Expressions Of Glucosylceramide Synthase Gene In Human K562/AO2 Cell Strain And Their Relationship To Leukemia Multidrug Resistance

Objective To investigate the relationship between the expression of glucosylceramide synthase (GCS) mRNA in human erythroleukemia cell strain K562/AO2 and multidrug resistance (MDR)of the tumor cells.To explore the molecular mechanism of multidrug resistance induced by GCS.Methods Alamar BlueTM multifunction cell staining method was applied to confirm the multidrug resistant of K562/AO2 cells. Using reverse transcriptional polymerase chain reaction (RT-PCR), the differential expressions of GCS mRNA,MDR1 mRNA,Bcl-2 mRNA and Bax mRNA between K562/AO2 and K562 cell strains were analyzed. ELISA was applied to detect Bcl-2 and Caspase-3 protein in K562/AO2 and K562 cells. RT-PCR was employed to analyze the expression of GCS gene in K562/AO2 cells which were treated by PPMP. Alamar BlueTM multifunction cell staining method was applied to analyze the change of MDR when K562/AO2 cells were treated by PPMP.Results 1.The MDR of cell strain K562/AO2 is confirmed; 2.K562/AO2 cells exhibited significantly higher expressions of GCS and MDR1 gene than K562 cells; 3.K562/AO2 cells exhibited higher expressions of Bcl-2 gene than K562 cells whereas the expressions of Bax gene were higher in K562 cells .4. K562/AO2 cells exhibited higher expressions of Bcl-2 protein (p<0.01), and exhibited lower expressions of Caspase-3(p<0.05); 5. PPMP within the concentrations ranging from 2.5 to 25μmol/L could inhibit the expression of GCS gene in K562/AO2 cells, with the maximum inhibition achieved at 25μmol/L; 6. K562/AO2 cells's MDR is obviously reversed after treated by PPMP at 25μmol/L.Conclusion GCS gene might play an important role in MDR during human leukemia progression. PPMP can modulate and partly reverse MDR by inhibiting GCS gene expression in K562/AO2 cells. Abnormally expressions of the genes in associated with cell apoptosis might be one of the main molecular pathology mechanisms of multidrug resistance caused by GCS gene.