Language：Japanese   Publisher：新潟大学医学部保健学科  

【目的】非アルコール性脂肪肝炎(NASH)は、近年急速に増加している原因不明の肝疾患である。本研究では、肝がん治療に有効とされる分子標的薬ラパマイシンの標的シグナルp70S6キナーゼが、NASH肝がんの病態に関与している可能性について検討した。【方法】根治的外科手術療法を施行したNASH肝がん22例の病変組織に対して、リン酸化型(活性型)p70S6キナーゼの免疫組織化学染色を行い、臨床因子・予後の比較検討を行った。【結果】NASH肝がん22例中12例(54.5%)がリン酸化型p70S6キナーゼを高発現しており、組織未分化度と相関した(p=0.047)。リン酸化型P70S6キナーゼ高発現群は、外科切除後3年以内再発率が有意に増加していた(p=0.045)。【総括】p70S6キナーゼを高発現しているNASH肝がんは、再発頻度が高い傾向がある。同シグナルを阻害する分子標的薬ラパマイシンは、本疾患の再発防止に有効である可能性が示唆された。(著者抄録)

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2014&ichushi_jid=J06421&link_issn=&doc_id=20140728400007&doc_link_id=http%3A%2F%2Fhdl.handle.net%2F10191%2F38939&url=http%3A%2F%2Fhdl.handle.net%2F10191%2F38939&type=%90V%8A%83%91%E5%8Aw%81F%90V%8A%83%91%E5%8Aw%8Aw%8Fp%83%8A%83%7C%83W%83g%83%8A_Nuar&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F80230_3.gif

Language：English   Publishing type：Research paper (scientific journal)   Publisher：E-CENTURY PUBLISHING CORP  

Sorafenib is a multi-kinase inhibitor approved for hepatocellular carcinoma, but rarely causes tumor regression in patients with chronic liver diseases. To investigate whether growth factor-mediated signaling is involved in sorafenib resistance, HepG2 and PLC/PRF/5 hepatoma cells were exposed to epidermal growth factor (EGF), hepatocyte growth factor (HGF) or transforming growth factor-beta (TGF-beta) prior to treatment with sorafenib. Furthermore, to identify an effective combination treatment with sorafenib, growth factor-sensitized cells were treated with sorafenib alone or in combination with celecoxib, lovastatin or valproic acid (VPA). Trypan blue staining and Annexin V assays showed that the cytotoxic effect of sorafenib was inhibited by 15-54% in cells sensitized to TGF-beta (P<0.05). Western blotting analysis showed that TGF-beta significantly activated extracellular signal-regulated kinase (ERK)-mediated AKT signaling, and sorafenib failed to suppress both ERK and AKT in TGF-beta-sensitized cells. The decreased anti-tumor effect of sorafenib was rescued by chemical inhibition of ERK and AKT. When TGF-beta-sensitized cells were treated with sorafenib plus VPA, the levels of phosphorylated ERK and AKT were considerably suppressed and the numbers of dead cells were increased by 3.7-5.7-fold compared with those exposed to sorafenib alone (P<0.05). Moreover, low dose sorafenib-induced cell migration was effectively suppressed by combination treatment with sorafenib and VPA. Collectively, TGF-beta/ERK/AKT signaling might play a critical role in sorafenib resistance in hepatoma cells, and combination treatment with VPA may be effective against this drug resistance.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：E-CENTURY PUBLISHING CORP  

