Verification of the expression trend and interaction prediction of innate immune cells and immune-checkpoint molecules in the process of oral mucosal carcinogenesis.

OBJECTIVES: This study aimed to explore the expression trends of innate immune cells and immune-checkpoint molecules validated by data calculation in the process of oral mucosal carcinogenesis, as well as to explore methods of suppressing oral mucosal carcinogenesis based on immunotherapy by predicting their interactions. Me-thods 1) The cancer genome atlas (TCGA) database comprehensively scores immune cells and immune-checkpoint molecules in the process of oral mucosal carcinogenesis and screens out intrinsic immune cells and immune-checkpoint molecules that interfere with tumor immune escape. 2) Clinical patient blood routine data were collected for the statistical analysis of peripheral blood immune cells during the progression of oral mucosal carcinogenesis. Immune cells in peripheral blood that may affect the progression of oral mucosal carcinogenesis were screened. 3) Immunohistochemical staining was performed on intrinsic immune cells and immune-checkpoint molecules validated based on data calculation in various stages of oral mucosal carcinogenesis. 4) Special staining was used to identify innate immune cells in various stages of oral mucosal carcinogenesis based on data-calculation verification. 5) Survival analysis was conducted on intrinsic immune cells and immune-checkpoint molecules validated based on data calculation during the process of oral mucosal carcinogenesis. The association of intrinsic immune cells and immune-checkpoint molecules with the prognosis of oral squamous cell carcinoma was verified. RESULTS: The expression of monocytes and neutrophils increased during the process of oral mucosal carcinogenesis. The expression of eosinophils showed a single peak trend of up and down. The expression of mast cells decreased. In the process of oral mucosal carcinogenesis, the expression of the immune-checkpoint molecules cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and programmed cell death-ligand (PD-L1) increased. The expression trends of monocytes, neutrophils, and eosinophils were positively correlated with those of CTLA4 and PD-L1 immune-checkpoint molecules. The expression trend of mast cells was negatively correlated with the expression of CTLA4 and PD-L1. Monocytes, neutrophils, and eosinophils may promote tumor immune escape mediated by CTLA4 and/or PD-L1, thereby accelerating the progression of oral mucosal carcinogenesis. Mast cells may inhibit tumor immune escape mediated by CTLA4 and/or PD-L1, delaying the progression of oral mucosal carcinogenesis. CONCLUSIONS: Therefore, interference with specific immune cells in innate immunity can regulate the expression of CTLA4 and/or PD-L1 to a certain extent, inhibit tumor immune escape, and delay the progression of oral mucosal carcinogenesis.

[Effect of up-regulation of Decorin on expression of EGFR, C-Myc and p21 in nude mice with oral squamous cell carcinoma].

PURPOSE: To explore the effect of overexpression of DCN（decorin） gene on the expression of epidermal growth factor receptor (EGFR), cellular-myelocytomatosis viral oncogene (C-Myc) and cyclin dependent kinase inhibitor (p21)in tumor-bearing nude mice with oral squamous cell carcinoma（OSCC）. METHODS: The expression of DCN gene in human oral squamous cell carcinoma(HSC-3) was up-regulated by liposome transfection. Nude mice were used as the carrier of OSCC. H-E staining was used to determine the pathological grade of tumor-bearing tissues in each group. Immunohistochemistry was used to detect the expression of EGFR, C-Myc and p21 protein in tumor-bearing tissues of each group after DCN overexpression. RT-qPCR and Western blot were used to quantitatively detect the expression of EGFR, C-Myc and p21 in tumor-bearing tissues of each group after DCN overexpression, and to determine the effects of DCN overexpression on the expression of EGFR, C-Myc and p21 in tumor-bearing tissues of OSCC nude mice. SPSS 20.0 software package was used for statistical analysis. RESULTS: H-E staining showed that the animal model of OSCC was successfully constructed. The tumor-bearing tissues of nude mice in the plasmid group were significantly lighter than those in the empty vector group and non-transfected group(P＜0.05). IHC results showed that DCN, EGFR, C-Myc and p21 proteins were expressed in the tumor-bearing tissues of nude mice in each group, the expression of DCN,EGFR and C-Myc proteins in the plasmid group was significantly different from the other groups(P＜0.05).There was no significant differece in p21 protein expression in each group(P＞0.05). RT-qPCR and Western blot results showed that DCN, EGFR, C-Myc and p21 were expressed in diffrent degrees in tumor-bearing tissues of nude mice（P＜0.05）. CONCLUSIONS: DCN can inhibit the growth of tumor in OSCC nude mice. In tumor-bearing tissues of nude mice with OSCC, overexpression of DCN can down-regulate the expression of EGFR and C-Myc, and up-regulate the expression of p21.DCN may play an inhibitory role in the occurrence and development of OSCC.

