Figure 3

GM-CSF induces EMT program through MAPK/ERK-ZEB1 signaling pathway. (a) SW480 cell line was stimulated with GM-CSF (25 ng/ml) for 5–120 min. At the indicated timepoints, the proteins were extracted and the phosphorylation of ERK1/2 and NF-κB p65 subunit was detected by immunoblotting. Representative data of cropped blots from three independent experiments were shown. (b) ERK1 and 2 in SW480 cell line were knockdown by RNA interference and cells were stimulated with GM-CSF (25 ng/ml) for three weeks. The expression of E-cadherin, N-cadherin, fibronectin and ZEB1 was examined by immunoblotting. Cropped blots were shown. (c,d) ERK1 and 2-knockdown SW480 cell line was treated with GM-CSF as described above. The ability of migration (c) and invasion (d) was detected by transwell experiments. (e) ZEB1 in SW480 cell line was knockdown by RNA interference and cells were stimulated with GM-CSF as described above. The expression of E-cadherin, N-cadherin, fibronectin and ERK1/2 was examined by immunoblotting. Cropped blots were shown. (f) ZEB1-knockdown SW480 cell line was treated with GM-CSF as described above. The ability of migration and invasion was detected by transwell experiments. Upper: representative images were shown. Bottom: the data were pooled from two experiments. EV: empty vector. **P <  < 0.01; ***P < 0.001 vs EV controls.