Channel: Basic Study https://www.kqjbfz.com EN-US https://www.kqjbfz.com/EN/current.shtml https://www.kqjbfz.com 5 Objective To investigate the effects of Erianin on cell proliferation and apoptosis in human oral squamous cell carcinoma (OSCC) cells, providing a research foundation for the clinical treatment of OSCC. Methods Erianin was applied to OSCC cells (CAL27 and SCC9) at concentrations of 0, 2.5, 5, and 10 μmol/L. The inhibitory effect of Erianin on OSCC cell proliferation was evaluated using CCK-8 and soft agar colony formation assays. Western blotting (WB) was employed to analyze the expression levels of anti-apoptotic proteins B-cell lymphoma-extra large (Bcl-xL), B-cell lymphoma-2 (Bcl-2), myeloid cell leukemia-1 (Mcl-1), and apoptotic protein cleaved-Caspase 3 (c-Caspase 3) in OSCC cells. Caspase 3 activity was further assessed using a caspase 3 activity detection kit to examine the pro-apoptotic effect of Erianin in OSCC cells. Mcl-1 overexpression was induced in CAL27 cells via plasmid transfection, and the influence of Mcl-1 on the effects of Erianin in CAL27 cells was analyzed by WB and caspase 3 activity measurement. All animal experiments were approved by the Ethics Committee of Hunan Cancer Hospital. A CAL27 xenograft mouse model was established and randomly divided into two groups (n = 5): the treatment group received intraperitoneal injection of Erianin (25 mg/kg), while the control group was injected with phosphate-buffered saline (PBS) as the vehicle. Immunohistochemistry (IHC) was used to detect the expression levels of Ki67 and Mcl-1 in the tumor tissues. Results Erianin inhibited the proliferation of CAL27 and SCC9 cells in a dose-dependent manner and downregulated the protein expression of Mcl-1, with minimal effects on Bcl-2 and Bcl-xL. Furthermore, Erianin induced apoptosis in OSCC cells, as evidenced by increased expression of c-Caspase 3 and enhanced caspase 3 activity (P<0.001). Overexpression of Mcl-1 inhibited the Erianin-induced increase in c-Caspase 3 protein levels and caspase 3 activity. In vivo results were consistent with the in vitro findings. After Erianin treatment, CAL27 cell growth in nude mice was suppressed (P<0.001), and the expression levels of the proliferation marker Ki67 and the anti-apoptotic protein Mcl-1 in the tumor tissues were downregulated (P<0.001). Conclusion Erianin exhibits potent anti-tumor effects, effectively inhibiting the proliferation of OSCC cells and inducing apoptosis. The underlying mechanism may involve the downregulation of the pro-survival protein Mcl-1.

]]> Objective To investigate the changes of dentin surface and the effects of different surface treatments on the rebonding effect following non-destructive restoration removal by an Er:YAG laser and to provide reference for oral clinical operation. Methods This study was approved by the ethics review committee of the unit. Using computer-aided design and computer-aided manufacturing (CAD/CAM) technology, 102 zirconia specimens (4 mm × 4 mm × 1.5 mm) were fabricated. In total, 110 impacted third molar teeth were extracted, and 102 dentine blocks (4 mm × 4 mm × 2 mm) were prepared. The zirconia specimen and dentin blocks were bonded with resin cement before removal with an Er: YAG laser. Three disassembled dentin blocks were randomly selected, and the components of dentin surface elements were analyzed by energy dispersive X-ray spectroscopy (EDX). The removed dentin blocks were randomly divided into three groups (n = 33) based on the different surface treatments: control group (no treatment), sandblasting group (50 μm, Al₂O₃ sandblasting), and laser irradiation group (Er: YAG laser irradiation, parameters were set to 10 Hz, 60 mJ, 0.6 W). Three dentin blocks were randomly selected in each group for scanning electron microscopy (SEM) observation, and the residual resin on dentin surface of remaining 30 dentin blocks in each group were observed under an optical microscope at 20 times magnification. Scores were obtained using the adhesive remnant index (ARI) method. Three groups of dentin blocks (n = 30) that underwent different surface treatments were rebonded with resin cement according to standard procedures and then divided into two subgroups for aging (n = 15). One subgroup was subjected to a 37 ℃ water bath for 24 h, and the other subgroup was subjected to 5 000 thermal cycles after a 37 ℃ water bath for 24 h, and the micro-shear bonding strength of each group was measured. The microshear bonding strength of each group was measured, and fracture modes were analyzed. The differences of dentine surface ARI between the three groups, as well as the inter-group differences in fracture mode, and bonding strength, and the intra-group differences before and after aging were compared between the three groups. Results When zirconia was removed by Er: YAG laser, there was no obvious damage on the dentin surface, but C and Si elements in dentin increased significantly. After different surface treatments, the ARI scores of the sandblasting and laser irradiation groups were lower than those of the control group (P<0.05), while ARI was not significantly different between the sandblasting and laser irradiation groups (P>0.05). The dentin surface morphology was also different. There was a large amount of residual resin on the dentin surface of the control group. In the sandblasting group, the residual resin was lower, the dentin surface was rough, and the dentin tubules were visible. A large amount of residual resin was observed on the dentin surface of the laser irradiation group. After 24 h of water bath at 37 ℃, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (6.13 ± 2.40) MPa, (9.39 ± 2.00) MPa, and (5.85 ± 1.44) MPa, respectively, and the bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). After being subjected to 24 h of water bath at 37 ℃ and 5 000 thermal cycles, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (5.39 ± 0.83) MPa, (8.45 ± 1.20) MPa and (4.84 ± 1.43) MPa, respectively. The bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). There was no significant difference between the control group, sandblasting group, and laser irradiation group before and after 5 000 thermal cycles following 24 h of water bath at 37 ℃ (P>0.05). In the control group, sandblasting group, and laser irradiation group, cohesive fracture was not observed. The fracture mode was mainly adhesive fracture. Before and after 5 000 thermal cycles, the frequency of mixed fracture in the sandblasting group was significantly higher than that in the other two groups (P<0.05). Conclusion Er: YAG laser removal of zirconia does not damage dentin, but a large amount of resin remains on the dentin surface after removal. The sandblasting process can effectively remove these residual resins, thereby improving the dentine rebonding effect.

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