Identification of the MMP family as therapeutic targets and prognostic biomarkers in the microenvironment of head and neck squamous cell carcinoma.

BACKGROUND: Head and Neck Squamous Cell Carcinoma is a malignant tumor with high morbidity and mortality. The MMP family plays an important role in tumor invasion and metastasis. However, the mechanistic value of the MMP family as a therapeutic target and prognostic biomarker in HNSC has not been fully elucidated. METHODS: Oncomine, UALCAN, GEPIA, cBioportal, GeneMANIA, STRING, DAVID6.8, TRRUST, TIMER and Linkedomics were used for analysis. RESULTS: The mRNA expression levels of MMP1, MMP3, ILF3, MMP7, MMP9, MMP10, MMP11, MMP12, MMP13 and MMP16 were higher in HNSC than those in normal tissues, while the mRNA expression level of MMP15 was reduced. The relative expression levels of MMP1 and MMP14 were the highest in HNSC tissues. A significant correlation was found between the expression of MMP3, MMP11, MMP25 and the pathological stage of HNSC patients. There was no significant associations between all the MMP family members expression levels and DFS. Increased mRNA levels of MMP1, MMP8 and MMP25 were significantly associated with OS. In addition, we investigated the genetic changes of the MMP family in HNSC and found that all the MMP family members had genetic changes, most of which were amplification and depth loss. In the analysis of neighbor gene network and protein interaction, we found that the MMP family interacted with 25 neighboring genes, except for ILF3, MMP19, MMP20, MMP21, MMP23B, MMP27 and MMP28, other MMP proteins interacted with each other. Functional enrichment analysis showed that the MMP family could be present in the extracellular matrix, regulate peptidase activity, and participate in the catabolism of collagen. Meanwhile, we identified the transcription factor targets and kinase targets of the MMP family and found that ATM and ATR were the two most common kinase targets in the MMP family. We also found a significant correlation between the MMP family expression and immune cell infiltration. Cox proportional risk model analysis showed that macrophages, MMP14, MMP16, and MMP19 were significantly associated with clinical outcomes in HNSC patients. CONCLUSION: The MMP family might serve as therapeutic target and prognostic biomarker in HNSC.

CGF-HLC-I repaired the bone defect repair of the rabbits mandible through tight junction pathway.

