The effect of various inhibitors of DNA synthesis on the repair of DNA photoproducts |
| |
Authors: | Judith M. Clarkson David L. Mitchell |
| |
Affiliation: | The University of Texas System Cancer Center, Science Park-Research Division, P.O. Box 389, Smithville, TX 78957 U.S.A. |
| |
Abstract: | The effect on DNA repair of several inhibitors of DNA synthesis has been investigated in CHO cells. Three assays were employed following ultraviolet irradiation of G1 cells: unscheduled DNA synthesis, removal of antibody binding sites and alkaline elution. Cytosine arabinoside and aphidicolin were found to reduce unscheduled DNA synthesis in a dose-dependent manner without affecting the removal of antibody-binding sites. Strand rejoining was also inhibited. These results are consistent with the hypothesis that inhibition is due to premature chain termination during repair synthesis some time after excision of the lesion. Conversely, inhibition of unscheduled DNA synthesis by novobiocin is paralleled by inhibition of excision of the lesion. However, no inhibition of incision was apparent. Since nalidixic acid, an inhibitor of topoisomerase II, did not inhibit excision, it is unlikely that the primary site of action of novobiocin is this topoisomerase. The possibility that a second topoisomerase and/or a polymerase are affected is discussed in the light of previously published data. |
| |
Keywords: | DNA repair DNA synthesis inhibitor Cytosine arabinoside Aphidicolin Novobiocin Nalidixic acid (Chinese hamster ovary cell) |
本文献已被 ScienceDirect 等数据库收录! |
|