Eupalinilide B as a novel anti-cancer agent that inhibits proliferation and epithelial-mesenchymal transition in laryngeal cancer cells

Objective To investigate the anti-cancer effects and potential mechanisms of eupalinilide B in laryngeal cancer cells. Methods Laryngeal cancer cell lines were selected to study the anti-tumor effects of eupalinilide B in vitro and in vivo. Lysine-specific demethylase 1 (LSD1) activity was assessed in vitro and dialysis experiments were performed to identify the anti-tumor target of the drug. Results Eupalinilide B concentration-dependently inhibited the proliferation of laryngeal cancer cells, exhibiting potent inhibitory activity against TU686 (IC50 = 6.73 mu M), TU212 (IC50 = 1.03 mu M), M4e (IC50 = 3.12 mu M), AMC-HN-8 (IC50 = 2.13 mu M), Hep-2 (IC50 = 9.07 mu M), and LCC cells (IC50 = 4.20 mu M). Subsequent target verification experiments demonstrated that eupalinilide B selectively and reversibly inhibited LSD1. Furthermore, eupalinilide B, as a natural product, suppressed epithelial-mesenchymal transition in TU212 cells. An in vivo experiment further indicated that eupalinilide B could significantly reduce the growth of tumors in TU212 xenograft mouse models. Conclusions Eupalinilide B might be a novel LSD1 inhibitor for treating laryngeal cancer.