Figure 4. Paclitaxel combined with MWE induced PTEN activation and expression in TSGH 8301 cells.

(a) Cytoplasmic lysates were prepared from TSGH 8301 cells treated with paclitaxel, MWE or both together at 48 hr and subjected to Western blotting analysis for the levels of PTEN. (b) TSGH 8301 cells were pre-treated with PTEN inhibitor SF1670 (2 μM) for 24 hr followed by paclitaxel, MWE or both together, as indicated. Cytoplasmic lysates were prepared and subjected to the detection of PTEN and EEA1 expression by Western blot analysis at 48 hr. (c) TSGH 8301 cells were pre-exposed to PTEN inhibitor SF1670 (2 μM) for 24 hr before treatment with paclitaxel, MWE or both together for 48 hr. The cells were harvested and subjected to cell cycle distribution analysis by flow cytometry. (d) TSGH 8301 cells were pre-treated with the PTEN inhibitor SF1670 (2 μM) and then treated with the indicated concentrations of paclitaxel, MWE or both for 24, 48 and 72 hr. The cells were harvested and subjected to an MTT assay for cell viability analysis. The data are expressed in means ± SD as a percentage of the control (not treated). One-way ANOVA with post-hoc Dunnett’s test was used to calculate the p value for each treatment compared to paclitaxel alone, (⁺p < 0.05; ⁺⁺p < 0.01) and between time points (^*p < 0.05; ^**p < 0.01). (e) and (f ) TSGH 8301 cells were treated with paclitaxel, MWE or both together for 72 hr and then subjected to quantitation of the cell cycle distribution by flow cytometry and Western blotting analysis for the detection of Caspase 3. The numbers under each blot of (a), (b) and (f ) are the intensity of each band relative to that of the control (not treated) or paclitaxel alone. β-actin was used as the protein loading control. The results shown are representative of three independent experiments with similar results.