Fig 3.

The Raf-MEK-ERK signaling pathway downstream of activated K-Ras is not required for invadopodia, but pharmacological inhibition of PI3K decreases invadopodium activity. (A) Western blot analysis for phospho-ERK 1/2 (pERK1/2), total ERK, and vinculin of CFPAC-1, PANC-1, and HPNE-K-Ras cell lysates following treatment with 10 μM U0126 for 24 h. (B and C) Number of invadopodia per cell (B) and percentage of invadopodium-positive cells (C). (D) Western blot analysis for phosphoserine 473 Akt (pS473 Akt), total Akt, and vinculin of CFPAC-1 and PANC-1 cell lysates following treatment with 10 μM LY294002 for 24 h. (E and F) Number of invadopodia per cell (E) and percentage of invadopodium-positive cells (F). Statistically significant differences between dimethyl sulfoxide (DMSO)- and LY294002-treated cells, as determined by a Mann-Whitney U test, are indicated by three asterisks (P value < 0.005). Ten fields (containing 15 to 40 cells each) per condition were used for all quantitation. Data are means ± SEM. Data shown are representative of at least two independent experiments.