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Publications (5)25.01 Total impact

  • Article: Neighbor of Punc E11, a novel oncofetal marker for hepatocellular carcinoma.
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    ABSTRACT: Hepatocellular carcinoma (HCC) is the 5th common malignancy worldwide, but established markers fail to detect up to one third of HCC. We have recently identified Neighbor of Punc E11 (Nope) as a surface marker for murine fetal liver stem cells. Similar to commonly used HCC markers such as α-Fetoprotein (Afp) and Glypican-3 (Gpc-3), we here establish Nope as an oncofetal marker of murine and human HCC and investigate its specific expression in hepatoma cell lines and primary HCC. Murine and human hepatoma cell lines and Cre-inducible SV40 T-antigen transgenic mice (Alb-SV40TAg(ind) ) were analyzed for Nope expression in comparison to common HCC markers by quantitative RT-PCR, Western blot analyses and immunohistochemistry. Nope expression in primary human HCC was investigated using Oncomine Microarray database. Nope expression was elevated in 8 of 10 investigated murine and human hepatoma cell lines and in all tumors of our oncogenic mouse model but remained undetectable in normal liver and at preneoplastic stages of murine hepatocarcinogenesis. Furthermore, a significant induction of Nope was detected in primary human cancers compared to corresponding normal or cirrhotic tissue. Nope expression in tumor specimens and murine cell lines correlated closely with expression levels of Gpc-3, whereas expression levels of Afp showed high variations. In conclusion, we identified Nope as a novel oncofetal surface marker for murine and human HCC. Nope is specifically expressed by epithelial tumor cells but not in preneoplastic stages and is a promising marker for clinical application because of its high detection rate in Afp-positive and Afp-negative tumors.
    International Journal of Cancer 05/2011; 128(10):2353-63. · 5.44 Impact Factor
  • Article: β-Adrenoceptor blockade in sclerosing cholangitis of Mdr2 knockout mice: antifibrotic effects in a model of nonsinusoidal fibrosis.
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    ABSTRACT: Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with high propensity to develop into cholangiocarcinoma. The hepatobiliary disorder of PSC is due to progressive fibrosis surrounding the intra- and extrahepatic bile ducts. Until now, no effective medical therapy exists. To study the progression of sclerosing cholangitis after inhibition of the sympathetic nervous system by blockade of the β-adrenoceptors, we used the Mdr2(-/-) mouse model, which develops periportal fibrosis similar to human PSC. Liver tissues of Mdr2(-/-) mice untreated or treated with the β-adrenoceptor antagonist propranolol were analyzed for inflammation and fibrosis progression at different time points by histological scoring and immunostaining for α-smooth muscle actin (α-SMA), CD45 and S100A4. Transaminases and hydroxyproline contents were determined. Expression of angiotensinogen, endothelin-1, TGF-β, TNF-α, CTGF and procollagen 1A1 was studied by real-time PCR on laser-microdissected areas of acinar zones I and II-III. After 3 months, periportal fibrosis had developed in Mdr2(-/-) mice, but immunostaining revealed no sinusoidal and only minor periportal contribution of myofibroblasts with prominent fibroblasts. Propranolol treatment of Mdr2(-/-) mice improved liver architecture. Additionally, inflammation and fibrosis were significantly reduced. After 3 months of treatment, the antifibrotic effect of the β-blockade was most obvious. The transcript levels of procollagen 1A1, TNF-α, TGF-β, CTGF and endothelin-1 were markedly repressed in the portal areas of treated mice. Taken together, these data show that propranolol efficiently delays progression of sclerosing cholangitis. Therefore, the blockade of β-adrenoceptors is a promising option to support future therapeutic strategies in the treatment of human PSC.
    Laboratory Investigation 10/2010; 91(2):252-61. · 3.64 Impact Factor
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    Article: Tissues from routine pathology archives are suitable for microRNA analyses by quantitative PCR.
