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)

Topoisomerase II from human placenta was strongly inhibited by prostaglandins such as delta 12,14-PGJ2, delta 12-PGJ2, PGA2, and PGA1, which have an antitumor activity. The topoisomerase II inhibitions by these prostaglandins were dose-dependent and IC50 values of delta 12,14-PGJ2, delta 12-PGJ2, PGA2, and PGA1 were 22 microM, 74 microM, 75 microM, and 98 microM, respectively. Topoisomerase I from calf thymus gland was inhibited by delta 12,14-PGJ2, delta 12-PGJ2, and PGA2, but not inhibited by other prostaglandins even at high concentrations. Only the prostaglandins having the antitumor activity inhibited topoisomerase II. The results suggest that the antitumor activity of prostaglandins may be related, at least in part, to inhibition of topoisomerase II in tumor cells.
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PMID:Inhibition of topoisomerases by antitumor prostaglandins. 983 48

Prostaglandins (PGs) having antitumor activity such as delta12,14-PGJ2, delta12-PGJ2, PGA2 and PGA1 strongly inhibited topoisomerase II (topo II) from human placenta, the potential order of inhibitory activity of the PGs resembling that of the antitumor activity. PGs having no antitumor activity did not inhibit topo II. Delta12,14-PGJ2 to be a potent inhibitor showed inhibitions to some extent against topo I from wheat germ, NIH3T3 and calf thymus gland, and showed no inhibition against the enzymes from Vero, A549, HeLa and COLO 201 cells. Delta12,14-PGJ2 differentially inhibited topo I from different sources. Delta12,14-PGJ2 was a topo inhibitor of the cleavable complex-nonforming type without DNA intercalation.
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PMID:Inhibitory properties of antitumor prostaglandins against topoisomerases. 1235 31