NOVEL ACTIONS OF INHIBITORS OF DNA TOPOISOMERASE-II IN DRUG-RESISTANTTUMOR-CELLS

We review herein current work on the cytotoxic and cellular actions of two classes of inhibitors of DNA topoisomerase II: one represented by etoposide and teniposide, which stabilize DNA-protein complexes, and another represented by merbarone and aclarubicin, which do not stabili ze such complexes. We discuss current concepts of protooncogene activa tion and cell cycle perturbations by some of these inhibitors and summ arize recent findings of novel actions of the latter compounds in tumo r cells that express a mutant topoisomerase II.