We used qRT-PCR to assess Snail mRNA expression directly in Caco-2 colon cancer and MDA-MB-231 breast cancer cells stimulated for 24h with alcohol. As seen in Figs.4B and 4C (upper sections), for Caco-2 cells the values for fold increase in Snail mRNA expression were 0.1%–7.5, 0.2%–8.5, and 1%–11.6 fold. To identify possible mechanisms stimulating Snail mRNA expression Caco-2 cells were also treated with an EGFR inhibitor AG1478 + 1% alcohol which blocked stimulation by 75% (2.8 fold vs. 11.6 fold). For MDA-MB-231 cells alcohol stimulated Snail mRNA expression by 0.2%–5.4 and 1%–8.2. Total Snail protein in cells stimulated under the same conditions (lower sections 4B and 4C) were: Caco-2: 0.1%–4.8, 0.2%–3.5, 1.0%–4.1, and 1.0%+ EGFR inhibitor 0.8 (inhibited 80%) and for MDA-MB-231: 0.2%–7.8, 1.0%–8.5 (p ≤ .05 for all increases and the EGFR inhibition, ANOVA with Dunnett post Hoc test).