Background: The human-like collagen I (HLC-I) combined concentrated growth factors was used to construct CGF-HLC-I composite biomaterials to repair the critical bone defect disease model of rabbit mandible. This study aimed to research the repair mechanism of CGF-HLC-I/Bio-Oss in rabbit mandibular critical bone defect, to provide a new treatment direction for clinical bone defect repair. Methods: The optimal concentration of HLC-I (0.75%) was selected in this study. Nine New Zealand white rabbits were randomly divided into 3 groups, normal control group, Bio-Gide/Bio-Oss and CGF-0.75%HLC-I/Bio-Oss group (n = 3, each group). CGF-0.75%HLC-I/Bio-Oss and Bio-Gide/Bio-Oss were implanted into rabbit mandibles, then X-ray, Micro-CT, HE and Masson staining, immunohistochemical staining and biomechanical testing were performed with the bone continuity or maturity at 4, 8 and 12 weeks after surgery. The repair mechanism was studied by bioinformatics experiments. Results: As the material degraded, the rate of new bone formation in the CGF-0.75% HLC-I/Bio-Oss group was better than that the control group by micro-CT. The biomechanical test showed that the compressive strength and elastic modulus of the CGF-0.75%HLC-I/Bio-Oss group were higher than those of the control group. HE and Masson staining showed that the bone continuity or maturity of the CGF-0.75%HLC-I/Bio-Oss group was better than that of the control group. Immunohistochemical staining showed significantly higher bone morphogenetic protein 2 (BMP2) and Runt-related transcription factor 2 (RUNX2) in the CGF-0.75%HLC-I/Bio-Oss group than the control group at 8 and 12 W and the difference gradually decreased with time. There were 131 differentially expressed proteins (DEPs) in the Bio-Gide/Bio-Oss and CGF-0.75%HLC-I/Bio-Oss groups, containing 95 up-regulated proteins and 36 down-regulated proteins. KEGG database enrichment analysis showed actinin alpha 1 (ACTN1) and myosin heavy-Chain 9 (MYH9) are the main potential differential proteins related to osteogenesis, and they are enriched in the TJs pathway. Conclusion: CGF-0.75%HLC-I/Bio-Oss materials are good biomaterials for bone regeneration which have strong osteoinductive activity. CGF-0.75%HLC-I/Bio-Oss materials can promote new bone formation, providing new ideas for the application of bone tissue engineering scaffold materials in oral clinics.

Identification and validation of potential novel biomarkers for oral squamous cell carcinoma.

Our study aimed to explore potential new diagnostic biomarkers in patients with oral squamous cell carcinoma (OSCC) to find new target molecules involved in the progression of OSCC. Potential novel biomarkers of OSCC were identified using a protein microarray assay. Compared with the healthy control group, there were five proteins (I309, GDF15, AXL, MMP3, and CTACK) in the serum of in situ oral cancer group. However, there were four differentially expressed proteins (MCSF, I309, MMP3, and CTACK) in the serum of the OSCC group. Receiver operating characteristic (ROC) curve analysis results suggested that these six proteins (I309, GDF15, AXL, MMP3, CTACK, and MCSF) had diagnostic value for OSCC. Based on The Cancer Genome Atlas (TCGA) database, we found that only GDF15 expression was associated with the prognosis of OSCC. Subsequently, we verified the expression levels of six proteins in HSC-3 and HaCaT cells, and the results showed that the level of these six proteins was significantly higher in HSC-3 cells than in normal HaCaT cells. Similarly, in the OSCC nude mouse model, the expression levels of these proteins were significantly upregulated in OSCC tumor tissue compared to the normal tissue. GDF15, MMP3, AXL, MCSF, I309, and CTACK may be used as biomarkers for OSCC diagnosis and provide a novel study direction for the treatment of OSCC.

[microRNA-1 gene delivery mediated by exosomes suppresses CAL-27 cell proliferation].

OBJECTIVES: This study aims to construct endogenous exosomes abundantly loaded with miR-1 and investigate the role of exosome-mediated microRNA-1 (miR-1) delivery on CAL-27 cell proliferation. METHODS: Exosomes secreted by miR-1-overexpressing HEK293 cells (miR1-EXO) were purified via ultracentrifugation and subjected to transmission electron microscopy, nanoparticle analysis, Western blot analysis, and quantitative polymerase chain reaction (qPCR). CAL-27 cells were cocultured with exosomes secreted by HEK293 cells (CON-EXO) and miR1-EXO and equivalent phosphate buffer saline. The intracellular transport of exosomes was measured by using immunofluorescence, the expression of miR-1 and its target gene MET were investigated via qPCR, CAL-27 cell proliferation was measured through MTT assay, and cell cycle state was determined by applying flow cytometry. RESULTS: Electron microscopy revealed that miR1-EXO and CON-EXO were spherical or cup-shaped with an average diameter of approximately 110 nm. The well-known exosome markers CD9, Tsg101, and Alix were enriched. The expression of miR-1 in miR1-EXO was higher than that in CON-EXO (285.80±14.33 vs 1.00±0.06, P<0.000 1). After coculture with CAL-27 cells, miR1-EXO was internalized and unloaded miR-1 into CAL-27 cells. After coculture with miR1-EXO, the expression of miR-1 in CAL-27 cells was upregulated, whereas that of MET, the target gene of miR-1, was suppressed and the proliferation of CAL-27 cells was inhibited significantly. Normal oral keratinocyte cell proliferation was negligibly affected after coculture with miR1-EXO. CONCLUSIONS: Exosomes secreted from miR1-EXO cells could load abundant miR-1. Exosomal miR-1 delivered into CAL-27 cells by using miR1-EXO suppressed the expression of MET mRNA and inhibited cell proliferation.

