Figure 2

Dox treatment upregulates ABC transporter expression only in invasive cells. (a) Phase-contrast microscopic images taken after 1 week of untreated (UT) and doxorubicin-treated (Dox) MCF10A, MCF7, and MDAMB231 breast epithelial cell lines. Scale bar=100 μm. (b) Graphs represent relative mRNA expression of 16 ABC transporters after 1-week Dox treatment in MCF10A, MCF7, and MDAMB231 breast epithelial cell lines, n=3. Statistical significance for all the experiments was determined using ratio t-test. Error bars denote ±S.E.M. ^*P<0.05; ^**P<0.01; ^***P<0.001. The insets represent immunoblot analysis of whole-cell lysates for the expression of three ABC transporters, viz, ABCB1, ABCC1, and ABCG2 in the absence or presence of Dox. (c) Phase-contrast microscopic images of primary breast tissue-derived cells in the presence (Dox) or absence (UT) of Dox for 7 days; scale bar=100 μm. (d) Representative graph showing relative mRNA expression of 16 ABC transporters after 1-week Dox treatment in primary normal- and tumor-derived breast epithelial cells, n=4. (e) Representative graph showing relative mRNA expression of ABC transporters in chemotherapy-treated patient-derived primary normal (CT-NB) and tumor (CT-CB) breast samples. n=2 for normal and n=3 for tumor samples