TY - JOUR A1 - Volohonsky, Gloria A1 - Tuby, Chen N. Y. H. A1 - Porat, Noga A1 - Wellman-Rousseau, Maria A1 - Visvikis, Athanase A1 - Leroy, Pierre A1 - Rashi, Sharon A1 - Steinberg, Pablo A1 - Stark, Avishay Abraham T1 - A spectrophotometric assay of gamma-glutamylcysteine synthetase and glutathione synthetase in crude extracts from tissues and cultured mammalian cells Y1 - 2002 ER - TY - JOUR A1 - Thierbach, René A1 - Drewes, Gunnar A1 - Fusser, Markus A1 - Wolfrum, Kathrin A1 - Epe, Bernd A1 - Ristow, Michael A1 - Steinberg, Pablo T1 - A role for iron-sulfur cluster proteins in DNA repair Y1 - 2009 UR - http://www.springerlink.com/content/100530 U6 - https://doi.org/10.1007/s00210-009-0404-1 SN - 0028-1298 ER - TY - JOUR A1 - Thierbach, René A1 - Drewes, Gunnar A1 - Fusser, Markus A1 - Voigt, Anja A1 - Kuhlow, Doreen A1 - Blume, Urte A1 - Schulz, Tim Julius A1 - Reiche, Carina A1 - Glatt, Hansruedi A1 - Epe, Bernd A1 - Steinberg, Pablo A1 - Ristow, Michael T1 - The Friedreich's ataxia protein frataxin modulates DNA base excision repair in prokaryotes and mammals N2 - DNA-repair mechanisms enable cells to maintain their genetic information by protecting it from mutations that may cause malignant growth. Recent evidence suggests that specific DNA-repair enzymes contain ISCs (iron-sulfur clusters). The nuclear-encoded protein frataxin is essential for the mitochondrial biosynthesis of ISCs. Frataxin deficiency causes a neurodegenerative disorder named Friedreich's ataxia in humans. Various types of cancer occurring at young age are associated with this disease, and hence with frataxin deficiency. Mice carrying a hepatocyte- specific disruption of the frataxin gene develop multiple liver tumours for unresolved reasons. In the present study, we show that frataxin deficiency in murine liver is associated with increased basal levels of oxidative DNA base damage. Accordingly, eukaryotic V79 fibroblasts overexpressing human frataxin show decreased basal levels of these modifications, while prokaryotic Salmonella enterica serotype Typhimurium TA 104 strains transformed with human frataxin show decreased mutation rates. The repair rates of oxidative DNA base modifications in V79 cells overexpressing frataxin were significantly higher than in control cells. Lastly, cleavage activity related to the ISC-independent repair enzyme 8-oxoguanine glycosylase was found to be unaltered by frataxin overexpression. These findings indicate that frataxin modulates DNA-repair mechanisms probably due to its impact on ISC-dependent repair proteins, linking mitochondrial dysfunction to DNA repair and tumour initiation. Y1 - 2010 UR - http://www.biochemj.org/bj/toc.htm U6 - https://doi.org/10.1042/Bj20101116 SN - 0264-6021 ER - TY - JOUR A1 - Thierbach, René A1 - Blume, Urte A1 - Wolfrum, K. A1 - Drewes, Gunnar A1 - Voigt, Anja A1 - Ristow, Michael A1 - Steinberg, Pablo T1 - Altered carbohydrate metabolism in a tumour developing knock-out mice model Y1 - 2010 UR - http://www.springerlink.com/content/100530 U6 - https://doi.org/10.1007/s00210-010-0508-7 SN - 0028-1298 ER - TY - JOUR A1 - Thierbach, Renè A1 - Schulz, Tim Julius A1 - Isken, Frank A1 - Voigt, Aanja A1 - Mietzner, Brun A1 - Drewes, Gunnar A1 - von Kleist-Retzow, Jürgen-Christoph A1 - Wiesner, Rudolf J. A1 - Magnuson, Mark A. A1 - Puccio, Helene A1 - Pfeiffer, Andreas F. H. A1 - Steinberg, Pablo A1 - Ristow, Michael T1 - Targeted disruption of hepatic frataxin expression causes impaired mitochondrial function, decreased life span and tumor growth in mice N2 - We have disrupted expression of the mitochondrial Friedreich ataxia protein frataxin specifically in murine hepatocytes to generate mice with impaired