licochalcone-a and Head-and-Neck-Neoplasms

We investigated Licochalcone-A (Lico-A)-induced apoptosis and the pathway underlying its activity in a pharyngeal squamous carcinoma FaDu cell line. Lico-A purified from root of Glycyrrhiza inflata had cytotoxic effects, significantly increasing cell death in FaDu cells. Using a cell viability assay, we determined that the IC50 value of Lico-A in FaDu cells was approximately 100 µM. Chromatin condensation was observed in FaDu cells treated with Lico-A for 24 h. Consistent with this finding, the number of apoptotic cells increased in a time-dependent manner when FaDu cells were treated with Lico-A. TRAIL was significantly up-regulated in Lico-A-treated FaDu cells in a dose-dependent manner. Apoptotic factors such as caspases and PARP were subsequently activated in a caspase-dependent manner. In addition, levels of pro-apoptotic factors increased significantly in response to Lico-A treatment, while levels of anti-apoptotic factors decreased. Lico-A-induced TRAIL expression was mediated in part by a MAPK signaling pathway involving ERK1/2 and p38. In xenograft mouse model, Lico-A treatment effectively suppressed the growth of FaDu cell xenografts by activating caspase-3, without affecting the body weight of mice. Taken together, these data suggest that Lico-A has potential chemopreventive effects and should therefore be developed as a chemotherapeutic agent for pharyngeal squamous carcinoma.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Caspase 3; Caspase 7; Cell Line, Tumor; Cell Survival; Chalcones; Chemoprevention; Glycyrrhiza; Head and Neck Neoplasms; Humans; Inhibitory Concentration 50; Keratinocytes; Male; Mice; Mice, Nude; Mitogen-Activated Protein Kinase 3; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Plant Extracts; Plant Roots; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; TNF-Related Apoptosis-Inducing Ligand; Xenograft Model Antitumor Assays