Abstract: Objective To investigate the role of urothelial carcinoma antigen 1 (UCA1) in regulation of invasion, migration and epithelial-mesenchymal transition (EMT) of trophoblast HTR-8/SVneo cells and its association with tubal pregnancy. Methods Cultured HTR- 8/SVneo cells stimulated with interleukin-6 (IL-6) were examined for changes in UCA1 expression and cell migration ability using qRT-PCR and scratch assay, respectively. A HTR-8/SVneo cell model with UCA1 silencing was constructed by transient transfection, and the migration and invasion abilities of the cells were assessed using Scratch assay and Transwell assay; qRT-PCR and Western blotting were performed to detect the mRNA and protein expression levels of EMT markers. Results HTR-8/SVneo cells stimulated with IL-6 exhibited significantly increased migration ability and up-regulated expression of UCA1 (P<0.01). UCA1 silencing obviously suppressed migration and invasion abilities of HTR-8/SVneo cells (P<0.01), significantly up-regulated the mRNA and protein expressions of EMT epithelial marker E-cadherin (P<0.01), and down-regulated the expressions of the mesenchymal markers integrin β3, vimentin and N-cadherin (P<0.05). Conclusion UCA1 may be a key gene that promotes the occurrence of tubal pregnancy and thus provides a new therapeutic target for tubal pregnancy.

Key words: tubal pregnancy; urothelial carcinoma antigen 1; migration; invasion; epithelial-mesenchymal transition