Licocoumarone induces BxPC-3 pancreatic adenocarcinoma cell death by inhibiting DYRK1A.

Protein kinases play an indispensable role in signaling pathways that regulate tumor cell functions, which represent potent therapeutic targets in cancers. Dual-specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) as a serine/threonine kinase has recently been reported to be upregulated in pancreatic ductal adenocarcinoma (PDAC) and show protumorigenic effect. By activity-guided phytochemical investigation of the extracts from Glycyrrhiza uralensis Fisch, we expect to find the effective constituents that can suppress pancreatic cancer cell proliferation and/or induce cells apoptotic by inhibiting DYRK1A. Eight isopentenyl-substituted compounds (1-8), including four coumarins (1-4), one benzofuran (5), and three flavonoids (6-8), were isolated and identified from G. uralensis Fisch. Among them, licocoumarone (LC, 5) showed effective inhibitory activity against DYRK1A with an IC₅₀ value of 12.56 μM. Molecular docking analysis suggested that LC completely occupied the whole pocket of DYRK1A and formed obvious hydrophobic interactions and hydrogen bonds with DYRK1A residues. Further in vitro validation, including Microscale Thermophoresis (MST) and drug affinity responsive target stability (DARTS) techniques, demonstrated the specific combining capacity of LC to DYRK1A. Meanwhile, LC induced significant cytotoxicity against DYRK1A-overexpressing BxPC-3 cells with an IC₅₀ value of 50.77 μM. Mechanism studies revealed that LC reduced c-MET protein level by inhibiting DYRK1A. These findings provide preliminary evidences that LC as a natural DYRK1A inhibitor suppresses human pancreatic adenocarcinoma BxPC-3 cell proliferation and induces cell apoptotic, which might present new options and possibilities for targeted therapies in pancreatic cancer therapy.