Abstract 3717: Animal model of cirrhosis with hepatocellular carcinoma: A reliable tool for testing new therapies
Authors: Kurma Keerthi , Jilkova Zuzana Macek , Marche Patrice N. , Sturm Nathalie , Lerat Hervé , Decaens Thomas 
Published: August 2019

Background and aim: Liver cancer is now the second most common cause of cancer related death worldwide, with hepatocellular carcinoma (HCC) accounting for the majority of these cases . 90% of HCC are associated with liver fibrosis or cirrhosis developed from chronic liver injuries.Small animal models represent essential tools in cancer research. As fibrosis/cirrhosis modifies liver vascularization, extracellular matrix composition, and drugs metabolism, it is essential to use a cirrhotic animal model to test HCC drugs for their efficiency against tumour initiation and/or progression. Current mouse model failed to reproduce all fibrosis stages, especially cirrhosis. One of the rodent models that most faithfully reproduce human cirrhosis is diethyl nitrosamine-injured rats (DEN rats).

The aim of our project is to deeply characterize DEN-induced HCC rat model during cirrhosis progression and HCC development with special focus on liver inflammatory micro-environment.

Method: 6-weeks-old Fischer 344 male rats were treated weekly with intra-peritoneal injections of 50 mg/kg DEN. 9 rats are sacrificed before starting DEN-injections at 0 week (control group), after 8 weeks of injections (8 weeks), after 14 weeks of injections (14 weeks) and at 20 weeks after start of DEN-injections (20 weeks). Histopathological analysis, immunohistochemical and FACS analysis were performed. Results were analysed in a double blind manner.

Results: Chronic DEN treatment induces tumour development that starts at 14 weeks. Tumour size significantly increases between 14 and 20 weeks but not tumour number. DEN injection was associated with a significant increase of hepatocyte proliferation at 8 weeks, 14 weeks, and 20 weeks when compared to 0 weeks. Similarly, CD34 positive cells were increased, suggesting enhanced angiogenesis at 14 & 20 weeks when compared to 0 weeks. DEN-induced liver fibrosis was significantly and gradually enhanced as suggested by upregulation of fibrosis deposition at 8 weeks, 14 weeks, 20 weeks compared to 0 weeks. We also observed significant decrease in CD4+ and increase in CD8+ T lymphocytes in the blood and non-tumour liver tissue at each time points. In parallel, CD8+ T lymphocytes were significantly decreasing in hepatic tumour tissue. CD152 expression was significantly increasing in blood samples and non- tumour liver tissues at 8, 14 and 20 weeks compared to 0 weeks.

Conclusion: DEN-induced HCC rat model displays tumour initiation, development and different stages of liver fibrosis, up to cirrhosis and also helps to understand related modulation of immune micro environment. Indeed we demonstrated CTLA-4 expression is upregulated in this model. In this context, DEN-induced cirrhotic HCC rat model might be a relevant tool as pre-clinical models to evaluate new HCC treatment efficacy and tolerance in liver cirrhotic background.

Citation Format: Keerthi Kurma, Zuzana Macek Jilkova, Patrice N. Marche, Nathalie Sturm, Hervé Lerat, Thomas Decaens. Animal model of cirrhosis with hepatocellular carcinoma: A reliable tool for testing new therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3717.