[DNA topoisomerase and telomerase activity with relation to multi-drug resistance in leukemia--review].

The appearance of multi-drug resistance becomes a key to treat many malignancies, and also is an important factor in the failure of chemotherapy. Presently, the studies on multi-drug resistance mechanism, reversor and associated exterior experiments in vivo and in vitro from different points of view and levels show that multi-drug resistance is the result of common action in many factors. In recent years non-representative mechanism of multi-drug resistance becomes more and more significant. This review aims at establishing rationale basis for reversing multi-drug resistance of leukemia and finding effective reversors by expounding the mechanism of apoptosis in drug resistance of leukemia with relation to DNA topoisomerase and telomerase activity.