[Inverse correlation between Snail and E-cadherin expression in carcinoma cell lines and invasive ability in vitro]

Malignant transformation of epithelial cell frequently coincides with loss of E-cadherin. Here we study the expression of Snail and E-cadherin and correlate their expression with cell differentiation and in vitro invasion.

The expression and localization of Snail and E-cadherin were studied by Northern blot and laser confocal microscopy in two normal cell lines (MDCK, NIH 3T3) and six carcinoma cell lines (A431, MCF-7, MDA-MB-453, HepG2, MDA-MB-435s, MDA-MB-231). Boyden chamber assay was done to detect the invasive ability of cells in vitro.

Snail mRNA and protein were detected in fibroblasts NIH 3T3 and poorly differentiated carcinoma cell lines HepG2, MDA-MB-435s and MDA-MB-231. On the contrary, E-cadherin mRNA and protein were detected in normal epithelial cell line MDCK and well differentiated carcinoma cell lines A431 and MDA-MB-453. In MCF-7 cells, Snail and E-cadherin expressions were revealed both at mRNA and protein levels. The cells with higher expression of Snail had stronger ability of invasion than those with lower expression of Snail.

There is an inverse correlation between Snail and E-cadherin expressions and their expressions are correlated with cell differentiation and tumor invasiveness.