepatic as well as systemic immune responses flow cytometry analysis was performed.
Results:
All mice developed liver tumors with a size of 0.6 cm2 or 1 cm2 on average after two or four weeks of Hep55.1C cell transplantation. Tumors showed features of highly differentiated cholangioarcinomas with characteristics of adenocarcinomas with tubular structures as determined by a hematoxylin-eosin-staining. Real-time PCR analysis of tumor tissue in comparison to surrounding tissue revealed high expression of cholangiocyte markers (CK7, CK19, SOX9) but not of hepatocyte (HNF4 α, transthyretin) or hepatocellular carcinoma markers (α-Fetoprotein, albumin). Supportively, immunohistological stainings showed a strong and ubiquitous signal for pan-cytokeratin within the tumor in contrast to HNF4α that was upregulated in the surrounding tissue. Intrahepatic cell composition analyzed by flow cytometry displayed an induction of both innate and adaptive immune response with an increase of neutrophils, B-cells, CD11b+ cells as well as Ly6C high and -low macrophages in the tumor tissue after two weeks. Surprisingly, this effect was partially reversed after four weeks following transplantation. Moreover, comparing transcriptomic analysis following RNA sequencing of tumor tissue from our mouse model with published data sets from human ICC tissue using gene set enrichment analysis, we were able to identify high similarities between our model and human ICC.
Conclusion:
We here present a novel, highly reproducible cholangiocarinoma mouse model characterized by two advantages from the experimental point of view: Tumor induction shows 100% success rate with fast progression and tumors recapitulates characteristic features of human ICC. Our model is therefore most suitable to define and evaluate interventional therapies.