[Study on expression of LIM domain only protein 1 in SD rat oral buccal mucosa carcinogenesis induced by 4-nitro-quinoline N-oxide].

OBJECTIVE: This work aimed to determine the expression changes in LIM domain only protein 1 (LMO1) in gene transcription and protein levels during oral squamous cell carcinoma (OSCC) development. METHODS: The tissues in this study were taken from our team's previous animal model building, and we performed hematoxylin-eosin (HE) staining on 49 cases. The pathological classification of the experiment group was determined on the basis of the abnormal epithelial hyperplasia degree. The expression part of LMO1 was determined by immunohistochemistry staining. The mRNA and protein LMO1 expression levels in five groups were detected by real-time fluorescent quantitative of nucleotide polymer chain reaction (RT-qPCR) and Western blot, respectively. RESULTS: HE staining determined 7 cases of the control group, 6 cases of mild epithelial dysplasia, 11 cases of moderate epithelial dysplasia, 9 cases of severe epithelial dysplasia, and 16 cases of OSCC. Immunohistochemistry results: LMO1 expression was localized in the cytoplasm, and the positive expression rates of the protein LMO1 in the control and experiment groups were 14.3% for normal buccal mucosal tissue, 33.3% for mild epithelial dysplasia, 81.8% for moderate epithelial dysplasia, 88.9% for severe epithelial dysplasia, and 93.8% for OSCC. RT-qPCR results: mRNA expression was lowest in the control group and highest in the OSCC group, the difference between the mild dysplasia and control groups was not significant (P>0.05). Pairwise comparison among other groups showed statistically significant differences (P<0.05). Western blot results: with the aggravation of the pathological degree, the protein LMO1 expression level increased gradually. The OSCC group expressed the highest LMO1 expression level. CONCLUSIONS: The oral mucosa carcinogenesis models showed abnormal the mRNA and protein LMO1 expression levels, and the mRNA and protein expression levels were positively correlated with the degree of abnormal proliferation.

[Effect of the focal adhesion kinase inhibitor TAE226 on the epithelial-mesenchymal transition in human oral squamous cell carcinoma cell line].

OBJECTIVE: To study the effect of the focal adhesion kinase inhibitor TAE226 on epithelial-mesenchymal transition (EMT) in human oral squamous cell carcinoma (OSCC) cell line. METHODS: HSC-3 and HSC-4 cells were cultured with TAE226 under different concentrations (0, 1, 5, and 10 µmol·L⁻¹) for 24, 48, and 72 h. Real-time quantitative polymerase chain reaction was performed to detect the mRNA expressions of E-cadherin and Vimentin. The protein expressions of E-cadherin and Vimentin were determined by Western blot assay after 48 h of TAE226 treatment. RESULTS: Real-time quantitative polymerase chain reaction showed that increasing the TAE226 dose and reaction time resulted in increased and decreased E-cadherin and Vimentin mRNA expressions, respectively (P<0.05). Western blot assays showed that increasing the TAE226 dose resulted in increased and decreased E-cadherin and Vimentin protein expressions, respectively (P<0.05). CONCLUSIONS: TAE226, which is expected to be an effective drug for OSCC treatment, can effectively inhibit the EMT of the OSCC cell line.

