Figure 4.

The inhibition of 5-LO significantly attenuated paclitaxel resistance in MCF-7/DOX cells. (A and E) MCF-7/DOX cells were incubated in the presence of 0.5% serum for 3 h and then were pre-treated with AA861 (10 μℳ) (A) or baicalein (20 μℳ) (E) for 30 min before paclitaxel (1 μℳ) treatment for 48 h. Cell morphology was visualised using an Olympus BX51 microscope at × 40 magnification. Scale bars, 50 μm. (B and F) MCF-7/DOX cells were pre-treated with AA861 (5 or 10 μℳ) (B), baicalein (10 or 20 μℳ) (F), or DMSO for 30 min, and then were treated with or without paclitaxel (1 μℳ) for 48 h. Cell viability was quantified using an MTT assay. (C and G) MCF-7/DOX cells were pre-treated with AA861 (5 or 10 μℳ) (C), baicalein (10 or 20 μℳ) (G), or DMSO for 30 min, and were then treated with or without paclitaxel (1 μℳ) for 48 h for determination of cell apoptosis by flow cytometric analysis of the sub-G₁ population. All quantitative data are the mean±s.d. of three independent experiments. *P<0.05, †P<0.01, ‡P<0.005. (D and H) MCF-7/DOX cells were pre-treated with AA861 (5 or 10 μℳ) (D), baicalein (10 or 20 μℳ) (H), or DMSO for 30 min, and were then treated with or without paclitaxel (1 μℳ) for 48 h for determination of cell apoptosis by PARP cleavage. The data are representative of three independent experiments.