Objective To investigate the effect and molecular mechanism of receptor tyrosine kinase-like orphan receptor (ROR1) on epithelial-mesenchymal transition(EMT) in human lung cancer A549 cells.

Methods Lung cancer A549 cells were transfected with ROR1 lentiviral expression vector; the abilities of invasion and migration were detected by wound healing assay and Transwell assay. The expression of ROR1 and EMT-associated markers were analyzed by real-time PCR and Western blot.

Results The overexpression of ROR1 could induce morphological alteration of A549 cells from epithelial morphology to mesenchymal morphology. Western blot results demonstrated that the expression of mesenchymal makers N-cadherin and Vimentin were increased but epithelial marker E-cadherin was decreased. Wound healing and Transwell assay showed that the number of invasive and migrated A549 cells was significantly increased (P=0.0023). Moreover, ROR1 overexpression significantly increased the expression of EMT-related transcription factor Snail. The knockdown of Snail reversed ROR1-induced EMT, decreasing the expression of N-cadherin and Vimentin, but increasing E-cadherin expression. Wound healing and Transwell assay showed that the knockdown of Snail significantly decreased the invasion and migration of A549 cells(P=0.013). Furthermore, the activation of AKT contributed to ROR1-mediated regulation of Snail.

Conclusion ROR1 could promote EMT in A549 cells, which is related to the activation of AKT/Snail signaling.