Fig. 3.
Elevated MDR1 expression is responsible for paclitaxel-resistance of EKVX cells expressing a wild-type LKB1. (A) Immunofluorescence assay of microtubule morphological changes after treatment with 0, 10, 50nM paclitaxel for 48hrs in EKVX isogenic cell lines. Original magnification 100×, green signaling for α-tubulin, and blue for nuclei. This experiment was repeated twice. (B) Mitotic index of EKVX isogenic cells after treated with 100nM taxol at 24 hrs (two-tail t-test, *P<0.01, **P<0.01 vs EKVX-LKB1-WT group). (C) Immunoblotting analysis of MDR1 protein expression in EKVX isogenic cell lines. (D) Annexin V-7AAD flow cytometry analysis of EKVX isogenic cell lines after treated with 4μM PSC833, 80nM paclitaxel, or the combination of these two drugs for 48 hrs. Experiments in panel B-C were repeated three times.