Fig 2: WS-716 stimulated ATP hydrolysis without changing the expression or subcellular localization of P-glycoprotein (P-gp). (A) WS-716 did not change the protein level of P-gp in SW620/Ad300 cells. (B) Effect of WS-716 on the subcellular localization of P-gp (green) after treatment for 76 h. The cell nuclei (blue) were stained by Hoechst 33258. The scale bar is 10 µm. (C) WS-716 stimulated ATP hydrolysis and reached the maximal value at 20 µmol/L. Data are presented as the mean ± SD, n = 3.

Fig 3: WS-716 reversed multidrug resistance mediated by P-glycoprotein (P-gp). (A) Chemical structure of WS-716. (B) P-gp was up-regulated in SW620/Ad300 cells. (C) WS-716 and verapamil (VPM) below 30 µmol/L had little inhibitory effect on the viability of SW620/Ad300 cells. (D) WS-716 significantly increased the sensitivity of SW620/Ad300 cells to paclitaxel (PTX) at 20 µmol/L. (E) P-gp was up-regulated in KB-C2 cells. (F) P-gp was over-expressed in HEK293/ABCB1 cells. ß-Actin was used as the loading control. Data are presented as the mean ± SD, n = 3.