| Main Title |
New Action for Topoisomerase Inhibitors. |
| Author |
Zucker, R. M. ;
Elstein, K. H. ;
|
| CORP Author |
ManTech Environmental Technology, Inc., Research Triangle Park, NC.;Health Effects Research Lab., Research Triangle Park, NC. |
| Publisher |
c1991 |
| Year Published |
1991 |
| Report Number |
EPA/600/J-91/242; |
| Stock Number |
PB92-110451 |
| Additional Subjects |
Enzyme inhibitors ;
DNA topoisomerase I ;
Camptothecin ;
Cell cycle ;
Biosynthesis ;
DNA replication ;
Acute erythroblastic leukemia ;
Cultured tumor cells ;
Ploidies ;
Flow cytometry ;
Mice ;
Chromosomes ;
Reprints ;
|
| Holdings |
| Library |
Call Number |
Additional Info |
Location |
Last
Modified |
Checkout
Status |
| NTIS |
PB92-110451 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
| Collation |
12p |
| Abstract |
Topoisomerases are known to aid DNA replication by breaking and resealing supercoiled DNA. Consequently, cells exposed to topoisomerase inhibitors before or during the S (DNA synthetic) phase of the cell cycle undergo abnormal DNA replication and become irreversibly blocked in the G2 (pre-mitosis) phase. The authors report that following a 4-h exposure to topoisomerase II inhibitors, murine erythroleukemic cells (MELC) do not form mitotic figures but exhibit a time-dependent progression into G2 (4N DNA) and > G2 (up to 8N DNA) stages of the cell cycle. Following exposure to the topoisomerase I inhibitor camptothecin, recovering MELC also exhibit > G2 polyploidy, but to a considerably lesser degree: mitotic figures are present and a subpopulation of cells resumes cycling. However, both topo I and topo II inhibitors induce maximal percentages of > G2 cells when synchronized MELC are in the G2/M phase at the time of exposure. This suggests that, in addition to their S-phase action, topoisomerase inhibitors can interfere with chromosome condensation during G2 and, in so doing, induce polyploidy. (Copyright (c) 1991 Elsevier Scientific Publishers Ireland Ltd.) |
| Supplementary Notes |
Pub. in Chemico-Biological Interactions, v79 n1 p31-40 Apr 91. Sponsored by Health Effects Research Lab., Research Triangle Park, NC. |
| NTIS Title Notes |
Journal article. |
| Title Annotations |
Reprint: New Action for Topoisomerase Inhibitors. |
| Category Codes |
57Q; 57F |
| NTIS Prices |
PC A03/MF A01 |
| Primary Description |
600/10 |
| Document Type |
NT |
| Cataloging Source |
NTIS/MT |
| Control Number |
133921309 |
| Origin |
NTIS |
| Type |
CAT |