Modulation of proliferation and differentiation of gingiva­derived mesenchymal stem cells by concentrated growth factors: Potential implications in tissue engineering for dental regeneration and repair.

The aim of the present study was to evaluate the proliferation and osteogenic differentiation ability of gingiva­derived mesenchymal stem cells (GMSCs) cultured with different concentrations of concentrated growth factors (CGF). GMSCs were isolated from gingival connective tissues and characterized by flow cytometry, immunofluorescence staining and immunohistochemical staining. Cell proliferation activity was determined by the MTT assay, and the effect of CGF on MCSCs was detected with the Cell Counting Kit (CCK)­8 assay. Mineralization induction was evaluated by alkaline phosphatase (ALP)­positive cell staining and mineralized nodule formation assay. Dentin matrix acidic phosphoprotein (DMP)1, dentin sialophosphoprotein (DSPP), bone morphogenetic protein (BMP)2 and runt­related transcription factor (RUNX)2 mRNA and protein expression were evaluated by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) analysis and western blotting. The flow cytometry, immunofluorescence staining and immunohistochemical staining results indicated that the cultured cells were GMSCs. The MTT assay results revealed that the third­generation gingival stem cells exhibited the highest proliferative capacity, and the CCK­8 results indicated that 10% CGF achieved the most prominent promotion of GMSC proliferation. ALP activity analysis and mineralized nodule assay demonstrated that CGF may successfully induce osteogenic differentiation of GMSCs, whereas RT­qPCR and western blot analyses demonstrated that CGF is involved in the differentiation of GMSCs by regulating the expression of DMP1, DSPP, BMP2 and RUNX2 (P<0.05). In conclusion, CGF were demonstrated to promote the proliferation and osteogenic differentiation of GMSCs. Therefore, CGF may be applied in tissue engineering for tooth regeneration and repair.

Roles of miR-138 and ISG15 in oral squamous cell carcinoma.

The aim of the present study was to investigate the roles of microRNA (miR)-138 and interferon-stimulated gene 15 (ISG15) in patients with oral squamous cell carcinoma (OSCC). miR-138 and ISG15 expression in cancer tissues was detected, and the influence on proliferation, migration and invasion of OSCC cell lines was assessed. Reverse transcription-quantitative polymerase chain reaction was performed to analyze the expression of miR-138 and ISG15 in resected cancer tissues and pericancerous tissues harvested from patients with OSCC. The protein level of ISG15 was determined via western blot analysis. The constructed pGCMV/EGFP/miR-138 plasmid was transfected into CAL27 and SCC-15 OSCC cell lines via a liposome method to upregulate miR-138 expression. The transfection efficiency was determined based on miR-138 expression levels, and changes in proliferation, migration and invasion were subsequently compared with those in untransfected cells. The expression of ISG15 mRNA and protein was also detected in OSCC cells. miR-138 was significantly downregulated (P<0.05) in cancer tissues compared with adjacent normal tissues in patients with OSCC, whereas ISG15 mRNA expression levels were significantly higher in pericancerous tissues (P<0.05). ISG15 protein levels were also significantly higher in pericancerous tissues (P<0.05). ISG15 protein and mRNA levels were significantly decreased in the transfected cells compared with the untransfected cells, which indicated that miR-138 overexpression inhibited ISG15 expression. Additionally, the invasion, migration and proliferation abilities of successfully transfected CAL27 and SCC-15 cells were significantly decreased compared with the untransfected cells (P<0.05). The results of the present study suggest that miR-138 functions as a tumor-suppressive miR and serves an important role in OSCC via regulating ISG15 expression. These findings suggest that miR-138 is able to inhibit the proliferation, migration and invasion of OSCC cell lines.

Local Application of Platelet-Rich Fibrin During Lower Third Molar Extraction Improves Treatment Outcomes.

