Figure 3

The association between cancer malignancy and CD63 in breast cancer cells. MDA-MB-231-luc-D3H2LN (MM231-LN) cells were transiently transfected with the control (N.C.), CD63 or RPN2 siRNAs (A-D). MCF7-ADR cells were transiently transfected with N.C., CD63 or RPN2 siRNAs (E-I). A) The cell extracts were subjected to qRT-PCR. The values on the y-axis are plotted relative to the expression level of control (N.C.), which is defined as 1. All data are shown as the mean   S.D., **P < 0.01. B) CD63 expression was detected using immunoblotting. β-actin was used as a loading control. C) Cell growth assessed by MTS assay. D) The following day, the cells were subjected to a Matrigel™ invasion assay. Quantification and representative photographs (lower figure) are shown. The size bar indicates 500  μm. All data are shown as the mean   S.D., **P < 0.01. E) The cell extracts were subjected to qRT-PCR. The values on the y-axis are plotted relative to the expression level of N.C., which is defined as 1. All data are shown as the mean   S.D., **P < 0.01. F) CD63 expression was detected using immunoblotting. G) The medium was replaced with fresh medium containing 25 nM of the chemotherapeutic agent docetaxel for an additional 72 hours. The effect of docetaxel pretreatment on cell viability was examined using an MTS assay. The values on the y-axis are plotted relative to the absorbance of N.C., which is defined as 1. All data are shown as the mean   S.D., **P < 0.01. H) The IC50 of MCF7-ADR cells for docetaxel was assessed by MTS assay after transient transfection with the N.C., RPN2 or CD63 siRNAs. All data are shown as the mean   S.D., *P < 0.05, **P < 0.01. I) MDR1 expression was detected using immunoblotting. The dashed lines show the molecular weight.