Abstract
Chrysin (ChR) inhibits various cancer cells and possesses anti-inflammatory activities. NF-kB has been shown to regulate the expression of genes involved in epithelial-mesenchymal transformation (EMT) by upregulation of TWIST1. This study aimed to assess whether ChR can inhibit EMT phenotype and cancer stem-like cell (CSLC) features in ovarian cancer cells co-treated with TNF-α and TGF-β. Here, OVCAR-3 cells were co-treated with TNF-α and TGF-β in the presence or absence of ChR. Then, the expression levels of E-cadherin, N-cadherin, CD133, CD44, NF-κBp65, and TWIST1 were analyzed by western blotting. Wound healing and tumor sphere formation assays were performed to assess the migration and sphere-forming capabilities of cells, respectively. Overexpression and/or knockdown of NF-κBp65 and/or TWIST1 were used to explore the molecular mechanisms. We showed that ChR inhibited EMT and CSLC properties in ovarian cancer cells administered TNF-α after prolonged TGF-β treatment, in a dose-dependent manner. Also, knockdown of NF-κBp65 and ChR cooperatively enhanced the inhibition of NF-κBp65 and TWIST1 expression, EMT phenotype, and CSLC properties. Conversely, overexpression of NF-κBp65 antagonized the above-mentioned activities of ChR. Furthermore, TWIST1 silencing or overexpression did not affect the ChR treatment effect on NF-κBp65 levels, but it reduced or enhanced EMT and CSLC properties. In conclusion, ChR can inhibit a proinflammatory cytokine to induce EMT and CSLC characteristics in OVCAR-3 cells, which may be involved in blocking the NF-κB/Twist axis.