mitochondrial function and decreased oxidative phosphorylation. These animals have a reduced life span and develop multiple hepatic tumors. Livers also show increased oxidative stress, impaired respiration and reduced ATP levels paralleled by reduced activity of iron-sulfur cluster (Fe/S) containing proteins (ISP), which all leads to increased hepatocyte turnover by promoting both apoptosis and proliferation. Accordingly, phosphorylation of the stress-inducible p38 MAP kinase was found to be specifically impaired following disruption of frataxin. Taken together, these findings indicate that frataxin may act as a mitochondrial tumor suppressor protein in mammals Y1 - 2005 ER - TY - JOUR A1 - Thierbach, Rene A1 - Schulz, Tim Julius A1 - Voigt, Aanja A1 - Drewes, Gunnar A1 - Isken, F. A1 - Pfeiffer, Andreas F. H. A1 - Ristow, Michael A1 - Steinberg, Pablo T1 - Targeted disruption of frataxin in hepatocytes causes spontaneous neoplasia accompanied by increased ROS formation Y1 - 2004 SN - 0028-1298 ER - TY - JOUR A1 - Thierbach, Rene A1 - Florian, Simone A1 - Wolfrum, Katharina A1 - Voigt, Anja A1 - Drewes, Gunnar A1 - Blume, Urte A1 - Bannasch, Peter A1 - Ristow, Michael A1 - Steinberg, Pablo T1 - Specific alterations of carbohydrate metabolism are associated with hepatocarcinogenesis in mitochondrially impaired mice JF - Human molecular genetics N2 - Friedreich's ataxia is an inherited neurodegenerative disease caused by the reduced expression of the mitochondrially active protein frataxin. We have previously shown that mice with a hepatocyte-specific frataxin knockout (AlbFxn(-/-)) develop multiple hepatic tumors in later life. In the present study, hepatic carbohydrate metabolism in AlbFxn(-/-) mice at an early and late life stage was analyzed. In young (5-week-old) AlbFxn(-/-) mice hepatic ATP, glucose-6-phosphate and glycogen levels were found to be reduced by similar to 74, 80 and 88%, respectively, when compared with control animals. This pronounced ATP, G6P and glycogen depletion in the livers of young mice reverted in older animals: while half of the mice die before 30 weeks of age, the other half reaches 17 months of age and exhibits glycogen, G6P and ATP levels similar to those in age-matched controls. A key event in this respect seems to be the up-regulation of GLUT1, the predominant glucose transporter in fetal liver parenchyma, which became evident in AlbFxn(-/-) mice being 5-12 weeks of age. The most significant histological findings in animals being 17 or 22 months of age were the appearance of multiple clear cell, mixed cell and basophilic foci throughout the liver parenchyma as well as the development of hepatocellular adenomas and carcinomas. The hepatocarcinogenic process in AlbFxn 2/2 mice shows remarkable differences regarding carbohydrate metabolism alterations when compared with all other chemically and virally driven liver cancer models described up to now. Y1 - 2012 U6 - https://doi.org/10.1093/hmg/ddr499 SN - 0964-6906 VL - 21 IS - 3 SP - 656 EP - 663 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Teubner, Wera A1 - Langheinrich, C. A1 - Seidel, Albrecht A1 - Steinberg, Pablo T1 - Inhibition of p53 transactivation activity does not promote mutagen-induced transformation of IEC-18 Y1 - 2004 SN - 0028-1298 ER - TY - JOUR A1 - Steinberg, Pablo A1 - Zschaler, Ingrid A1 - Thom, Elke A1 - Kuna, Manuela A1 - Wüst, Günter A1 - Schäfer-Schwebel, Angelika A1 - Müller, Rolf A1 - Kramer, Peter-Jürgen A1 - Weiße, Günter T1 - The polycyclic musk 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthaline lacks liver tumor initiating and promoting activity in rats exposed to human-relevant doses Y1 - 2001 UR - http://www.springerlink.com/content/100462 