BACKGROUND & OBJECTIVE: Drug resistance is a major factor in chemotherapeutic failure of leukemia. Multidrug resistant cell lines are the good models for investigating the mechanisms and reversal of acquired drug resistance. This study was designed to explore the multidrug resistance (MDR) mechanisms in cell line HL-60/VCR. METHODS: Flow cytometry and a panel of antibodies were used to analyze the expression of MDR proteins (P-gp, MRP, LRP, BCRP, GST-pi) and apoptosis-modulating proteins (bcl-2, bcl-x, bax, bad) in MDR cell line HL-60/VCR and drug sensitive cell line HL-60. RESULTS: The expression levels of MDR proteins (P-gp, MRP, BCRP, GST-pi) were (18.62, 1.19, 1.50, 1.32-flod) higher in HL-60/VCR than in HL-60, while the expression of LRP level was similar. The levels of apoptosis-modulating proteins(bcl-2, bcl-x, bad) were (2.48, 1.25, 1.08-fold) higher in HL-60/VCR than in HL-60, while the pro-apoptosis protein bax contrarily decreased in HL-60/VCR. CONCLUSION: Various MDR mechanisms were involved in multi-drug resistance HL-60/VCR cell line, which including increasing expression of drug-resistance protein (P-gp, MRP, BCRP, and GST-pi); the apoptosis-modulating proteins (bcl-2, bcl-x, bax, and bad) might take part in the mechanism of drug resistance.
BACKGROUND & OBJECTIVE: Drug resistance is a major factor in chemotherapeutic failure of leukemia. Multidrug resistant cell lines are the good models for investigating the mechanisms and reversal of acquired drug resistance. This study was designed to explore the multidrug resistance (MDR) mechanisms in cell line HL-60/VCR. METHODS: Flow cytometry and a panel of antibodies were used to analyze the expression of MDR proteins (P-gp, MRP, LRP, BCRP, GST-pi) and apoptosis-modulating proteins (bcl-2, bcl-x, bax, bad) in MDR cell line HL-60/VCR and drug sensitive cell line HL-60. RESULTS: The expression levels of MDR proteins (P-gp, MRP, BCRP, GST-pi) were (18.62, 1.19, 1.50, 1.32-flod) higher in HL-60/VCR than in HL-60, while the expression of LRP level was similar. The levels of apoptosis-modulating proteins(bcl-2, bcl-x, bad) were (2.48, 1.25, 1.08-fold) higher in HL-60/VCR than in HL-60, while the pro-apoptosis protein bax contrarily decreased in HL-60/VCR. CONCLUSION: Various MDR mechanisms were involved in multi-drug resistance HL-60/VCR cell line, which including increasing expression of drug-resistance protein (P-gp, MRP, BCRP, and GST-pi); the apoptosis-modulating proteins (bcl-2, bcl-x, bax, and bad) might take part in the mechanism of drug resistance.