Page 58 - ebook HCC

56 PROGRAMME AND ABSTRACTS GENEVA, SWITZERLAND EASL HCC SUMMIT 57
FEBRUARY 13 - 16, 2014

RAGE SIGNALING IN OVAL CELL ACTIVATION RESECTABLE TRANSGENIC TUMOR
DURING LIVER DAMAGE MODEL IN MICE FOR INTRAHEPATIC
CHOLANGIOCARCINOMA
Aurora M. De Ponti , Tobias Pusterla , Ilan Stein , David Knigin ,
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Eli Pikarsky , Jochen Hess , Peter Angel 1
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1 Signal Transduction and Growth Control, German Cancer Research Center- Dkfz, Engin Gürlevik , Bettina Fleischmann-Mundt , Norman Woller , Jennifer Brooks ,
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Heidelberg, Germany, Department of Pathology and the Lautenberg Center for 1 Michael Manns , Stefan Kubicka , Florian Kühnel 1
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Immunology, Hebrew University - Hadassah Medical School, Jerusalem, Israel, Gastroenterology, Hepatology, and Endocrinology, Hannover Medical School, Hannover, Germany
3 Department of Otolaryngology, Head and Neck Surgery, University Hospital Heidelberg,
Heidelberg, Germany Corresponding author’s e-mail: guerlevik.engin@mh-hannover.de
Corresponding author’s e-mail: a.deponti@dkfz-heidelberg.de Introduction: Surgical complete resection (R0) of the primary tumor is the only potential
curative treatment option for many tumor entities. Despite surgical resection, patients with
Introduction: The Receptor for Advanced Glycation End-products (RAGE) is a pattern- intrahepatic cholangiocarcinoma (ICC) have poor prognosis, because of frequent tumor
recognition receptor, able to bind different types of damage- associated molecular pattern recurrence and outgrowth of metastases after surgery. Unfortunately, the current animal
tumor models do not reflect the aspect of resectability, though surgery and adjuvant
(DAMP) molecules, such as HMGB1 and several calcium-binding S100 proteins, which
BASIC SPEAKERS ABSTRACTS conditions and in cancer i) upregulates the receptor itself, ii) activates different pro- Aims: To address the aspect of tumor resection in murine tumor models, we established a BASIC SPEAKERS ABSTRACTS
therapy is still the most important and potentially curative therapeutic intervention for
are released during tissue damage and inflammation. Rage engagement in inflammatory
cancer patients.
inflammatory responses and iii) promotes tumor development. We previously demonstrated
that in Mdr2 knockout mice, a model of inflammation-associated HCC development,
corresponding model for ICC in mice by facilitating endogenous induction of a single tumor
Rage ablation impairs tumor development and causes a delay in the onset of chronic
in situ that is suitable for surgical resection.
liver damage and fibrosis. This phenotype is associated with a reduced activation of oval
cells, the hepatic progenitor cells involved in liver regeneration. We found that primary
oval cells and BMOL cells (an oval cell line) express Rage. In BMOL cells stimulation by
plasmids followed by subsequent local electroporation leads to formation of a locally
HMGB1 promotes cell proliferation. In accordance, Rage knock-down reduces BMOL cell
restricted, resectable primary tumor. The injected DNA includes a transposon vector for
proliferation, and in vivo blockade of the receptor signaling by means of injection of the Methodology: Intratissue injection of Sleeping Beauty-based, oncogenic transposon
decoy receptor sRAGE reduces oval cell activation (Pusterla et al., 2013). expression of mutated KRas-G12V and a plasmid for expression of Cre-recombinase.
In p53-fl/fl-mice, the Cre recombinase induces the knockout of p53 and simultaneous
Aims: The project aims to establish a protocol to isolate and cultivate primary liver transformation by genomic insertion and expression of the RasG12V transposon.
progenitor cells, and to demonstrate the involvement of RAGE in oval cell proliferation,
migration and differentiation, as well as to investigate the role of RAGE-dependent Results: According to our aims, mice developed a single tumor lesion at the electroporated
signaling and gene regulatory networks in these processes. tissue locus. Formation of ICC was verified by histological analysis. Molecular analysis
after electroporation provided evidence for hepatocytes as origin of tumor formation.
Methodology: In order to compare the biological processes occurring in control or Rage- Metastases in the lung and peritoneum could be detected. By R0-resection of the
deleted ex vivo isolated oval cells, we ablated Rage by adding 4-OH tamoxifen to the primary tumor, we were able to prolong median survival with the observation of local
culture medium, which posttranslationally activates the Cre recombinase enzyme. Rage- disease recurrence, peritoneal carcinomatosis, and metastases in liver and lung. Using
positive and Rage-deficient oval cells are currently used to characterize cellular responses gemcitabine as therapeutic standard for biliary cancer, we could observe a survival benefit
(proliferation, migration, apoptosis, differentiation and cytokines release) and signalling only in the adjuvant approach. Palliative gemcitabine application did not improve survival.
pathways promoted by RAGE ligands. These results indicate different mode of action of gemcitabine in the adjuvant or palliative
situation, respectively.
Results: We are able to isolate and cultivate primary oval cells, which express several
indicative markers of liver progenitor cells but are negative for hepatocyte specific gene Conclusions: Our resection models reflect the clinical situation in humans and holds great
expression. Importantly, these cells migrate towards a HMGB1 gradient strongly implying promise for preclinical evaluation of novel multimodal and adjuvant therapies in genetically
that this DAMP molecule controls oval cell chemotaxis. defined biliary cancers to prevent recurrence and outgrowth of metastases. Furthermore,
the results suggest that therapies have to be evaluated separately for palliative or adjuvant
Conclusions: Our data strongly suggest that stimulation of RAGE by HMGB1 during liver approaches, respectively.
damage plays a decisive role in oval cell activation.