U6 - https://doi.org/10.1007/s002040100274 SN - 0340-5761 ER - TY - JOUR A1 - Steinberg, Pablo A1 - Klingelhöffer, Alexandra A1 - Schäfer, Angelika A1 - Wüst, Günter A1 - Weiße, Günter A1 - Oesch, Franz A1 - Eigenbrodt, Erich T1 - Expression of pyruvate kinase M2 in preneoplastic hepatic foci of N-nitrosomorpholine-treated rats Y1 - 1999 ER - TY - JOUR A1 - Steinberg, Pablo A1 - Fischer, Thomas M. A1 - Kiulies, Sandra A1 - Biefang, Katja A1 - Platt, Karl-Ludwig A1 - Oesch, Franz A1 - Böttger, Thomas A1 - Bulitta, Clemens A1 - Kempf, Peter A1 - Hengstler, Jan Georg T1 - Drug metabolizing capacity of cryopreserved human, rat and mouse liver parenchymal cells in suspension Y1 - 1999 ER - TY - JOUR A1 - Steinberg, Pablo A1 - Fischer, Thomas M. A1 - Arand, Michael A1 - Park, Eunju A1 - Elmadfa, Ibrahim A1 - Rimkus, Gerhard A1 - Brunn, Hubertus A1 - Dienes, Hans-Peter T1 - Acute hepatotoxicity of the polycyclic musk 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthaline (AHTN) Y1 - 1999 ER - TY - GEN A1 - Steinberg, Pablo T1 - Only one Component of a holistic Nutrition Policy T1 - Nur ein Baustein einer ganzheitlichen Ernährungspolitik T2 - Fleischwirtschaft Y1 - 2018 SN - 0015-363X VL - 98 IS - 11 SP - 8 EP - 9 PB - Deutscher Fachverlag GmbH CY - Frankfurt am Main ER - TY - JOUR A1 - Stark, Avishay abraham A1 - Porat, Noga A1 - Volohonsky, Gloria A1 - Konlosh, A. A1 - Bluvshtein, Evgenia A1 - Tubi, C. A1 - Steinberg, Pablo T1 - The role of gamma-glutamyl transpeptidase in the biosynthesis of glutathione Y1 - 2003 ER - TY - JOUR A1 - Singh, Jasbir A1 - Singh, S. A1 - Dani, H. M. A1 - Sharma, Reeta A1 - Steinberg, Pablo T1 - Interactions of aflatoxin B-1 with SRP components can disrupt protein targeting N2 - Spectrofluorimetric studies have revealed that aflatoxin B-1 (AFB(1)) interacts with signal recognition particle (SRP), which acts as an escort for polyribosomes with signal peptides to be transported and bound to the cytoplasmic face of the endoplasmic reticulum (ER). We further report that the binding of AFB(1) to SRP is selective as it only binds to two (SRP9 and 14) out of its three constituent polypeptides studied. Binding of AFB(1) to proteins is known to alter their conformations. Interactions of AFB(1) with SRP polypeptides may generate structural and functional alterations in this particle and hinder secretory protein synthesis. Copyright (C) 2004 John Wiley Sons, Ltd Y1 - 2005 SN - 0263-6484 ER - TY - GEN A1 - Scholtka, Bettina A1 - Schneider, Mandy A1 - Melcher, Ralph A1 - Katzenberger, Tiemo A1 - Friedrich, Daniela A1 - Berghof-Jäger, Kornelia A1 - Scheppach, Wolfgang A1 - Steinberg, Pablo T1 - A gene marker panel covering the Wnt and the Ras-Raf-MEK-MAPK signalling pathways allows to detect gene mutations in 80% of early (UICC I) colon cancer stages in humans N2 - Background: Very recently a gene marker panel that allows the mutational analysis of APC, CTNNB1, B-RAF and K-RAS was conceived. The aim of the present study was to use the 4-gene marker panel covering the Wnt and Ras-Raf-MEK-MAPK signalling pathways to determine the percentage of sporadic colorectal carcinomas (CRC) carrying at least one of the four above-mentioned genes in a mutated form alone and/or in combination with microsatellite instability (MSI) and to compare the sensitivity of the gene marker panel used in this study with that of gene marker panels previously reported in the scientific literature. Methods: CTNNB1 and B-RAF were screened by PCR-single-strand conformation polymorphism analysis and K-RAS gene mutations by restriction fragment length polymorphism analysis. For the mutational analysis of the APC gene mutation cluster region (codons 