Abstract: Objective To investigate the correlation between miR-221 and epithelial-mesenchymal transition (EMT) in
drug-resistant glioma cells. Methods The expression levels of miR-221, PTEN, p-Akt, E-cadherin, vimentin, and MRP1 were
quantitatively analyzed in Z1 cells (primary drug-resistant cells), Z2 cells (drug-sensitive cells) and Z2-BCNU cells
(drug-resistant cells) using fluorescent real-time PCR and Western blotting. Results The expression levels of PTEN were
significantly increased in Z2 cells compared with Z1 and Z2-BCNU cells which overexpressed miR-221 and vimentin. The
expression levels of vimentin, p-Akt and MRP1 were significantly decreased in Z2 cells overexpressing E-cadherin.
Conclusion MiR-221 regulates the expression of EMT-related genes through down-regulation of PTEN and activation of PI3-K/
Akt signaling.