Cytotoxicity of BPR0L075 in parental and paclitaxel-resistant ovarian cancer cells.

<p>(A) Proliferating human ovarian cancer cells (SKOV-3, OVCAR-3, and A2780-1A9) and paclitaxel-resistant sublines (SKOV-3-TR, OVCAR-3-TR, and 1A9-PTX10) were treated with BPR0L075 (red circle) or paclitaxel (blue square) at 3–15 nM concentrations for 4 days and the cytotoxicity was evaluated by SRB assay. Fraction of cell survival relative to controls represents mean ± SD of 12 determinations. (B) Summary of the P-gp expression, βIII-tubulin expression, and sensitivity of paired ovarian cancer cell lines to paclitaxel, doxorubicin, and BPR0L075 treatment. Numbers in parenthesis represents the degree of resistance (x-fold), expressed as the ratio of the IC₅₀ values as compared with the corresponding parental lines. All experiments were repeated three times.