Objective：To investigate the relationship between O-linked N-acetylglucosamine (O-GlcNAc) and oral squamous cell carcinoma. Methods：The expression of O-GlcNAc, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) in 30 cases of oral squamous cell carcinoma and 10 normal oral mucosa were detected using immunohistochemical staining. The proliferation of TCA8113 with transglycosylation (TG) and deoxynorleucine (DON) was examined by Immunofluence and Western blotting. Results：There was significant difference of O-GlcNAc and OGT between normal mucosa and oral squamous cell carcinoma (P<0.05). The expression of O-GlcNAc and OGT increased with higher grade of the carcinoma. The expression of OGA was inconsistent with O-GlcNAc and OGT. TG could activate the expression of O-GlcNAc and OGT, DON could inhibit the expression of O-GlcNAc and OGT. Besides, DON could inhibit the proliferation of TCA8113 cells and the expression of PCNA. Conclusions：O-GlcNAc could activate the oral squamous cell carcinoma. Inhibitor DON could depress the proliferation of TCA8113.

Objective：To investigate the regulation of let-7i on the cell proliferation, apoptosis, migration and invasion in oral squamous cell carcinoma (OSCC). Methods：The expressions of let-7i were measured in OSCC tissues, the adjacent normal tissues and OSCC cell lines by qRT-PCR to investigate the differentiation of paired samples. The inhibition or enhancement of let-7i in OSCC cells after let-7i inhibitor or let-7i mimics were transfected into the cells. Then cell proliferation, single cell clone formation, flow cytometry, transwell migration and invasion tests were carried out to study the effects of let-7i on biological behaviors of OSCC cells. Results：The expression of let-7i increased in OSCC tissues（n=29, t=8.215, P<0.01）and cell lines compared with adjacent normal tissues. Let-7i inhibitor or mimics could decrease or enhance the expressions of let-7i in SCC25 cells significantly. After let-7i inhibitor was transfected, the cell proliferation, cell migration and invasion abilities of SCC25 cells were reduced significantly, and higher apoptotic rate was observed. Instead, when transfected with let-7i mimics, SCC25 cells showed an opposite change on biological behaviors. Conclusions：Let-7i can promote the cell proliferation, migration and invasion in OSCCs. As let-7i inhibitor is an effective anticancer factor by interfering with let-7i, providing us a novel candidate to treat OSCCs.

Objective：The aim of this study was to investigate the expression of nuclear matrix proteins special AT-rich sequence-binding protein 2 (SATB2) and associated molecules in female mandible-derived bone marrow stromal cells (BMSCs) taken from subjects at different ages, and their relationship with senescence phenotypes of BMSCs. Methods：Trabecular bones of female mandible were isolated from volunteers who sought treatment of impacted tooth or tooth implantation and divided into Y group, M group and O group. MTT and β-Gal staining were performed for analysis of cell proliferation and senescence, Western blot was used to examine the expression of SATB2, stemness factors and senescence-associated proteins. The effects of SATB2 on BMSCs stemness and senescence phenotypes were analyzed by overexpressed SATB2. Results：The proliferation ability, SATB2 and stemness factors expressions of BMSCs decreased with aging, meanwhile, showing increasing senescence phenotypes. SATB2 and stemness factors were closely associated with replicative senescence of BMSCs and mammalian target of rapamycin (mTOR) signaling. After overexpression SATB2 in older BMSCs, the number of senescence positive cells and expression of stemness factors increased, but expression of mTOR, P-mTOR and senescence associated proteins decreased. Conclusions： Senescence of female mandible-derived BMSCs increased with aging. SATB2 may improve anti-senescence ability of BMSCs by regulating stemness factors and inhibiting mTOR signaling.

Objective: OSCC is associated with poor prognosis, which has improved only marginally over the past three decades. A proteomic analysis of OSCC lesions may help identify novel molecular targets for the early detection, prevention, and treatment of it. Methods: Laser capture microdissection was combined with recently developed techniques for protein extraction from formalin-fixed paraffin-embedded (FFPE) tissues and a novel proteomics platform. Approximately 10,000 cells procured from FFPE tissue sections of normal oral epithelium and OSCC epithelium were processed for mass spectrometry and bioinformatic analysis. Results: A large number of proteins expressed in normal oral epithelium and OSCC, including cytokeratins, intermediate filaments, differentiation markers, and proteins involved in stem cell maintenance, signal transduction, migration, cell cycle regulation, growth and angiogenesis, matrix degradation, and proteins with tumor suppressive and oncogenic potential, were readily detected. Of interest, the relative expression of many of these molecules followed a distinct pattern in normal squamous epithelia and OSCC tumor tissues. Representative proteins were further validated basing on article reviews. CKs expression pattern may afford potential predict biomarkers for oral mucosa carcinogenesis. Conclusions: The ability to combine laser capture microdissection and in-depth proteomic analysis of FFPE tissues provided a wealth of information regarding the nature of the proteins expressed in normal squamous epithelium and during OSCC progression, which may allow the development of novel biomarkers of diagnostic and prognostic value and the identification of novel targets for therapeutic intervention in OSCC.

