Abstract: OBJECTIVE：To investigate mechanisms of RNA-binding motif protein X-linked(RBMX) on biological behavior of esophageal cancer cells in vitro. METHODS：Logarithmic Eca109 cells in culture were divided into control and experimental groups. Lipofectamine^TM 3000 was used to transfect small interfering RNA (siRNA) and overexpression vector of RBMX. The mRNA and protein expression levels of RBMX were detected by RT-qPCR and Western blot，respectively. CCK-8，Transwell and Western blot were used to detect changes of cell proliferation， migration and EMT marker protein expression after transfection. RESULTS： Following transfection with RBMX siRNA， the mRNA and protein expression levels of RBMX in Eca109 cells were markedly reduced compared to the control group (P<0.05). Conversely， transfection with the overexpression vector resulted in a significant increase in RBMX mRNA and protein expression levels (P<0.05). After 24 hours of siRNA transfection，proliferation and migration of Eca109 cells were significantly inhibited (P<0.05)， accompanied by an increase in E-cadherin protein expression and a decrease in N-cadherin and Vimentin protein expression (P<0.05). In contrast，48 hours post-transfection with the overexpression vector，proliferative and migratory capabilities of Eca109 cells were notably enhanced (P<0.05)，with decreased E-cadherin protein expression and increased N-cadherin and Vimentin protein expression (P<0.05). CONCLUSION： RBMX influenced the proliferation and migration of Eca109 cells in vitro，potentially contributing to esophageal cancer development through its impact on the epithelial-mesenchymal transition process.

Key words: esophageal squamous cell carcinoma, RNA binding motif protein X-linked, siRNA, epithelialmesenchymal transition