Investigation of Mechanism Activity of Antitumor and Radiosensitizing Activity of Preparations К-26 and K-26w
Аннотация
Introduction. Tropolone alkaloid – colchicine, there is very interesting object for synthesis of its derivatives, with such properties as, alkylation, a low toxicity, high antineoplastic activity and especially overcoming of multidrug resistance (MDR). We had been developed the antineoplastic preparation К-26 derivative of colchicine. К-26 has shown high cytotoxic activity on 60 lines of tumoral cells of the human <i>in vitro</i>, at National Institute of the Cancer of the USA (NCI). Further on the basis of К-26 its water-soluble form named term К-26w has been received. The work purpose. Studying of the mechanism of action of preparations К-26 and К-26w on: alkylating ability, mitotic activity, topoisomerase II, MDR2, р53 and colony-forming cells spleen (CFCs). Materials and methods. All researches have been carrying out by a standard technique. Studying mitotic activity of preparations was carrying out on duodenum and tumor СаРа after preparation influence. On models of a tumor of the Sarcoma 180 action of preparations has been investigated: the alkylating - on synthesis DNA/RNA, nucleosoma DNA degradation, activity topoisomerase II; on an expression MDR2 and р53 genes. Studying CFCs carry out by a standard technique on outbred mice. Results. К-26, К-26w and etoposide inhibited in cells of the Sarcoma 180: synthesis DNA/RNA on 84/65%, 95/85% and 55/35%, accordingly, in relation to the control; activity topoisomerase II on 80%, 90% and 60% accordingly. By method RT-PCR it is shown, К-26, К-26w and etoposide: inhibited an expression of MDR2 gene on 83%, 91% and 62%; increase expression р53 gene to 74%, 88% and 55%, accordingly, under the relation of the control of referential gene GARDH (100%). High ability К-26 and К-26w in an induction apoptosis tumoral cells and CFCs to 12 units is shown. Conclusion. Revealed ability К-26 and К-26w to suppress synthesis DNA/RNA activity topoisomerases, to stimulate р53, and also to suppress an expression of a multidrug resistance MDR2 gene, it explains their high antineoplastic activity which is connected with mitotic activity leading to cell fission synchronization, and radiosensitization activity. Special interest represents found at К-26w and К-26 suppression MDR2 as they are aimed for treatment of such resistant tumor as a kidney cancer. Stimulation CFCs which provides formation of haemopoetic and immune cells can protect an organism from their intensive cytotoxic action.