studies

1174A AASLD ABSTRACTS HEPATOLOGY, October, 2015
up-regurated in the above hypomethylated miRNA clusters.
[Conclusions] Several major miRNA clusters were markedly
hypomethylated in tumor tissues, and expression of miRNAs
coded in clustered-regions were broadly up-regulated. We will
present the results of further advanced analyses including the
influence of hypermethylation for target genes, and integration
of clinical information.
Disclosures:
Yasuhito Tanaka - Grant/Research Support: Chugai Pharmaceutical CO., LTD.,
MSD, Bristol-Myers Squibb; Speaking and Teaching: janssen pharma, Bristol-Myers
Squibb
The following authors have nothing to disclose: Takeshi Matsui, Masanori
Nojima, Etsuko Iio, Akihiro Tamori, Shoji Kubo, Ken Shirabe, Koichi Kimura,
Mitsuo Shimada, Tohru Utsunomiya, Yasuteru Kondo
1984
The analyses of oxidative DNA repair genes and hepatocarcinogenesis
in patients with chronic hepatitis C
Koji Miyanishi, Masayoshi Kobune, Shingo Tanaka, Toshifumi
Hoki, Tsutomu Sato, Yasushi Sato, Rishu Takimoto, Junji Kato;
Medical Oncology and Hematology, Sapporo Medical University,
Sapporo, Japan
Background and aim: Recent studies have shown that excess
hepatic iron accumulation contributes to liver injury in patients
with chronic hepatitis C (CHC). Free iron in the liver is believed
to facilitate the formation of reactive oxygen species (ROS),
including hydroxyl (OH) radicals, which cause oxidative damage
of numerous cellular components such as nucleic acids.
The OH radical is known to generate promutagenic bases such
as 8-hydroxy-2-deoxyguanosine (8-OHdG), which has been
implicated in DNA mutagenesis and carcinogenesis. 8-OHdG
lesions may be promptly repaired by human 8-oxo-guanine
DNA glycosylase (hOGG1) and human MUTY homolog
(MUTYH). Therefore, it is plausible that the development of
hepatocellular carcinoma (HCC) from CHC is determined by
the balance between DNA damage and repair. In this study,
we conducted analyses of single nucleotide polymorphisms
(SNPs) of hOGG1 and MUTYH genes in CHC patients with
or without development of HCC. Further, we examined the
efficacy of N-acetyl cysteine (NAC) as a treatment to prevent
the development of HCC using MUYTH null mice. Methods:
Genomic DNA and total RNA were extracted from peripheral-blood
mononuclear cells obtained from 63 CHC patients with
(HCC group, n=39) or without HCC (non-HCC group, n=24).
We analyzed the SNPs of hOGG1 and MUTYH by target
resequence using next generation sequencer (ION PGM) and
mRNA of hOGG1 and MUTYH by Taqman RT-PCR. The HCC
incidence rate was calculated based on the period between
the diagnosis of CHC and the appearance of HCC, using the
Kaplan-Meier technique. In vivo study, male C57BL/6 MUTYH
null mice were fed an excess-iron diet or control diet with or
without NAC. Results: The frequency of SNPs in hOGG1 did
not differ between HCC group and non-HCC group. In one
of MUTYH SNPs (rs3219487), the frequency of minor allele
carrier in the HCC group significantly higher than that in HCC
group. In addition, the expression of MUTYH mRNA in minor
homo allele were lower than that in major homo allele. Multivariate
Cox regression analysis indicated that age, liver fibrosis
factor and the minor allele carrier independently associated
with hepatocarcinogenesis. Hepatocarcinogenesis rate in
MUTYH null mice which were fed an excess-iron diet were significantly
higher than that in wild type C57BL/6 or in null mice
which were fed a control diet. NAC administration decreased
the development of HCC in null mice. Conclusions: These results
indicated that the minor allele of this SNP in MUTYH could be
a significant risk factor of liver carcinogenesis and could be
a predictive marker of HCC development in CHC patients.
Further, NAC may be useful for prevention of HCC in such
patients.
Disclosures:
The following authors have nothing to disclose: Koji Miyanishi, Masayoshi
Kobune, Shingo Tanaka, Toshifumi Hoki, Tsutomu Sato, Yasushi Sato, Rishu
Takimoto, Junji Kato
1985
Continuous hepatocyte apoptosis accelerates diethylnitrosamine-induced
tumor development in the liver
Yasutoshi Nozaki, Hayato Hikita, Satoshi Tanaka, Sadatsugu
Sakane, Yugo Kai, Yuki Makino, Tasuku Nakabori, Yoshinobu
Saito, Ryotaro Sakamori, Naoki Hiramatsu, Tomohide Tatsumi,
Tetsuo Takehara; Osaka University Graduate School of Medicine,
Suita, Osaka, Japan
Background and Aim: Apoptosis serves as an important mechanism
for removing DNA damaged-cells and is considered to
inhibit carcinogenesis. On the other hand, hepatocyte apoptosis
is a key feature of chronic liver disease including viral hepatitis
and steatohepatitis, which are well-known risk factors for
HCC. Thus, it remains unclear whether the apoptosis inhibition
accelerates or decelerates liver tumor development. The present
study examined the impact of continuous hepatocyte apoptosis
and inhibition of apoptosis on liver tumor development.
Methods: We used male hepatocyte-specific knockout (KO)
mice of Mcl-1, one of anti-apoptotic proteins, as a model of
apoptosis-prone liver, and hepatocyte-specific single or double
KO mice of Bak and Bax, proapoptotic proteins, as a model
of apoptosis-resistant liver . To induce liver tumors those KO
mice were intraperitoneally administered 20 mg/kg diethylnitrosamine
(DEN) at the age of 2 weeks. Results: Mcl-1 KO
mice spontaneous hepatocyte apoptosis as evidenced by HE
staining of the liver sections, increasing serum ALT levels and
serum caspase-3/7 activities. The number of TUNEL positive
hepatocytes also increased in Mcl-1 KO mice. No liver tumors
were observed at 6 months in both Mcl-1 KO and wild-type
(WT) mice without DEN. On the other hand, while only 11.8%
(2/17) of WT mice treated with DEN developed macroscopic
liver tumors in 6 months, 100% (7/7) of Mcl-1 KO littermates
developed (p