Discovery of a selective and reversible LSD1 inhibitor with potent anticancer effects <i>in vitro</i> and <i>in vivo</i>

Lysine-specific demethylase 1 (LSD1) is abnormally overexpressed in various tumour tissues of patients and has been an attractive anticancer target. In this work, a potent LSD1 inhibitor (compound <b>14</b>) was designed and synthesised by the molecular hybridisation strategy. It displays the potent antiproliferative activity against HepG2, HEP3B, HUH6, and HUH7 cells with IC₅₀ values of 0.93, 2.09, 1.43, and 4.37 μM, respectively. Furthermore, compound <b>14</b> is a selective and reversible LSD1 inhibitor with an IC₅₀ value of 0.18 μM and increases the methylation levels of H3K4me1/2. Molecular docking studies showed that it formed hydrogen bonds, hydrophilic interactions and hydrophobic interactions with residues of LSD1. Anticancer mechanisms demonstrated that it suppresses migration and epithelial-mesenchymal transition process in HepG2 cells. Importantly, it exhibits potent anti-liver cancer effects <i>in vivo</i> without obvious toxic effects. These interesting findings suggested that compound <b>14</b>, a novel LSD1 inhibitor, may be a promising therapeutic agent to treat liver cancer.