Fig 6. MENA isoforms confer resistance to paclitaxel by increasing MAPK signaling.

(A) Representative Western Blot for pERK Y204 for in 231-Control, MENA or MENA^INV cells treated with vehicle (0.01% DMSO), 10 or 100nM paclitaxel for 72h. Loading control is GAPDH. (B) Quantification of Western Blot shown in A, for pERK relative to GAPH. Data pooled from 4 experiments, two technical replicates per experiment. 231-Control (C), 231-MENA (D) and 231-MENA^INV (E) cells were treated with varying combinations of MEKi PD0329501 and paclitaxel for 72h, after which cell count was measured (shown as numbers and heatmap as a fraction of the max cell count for each plate). (F) Representative Western Blot for pERK Y204 for 231-MENA^INV cells treated with vehicle (0.01% DMSO), 10nM paclitaxel, 0.1 μM PD0329501 alone or in combination for 72h. Loading control is GAPDH. (G) Representative images 231-MENA^INV cells with vehicle (0.01% DMSO), 10nM paclitaxel, 0.1 μM PD0329501 alone or in combination for 24h, and immunostained for detyrosinated or Glu-Tubulin (red) and tyrosinated or Tyr-Tubulin (green). Scale bar is 1μm, 0.25 μm in inset. (H) Quantification of the ratio of Glu-MT relative to Tyr-MT in 231-MENA^INV cells treated with vehicle (0.01% DMSO) or 10nM paclitaxel for 24h. Data pooled from 3 separate experiments, at least 8 cells analyzed per experiment. Data presented as mean± SEM. Statistics determined by one-way ANOVA, where *** p<0.001, ** p<0.01, * p<0.05.