MiR-145 inhibits the lung adenocarcinoma initiating cells genesis via regulating epithelial-mesenchymal transition progress

Abstract

Objective To investigate whether microRNA-145 (miR-145) could regulate the lung adenocarcinoma initiating cells genesis by using A549 cell line,and the possible molecular mechanisms.Methods The initiating cells microspheres were derived from the serum-free-cultured A549 celld.Pre-miR-145 mimics and anti-miR-145 inhibitor were transfected into A549 initiating cells microspheres by Lipofectamine 2000.The number of A549 initiating cell microspheres was counted by light microscopy,and the percent of CD133 + cells wsd measured by flow cytometry.Western blotting was applied for determining the protein levels of epithelial-mesenchymal transition (EMT) related proteins:Snail,Slug (EMT-related transcription factor),Cytokeratin 18,E-cadherin (epithelial markers) and N-cadherin,Vimentin (mesenchymal markers).Results As compared with the control group,the percent of CD133 + cells was remarkably decreased in Pre-miR-145 mimics groups [(25.39 ± 12.37) ％ vs (43.70 ± 17.58) ％,(P ＜0.05)],whereas significantly increased in the anti-miR-145 inhibitor groups [(58.89 ± 23.54) ％ vs (45.60 ± 18.58)％,(P ＜ 0.05)].The overexpression of miR-145 led to the downregulation of Snail,Slug,Vimentin and N-cadherin,but the upregulation of E-cadherin and Cytokeratin 18.However,repressing miR-145 apparently up-regulated the Snail,Slug,Vimentin and N-cadherin,and down-regulated the Ecadherin and Cytokeratin 18.Conclusion miR-145 can inhibit the A549 initiating cells genesis,which might be controbuted to the regulation of EMT pathway. Key words: Lung cancer; miR-145; Epithelial-mesenchymal transition