No abstract

Esculetin, a coumarin compound, has anti-proliferative effects on various types of human cancer cells, but its effect on oral squamous cell carcinoma (OSCC) is unknown. In this study, we determined whether esculetin had anti-proliferative effects on two oral squamous cell lines, HN22, and HSC2. We found that esculetin inhibited cell viability by inducing apoptosis, as evinced by apoptotic cell morphologies, nuclear fragmentation, and the multi-caspase/MMP activity. Furthermore, proteomic analysis was used to identify the target-specific proteins involved in esculetin treatment. Intriguingly, apoptotic cell death by esculetin was associated with significant inhibition of the EGFR/PI3K/Akt signaling pathway. We also demonstrated that the expression of nucleophosmin (NPM) markedly decreased after esculetin treatment, and relocalization of NPM from the nucleous to the cytoplasm, together with p65, potentiated apoptotic stimulation. Additionally, our data indicated that NPM expression was markedly higher in OSCC tissues than in normal tissues. Our results collectively indicated that esculetin inhibited the proliferation of OSCC through EGFR-mediated signaling pathways and down-regulation of NPM as well as the perturbation of NPM trafficking from the nucleolus to the cytoplasm resulted in apoptosis.

It is necessary to prevent the invasion of soft tissue into bone defects for successful outcomes in guided bone regeneration (GBR). For this reason, many materials are used as protective barriers to bone defects. In this study, a gellan gum/tuna skin gelatin (GEL/TSG) film was prepared, and its effectiveness in bone regeneration was evaluated. The film exhibited average cell viability in vitro. Experimental bone defects were prepared in rabbit calvaria, and a bone graft procedure with beta-tricalcium phosphate was done. The film was used as a membrane of GBR and compared with results using a commercial collagen membrane. Grafted material did not show dispersion outside of bone defects and the film did not collapse into the bone defect. New bone formation was comparable to that using the collagen membrane. These results suggest that the GEL/TSG film could be used as a membrane for GBR.

No abstract

The purpose of this study was to evaluate the effect of the periosteum attached to an iliac block bone graft on resorption of the grafted bone. Twenty-one rabbits were used. Iliac bone was harvested with (experimental group) or without a periosteum (control group) and grafted on the rabbit calvarium and fixed with miniscrews. The animals were killed, and specimens were harvested at 1, 4, and 8 weeks after the surgery. Histologic examination and histomorphometry were done. Grafted bones were severely resorbed, and the overall shapes were changed in the control group. On the contrary, the overall shape of the grafted bone was maintained, although the grafted bone was resorbed in the experimental group. Moreover, there were no osteoclasts adjacent to the periosteum of the graft. These results suggest that the periosteum attached to grafted bone can help establish early revascularization and prevent the resorption of grafted bone.