TY  - THES
A1  - Schäfer, Barbara
T1  - Untersuchungen zur Regulation der Invertaseaktivität und zu Invertaseinhibitoren aus Pflanzenextrakten
T1  - Investigations about Changes in Activities of Invertases and about Invertase Inhibitors
N2  - Die Spaltung verschiedener Zuckerverbindungen ist ein elementarer Vorgang in allen Lebewesen. Im Rahmen dieser Arbeit wurden Enzyme untersucht, die Saccharose, einen wichtigen Energieträger und Botenstoff, in Fructose und Glucose spalten. Sie liefert einen umfassenden Überblick saccharosespaltender Enzyme und deren Inhibitoren, der erstmals die Gebiete der β-Fructofuranosidasen und der α-Glucosidasen vereinigt. Invertasen (β-Fructofuranosidasen, Abspaltung der Fructose) spielen eine zentrale Rolle im Metabolismus der Pflanzen und werden auf vielfältige Art und Weise reguliert. Im Rahmen dieser Arbeit wurden Veränderungen in der Aktivität durch verschiedene Einflüsse in vitro untersucht. Dabei konnte gezeigt werden, dass die Temperaturoptima der Invertasen erstaunlich hoch liegen. Das Verhalten der getesteten alkalischen / neutralen Invertase aus Lolium temulentum unterschied sich bei vielen Tests von dem der anderen eingesetzten Invertasen. Auch in Tieren bzw. im Menschen sind saccharosespaltende Enzyme, hier bezeichnet als Sucrasen bzw. α-Glucosidasen (Abspaltung der Glucose), an vielen wichtigen Vorgängen beteiligt, etwa der Glykosilierung von Proteinen oder der Verdauung. Die humane Sucrase-Isomaltase aus dem Dünndarm ist ein Target in der Diabetestherapie. Erstmals konnte die humane Sucrase als aktive Untereinheit in der Hefe Pichia pastoris exprimiert werden. Neben den Enzymen selbst wurden das Wirkspektrum und die Wirkstärke verschiedener Inhibitoren untersucht. Dabei konnte festgestellt werden, dass Acarbose, ein Pseudotetrasaccharid, das in der Diabetestherapie verwendet wird, auch pflanzliche Invertasen hemmt. Die in ihrer Struktur zueinander sehr ähnlichen Iminozucker DMDP, Miglitol und Calystegin B2 unterschieden sich erheblich in ihrer Hemmaktivität. DMDP ist dabei am potentesten, Miglitol führt teilweise zu einer erhöhten Invertaseaktivität und Calystegin B2 verfügt nur über ein beschränktes Hemmspektrum. Pflanzliche proteinogene Invertaseinhibitoren hemmten auch die humane Sucrase und die Hefeinvertase; wurden die Inhibitorproteine in P. pastoris exprimiert und dabei glykosiliert, hatten sie keine Hemmaktivität. Als einziger Inhibitor zeigte Miglitol der getesteten alkalischen / neutralen Invertase gegenüber ein Verhalten, das als selektiv bezeichnet werden kann, da die Hemmung mit Konzentrationen, die um den Faktor 1000 niedriger waren als bei anderen Invertasen, eintrat. Für die Suche nach neuen Inhibitoren wurden ein Screening und eine Literaturrecherche zum Thema Pflanzen in der Diabetestherapie bzw. pflanzliche Glucosidasehemmstoffe durchgeführt. Die Literaturrecherche weist darauf hin, dass eine große Anzahl an Pflanzen potentielle Wirkstoffe beinhalten könnte. Das Screening nach neuen Hemmstoffen wurde größtenteils mit Pflanzenextrakten aus der Traditionellen Chinesischen Medizin durchgeführt. Dabei wurden hemmende Extrakte entdeckt, die weiter auf ihre aktiven Komponenten hin untersucht werden sollten.
