Page 317 - ebook HCC

PROGRAMME AND ABSTRACTSAND ABSTRACTS
GENEV
EASL
314 PROGRAMME GENEVA, SWITZERLANDA, SWITZERLAND EASL HCC SUMMITHCC SUMMIT 315
315
314
FEBRUARY 13 - 16, 2014Y 13 - 16, 2014
FEBRUAR
Poster Board Number C79 Poster Board Number C80
ROLE OF THE ERK5 SIGNALLING IN THE HUMAN GENETIC AND EPIGENETIC ALTERATIONS OF
HEPATOCELLULAR CARCINOMA P16 & RASSF1A GENE IN HEPATOCELLULAR
CARCINOMA FROM NORTH INDIA
Giovanni Di Maira , Elisabetta Rovida , Nadia Navari , Stefania Cannito 1 2 3 ,
1 2
1
1
Persio Dello Sbarba 1 2 3 , Maurizio Parola 1 2 3 , Fabio Marra 1 2 3 Sunil K. Polipalli , Vijay K. Karra , Rajesh Ruttala ,
1
1
1
1 Dipartimento di Oncologia Sperimentale, Medicina Sperimentale e Clinica, University of Phani K. Gumma , Premashis Kar , Seema Kapoor 2
2
1
1
3
Florence, Florence, Dipartimento di Medicina e Oncologia Sperimentali , 1 Medicine, Pediatrics, Maulana Azad Medical College & Associated Lok
2
University of Turin, Turin, Italy Nayak Hospital, New Delhi, India
Corresponding author’s e-mail: giovanni.dimaira@unifi.it Corresponding author’s e-mail: sunilpkumar18@gmail.com
Introduction: The large majority of hepatocellular carcinomas (HCC) arises on a chronically Introduction: The tumor suppressor genes are mainly inactivated by an epigenetic
injured liver, in the presence of fibrosis or cirrhosis, underscoring the relationship between change involving promoter hypermethylation in hepatocarcinogenesis. Our knowledge
stromal changes and the onset of cancer. As current treatment options for hepatocellular
carcinoma (HCC) are limited, it is critical to identify novel therapeutic targets. about molecular alterations during hepatocarcinogenesis is still fragmentary, due to lack
of comprehensive genetic and epigenetic analyses in the same set of hepatocellular
Aims: ERK5 is a member of the MAPK family implicated in several biologic actions relevant carcinomas (HCCs).
for tumor development. Deregulation of the ERK5 pathway has been associated with cancer.
Aim of this study was to understand the role of ERK5 in HCC in vitro and in vivo. Aims: The study aims at the possible clinical impact of p16INK4A & RASSF1A methylation
and the potential risk factors for this epigenetic alteration
Methodology: Huh-7 and HepG2 were cultured by standard methods. Liver tissue was
obtained from HCC and peritumoral areas. ERK5 was silenced by siRNA transfection or Methodology: In this study, we conducted mutational screening in p16 gene and methylation
with shRNA and lentiviral vectors. The specific ERK5 inhibitor XMD8-92 was also used. assays of p16 and RASSF1A genes in 50 patients of HCCs and their neighboring non-
In vivo development of HCC was evaluated using the Huh-7 xenograft model in athymic cancerous tissues. All samples were collected from the residents in North India.
nude mice.
Results: We found HBV infection and chronic hepatitis/cirrhosis in 80.3% and 94.1%
Results: ERK5 showed more abundant nuclear localization in patients with HCC or of the cases, respectively. Mutations were identified in 18 out of 50 (36.0%) samples,
cirrhosis than in normal liver, indicating ERK activation. ERK5 silencing in HCC cells or
with p16 alterations in 14 cases and β-catenin mutations in two tumors. No mutations
CLINICAL POSTER ABSTRACTS serum. Similar results were observed in response to hypoxia. ERK5 silencing or inhibition carrying p16 mutations displayed substitution of GTG to ATG (Val Met) at codon 74, a CLINICAL POSTER ABSTRACTS
exposure to XMD8-92 blocked the increase in migration and invasion induced by EGF or
were identified in the neighboring tissues. Interestingly, 9 out of 14 (64.3%) tumors
caused cytoskeletal remodeling and rearrangement of focal adhesions, consistent with
characteristic change believed to be induced by aflatoxin-B1. Furthermore, p16 mutation
a reduction in cell motility. ERK5 activation was necessary for the growth of HCC cells,
was significantly associated with shorter recurrence-free survival (P = 0.004). The results
affecting the G1/S transition. In a mouse model of HCC xenograft, administration of XMD8-
also revealed aberrant methylation in two genes in as high as 80% of tumors and 30%
92 significantly decreased tumor volume by 40% compared to vehicle. In mice injected with
of adjacent tissues. The frequency of RASSF1A hypermethylation was much higher than
Huh-7 silenced for ERK5 using a lentiviral shRNA vector, the rate of tumor appearance
was significantly lower (4/16 mice, 25%) than in animals inoculated with cells transduced
RASSF1A may precede the p16 genes.
with non targeting shRNA (9/15, 60%). In addition, at the end of the experiment, tumor
volume was smaller in the presence of ERK5 silencing. that of p16INK4a in both HCC and neighboring tissues, indicating that deregulation of
Conclusion: Our data suggest that aberrant methylation occurs before mutation and is
Conclusion: The ERK5 pathway is critical for HCC tumor development and growth in an early event in the development of this set of HCC. Our findings highlight p16 as a
vivo. Blocking the ERK5 pathway should be further investigated as a novel approach for prognostic factor of HCC and RASSF1A as a potential target in preventing malignant
the treatment of HCC. transformation of hepatocytes.