PURPOSE: Application of platelet-rich fibrin (PRF) during tooth extraction is able to accelerate wound healing, stimulate osseous and soft tissue regeneration, and reduce unwanted side effects. The aim of this meta-analysis was to investigate the effect of local application of PRF on controlling postoperative signs and symptoms after the extraction of an impacted lower third molar. MATERIALS AND METHODS: A systematic search of PubMed, Web of Science, Embase, and the Cochrane Library was performed to identify all studies published up to October 2016 that investigated the effect of PRF on lower third molar extraction. Pain, swelling, trismus, alveolar osteitis (AO), and osteoblastic activity were extracted to evaluate the effect of PRF. After quality assessment, meta-analysis was performed with RevMan software (version 5.3; Cochrane Library Software, Oxford, UK). RESULTS: After the search and selection process, 10 studies were selected in this meta-analysis, including 468 cases of PRF application and 467 cases of non-PRF application. Of the studies, 9 were randomized controlled trials, including 7 split-mouth studies, and there was 1 retrospective case-control study. The results indicated that PRF significantly relieves pain (P = .01) and 3-day postoperative swelling (P = .03) and reduces the incidence of AO (P < .0001). However, there were no significant differences between the PRF and non-PRF groups with respect to 1-day postoperative swelling and osteoblastic activity. CONCLUSIONS: Local application of PRF after lower third molar extraction is a valid method for relieving pain and 3-day postoperative swelling and reducing the incidence of AO. For patients undergoing complicated surgical extraction, PRF might be a recommendation for local application into the sockets.

Application of Endodontic Files for the Extraction of Root Tips: A Biomechanical Investigation and Case Study.

PURPOSE: To investigate the appropriate endodontic file for the extraction of root tips through a biomechanical study and to evaluate the clinic efficiency of this technique. MATERIALS AND METHODS: Nine hundred molar roots were randomly divided into 3 groups (3, 5, and 7 mm) and amputated to the corresponding length. Different files were inserted into the root tips, and a pullout test was conducted using a universal testing machine. The pullout force was recorded and files with greatest pullout force were selected for clinical study. Patients' root tips were extracted using these files. The duration and incidence of postoperative complications were recorded. RESULTS: The greatest pullout force was obtained for the 25# Hedström file, regardless of the length of the root tip and the type of file. The pullout force of Hedström files was significantly greater than that of Kerr files in each file group and root length group (P < .05). Clinically, the direct success ratio of this technique was 81.4%. The incidence of postoperative complications was very low. CONCLUSION: The results of this study suggest that the application of endodontic files for the extraction of root tips is an acceptable technique. The 25# Hedström file is the optimum choice for root extraction in most cases when using endodontic files.

[Expression of cytokeratin 19 in the development and progression of oral squamous cell carcinoma].

PURPOSE: To investigate the expression of cytokeratin 19 (CK19) in various stages of oral squamous cell carcinoma (OSCC), and to explore the relation between CK19 and OSCC. METHODS: Forty-nine specimens including normal oral mucosa, epithelial hyperplasia, epithelial dysplasia, and oral squamous carcinoma were investigated. The expression of CK19 was detected by immunohistochemistry and Western blot. The serum of OSCC patients and healthy people was collected and CYFRA21-1 level was determined by ELISA. SPSS17.0 software package was used for data elevated. RESULTS: CK19 was detectable in suprabasal cell layers in epithelia dysplasia and in oral cancer, especially in poorly-differentiated cancerous cells. With epithelia dysplasia becoming worse, the positive rate and the intensity of CKI9 raised significantly. CYKA21-1 in OSCC was significantly higher than that in normal control group(P<0.01). CONCLUSIONS: CK19 overexpression is an early event in the process of oral mucosal canceration. Its abnormal expression can be used as one of the reliable indexes of early diagnosis of OSCC.

[Expression of cytokeratin 19 and connexin 43 in 4-nitroquinoline-l-oxide-induced rat tongue carcinogenesis].