N2  - The cleavage of different sugars is a fundamental process in all living organisms. In this thesis, enzymes which cleave sucrose – an important messenger molecule and energy carrier - in glucose and fructose were analyzed. It shows a broad overview of sucrose cleaving enzymes, which for the first time, combines α-glucosidases and β-fructofuranosidases and their inhibitors. Invertases (β-fructofuranosidases, fructose split-off) play a pivotal role in plant metabolism and are regulated in varied manners. Investigations about the changes in activities of different invertase preparations by different influences were done in vitro. It could be shown that temperature optimum of invertases is impressingly high. The behavior of alkaline / neutral invertase differentiates in many tests from that of others invertases. Also in animals and human beings, sucrose cleaving enzymes, named α-glucosidase or sucrase (glucose split-off), are part of important processes like glycosilation of proteins or digestion. The human sucrase-isomaltase from small intestine is a target in diabetes therapy. As an active subunit the sucrase could be expressed in the yeast Pichia pastoris for the first time. Aside from the enzymes, the spectrum of activity and the potency of different invertase inhibitors were analyzed. It could be shown that acarbose, which is used in diabetes therapy, can also inhibit plant invertases. DMDP, miglitol and calystegine B2, structurally similar imino sugars, differ extensively in their potency. DMDP is the most potent inhibitor, Miglitol partly increases invertase activity and calystegin B2 inhibits only some enzymes. Proteinaceous invertase inhibitors inhibit humane sucrase and yeast invertase as well as plant invertases; in P. pastoris expressed and glycosylated inhibitors showed no potency. As the only inhibitor, miglitol could selectively inhibit the alkaline / neutral invertase, inhibition occured at concentrations 1000 times lower than with other invertases. The search for new invertase inhibitors comprised a screening of different extracts and a literature research dealing with plants in diabetic therapy and plant derived glucosidase inhibitors. A large number of plants with potential active ingredients were investigated. The screening for new invertase inhibitors was mainly conducted with extracts of plants from traditional chinese medicine. As result, inhibitory extracts were found which should be further investigated.
KW  - Invertase
KW  - Inhibitor
KW  - Diabetes
KW  - Pflanzen
KW  - Alpha-Glucosidase
KW  - Invertase
KW  - Inhibitor
KW  - Alpha-Glucosidase
KW  - Diabetes
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-71469
ER  - 
TY  - JOUR
A1  - Donat, Ulrike
A1  - Rother, Juliane
A1  - Schäfer, Simon
A1  - Hess, Michael
A1  - Härtl, Barbara
A1  - Kober, Christina
A1  - Langbein-Laugwitz, Johanna
A1  - Stritzker, Jochen
A1  - Chen, Nanhai G.
A1  - Aguilar, Richard J.
A1  - Weibel, Stephanie
A1  - Szalay, Alandar A.
T1  - Characterization of Metastasis Formation and Virotherapy in the Human C33A Cervical Cancer Model
JF  - PLoS ONE
N2  - More than 90% of cancer mortalities are due to cancer that has metastasized. Therefore, it is crucial to intensify research on metastasis formation and therapy. Here, we describe for the first time the metastasizing ability of the human cervical cancer cell line C33A in athymic nude mice after subcutaneous implantation of tumor cells. In this model, we demonstrated a steady progression of lumbar and renal lymph node metastases during tumor development. Besides predominantly occurring lymphatic metastases, we visualized the formation of hematogenous metastases utilizing red fluorescent protein (RFP) expressing C33A-RFP cells. RFP positive cancer cells were found migrating in blood vessels and forming micrometastases in lungs of tumor-bearing mice. Next, we set out to analyze the influence of oncolytic virotherapy in the C33A-RFP model and demonstrated an efficient virus-mediated reduction of tumor size and metastatic burden. These results suggest the C33A-RFP cervical cancer model as a new platform to analyze cancer metastases as well as to test novel treatment options to combat metastases.
KW  - metastasis
KW  - renal cancer
KW  - oncolytic viruses
KW  - lymph nodes
KW  - kidneys
KW  - lung and intrathoracic tumors
KW  - secondary lung tumors
KW  - cancer treatment
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119674
SN  - 1932-6203
VL  - 9
IS  - 6
ER  - 
TY  - JOUR
A1  - Antoniou, Antonis C.
A1  - Kuchenbaecker, Karoline B.
A1  - Soucy, Penny
A1  - Beesley, Jonathan
A1  - Chen, Xiaoqing
A1  - McGuffog, Lesley
A1  - Lee, Andrew
A1  - Barrowdale, Daniel
A1  - Healey, Sue
A1  - Sinilnikova, Olga M.
A1  - Caligo, Maria A.
A1  - Loman, Niklas
A1  - Harbst, Katja
A1  - Lindblom, Annika
A1  - Arver, Brita
A1  - Rosenquist, Richard
A1  - Karlsson, Per
A1  - Nathanson, Kate
A1  - Domchek, Susan
A1  - Rebbeck, Tim
A1  - Jakubowska, Anna
A1  - Lubinski, Jan
A1  - Jaworska, Katarzyna
A1  - Durda, Katarzyna
A1  - Zlowowcka-Perłowska, Elżbieta
A1  - Osorio, Ana
A1  - Durán, Mercedes
A1  - Andrés, Raquel
A1  - Benítez, Javier
A1  - Hamann, Ute
A1  - Hogervorst, Frans B.
A1  - van Os, Theo A.
A1  - Verhoef, Senno
A1  - Meijers-Heijboer, Hanne E. J.
A1  - Wijnen, Juul
A1  - Garcia, Encarna B. Gómez
A1  - Ligtenberg, Marjolijn J.
A1  - Kriege, Mieke
A1  - Collée, Margriet
A1  - Ausems, Margreet G. E. M.
