Figure 5

Differential expression patterns of YB-1, c-Kit, MAPT and GST in time course. MCF-7 cells that incubated with 20 nM doxorubicin for the indicated periods of time revealed different kinetic patterns for YB-1 and GST expressions between sensitive and resistant MCF-7 cells. A: Dot blot array analysis on doxorubicin sensitive MCF-7 cells. B: Dot blot array analysis on the doxorubicin resistant MCF-7 cells. A and B: The scale on x-axis is not in proportion with time. In the time course study, actin was employed as a control for normalization, because GAPDH was regulated in doxorubicin resistant MCF-7 cells. C: Effect of doxorubicin on the expression of drug resistance related target proteins YB-1, c-Kit, ERK1/2, ERK3, FAS, MAPT, MDR1, ABCB5 and PARP-1 in the four subtypes of MCF-7 cells. 1, 2 are MCF-7 and MCF-7/vector-YB-1 respectively without treatment of doxorubicin. 3, MCF-7/vector-YB-1 with treatment of doxorubicin for 6 h (not fused cells); 4, MCF-7/vector-YB-1 with treatment of doxorubicin for 6 h (fused cells, FACS sorted R2); 5, doxorubicin resistant MCF-7 cell line. Numbers indicate a relative level of protein expression based on the level of intensity of β-actin after normalization.