Hepatitis B virus X (HBX) protein plays a crucial role in carcinogenesis, but its mechanism is unclear. The involvement of ataxia telangiectasia mutated (ATM) kinase in the enhanced redox system was investigated by examining the phosphorylation level of ATM in HBX gene-transfected cells and in transgenic mice following redox system manipulation by treatment with hydrogen peroxide (H2O2) or antioxidant. Western blotting and immunostaining showed that phospho-ATM was significantly increased by HBX both in vitro (3.2-fold; p<0.05) and in vivo (4-fold; p<0.05), and this effect was abrogated by antioxidant treatment. The level of PKC-delta in HBX-expressing cells was increased 3.5-fold compared to controls. Nuclear localized NF-E2-related factor 2 (Nrf2) was increased in HBX-expressing cells exposed to H2O2, but remained at lower levels after the treatment with rottlerin, KU55933, or caffeine. The levels of anti-oxidant molecules were increased in HBX expressing cells and in transgenic mice, indicating that HBX stimulates the Nrf2-mediated redox system. The levels of intracellular reactive oxygen species (ROS) were significantly increased in HBX-expressing cells treated with hydrogen peroxide in the presence of ATM inhibitor KU55933 or caffeine. Treatment of HBX-expressing cells with KU55933 or caffeine before the exposure to H2O2 increased the ratio of cell apoptosis to 33 +/- 4% (p<0.05) and 22 +/- 4% (p<0.05), respectively. Collectively, HBX stimulates the ATM-mediated PKC-delta/Nrf2 pathway, and maintains the enhanced activity of the redox system. Therefore, manipulating ATM kinase activity might be a useful strategy for treating HBX-induced carcinogenesis.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER JAPAN KK  

It is well accepted that cell cycle regulators are strongly implicated in the progression of cancer development. p16 and p27 are potent cyclin-dependent kinase (CDK) inhibitors involved in G1 phase progression, and are regarded as adverse prognostic biomarkers for various types of cancers. It has been reported that the main mechanism for p16 inactivation is aberrant DNA methylation, while p27 is exclusively inactivated by proteasome-mediated protein degradation. We have found that p27 is decreased in around half of hepatocellular carcinomas (HCCs), and in some cases p27 is inactivated by inappropriate interaction with cyclin D1/CDK4 complexes. In such cases, p16 is concomitantly inactivated through DNA methylation. Taking into consideration the complex interaction between p16 and p27, a comprehensive analysis including p16 and p27 would be useful for predicting the prognosis of HCC patients.

DOI： 10.1007/s00795-013-0047-7

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Non-alcoholic steatohepatitis (NASH) is a recently identified chronic liver disease, which progresses to liver cirrhosis and hepatocellular carcinoma (HCC). As the number of patients studied to date has been limited, clinically useful prognostic biomarkers of NASH-related HCC have not been available. In this study, we investigated the status of a cell-cycle regulator, p27, in NASH-related HCC. p27 has been regarded as a prognostic factor in various types of cancer patients. A total of 22 cases with NASH-related HCC were analyzed for p27 protein expression, and phosphorylation at threonine 157 (T157) and serine 10 (S10) by immunohistochemical analysis. The correlation of p27 with tumor characteristics, disease-free survival (DFS), and overall survival was analyzed. p27 expression was decreased in 13 HCCs (59%), and was significantly correlated with enlarged tumor size (p = 0.01) and increased cell proliferation (p < 0.01). Phospho-p27 at T157 and S10 was detected in four (18%) and seven (32%) cases, respectively, and patients positive for phospho-p27 (S10) showed reduced DFS (hazard ratio 7.623, p = 0.016) by univariate analysis. Further studies with more patients are required to verify the usefulness of p27 as a biomarker for predicting tumor recurrence in NASH patients.

DOI： 10.3390/ijms141223499

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Language：English   Publishing type：Research paper (international conference proceedings)  

Introduction: In experiments involving tracheal wall defects in rabbits, metallic coil stents inevitably induce granulation formation in the defects. We examined the involvement of the mammalian target of rapamycin (mTOR) signaling pathway in granulation formation and examined the effects of rapamycin. Methods: The anterior half of the tracheal wall was removed for a longitudinal length of six tracheal rings. Metallic coils were placed into the tracheal lumen through a wall defect. The rabbits were sacrificed two months after undergoing an endoscopic examination, and the granulation tissue in the tracheal defects was removed for a Western blot analysis and immunohistochemical analysis. Rapamycin (0.5 mg kg- 1 day- 1) was administered three times per week intramuscularly. The data were expressed as the relative expression versus the expression of actin. Results: The level of mTOR phosphorylation in the resected trachea was 0.72 ± 0.45, and it significantly increased in the granulation tissue to 11.6 ± 5.2, with concomitant increases in the phosphorylation levels of p70S6K and S6RP in all five rabbits. Although the systemic administration of rapamycin significantly decreased the levels of phosphorylated mTOR to 4.0 ± 2.4 in the five treated rabbits, the clinical outcomes were unsatisfactory. Three of the five treated rabbits exhibited signs of wound complications, and wet granulation tissue that caused respiratory symptoms was found inside and outside of the coils in four rabbits. Conclusions: Although rapamycin effectively reduced the mTOR activity in the granulation tissue, the granulation formation process seemed to be disturbed, most likely owing to the immunosuppressive effects of rapamycin. © 2013 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jpedsurg.2013.08.013

