Figure 1. Establishment of paclitaxel resistant H460 lung cancer cells and their cross resistance to doxorubicin.

(A) H460 parental and paclitaxel resistant lung cancer cells were plated and treated with indicated concentrations of paclitaxel, images were captured at 10x magnification after 48 hours. (B) Effect of paclitaxel, doxorubicin on H69AR multidrug resistant and H460 parental and derived paclitaxel resistant lung cancer cells after 72 hours of treatment. Percentage viability is calculated relative to vehicle treatment. Data is representative of three independent assays done in triplicate. One-way ANOVA with Dunnett's multiple comparisons post-test, ^***P<0.0001. (C) Clonogenic survival assays with H460 parental and resistant cells treated continuously for 14 days with vehicle or indicated concentration of paclitaxel and doxorubicin. Colony forming ability (%) is calculated from the number of colonies relative to vehicle treatment. Data is representative of three independent assays conducted in triplicate. Two-way ANOVA with Dunnett's multiple comparisons post-test, ^*P<0.05, ^**P<0.001. (D) 3D soft agar tumorigenicity assay with H460 parental and resistant cells treated continuously for 14 days with vehicle or indicated concentration of paclitaxel (colonies indicated in blue). 3D colony forming ability (%) is calculated relative to vehicle treatment. Two-way ANOVA with Dunnett's multiple comparisons post-test, ^*P<0.05. (E) Annexin V staining of H460 cells treated for 48 hours with vehicle or paclitaxel 10 nM. Histogram gate indicates percentage of apoptotic cells after paclitaxel treatment. Black line, Vehicle; Red line, Paclitaxel 10 nM. Results are the representative of three independent experiments.