RESUMO
OBJECTIVE: To investigate the expression profile of long non-coding RNA H19 (LncRNA H19) in tamoxifen-resistant breast cancer cell lines, and to study its biological functions on cell invasion. METHODS: Quantitative reverse-transcription PCR(Q-PCR) was performed to detect the expression of LncRNA H19 in MCF-7W and MCF-7R cells. To further explore its biological function, RNA interference was applied. siRNA H19 was transfected to down-regulate H19 expression, and transfection efficiency was evaluated by Q-PCR. The epidermal mesenchymal transition-related transcription gene Snail 2 was also evaluated by Q-PCR. Transwell assay was performed to evaluate the effect of H19 expression on invasion potential of MCF-7R cells. RESULTS: Compared with MCF-7W cells, MCF-7R cells exhibit a relatively high expression of lncRNA H19 and Snail2. LncRNA H19 expression was down-regulated in MCF-7R after transfection of siRNA H19 for 24 h. Snail 2 mRNA expression was significantly inhibited after down regulating H19 expression (P<0.01). Transwell assay indicated that inhibition of LncRNA H19 by siRNA H19 could repress cell invasion (P<0.01). CONCLUSION: The expression of LncRNA H19 is significantly up-regulated in MCF-7R, and its downregulation attenuated the invasion behavior and related gene expression of tamoxifen-resistant breast cancer cell. H19 may be a drug treatment target of tamoxifen-resistant breast cancer metastasis.