[Features of epithelial-to-mesenchymal transition in nasal polyposis].

Objective: To detect the expression of epithelial-to-mesenchymal transition (EMT) biomarkers in nasal polyposis (NP) and to determine the effect of transforming growth factor β1 (TGF-β1) on EMT in cultured nasal epithelial cells.

Methods: The specimens were obtained from sinus mucosa of 10 NP patients and inferior turbinate mucosa of 10 nasal septum deviation patients. The difference of mRNA expression of E-cadherin, β-catenin , zonula occludens 1 (ZO-1), vimentin and α-smooth muscle actin (α-SMA) in tissue and cultured nasal epithelial cells was detected by real-time PCR. The difference of protein exprssion of E-cadherin and vimentin in cultured nasal epithelial cells was detected by Western blot.SPSS 16.0 software was used to analyze the data.

Results: The relative expression of E-cadherin and ZO-1 in NP tissues (0.012±0.007; 0.006±0.003) was higher than in normal nasal mucosa (0.041±0.024; 0.011±0.005), the difference was significant (t=3.675, P<0.01; t=2.956, P<0.05). However, there was no significant difference in the relative expression of β-catenin, vimentin and α-SMA between two groups (t value was 0.990, 0.429, 0.326, all P>0.05). In cultured nasal epithelial cells both from two groups, TGF-β1 induced the decreased E-cadherin, ZO-1 (tcontrol value was 3.639, 3.430, both P<0.05; tNP value was 3.279, 2.864, both P<0.05) and increased α-SMA, vimentin mRNA expression (tcontrol value was -6.393, -3.085, all P<0.05; tNP value was -2.981, -3.087, both P<0.05). Also, TGF-β1 induced the decreased E-cadherin and increased vimentin protein expression (tcontrol value was 3.583, -3.844, both P<0.05; tNP value was 5.113, -3.642, both P<0.05).

Conclusion: EMT is likely to contribute to nasal polyposis and TGF-β1 is involved in this process.