ANTIPROLIFERATIVE EFFECTS ON BREAST CANCER CELLS AND SOME INTERACTIONS OF NEW DISTAMYCIN ANALOGUES WITH DNA, ENDONUCLEASES AND DNA TOPOISOMERASES.

The evaluation of a new group of distamycin analogues 1-6 as potential minor groove binders for the treatment of cancer were investigated. The activity of the new compounds against several restriction enzymes was examined. The studied compounds did not block GC-rich sequences regions of DNA but inhibited catalytic action of endonucleases in AA, AT, TT and AG restriction sites. Determination of association constants using calf thymus DNA, T4 coliphage DNA, poly(dA-dT)₂ and poly(dG-dC)₂ have confirmed that the tested compounds bind within minor groove of B-DNA. All of the compounds demonstrated activity against DNA topoisomerases II at the concentration 10 µM, but they did not inhibit activity of topoisomerase I. The studied derivatives were evaluated in human MCF-7 breast cancer cells and showed antiproliferative and cytotoxic effects in the range of 81.70 µM and 200.00 µM.