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    ABSTRACT: MicroRNAs have recently taken centre stage as short non-coding RNAs that regulate mRNA expression. To assess the feasibility of using microRNA techniques on routinely processed tissues, the accessibility of two representative microRNAs was examined by real-time quantitative PCR in 86 human formalin-fixed paraffin-embedded (FFPE) samples from liver, breast, bone marrow, lymphatic tissues and colon. Murine liver was used to analyse the influence of fixation time and different fixatives. High-quality microRNA was successfully extracted from routinely processed formalin-fixed tissues, resembling PCR amplification results from snap-frozen material analysed in parallel. While fixation time did not affect microRNA accessibility, non-buffered formalin or fixative supplements such as glutaraldehyde influenced PCR results. Storage of human tissues for up to 7 years did not cause a significant deterioration of microRNA. However, microRNA quality in human archival material following routine processing 10-20 years ago was decreased. Oxidation by ambient air during storage and fixation in non-buffered formalin is a possible reason for loss of microRNA quality. The assessment of microRNAs in readily obtained formalin-fixed paraffin-embedded samples is a highly promising tool in molecular pathology when similarly treated samples are analysed. Therefore, microRNA analyses will gain wider acceptance as an adjunct to morphological tissue assessment in routine pathology and retrospective studies.
    Journal of clinical pathology 09/2008; 62(1):84-8. · 2.43 Impact Factor
  • Article: MicroRNA gene expression profile of hepatitis C virus-associated hepatocellular carcinoma.
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    ABSTRACT: MicroRNAs are small noncoding RNAs that regulate gene expression by targeting messenger RNAs (mRNAs) through translational repression or RNA degradation. Many fundamental biological processes are modulated by microRNAs, and an important role for microRNAs in carcinogenesis is emerging. Because understanding the pathogenesis of viral-associated hepatocellular carcinomas is important in developing effective means of classification, prognosis, and therapy, we examined the microRNA expression profiles in a large set of 52 human primary liver tumors consisting of premalignant dysplastic liver nodules and hepatocellular carcinomas by quantitative real-time polymerase chain reaction. All patients were infected with hepatitis C, and most had liver cirrhosis. Initially, the accessibility of microRNAs from formalin-fixed paraffin-embedded archival liver tissue by real-time polymerase chain reaction assays was shown. Subsequently, target parenchyma from routinely processed tissue was macrodissected, RNA was extracted, and reverse transcription followed by quantitative real-time polymerase chain reaction was performed. Relative quantification was performed by the 2(-DeltaDeltaCt) method with normal livers as a calibrator. In order to obtain a comprehensive microRNA gene expression profile, 80 microRNAs were examined in a subset of tumors, which yielded 10 up-regulated and 19 down-regulated microRNAs compared to normal liver. Subsequently, five microRNAs (miR-122, miR-100, miR-10a, miR-198, and miR-145) were selected on the basis of the initial results and further examined in an extended tumor sample set of 43 hepatocellular carcinomas and 9 dysplastic nodules. miR-122, miR-100, and miR-10a were overexpressed whereas miR-198 and miR-145 were up to 5-fold down-regulated in hepatic tumors compared to normal liver parenchyma. Conclusion: A subset of microRNAs are aberrantly expressed in primary liver tumors, serving both as putative tumor suppressors and as oncogenic regulators.
    Hepatology 05/2008; 47(4):1223-32. · 11.66 Impact Factor
  • Article: C-met and hepatocyte growth factor expression in combined hepatocellular and cholangiocarcinoma.
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    ABSTRACT: The membranous tyrosine kinase receptor c-met and its natural ligand hepatocyte growth factor are prominent mitogens, motogens and morphogens for hepatocytes and many other cell types in vitro as well as in vivo. To clarify the significance of the c-met/hepatocyte growth factor system in the development and spread of combined hepatocellular and cholangiocarcinoma, surgical specimen from 30 patients, consisting of 4 double cancers, 20 combined types and 6 mixed types, were examined immunohistochemically. Immunoreactivity for HGF was significantly correlated with the differentiation degree of cholangiocellular components, being highest in well and moderately differentiated and lowest in poorly differentiated components (p=0.0119). No significant association was observed between expression of c-met or HGF and the presence of liver cirrhosis, vascular invasion, perineural invasion, lymphatic permeation, intrahepatic metastasis or lymph node metastasis. HGF may have an important impact on the differentiation of certain cHCC-CC. Other clinicopathologic factors related to tumor development and spread may not be influenced by c-met or HGF, at least not on the protein level.
    Oncology Reports 9(1):35-41. · 1.84 Impact Factor