licochalcone-a and Mouth-Neoplasms

Licochalcone A (Lico-A) is a natural phenol licorice compound with multiple bioactivities, including anti-inflammatory, anti-microbial, anti-fungal and osteogenesis-inducing properties. In the present study, we investigated the Lico-A-induced apoptotic effects and examined the associated apoptosis pathway in KB human oral cancer cells. Lico-A decreased the number of viable KB oral cancer cells. However, Lico-A did not have an effect on primary normal human oral keratinocytes. In addition, the IC50 value of Lico-A was determined to be ~50 µM following dose-dependent stimulation. KB oral cancer cells stimulated with Lico-A for 24 h showed chromatin condensation by DAPI staining, genomic DNA fragmentation by agarose gel electrophoresis and a gradually increased apoptotic cell population by FACS analysis. These data suggest that Lico-A induces apoptosis in KB oral cancer cells. Additionally, Lico‑A‑induced apoptosis in KB oral cancer cells was mediated by the expression of factor associated suicide ligand (FasL) and activated caspase-8 and -3 and poly(ADP-ribose) polymerase (PARP). Furthermore, in the KB oral cancer cells co-stimulation with a caspase inhibitor (Z-VAD-fmk) and Lico-A significantly abolished the apoptotic phenomena. Our findings demonstrated that Lico‑A-induced apoptosis in KB oral cancer cells involves the extrinsic apoptotic signaling pathway, which involves a caspase-dependent FasL-mediated death receptor pathway. Our data suggest that Lico-A be developed as a chemotherapeutic agent for the management of oral cancer.

Topics: Amino Acid Chloromethyl Ketones; Apoptosis; Caspase 3; Caspase 8; Caspase Inhibitors; Cell Line, Tumor; Cell Survival; Chalcones; Chromatin; DNA Fragmentation; Extracellular Signal-Regulated MAP Kinases; Fas Ligand Protein; Flavonoids; Humans; Imidazoles; KB Cells; Keratinocytes; Mouth Neoplasms; p38 Mitogen-Activated Protein Kinases; Poly(ADP-ribose) Polymerases; Protein Kinase Inhibitors; Pyridines; Signal Transduction

The majority of anticancer drugs are of natural origin. However, it is unknown whether licochalcone A is cytotoxic towards oral squamous cell carcinoma (OSCC) cells. The goal of this study was to investigate the cytotoxic effects of licochalcone A on the human OSCC SCC-25 cells and to identify the underlying molecular mechanism. Exposure of SCC-25 cells to licochalcone A dose- and time-dependently decreased cell viability by arresting cell cycle at the S and G2/M phase as well as inducing apoptosis. Furthermore, the proapoptotic activity of licochalcone A was revealed by DNA fragmentation. Concomitantly, we observed activation of the effector caspases-3, induced by activation of the initiator caspases -8 and -9, which subsequent trigger both death receptor pathway and the mitochondrial apoptotic pathway in licochalcone A-mediated SCC-25 cell apoptosis. Besides, treatment with 50 μg/mL of licochalcone A for 36 h led to the cleavage of PARP, an indicator of apoptosis induction. Therefore licochalcone A may be a good candidate for development as a possible chemopreventive agent against OSCC.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Squamous Cell; Caspase 3; Cell Line, Tumor; Cell Survival; Chalcones; G2 Phase; Humans; Mouth Neoplasms; Signal Transduction

Licochalcone A, a major phenolic constituent of the licorice species Glycyrrhiza inflata, has been proven to possess various biological benefits including anti-cancer activity. However, the detailed effects and molecular mechanisms of licochalcone A on the invasiveness and metastasis of oral cancer cells have not been fully understood. Thus, SCC-25 oral cancer cells were subjected to a treatment with licochalcone A at indicated concentrations (25, 50, and 100 μg/mL) for 36 h and then analyzed for the effect of licochalcone A on the cell migration and invasion. In vitro assays, including wound healing, cell adhesion, and cell invasion/migration assays, revealed that licochalcone A treatment significantly inhibited the cell migration/invasion capacities of SCC-25 cells. Also, results of zymography and Western blotting showed that activity and protein level of matrix metalloproteinase-2 (MMP-2) was suppressed, but TIMP-2 level was increased, indicating the important role of MMP-2 and TIPM-2 in anti-metastatic regulation of SCC-25 cells. Furthermore, licochalcone A was shown to suppress the nuclear factor-kappa B (NF-κB) signal, as evidenced by the decreased expression of phosphorylated p65 (p-65) protein in licochalcone A-treated SCC-25 cells. Notably, we also found that licochalcone A treatment increased the expression of the epithelial marker E-cadherin and decreased the expression of mesenchymal markers N-cadherin in SCC-25 cells. This is the first report describing the effects and possible mechanisms of licochalcone A on tumor invasion and metastasis of SCC-25 cells. Taken together, our findings support that licochalcone A can be developed to a potent anti-metastatic candidate for oral cancer therapy.

Topics: Cadherins; Cell Adhesion; Cell Line, Tumor; Cell Movement; Chalcones; Epithelial-Mesenchymal Transition; Humans; Matrix Metalloproteinase 2; Mouth Neoplasms; Neoplasm Invasiveness; Neoplasm Metastasis; NF-kappa B; Tissue Inhibitor of Metalloproteinase-2; Wound Healing

Licochalcone A (LCA), a chalconoid derived from root of Glycyrrhiza inflata, has been known to possess a wide range of biological functions such as antitumor, anti-angiogenesis, antiparasitic, anti-oxidant, antibacterial and anti-inflammatory effects. However, the anticancer effects of LCA on oral squamous cell carcinoma (OSCC) have not been reported. Our data showed that LCA inhibited OSCC cell (HN22 and HSC4) growth in a concentration- and time-dependent manner. Mechanistically, it was mediated via downregulation of specificity protein 1 (Sp1) expression and subsequent regulation of Sp1 downstream proteins such as p27, p21, cyclin D1, Mcl-1 and survivin. Here, we found that LCA caused apoptotic cell death in HSC4 and HN22 cells, as characterized by sub-G1 population, nuclear condensation, Annexin V staining, and multi-caspase activity and apoptotic regulatory proteins such as Bax, Bid, Bcl(-xl), caspase-3 and PARP. Consequently, this study strongly suggests that LCA induces apoptotic cell death of OSCC cells via downregulation of Sp1 expression, prompting its potential use for the treatment of human OSCC.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Regulatory Proteins; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Chalcones; Glycyrrhiza; Humans; Mouth Neoplasms; Phytotherapy; Plant Extracts; Plant Roots; Reverse Transcriptase Polymerase Chain Reaction; Sp1 Transcription Factor