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BACKGROUND AND AIM: Transforming growth factor-beta (TGF-beta) has been shown to play a central role in the promotion of cell motility, but its functional mechanism has remained unclear. With the aim of investigating the diagnostic and treatment modalities for patients with hepatocellular carcinoma (HCC), the signaling pathway that may contribute to TGF-beta-mediated cell invasion in hepatoma cells was evaluated. METHODS: Three hepatoma cell lines, HepG2, PLC/PRF/5, and HLF, were treated with TGF-beta, and the involvement of the non-canonical TGF-beta pathway was analyzed by cell migration assays. HepG2 cells were treated with a p21-activated kinase-2 (PAK2)-targeting small interfering RNA and analyzed for their cell motility. The relationships between the PAK2 status and the clinicopathological characteristics of 62 HCC patients were also analyzed. RESULTS: The cell migration assays showed that Akt is a critical regulator of TGF-beta-mediated cell migration. Western blotting analyses showed that TGF-beta stimulated Akt and PAK2 in all three hepatoma cell lines, and phosphorylated PAK2 was blocked by Akt inhibitor. Suppression of PAK2 expression by small interfering RNA resulted

DOI： 10.1111/jgh.12150

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BAISHIDENG PUBLISHING GROUP INC  

Hepatocellular carcinoma (HCC) is a common malignant disease with poor prognosis. To improve the clinical outcome, early diagnosis of HCC arising from nonviral agents and hepatitis virus is important. Among several etiological factors, mycotoxins defined as carcinogens by the International Agency for Research in Cancer (IARC) might be one of the critical risk factors for nonviral HCC. Aflatoxin B1 is the most well-known carcinogenic mycotoxin for HCC, but the role of the other types of mycotoxin remains unclear. Several studies have reported that a chromatographic separation technique based on high-performance liquid chromatography can successfully detect the concentration of mycotoxins in plasma. Recently, serum level of ochratoxin A (OTA), a widely distributed mycotoxin classified as Group 2B by IARC, was evaluated in HCC patients in Egypt. The results suggested that serum OTA levels might be a good biomarker for HCC. In this article, we review recent studies of OTA, and discuss its possible significance as a biomarker of HCC. (C) 2013 Baishideng. All rights reserved.

DOI： 10.3748/wjg.v19.i17.2587

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BACKGROUND: Phosphorylated histone H2AX ( gamma -H2AX) is a potential regulator of DNA repair and is a useful tool for detecting DNA damage. To evaluate the clinical usefulness of gamma -H2AX in hepatocellular carcinoma (HCC), we measured the level of gamma -H2AX in HCC, dysplastic nodule, and nontumorous liver diseases. METHODS: The level of gamma -H2AX was measured by immunohistochemistry in fifty-eight HCC, 18 chronic hepatitis, 22 liver cirrhosis, and 19 dysplastic nodules. Appropriate cases were also examined by fluorescence analysis and western blotting. results: All cases with chronic liver disease showed increased levels of gamma -H2AX expression. In 40 (69.9%) of 58 cases with HCC, the labeling index (LI) of gamma -H2AX was above 50% and was inversely correlated with the histological grade. Mean gamma -H2AX LI was the highest in dysplastic nodule (74.1 +/- 22.1%), which was significantly higher than HCC (P < 0.005). Moreover, gamma -H2AX was significantly increased in nontumorous tissues of HCC as compared with liver cirrhosis without HCC (62.5 +/- 24.7%, from 5.1 to 96.0%, P < 0.005). CONCLUSIONS: gamma -H2AX was increased in the preneoplastic lesions of HCC and

DOI： 10.1155/2013/597095

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