Reversal effect of hyperthemia on multidrug resistant phenomena]

The purpose of this study was investigate the effect of hyperthemia on multidrug resistance in K562/ADM cell.The MDR1 (mulitdrug resistance gene) and MRP (multidrug resistant associated gene) gene expressions in Tca8113 and K562/ADM cell lines were analyzed by RT-PCR after treated with different cytotoxic drugs and different temperature (37 degrees C and 41 degrees C). The function and expression of Pgp and MRP were detected by fluorescence photometeric assays.Inhibition rate of both cells was significantly enhanced by exposure to chemotherapeutic drugs and 41 degrees C temperature; Exposing to 41 degrees C hyperthemia reduced MDR1 and MRP expression and enhanced intracellular drug concentration as well in K562/ADM.41 degrees C hyperthemia could effectively enhance the inhibition rate of chemotherapeutic drugs and partially reverse the multidrug resistance. It is suggested that hyperthemia could be used as a method to overcome multidrug resistance.