STUDY OF RELATIONSHIP BETWEEN MULTIDRUG RESISTANCE AND APOPTOSIS IN LEUKEMIA CELL LINE K562

Objective:To illustrate the relationship between multidrug resistance (MDR)and apoptosis in leukemia cell line K562.Methods:K562 cell MDR was gradually induced with ADM in vitro. Using flow cytometry(FCM) assay, the expression of P glycoprotein (P gp) was examined. The mRNA expressions of MDR was measured by fluorescent quantitative reverse transcriptase polymerase chain reaction(RT PCR).Apoptotic changes were observed by Anexin V.Results:After treatment with ADM 5 μmol/L for 24 h,48 h or 72 h, both MDR 1 mRNA and P gp began to rise,and reached highest level at 72 h. They were negatively correlated with the number of apoptosis K562 cells( r =0.68, P 0.01).The increase in apoptosis and decrease in P gp happened at same time when cells were treated with As 2O 3 for 72 h.Conclusion:MDR of K562 cells is closely related with suppresion of cell apoptosis. MDR can be reversed by inducing cell apoptosis.