Fig. 1

Snail is required for induction of EMT by lactate in lung cancer cells. a Western blot examines epithelial marker E-cadherin, mesenchymal markers N-cadherin, Fibronectin, Vimentin, and EMT inducer Snail, Twist and Slug expression following 3 h of lactate (0, 5, 10, 15, 20 and 30 mM) stimulation in different histological non-small-cell lung cancer cell lines (A549 and H1299). Snail was dose-dependently increased by lactate treatment. b Wound Healing Assay and (c) Cell Invasion Assays reveal a dose-dependent (lactate 0, 10, 20 mM) and time dependence (0, 48, 72 h) increase in cell migratory as well as invasiveness (upper panel). The quantification was present in lower panel. The bars represent the mean ± s.d. of triplicates (*P < 0.05, **P < 0.01 for difference from untreated control by ANOVA with Dunnett’s correction for multiple comparisons). d The cell migration of A549 and H1299 after transfection of Snail siRNAs and lactate treatment (lactate 0, 10, 20 mM) was assessed by the Wound healing assay. Wound healing was quantified using image-Pro Plus software and the bars represent the mean ± s.d. of triplicates (*P < 0.05, **P < 0.01 for difference from untreated control by ANOVA with Dunnett’s correction for multiple comparisons). e The cell invasion and motility of A549 and H1299 after transfection of Snail siRNAs and lactate treatment was assessed by the Cell Invasion and Motility Assays. Representative pictures (magnification 100×) of the cell invasion and motility experiment showing the cells cling to the bottom of the polycarbonate membrane after 48 h of incubation (upper panel). Cell Invasion and Motility Assays was quantified using image J software and the bars represent the mean ± s.d. of triplicates (lower panel) (***P < 0.001, for difference from untreated control by ANOVA with Dunnett’s correction for multiple comparisons)