Objective：To characterize and observe the effect of Osterix on the osteogenic differentiation of mouse iPSCs. Methods： Through iPS cell culture, gene transfection, semi-quantitative RT-PCR and histology, we analyzed the alteration of osteogenesis related genes and protein in the mouse iPSCs before and after Osterix transfection. Results：Suspension of iPS cells in differentiation culture (drop) can form embryoid bodies (EB). After the plasmid transfection, the potential of multi-directional differentiation of iPS cells was not found to have changed. Moreover, compared with the control group, the activity of ALP in the formation of mineralized nodules, osteogenesis related genes (Runx2, bone sialoprotein and osteocalcin) expression were significantly enhanced in the iPSCs transfected with Osterix (P<0.05). Conclusions：iPSCs can be differentiated to bone cells, and the transcription factor Osterix can promote the osteogenic differentiation of iPS cells.

Objective: To investigate the effect exogenous inhibition of Neuropilin-1(NRP-1) on the migration and the differentiation of the human tongue squamous carcinoma cell line SCC9. Methods: Western blot were performed to examine the expression of NRP-1 in cell line SCC9 and the human tongue squamous carcinoma cell cancer tissue. Besides, scratch test and transwell assay were employed to show the influence of exogenous inhibition of Neuropilin-1(NRP-1)on the migration of the SCC9 cells. And Real-time RT PCR were used to detect the expression of differentiation markers in the SCC9 cells exogenously inhibited of NRP-1. Results: NRP-1 express at high level in the SCC9 cells, and exogenous inhibition of NRP-1 depressed the migration of SCC9 cells. Real-time RT PCR showd the expression of epithelial cadherin and β-catenin increased, while the expression of snail, fibronectin and α-smooth muscle actin decreased. Conclusions: Exogenous inhibition of NRP-1 depressed the migration and differentiation of SCC9 cells.

Objective: To establish the digital slides database for oral histopathology teaching. Methods: Using Nano Zoomer 2.0-HT system scanned classic oral histopathology slides. Results: Seventy-eight slides have been scanned, including 10 pieces of grinding slides and 68 pieces of soft tissue slides. Conclusions: The teaching digital slides database may promote the oral histopathology teaching reform and accelerate the process of informatization.

Objective： To evaluate the occluding effect of bioactive glass combined with Er laser irradiation on dentinal tubules. Methods：45 dentine discs were prepared and etched with 0.5 mol/L EDTA. They were randomly divided into 5 groups with different treatments: Group A(without treatment as control), Group B(treated with bioactive glass) , Group C(treated with Er,Cr:YSGG laser irradiation), Group D(bioactive glass followed by Er,Cr:YSGG laser irradiation), Group E(Er,Cr:YSGG laser irradiation followed by bioactive glass). The occluding effect and mineral content was examined by scanning electron microscopy (SEM) and X-ray energy spectrum analysis (EDXA). Results： Micrographs of SEM showed obvious occluding effect in Group B,C,D and E,with the best effect in Group D, and the dentinal tubule exposure rates were Group D

Objective: To explore the influences of different cooling methods and cryopreservation with different cryoprotectants on biomechanical performances of in vitro dental tissues. Methods: A total of 50 fresh teeth (the first premolar or second premolar) were collected and divided into five groups. The tissues of four experimental groups were cooled to -196 ℃ by programmed cooling method and rapid cooling method in cryoprotectant with or without trehalose, for 1 week cryostorage. And the fresh teeth of the control group were not given any treatment. Five teeth from each group were made into solid mass dental tissues, which were measured for compression strength and modulus of elasticity; another 5 teeth, in which Ⅴ-type dental cavities were made in the maxillofacial region and filled with resin, were given dye penetration test with 2% methylene blue solution after 500 temperature cycles. Micro leaking at the edge of dental filling materials in each group was measured and compared. Results: There were no significant differences between groups with different cooling methods and different cryoprotectants in dental compression strength, modulus of elasticity, and micro leaking at the edge of dental filling materials. Conclusions: There are no signicant differences in biomechanical properties of dental tissue and micro leaking at the edge of filling materials in cryopreservation for teeth preservation.

Objective：The primary aim of this study was to measure the buccolingual alveolar bone thickness between the maxillary central incisors by CBCT, providing reference for the safe miniscrew placement. Methods：The cone beam computed tomography images of 80 patients were used. For each subject, the distance between the anterior nasopalatine canal and maxillary anterior buccal bone were measured. Besides, the buccolingual alveolar bone thickness on the median sagittal plane were measured at four different levels of 14.0, 16.0, 18.0 and 20.0mm from the reference plane. Results：Distance between the anterior nasopalatine canal and maxillary anterior buccal bone were (7.98±1.24) mm,(8.27±1.44) mm,(10.31±2.00) mm.It increased from the oral cavity to the nasal cavity, and had significant difference. No significant difference was noted between age groups. The buccolingual alveolar bone thickness has no significant difference at four different levels. Male has greater bone thickness than female at every level. No significant difference was noted between age groups. Conclusions：The miniscrew with 6mm length in the bone is safe to be placed. It is safe to implant miniscrews of 6mm length between the maxillary central incisors, which will avoid the nasoplatine canal injury.