Аннотация:Abstract Epithelial–mesenchymal transition (EMT) is an essential step for cancer metastasis. MicroRNAs (miRNAs) are small non‐coding RNAs that regulate target‐mRNAs post‐transcriptionally. The expression and function of miRNAs in EMT of HT‐29 colonic cells remain elusive. This study looks at expression of miRNAs in EMT and explores the effects of miRNAs on EMT in HT‐29 cell line. HT‐29 was treated with TGF β to establish an EMT model, in which a collection of miRNAs was dynamically regulated by real‐time PCR (qPCR) analysis. Among them, miR‐21 and miR‐27 were significantly upregulated, while miR‐22, miR‐26, miR‐30, miR‐181, miR‐200b, miR‐200c and miR‐214 were markedly downregulated. MiRNA‐inhibitors were used to knockdown miRNAs in HT‐29 and EMT markers were determined by qPCR to monitor the effects of miRNAs on EMT process. Results showed that miR‐22 could not alter the expression of EMT markers, while knockdown of miR‐200b could significantly increase that of epithelial markers, N‐cadherin , Vimentin , α‐Sma and Twist1 and decrease that of mesenchymal marker, E‐cadherin . Bioinformatic analysis and Western blot showed that ZEB1 was directly suppressed by miR‐200b. In conclusion, miRNAs are dynamically regulated in TGF β‐induced EMT of HT‐29 and miR‐200b was essential for EMT by suppressing the expression of ZEB1 in HT‐29.