A1  - Oosterwijk, Jan C.
A1  - Peock, Susan
A1  - Frost, Debra
A1  - Ellis, Steve D.
A1  - Platte, Radka
A1  - Fineberg, Elena
A1  - Evans, D. Gareth
A1  - Lalloo, Fiona
A1  - Jacobs, Chris
A1  - Eeles, Ros
A1  - Adlard, Julian
A1  - Davidson, Rosemarie
A1  - Cole, Trevor
A1  - Cook, Jackie
A1  - Paterson, Joan
A1  - Douglas, Fiona
A1  - Brewer, Carole
A1  - Hodgson, Shirley
A1  - Morrison, Patrick J.
A1  - Walker, Lisa
A1  - Rogers, Mark T.
A1  - Donaldson, Alan
A1  - Dorkins, Huw
A1  - Godwin, Andrew K.
A1  - Bove, Betsy
A1  - Stoppa-Lyonnet, Dominique
A1  - Houdayer, Claude
A1  - Buecher, Bruno
A1  - de Pauw, Antoine
A1  - Mazoyer, Sylvie
A1  - Calender, Alain
A1  - Léoné, Mélanie
A1  - Bressac-de Paillerets, Brigitte
A1  - Caron, Olivier
A1  - Sobol, Hagay
A1  - Frenay, Marc
A1  - Prieur, Fabienne
A1  - Ferrer, Sandra Fert
A1  - Mortemousque, Isabelle
A1  - Buys, Saundra
A1  - Daly, Mary
A1  - Miron, Alexander
A1  - Terry, Mary Beth
A1  - Hopper, John L.
A1  - John, Esther M.
A1  - Southey, Melissa
A1  - Goldgar, David
A1  - Singer, Christian F.
A1  - Fink-Retter, Anneliese
A1  - Muy-Kheng, Tea
A1  - Geschwantler Kaulich, Daphne
A1  - Hansen, Thomas V. O.
A1  - Nielsen, Finn C.
A1  - Barkardottir, Rosa B.
A1  - Gaudet, Mia
A1  - Kirchhoff, Tomas
A1  - Joseph, Vijai
A1  - Dutra-Clarke, Ana
A1  - Offit, Kenneth
A1  - Piedmonte, Marion
A1  - Kirk, Judy
A1  - Cohn, David
A1  - Hurteau, Jean
A1  - Byron, John
A1  - Fiorica, James
A1  - Toland, Amanda E.
A1  - Montagna, Marco
A1  - Oliani, Cristina
A1  - Imyanitov, Evgeny
A1  - Isaacs, Claudine
A1  - Tihomirova, Laima
A1  - Blanco, Ignacio
A1  - Lazaro, Conxi
A1  - Teulé, Alex
A1  - Del Valle, J.
A1  - Gayther, Simon A.
A1  - Odunsi, Kunle
A1  - Gross, Jenny
A1  - Karlan, Beth Y.
A1  - Olah, Edith
A1  - Teo, Soo-Hwang
A1  - Ganz, Patricia A.
A1  - Beattie, Mary S.
A1  - Dorfling, Cecelia M.
A1  - Jansen van Rensburg, Elizabeth
A1  - Diez, Orland
A1  - Kwong, Ava
A1  - Schmutzler, Rita K.
A1  - Wappenschmidt, Barbara
A1  - Engel, Christoph
A1  - Meindl, Alfons
A1  - Ditsch, Nina
A1  - Arnold, Norbert
A1  - Heidemann, Simone
A1  - Niederacher, Dieter
A1  - Preisler-Adams, Sabine
A1  - Gadzicki, Dorothea
A1  - Varon-Mateeva, Raymonda
A1  - Deissler, Helmut
A1  - Gehrig, Andrea
A1  - Sutter, Christian
A1  - Kast, Karin
A1  - Fiebig, Britta
A1  - Schäfer, Dieter
A1  - Caldes, Trinidad
A1  - de la Hoya, Miguel
A1  - Nevanlinna, Heli
A1  - Muranen, Taru A.
A1  - Lespérance, Bernard
A1  - Spurdle, Amanda B.
A1  - Neuhausen, Susan L.
A1  - Ding, Yuan C.
A1  - Wang, Xianshu
A1  - Fredericksen, Zachary
A1  - Pankratz, Vernon S.
A1  - Lindor, Noralane M.
A1  - Peterlongo, Paulo
A1  - Manoukian, Siranoush
A1  - Peissel, Bernard
A1  - Zaffaroni, Daniela
A1  - Bonanni, Bernardo
A1  - Bernard, Loris
A1  - Dolcetti, Riccardo
A1  - Papi, Laura
A1  - Ottini, Laura
A1  - Radice, Paolo
A1  - Greene, Mark H.
A1  - Loud, Jennifer T.
A1  - Andrulis, Irene L.
