Studies On Methods And Mechanisms Of Purging Multidrug-resistant Leukemic Cells With Microwave

Autologus stem cell transplantation (ASCT) is an effectual way to cure leukemia and some other solid tumors. Resistance of tumor cells to chemotherapeutic drugs should be taken into account. When purifying the tumor cells in vitro, overcoming the drug resistance is of great importance to improve the efficacy of ASCT. In this dissertation, the possibility of taking microwave as a physical method for the purification of drug-resistant leukemia cells during ASCT and its mechanisms were studied. The dissertation consists of 6 chapters.In chapter 1, recent progress on relevant subjects was discussed, including autologus stem cell transplantation, causes and reverse of drug resistance in tumor cells, special effect of microwave and its influence on cell membrane, heat shock proteins and their protection for cells.In chapter 2, effects of microwave on the surviving fraction (SF) of multidrug-resistant leukemic cell line K562/MDR and normal leukocytes were studied. It was found that microwave could inhibit the SF of K562/MDR cells and normal leukocytes. The inhibition depended on the dose of microwave and the temperature. Compared with water-bath hyperthermia, microwave showed greater selective killing effect on K562/MDR cells.In chapter 3, the relationship between the inducing apoptosis and expression of HSP70 in K562/MDR cells by microwave was investigated. It was found that the treatment of microwave at 43 °C could induce K562/MDR cells to apoptosis and the expression of HSP70 in K562/MDR cells decreased after the treatment. These results indicated that microwave could induce apoptosis in K562/MDR cells and it was one of the reasons that at 43°C the.