Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Elsamicin (EM) is a recently discovered antitumour agent that is structurally related to several other compounds displaying anticancer activities, including chartreusin (CT), chrysomycin V (CV) and M (CM), gilvocarcin V (GV) and ravidomycin (RM). The biochemical events resulting in cytotoxicity for most of these compounds have not been clearly elucidated. There is some evidence that GV and CT bind to DNA and that GV is photosensitive, causing DNA damage. Therefore, we investigated the effects of these chemicals on DNA in cells and on pBR322 plasmid DNA. Using alkaline elution techniques, we found that all these compounds induced, to a different extent, DNA breakage in the human lung adenocarcinoma A549 cell line. In addition, all either bound to or intercalated into DNA, as indicated by their ability to alter the electrophoretic migration of DNA in agarose gels. Using the P4 unknotting assay, EM, CT, CV, CM, GV and RM were found to be potent inhibitors of the catalytic activity of topoisomerase II (topo II). Their potencies were compared with the known topo II inhibitors teniposide (VM-26) and doxorubicin (DX). EM was the most potent, with an IC50 of 0.4 mumol/l followed in order by CV, GV, and CT. VM-26 was the least potent with an IC50 of 15 mumol/l. It was concluded from these results that EM, GV, CV, CM and CT are capable of inhibiting topo II and that EM is the most potent inhibitor of topo II yet discovered.
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PMID:Biochemical characterisation of elsamicin and other coumarin-related antitumour agents as potent inhibitors of human topoisomerase II. 828 Apr 93

Chartreusin and elsamicin A are structurally related antibiotics that bind to GC-rich tracts in DNA, with a clear preference for B-DNA over Z-DNA. They inhibit RNA synthesis and cause single-strand scission of DNA via the formation of free radicals. Elsamicin A can also be regarded as the most potent inhibitor of topoisomerase II reported so far. It can inhibit the formation of several DNA-protein complexes. Elsamicin A binding to the P1 and P2 promoter regions of the c-myc oncogene inhibits the binding of the Sp1 transcription factor, thus inhibiting transcription. Despite the pharmacological interest in chartreusin, elsamicin A and their derivatives, there is no experimental data on the structure of their complexes with DNA. This shortcoming has been partially solved by a theoretical approach, which provided some details about the DNA-elsamicin A interaction, and the thermodynamic characterization of the binding of chartreusin and elsamicin A to DNA. Elsamicin A but not chartreusin is being developed clinically as an anti-cancer agent. IST-622 (6-O-(3-ethoxypropylonyl)-3',4'-O-exo-benzylidene-chartreusin), a novel semi-synthetic derivative of chartreusin, which has shown a promising anti-cancer activity in a phase II study, appears to be a pro-drug with a more suitable pharmacokinetic profile than chartreusin.
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PMID:Chartreusin, elsamicin A and related anti-cancer antibiotics. 1452 49