A1  - Ozcelik, Hilmi
A1  - Mulligan, Anna Marie
A1  - Glendon, Gord
A1  - Thomassen, Mads
A1  - Gerdes, Anne-Marie
A1  - Jensen, Uffe B.
A1  - Skytte, Anne-Bine
A1  - Kruse, Torben A.
A1  - Chenevix-Trench, Georgia
A1  - Couch, Fergus J.
A1  - Simard, Jacques
A1  - Easton, Douglas F.
T1  - Common variants at 12p11, 12q24, 9p21, 9q31.2 and in ZNF365 are associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers
JF  - Breast Cancer Research
N2  - Introduction: Several common alleles have been shown to be associated with breast and/or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Recent genome-wide association studies of breast cancer have identified eight additional breast cancer susceptibility loci: rs1011970 (9p21, CDKN2A/B), rs10995190 (ZNF365), rs704010 (ZMIZ1), rs2380205 (10p15), rs614367 (11q13), rs1292011 (12q24), rs10771399 (12p11 near PTHLH) and rs865686 (9q31.2). 
Methods: To evaluate whether these single nucleotide polymorphisms (SNPs) are associated with breast cancer risk for BRCA1 and BRCA2 carriers, we genotyped these SNPs in 12,599 BRCA1 and 7,132 BRCA2 mutation carriers and analysed the associations with breast cancer risk within a retrospective likelihood framework. 
Results: Only SNP rs10771399 near PTHLH was associated with breast cancer risk for BRCA1 mutation carriers (per-allele hazard ratio (HR) = 0.87, 95% CI: 0.81 to 0.94, P-trend = 3 x 10\(^{-4}\)). The association was restricted to mutations proven or predicted to lead to absence of protein expression (HR = 0.82, 95% CI: 0.74 to 0.90, P-trend = 3.1 x 10\(^{-5}\), P-difference = 0.03). Four SNPs were associated with the risk of breast cancer for BRCA2 mutation carriers: rs10995190, P-trend = 0.015; rs1011970, P-trend = 0.048; rs865686, 2df P = 0.007; rs1292011 2df P = 0.03. rs10771399 (PTHLH) was predominantly associated with estrogen receptor (ER)-negative breast cancer for BRCA1 mutation carriers (HR = 0.81, 95% CI: 0.74 to 0.90, P-trend = 4 x 10\(^{-5}\)) and there was marginal evidence of association with ER- negative breast cancer for BRCA2 mutation carriers (HR = 0.78, 95% CI: 0.62 to 1.00, P-trend = 0.049). 
Conclusions: The present findings, in combination with previously identified modifiers of risk, will ultimately lead to more accurate risk prediction and an improved understanding of the disease etiology in BRCA1 and BRCA2 mutation carriers.
KW  - investigators
KW  - genetic modifiers
KW  - mammographic density
KW  - susceptibility loci
KW  - ovarian cancer
KW  - hormone-related protein
KW  - genome-wide association
KW  - tumor subtypes
KW  - alleles
KW  - consortium
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130449
VL  - 14
IS  - R33
ER  - 
TY  - JOUR
A1  - Alepee, Natalie
A1  - Bahinski, Anthony
A1  - Daneshian, Mardas
A1  - De Weyer, Bart
A1  - Fritsche, Ellen
A1  - Goldberg, Alan
A1  - Hansmann, Jan
A1  - Hartung, Thomas
A1  - Haycock, John
A1  - Hogberg, Helena T.
A1  - Hoelting, Lisa
A1  - Kelm, Jens M.
A1  - Kadereit, Suzanne
A1  - McVey, Emily
A1  - Landsiedel, Robert
A1  - Leist, Marcel
A1  - Lübberstedt, Marc
A1  - Noor, Fozia
A1  - Pellevoisin, Christian
A1  - Petersohn, Dirk
A1  - Pfannenbecker, Uwe
A1  - Reisinger, Kerstin
A1  - Ramirez, Tzutzuy
A1  - Rothen-Rutishauser, Barbara
A1  - Schäfer-Korting, Monika
A1  - Zeilinger, Katrin
A1  - Zurich, Marie-Gabriele
T1  - State-of-the-Art of 3D Cultures (Organs-on-a-Chip) in Safety Testing and Pathophysiology
JF  - ALTEX - Alternatives to Animal Experimentation
N2  - Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs liver, lung, skin, brain are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing.
KW  - 3D models
KW  - organotypic
KW  - organ-on-a-chip
KW  - multicellular tumor spheroids
KW  - primary human hepatocytes
KW  - embryonic stem cell
KW  - reconstructed human epidermis
KW  - in-vitro models
KW  - full thickness skin
KW  - necrosis-factor-alpha
KW  - metabolic flux analysis
KW  - long-term
KW  - human liver cells
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117826
VL  - 31
IS  - 4
ER  -