AEG-1 3′-untranslated region functions as a ceRNA in inducing epithelial-mesenchymal transition of human non-small cell lung cancer by regulating miR-30a activity

Competitive endogenous messenger RNA regulates the transcription of other RNA moleculars through competing for the shared microRNAs. This study was carried out to explore the regulation of AEG-1 messenger RNA as a competitive endogenous RNA in the epithelial-mesenchymal transition and metastasis of lung tumor cells. It is shown that the epithelial-mesenchymal transition was associated with the down-regulation of miR-30a, up-regulation of AEG-1 and mesenchymal markers (Snail and Vimentin); miR-30a inhibited the metastasis of lung tumor A549 cells in vitro, whereas AEG-1 promoted it. These results suggested the potential linkage between miR-30a and genes (AEG-1, Snail and Vimentin) in the epithelial-mesenchymal transition and metastasis of lung tumor cell. It was verified later that the 3′-untranslated regions of AEG-1, Snail and Vimentin bind to miR-30a in A549 cells. Therefore, a competitive endogenous RNAs regulatory network among AEG-1, Snail and Vimentin mediated via competitive binding to miR-30a was proved. That is, the 3′-untranslated region of AEG-1, functioning as the competitive endogenous RNAs, indirectly regulated the expression of Vimentin and Snail in inducing epithelial-mesenchymal transition of human non-small cell lung cancer. In conclusion, our findings demonstrated a competitive endogenous RNAs regulatory network which will help understand the metastasis mechanisms of lung cancer and improve the prevention and treatment of lung cancer.