MiR-30a Suppresses SiO₂ Dust-induced EMT In A549 Cells By Targeting Transcription Factor Snail

Objective:We established an in vitro model of SiO₂-induced epithelial-mesenchymal transition（EMT）in A549 cells to investigate the role of miR-30a in regulating SiO₂-induced EMT by targeting transcription factor Snail and its mechanism.Methods:A549 cells were stimulated with SiO₂ dust suspension to establish the in vitro model of EMT.The miR-30a mimic and miR-30a inhibitor were used to interfere the EMT that induced by SiO₂ dust,and the cell transfection technique was used to silence SNAIL gene in A549 cells.Cell viability was detected by MTT method.The RNA and protein expression of E-cadherin（E-cad）,alpha-smooth muscle actin（α-SMA）,Vimentin,Snail were determined by q RT-PCR and Western Blot.Immunofluorescence was used to detect the expression and distribution of E-cad andα-SMA in A549 cells.Dual luciferase reporter gene assays were used to explore the targeting relationship between Snail and miR-30a in SiO₂-induced EMT in A549 cells.Results:Combined with the results of cell viability and EMT-related protein expression,50μg/ml SiO₂ dust suspension and 24 h were selected to establish the in vitro model of SiO₂-induced EMT in A549 cells.The expression of miR-30a and E-cad decreased,and the expression ofα-SMA,Vimentin and Snail increased after SiO₂ dust treatment of A549 cells.Mi R-30a mimic increased the expression of E-cad and decreased the expression ofα-SMA,Vimentin and Snail,while miR-30a inhibitor function conversely.Silencing of SNAIL gene in A549 cells was able to increase the m RNA and protein expression of E-cad,and decrease the expression ofα-SMA and Vimentin.Conclusions:SiO₂ dust suspension stimulated EMT in A549 cells,and miR-30a inhibited SiO₂ dust-induced EMT by downregulating the expression of transcription factor Snail.Silencing of SNAIL gene in A549cells slowed down SiO₂ dust-induced EMT in A549 cells.