1243–1567) direct DNA sequencing was performed. The U.S. National Cancer Institute microsatellite panel (BAT25, BAT26, D2S123, D5S346 and D17S250) was used for MSI analysis. Results: It could be shown that about 80% of early stage CRC (UICC stages I and II) and over 90% of CRC in the UICC stage IV carried at least one mutated gene and/or showed MSI. No significant increase in the gene mutation frequencies could be determined when comparing tumours in the UICC stage I with those in UICC stage IV. Conclusions: When compared with previously published gene marker panels the 4-gene marker panel used in the present study shows an excellent performance, allowing to detect genetic alterations in 80–90% of human sporadic CRC samples analyzed. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 120 KW - Colorectal carcinomas KW - K-RAS KW - Microsatellite instability KW - Oncogenes KW - Tumour suppressor genes Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44587 ER - TY - GEN A1 - Scholtka, Bettina A1 - Kühnel, Dana A1 - Taugner, Felicitas A1 - Steinberg, Pablo T1 - Inflammation does not precede or accompany the induction of perneoplastic lesions in the colon of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-fed rats N2 - Heterocyclic aromatic amines (HCAs) are formed in meat cooked at high temperatures for a long time or over an open flame. In this context 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant HCA in cooked meat, has been suggested to be involved in colon and prostate carcinogenesis. In the latter case it has been reported that: (1) roughly 50% of Fischer F344 male rats treated with PhIP develop carcinomas in the ventral prostate lobe at 1 year of age; (2) inflammation precedes prostatic intraepithelial neoplasia in PhIP-fed rats; (3) inflammation specifically occurs in the ventral prostate lobe of PhIP-fed rats. To test whether PhIP by itself leads to inflammation in the colon and whether a human-relevant concentration of PhIP is able to induce preneoplastic lesions in the colon, male F344 rats were fed 0.1 or 100 ppm PhIP for up to 10 months and thereafter the colon tissue was analyzed histochemically. In none of the experimental groups signs of acute or chronic colonic inflammation were observed. 0.1 ppm PhIP leads to the development of hyperplastic and dysplastic lesions in the colon of single animals, but the incidence of these lesions does not reach a statistical significance. In contrast, in rats fed 100 ppm PhIP for 10 months hyperplastic and dysplastic colonic lesions were induced in a statistically significant number of animals. It is concluded that: (1) the induction of preneoplastic lesions in rat colon by PhIP is not preceded or accompanied by an inflammatory process; (2) a human-relevant concentration of PhIP alone is not sufficient to initiate colon carcinogenesis in rats. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 119 KW - Colorectal cancer KW - Heterocyclic aromatic amines KW - Inflammation Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44570 ER - TY - JOUR A1 - Schleger, C. A1 - Heck, R. A1 - Steinberg, Pablo T1 - The role of wild-type and mutated N-ras in the malignant transformation of liver cells Y1 - 2000 ER - TY - JOUR A1 - Schleger, C. A1 - Becker, Rolf A1 - Oesch, Franz A1 - Steinberg, Pablo T1 - The human p53 gene mutated at position 249 per se is not sufficient to immortalize human liver cells Y1 - 1999 ER - TY - JOUR A1 - Okano, J. A1 - Shiota, G. A1 - Matsumoto, K. A1 - Yasui, S. A1 - Kurimasa, A. A1 - Hisatome, I. A1 - Steinberg, Pablo A1 - Murawaki, Y. T1 - Hepatocyte growth factor exerts a proliferative effect on oval cells through the PI3K/AKT signaling pathway Y1 - 2003 ER -