RÉSUMÉ
BACKGROUND: The lncRNA HOTAIR is frequently overexpressed in breast cancer tissues and plays an important role in the development of breast cancer. Here, we investigated the effect of the lncRNA HOTAIR on the biological behaviour of breast cancer cells and its molecular mechanism. METHODS: We investigated the level of HOTAIR in breast cancer and its clinical pathological characteristics by bioinformatic methods. Then, we evaluated the effects of HOTAIR and miRNA-1 expression on the biological behaviour of breast cancer cells by qPCR, Cell Counting Kit-8 (CCK-8) assay, clonogenic assays, Transwell assay and flow cytometry for cell proliferation, invasion migration and apoptosis, and cell cycle analysis. Finally, the target genes of the lncRNA HOTAIR/miR-1/GOLPH3 regulatory axis were validated by luciferase reports. RESULTS: The expression of HOTAIR in breast cancer tissues was significantly higher than that in normal breast tissues (P < 0.05). Silencing of HOTAIR suppressed cell proliferation, invasion and migration, promoted apoptosis and induced G1 phase block in breast cancer (P < 0.0001). We also verified that miR-1 is a target of HOTAIR and that GOLPH3 is a target of miR-1 by luciferase reporter assays (P < 0.001). CONCLUSIONS: The expression of HOTAIR was significantly elevated in breast cancer tissues. Reducing the expression of HOTAIR inhibited the proliferation, invasion and migration of breast cancer cells and promoted apoptosis, and the mechanism was mainly the effect of the lncRNA HOTAIR/miR-1/GOLPH3 regulatory axis on the biological behaviour of breast cancer cells.