A long term, non-tumorigenic rat hepatocyte cell line and its malignant counterpart, as tools to study hepatocarcinogenesis.

// Maria Maddalena Angioni 1, * , Kevin Bellofatto 2, * , Simone Merlin 2 , Silvia Menegon 3 , Andrea Perra 1 , Annalisa Petrelli 3 , Pia Sulas 1 , Silvia Giordano 3 , Amedeo Columbano 1 , Antonia Follenzi 2 1 Department of Biomedical Sciences, University of Cagliari, 09124 Cagliari, Italy 2 Department of Health Sciences, University of Piemonte Orientale, 28100 Novara, Italy 3 Department of Oncology, University of Torino School of Medicine, Candiolo Cancer Institute-FPO, IRCCS, 10060 Candiolo, Italy * These authors have contributed equally to this work Correspondence to: Antonia Follenzi, email: antonia.follenzi@med.uniupo.it Amedeo Columbano, email: columbano@unica.it Silvia Giordano, email: silvia.giordano@unito.it Keywords: resistant hepatocyte, CD90.1, CD24, HCC cell lines, immortalized non-tumorigenic cells Received: March 03, 2016     Accepted: January 03, 2017     Published: February 01, 2017 ABSTRACT Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the second cause of cancer-related death. Search for genes/proteins whose expression can discriminate between normal and neoplastic liver is fundamental for diagnostic, prognostic and therapeutic purposes. Currently, the most used in vitro hepatocyte models to study molecular alterations underlying transformation include primary hepatocytes and transformed cell lines. However, each of these models presents limitations. Here we describe the isolation and characterization of two rat hepatocyte cell lines as tools to study liver carcinogenesis. Long-term stable cell lines were obtained from a HCC-bearing rat exposed to the Resistant-Hepatocyte protocol (RH cells) and from a rat subjected to the same model in the absence of carcinogenic treatment, thus not developing HCCs (RNT cells). The presence of several markers identified the hepatocytic origin of both cell lines and confirmed their purity. Although morphologically similar to normal primary hepatocytes, RNT cells were able to survive and grow in monolayer culture for months and were not tumorigenic in vivo . On the contrary, RH cells displayed tumor-initiating cell markers, formed numerous colonies in soft agar and spheroids when grown in 3D and were highly tumorigenic and metastatic after injection into syngeneic rats and immunocompromised mice. Moreover, RNT gene expression profile was similar to normal liver, while that of RH resembled HCC. In conclusion, the two cell lines here described represent a useful tool to investigate the molecular changes underlying hepatocyte transformation and to experimentally demonstrate their role in HCC development.