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Category: TopoGEN News

TopoGEN Activity Assays: Topo II Inhibitor Study

TopoGEN Activity Assays: Topo II Inhibitor Study

Thanatop: A Novel 5-Nitrofuran that Is a Highly Active, Cell-Permeable Inhibitor of Topoisomerase II Abstract A series of nitrofuran-based compounds were identified as inhibitors of estrogen signaling in a cell-based, high-throughput screen of a diverse library of small molecules. These highly related compounds were subsequently found to inhibit topoisomerase II in vitro at concentrations similar to that required for the inhibition of estrogen signaling in cells. The most potent nitrofuran discovered is f10-fold more active than etoposide phosphate, a topoisomerase…

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Topo I Assay Kit Aids Breast Cancer Study

Topo I Assay Kit Aids Breast Cancer Study

Epidermal Growth Factor-Induced Heparanase Nucleolar Localization Augments DNA Topoisomerase I Activity in Brain Metastatic Breast Cancer Abstract Identification of molecular mechanisms responsible for brain metastatic breast cancer (BMBC) is imperative to develop novel therapies. However, current understanding of the molecular circuitry that governs BMBC dissemination remains fragmentary. Heparanase (HPSE) is the only functional mammalian endoglycosidase whose activity correlates with cancer metastasis, angiogenesis, and the reduced postoperative survival of cancer patients, making it an active target for anticancer therapeutics. We hypothesized…

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DNA Cleavage Assay Aids The Clinical Search for New Top1 Inhibitors

DNA Cleavage Assay Aids The Clinical Search for New Top1 Inhibitors

DNA cleavage assay for the identification of topoisomerase I inhibitors The inhibition of DNA topoisomerase I (Top1) has proven to be a successful approach in the design of anticancer agents. However, despite the clinical successes of the camptothecin derivatives, a significant need for less toxic and more chemically stable Top1 inhibitors still persists. Here, we describe one of the most frequently used protocols to identify novel Top1 inhibitors. These methods use uniquely 3′-radiolabeled DNA substrates and denaturing polyacrylamide gel electrophoresis…

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TopoGEN Topoisomerase Antibodies Used in Chemotherapy Study

TopoGEN Topoisomerase Antibodies Used in Chemotherapy Study

Topoisomerase levels determine chemotherapy response in vitro and in vivo Darren J. Burgess*, Jason Doles†, Lars Zender*, Wen Xue*, Beicong Ma*‡, W. Richard McCombie*, Gregory J. Hannon*‡, Scott W. Lowe*‡§, and Michael T. Hemann*† *Cold Spring Harbor Laboratory and ‡Howard Hughes Medical Institute, 1 Bungtown Road, Cold Spring Harbor, NY 11724; and †Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139 Communicated by Michael H. Wigler, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, April 14, 2008 (received…

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Decatenation Assays and Topo II – Supercoiled pBR322 Provided by TopoGEN

Decatenation Assays and Topo II – Supercoiled pBR322 Provided by TopoGEN

A non-canonical function of topoisomerase II  in disentangling dysfunctional telomeres Thomas Germe, Kyle Miller1 and  Julia Promisel Cooper Telomere Biology Laboratory, Cancer Research, London, UK The decatenation activity of topoisomerase II (Top2), which is widely conserved within the eukaryotic domain, is essential for chromosomal segregation in mitosis.  It is less clear, however, whether Top2 performs the same function uniformly across the whole genome, and whether all its functions rely on decatenation.  In the fission yeast, Schizosaccharomyces pombe, telomeres are bound…

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New Solid Phase Assay Coming Soon

New Solid Phase Assay Coming Soon

TopoGEN scientists have developed a novel solid phase screening assay suitable for High Throughput Screening. This method has the ability to unambiguously identify topoisomerase targeting drugs. In addition, this HTS method will predict if a test drug is an INTERFACIAL POISON or a CATALYTIC INHIBITOR. Stay tuned for more details! The paper has been submitted for publication and will be released on this blog. In the meantime feel free to contact us with any questions about this exciting new development.

Nuclease Assays with pN01 from TopoGEN

Nuclease Assays with pN01 from TopoGEN

Saccharomyces cerevisiae Mre11/Rad50/Xrs2 and Ku proteins regulate association of Exo1 and Dna2 with DNA breaks Eun Yong Shim1,4, Woo-Hyun Chung2,4, Matthew L Nicolette3, Yu Zhang1, Melody Davis1, Zhu Zhu2, Tanya T Paull3, Grzegorz Ira2,* and Sang Eun Lee1,* 1Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA, 2Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA and 3Department of Molecular Genetics and…

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Upcoming Holiday Closure

Upcoming Holiday Closure

TopoGEN will be closed for shipping November 24-26 for Thanksgiving. Our last official ship-day before Christmas is December 20. We will resume normal shipping operation on January 10, 2011. During this time our staff will remain available via e-mail to respond to technical questions, internet orders, and general information. Feel free to drop us a line.