DOX resistant MCF7 breast cancer cells are associated with chromatin alterations and DNA damage.

<p>(<b>A</b>) MCF7 cells before and after DOX selection were stained with DAPI to visualize DNA (blue) and with antibodies against BCRP (red). (<b>B</b>) Protein lysates were prepared from parental and selected MCF7 cells and analyzed by Western analyses using the antibodies shown. (<b>C</b>) Volcano plot of genes differentially expressed following the full DOX selection protocol compared to starting parental cells. The X-axis denotes expression changes with positive to the right and negative to the left. The Y-axis shows statistical significance (p-value) of the changes observed. The vertical red lines define the threshold for 2-fold positive and negative changes. (<b>D</b>) Volcano plot of differentially expressed genes following acute exposure to 1 µM DOX for 48 hours. The dots in green and yellow define the genes that were up-regulated and down-regulated, respectively. (<b>E</b>) Volcano plot demonstrating the differential expression of genes following the 2-week chronic exposure phase after the 48-hour treatment. The Tissue Factor Pathway Inhibitor family members are shown (TFPI1α, TFPI1β and TFPI2).