Breast cancer is the most common cancer in women and a leading cause of cancer‑associated mortalities in the world. Epithelial‑to‑mesenchymal transition (EMT) serves an important role in the process of metastasis and invasive ability in cancer cells, and transforming growth factor β1 (TGF‑β1) have been investigated for promoting EMT. However, in the present study, the role of the sphingomyelin synthase 1 (SMS1) in TGF‑β1‑induced EMT development was investigated. Firstly, bioinformatics analysis demonstrated that the overexpression of SMS1 negatively regulated the TGFβ receptor I (TβRI) level of expression. Subsequently, the expression of SMS1 was decreased, whereas, SMS2 had no significant difference when MDA‑MB‑231 cells were treated by TGF‑β1 for 72 h. Furthermore, the present study constructed an overexpression cells model of SMS1 and these cells were treated by TGF‑β1. These results demonstrated that overexpression of SMS1 inhibited TGF‑β1‑induced EMT and the migration and invasion of MDA‑MB‑231 cells, increasing the expression of E‑cadherin while decreasing the expression of vimentin. Furthermore, the present study further confirmed that SMS1 overexpression could decrease TβRI expression levels and blocked smad family member 2 phosphorylation. Overall, the present results suggested that SMS1 could inhibit EMT and the migration and invasion of MDA‑MB‑231 cells via TGF‑β/Smad signaling pathway.
Keywords: sphingomyelin synthase 1; transforming growth factor β1; epithelial-to-mesenchymal transition; MDA-MB-231 cells.