Licochalcone-E induces caspase-dependent death of human pharyngeal squamous carcinoma cells through the extrinsic and intrinsic apoptotic signaling pathways.

The aim of the present study was to investigate licochalcone-E (Lico-E)-induced apoptosis and the associated apoptotic signaling pathway in FaDu cells, a human pharyngeal squamous carcinoma cell line. Treatment with Lico-E exhibited significant cytotoxicity on FaDu cells in a concentration-dependent manner. The IC50 value of Lico-E in FaDu cells was ~50 µM. Treatment with Lico-E increased the number of dead FaDu cells. Furthermore, chromatin condensation, which is associated with apoptotic cell death, was observed in FaDu cells treated with Lico-E for 24 h. By contrast, Lico-E did not produce cytotoxicity or increase the number of dead cells when applied to human normal oral keratinocytes (hNOKs). Furthermore, chromatin condensation was not observed in hNOKs treated with Lico-E. Treatment with Lico-E increased the expression of Fas ligand and the cleaved form of caspase-8 in FaDu cells. Furthermore, treatment with Lico-E increased the expression of pro-apoptotic factors, including apoptosis regulator BAX, Bcl-2-associated agonist of cell death, apoptotic protease-activating factor 1, caspase-9 and tumor suppressor p53, while decreasing the expression of anti-apoptotic factors, including apoptosis regulator Bcl-2 and Bcl-2-like protein 1 in FaDu cells. The expression of cleaved caspases-3 and poly (ADP-ribose) polymerase was significantly upregulated following treatment with Lico-E in FaDu cells, while Lico-E-induced apoptotic FaDu cell death was partially suppressed by treatment with Z-VAD-FMK, a pan caspase inhibitor. Therefore, Lico-E-induced oral cancer (OC) cell-specific apoptosis is mediated by the death receptor-dependent extrinsic and mitochondrial-dependent intrinsic apoptotic signaling pathways. In conclusion, these data suggested that Lico-E exhibits potential chemopreventive effects and warrants further developed as a chemotherapeutic agent against OC.

Inhibitory effect of Korean Red Ginseng on melanocyte proliferation and its possible implication in GM-CSF mediated signaling.

Korean Red Ginseng (KRG) has been reported to exert anticancer, anti-oxidant, and anti-inflammatory effects. However, there has been no report on the effect of KRG on skin pigmentation. In this study, we investigated the inhibitory effect of KRG on melanocyte proliferation. KRG extract (KRGE) at different concentrations had no effect on melanin synthesis in melan-A melanocytes. Saponin of KRG (SKRG) inhibited melanin content to 80% of the control at 100 ppm. Keratinocyte-derived factors induced by UV-irradiation were reported to stimulate melanogenesis, differentiation, proliferation, and dendrite formation. In this study, treatment of melan-A melanocytes with conditioned media from UV-irradiated SP-1 keratinocytes increased melanocyte proliferation. When UV-irradiated SP-1 keratinocytes were treated with KRGE or SKRG, the increase of melanocyte proliferation by the conditioned media was blocked. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was produced and released from UV-irradiated keratinocytes. This factor has been reported to be involved in regulating the proliferation and differentiation of epidermal melanocytes. In this study, GM-CSF was significantly increased in SP-1 keratinocytes by UVB irradiation (30 mJ/cm(2)), and the proliferation of melan-A melanocytes increased significantly by GM-CSF treatment. In addition, the proliferative effect of keratinocyte-conditioned media on melan-A melanocytes was blocked by anti-GM-CSF treatment. KRGE or SKRG treatment decreased the expression of GM-CSF in SP-1 keratinocytes induced by UVB irradiation. These results demonstrate that UV irradiation induced GM-CSF expression in keratinocytes and KRGE or SKRG inhibited its expression. Therefore, KRG could be a good candidate for regulating UV-induced melanocyte proliferation.

Placement angle effects on the success rate of orthodontic microimplants and other factors with cone-beam computed tomography.

INTRODUCTION: The purpose of this study was to evaluate the effect of placement angles on the success rate of orthodontic microimplants and other factors with cone-beam computed tomography images. METHODS: We examined 228 orthodontic microimplants implanted into the maxillary buccal alveolar bone of 130 patients (33 men, 97 women) with malocclusion. Vertical placement angle, horizontal placement angle, root proximity, and cortical bone thickness were measured, and the correlations between these measurements and orthodontic microimplant success rates and the correlations among the measurements were evaluated. RESULTS: The overall success rate was 87.7% (200 of 228). The orthodontic microimplant success rate statistically significantly increased as root proximity (distance from the orthodontic microimplant to the root surface) increased (P <0.05), but there were no statistical significances between placement angles and success rates, and cortical bone thickness and success rate (P >0.05). Correlations between placement angles and root proximity showed no statistical significance (P >0.05), but correlations between vertical placement angle and cortical bone thickness (P <0.001) and between horizontal placement angle and cortical bone thickness (P <0.01) showed statistical significance. A statistically significant (negative) correlation was found between vertical and horizontal placement angles (P <0.001). CONCLUSIONS: The success rate of orthodontic microimplants is not affected by placement angles and is more significantly affected by root proximity than by cortical bone thickness. Cortical bone thickness is affected by placement angles, but root proximity is not affected by placement angles.