TABLE 2

Effect of reserpine on intracellular CPT-11 and SN-38 concentrations in ABCG2-expressing Saos-2 cells

Only one CE activity is indicated per cell line because drug accumulation studies were performed with aliquots of the same batch of cells. One unit of CE activity is the amount of enzyme that converts 1 μ mol of o-nitrophenyl acetate to o-nitrophenol per minute

Cell Line Reserpine CE Activity [CPT-11] [SN-38] SN-38 per 1000 U CE Increase in [SN-38] by Reserpine
μmol/min/mg μM pM %
pcDNA#2 1842.7 ± 117.9 7.1 134.5 73.0
pcDNA#2 + 4.6 142.5 77.3 5.9
ABCG2#4 1658.3 ± 180.6 4.8 50.6 30.5
ABCG2#4 + 4.4 90.5 54.5 79
ABCG2#7 5771.3 ± 538.6 4.0 364.4 63.1
ABCG2#7 + 4.4 370.9 64.3 1.9