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Category: TopoGEN News

Topoisomerase I and DNA Relaxation

Topoisomerase I and DNA Relaxation

Par-4 Binds to Topoisomerase I and Attenuates Its DNA Relaxation Activity The authors of this paper have identified a tumor suppressor protein that regulates Topo I, and in so doing provide a nice review of the mechanistic nature of DNA and cancer cell metabolism.  Human Topo I and polyclonal antibodies were provided by TopoGEN. Article Source: Cancer Research Website

Custom Drug Screening Services

Custom Drug Screening Services

In addition to manufacturing, TopoGEN has quietly developed into a CRO powerhouse in recent years.  Utilizing our own regimes and expertise that comes with 30+ years of experience, we tailor-build a custom screening solution for your novel anti-cancer studies.  Specific targets include eukaryotic topoisomerases (topo I, topo II, topo III), prokaryotic topoisomerases (gyrase, topo IV) in E. Coli and S. Aureus, and recently we added DNA methyltransferase targets.  We are also developing a solid phase assay for topo I (provisional…

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Novel Gold Compounds Potential Anti-cancer Therapies

Novel Gold Compounds Potential Anti-cancer Therapies

TopoGEN is partnering with a prominent analytical chemist based in South Africa on the development of innovative anti-topo I and II targeting drugs based on synthetic structures containing gold.  Evidence demonstrates the combination of poisoning and catalytic inhibition of the DNA topoisomerase pathways.  Initial screens performed by NCI demonstrated efficacy in cancer and subsequent confirmation by TopoGEN is showing topoisomerase targeting.   Further studies are pending SBIR phase I review and the acquisition of patents filed in the U.S. and abroad. …

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Novel Targeting In Vivo based on DNA DS Breaks and Homologous Recombination

Novel Targeting In Vivo based on DNA DS Breaks and Homologous Recombination

TopoGEN scientists are working on a novel screening kit that reports on the topo II mediated DNA damage.  The kit comes bundled with a HR repair reporter that TopoGEN scientist engineered using GFP inside cells that contain an ultra-high affinity site for topoisomerase II cleavages.  The quantitative GFP readout will allow in vivo screening for topo active and DNA damaging agents.  This kit is slated for release in 2012, so please contact us for more information.

Monitor Drug Efficacy with the In Vivo Link Kit from TopoGEN

Monitor Drug Efficacy with the In Vivo Link Kit from TopoGEN

TopoGEN has developed a kit to clearly demonstrate topo I and II poisoning in the context of the cell.  Use of the In Vivo Link Kit™ provides the researcher unambiguous evidence of drug efficacy within tumor cells. Frequently, when a new drug or compound is identified as a topo targeting agent, the investigator needs to ask basic questions about its entry into the cell.  For example, a positive in vitro hit may not translate into the context of a tumor…

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Human Topoisomerase II and Transcription

Human Topoisomerase II and Transcription

DNA topoisomerase IIa is required for RNA polymerase II transcription on chromatin templates Neelima Mondal & Jeffrey D. Parvin Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA Abstract In the nucleus of the cell, core RNA polymerase II (pol II) is associated with a large complex called the pol II holoenzyme (holo-pol)1,2. Transcription by core pol II in vitro on nucleosomal templates is repressed compared with that on templates of histone-free naked DNA3±5. We…

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Topo I Cleavage Complexes and Transcription

Topo I Cleavage Complexes and Transcription

Role for topoisomerase 1 in transcription-associated mutagenesis in yeast High levels of transcription in Saccharomyces cerevisiae are associated with increased genetic instability, which has been linked to DNA damage. Here, we describe a pGAL-CAN1 forward mutation assay for studying transcription-associated mutagenesis (TAM) in yeast. In a wild-type background with no alterations in DNA repair capacity, ≈50% of forward mutations that arise in the CAN1 gene under high-transcription conditions are deletions of 2–5 bp. Furthermore, the deletions characteristic of TAM localize…

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DNA Decatenation Study

DNA Decatenation Study

BRCA1 Participates in DNA Decatenation Zhenkun Lou, Katherine Minter-Dykhouse & Junjie Chen The tumor suppressor BRCA1 has an important function in the maintenance of genomic stability. Increasing evidence suggests that BRCA1 regulates cell cycle checkpoints and DNA repair after DNA damage. However, little is known about its normal function in the absence of DNA damage. Here we show that BRCA1 interacts and colocalizes with topoisomerase IIa in S phase cells. Similar to cells treated with the topoisomerase IIa inhibitor ICRF-193,…

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Upcoming Closure May 4-18

Upcoming Closure May 4-18

Our business and shipping facilities will be closed May 4-18 while our staff visits with collaborators in Europe. During this time we will be answering voicemails and emails, so please do continue to contact us. Our offices will be resume our normal product shipping regimen on May 23. Thank you!

Rapid Transport of Novel Topo II Inhibitor into Cancer Cells

Rapid Transport of Novel Topo II Inhibitor into Cancer Cells

F14512, a Potent Antitumor Agent Targeting Topoisomerase II Vectored into Cancer Cells via the Polyamine Transport System Jean-Marc Barret, Anna Kruczynski, Stéphane Vispé, et al. Abstract The polyamine transport system (PTS) is an energy-dependent machinery frequently overactivated in cancer cells with a high demand for polyamines. We have exploited the PTS to selectively deliver a polyamine-containing drug to cancer cells. F14512 combines an epipodophyllotoxin core-targeting topoisomerase II with a spermine moiety introduced as a cell delivery vector. The polyamine tail…

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