OBJECTIVE: To evaluate the expression of cytokeratin 19(CK19) and connexin 43(Cx43) in various stages of oral carcinogenesis and investigate the relationship of CK19 and Cx43 in the process of oral cancer. METHODS: 4-nitroquinoline-1-oxide(4NQO) was used to induce oral carcinogenesis in the mucosa of SD rats and immunohistoche-mical technique was used to study the expression of CK19 and Cx43 in various stages of oral carcinogenesis. RESULTS: The CK19 positive staining were distributed in the basal cell layer in the normal rat lingual mucosa. While CK19 positive staining were distributed in cytoplasm of supra-basal layers in the mild dysplasia, moderate dysplasia and severe dysplasia. In oral squamous cell carcinoma(OSCC) tissue, CK19 were expressed in all the stratum of epithelium. The positive rate of CK19 in normal, mild, moderate, severe dysplasia and OSCC tissues were respectively 30.00%, 50.00%, 58.33%, 80.00%, and 91.67%. With the lesions getting worse, the positive rate and the intensity of CK19 raised significantly (P<0.05). In normal tongue mucosa, Cx43 proteins were mainly expressed in the membrane of the epithelial cells of the rat tongue. It was weakly positive in the basal cell layer, increased in the stratum spinosum and stratum granulosum, and negative in the stratum corneum. Compared with normal epithelia, the expression of Cx43 in dysplastic and OSCC epithelia decreased significantly. The positive rate of Cx43 in normal, mild, moderate, severe dysplasia and OSCC tissues were respectively 100.00%, 85.71%, 66.67%, 40.00%, and 33.33%. The expression of Cx43 was significantly decreased with severity increasing (P<0.05). CONCLUSION: The expression of CK19 protein significantly increases with the development of rat tongue carcinoma, suggesting that CK19 is associated with carcinogenesis. The expression of Cx43 protein dramatically decrease with the development of rat tongue carcinoma, suggesting that the abnormal expression of Cx43 protein is associated with oral mucosa carcinoma origination. The expression of CK19 and Cx43 has negative correlation. Combined detection of CK19 and Cx43 has an important role in the early diagnosis of OSCC and can help to improve the sensitivity and specificity of the early diagnosis of OSCC.

[Expression of connexin 43 in tongue carcinogenesis].

OBJECTIVE: To study the expression of connexin 43 (Cx43) in various stages of oral carcinogenesis and explore the relation between Cx43 and oral mucous carcinogenesis. METHODS: 4-nitroquinoline-1-oxide (4NQO) was used for inducing oral carcinogenesis in SD rats. Tissue samples were obtained from various stages of the disease including normal oral mucosa, precancerous lesions and oral squamous cell carcinoma. Immunohistochemical method was used to determine the expression of Cx43 in various stages of oral carcinogenesis. RESULTS: In the normal rat lingual mucosa, immunohistochemical staining of Cx43 protein was mainly found in the cell membrane, weakly positive in the basal cell layer, increased in stratum spinosum and stratum granulosum, but was negative in the stratum corneum of normal epithelia. Compared with normal epithelia, was significantly decreased in dysplastic and cancerous oral epithelia the staining. The positive rates of Cx43 were respectively 100.00% (10/10), 85.71% (12/14), 66.67% (8/12), 40.00% (4/10), and 33.33% (4/12) in tongue carcinogenesis (in normal, mild, moderate and severe dysplasia, and squamous cell carcinoma tissues). The differences were statistically significant (P<0.05). CONCLUSION: Expression level of Cx43 protein was dramatically decreased with the development of rat tongue carcinoma induced by 4NQO, suggesting that abnormal expression of Cx43 protein is involved in oral mucosa carcinogenesis. Decreased Cx43 expression is an early sign of oral mucosa carcinogenesis.

[Study on the expression of cytokeratin 19 mRNA in oral squamous cell carcinoma].

OBJECTIVE: To elucidate the possible mechanism of oral carcinogenesis and to explore the value of clinical application of the detection of cytokeratin (CK) 19 for oral squamous cell carcinoma (OSCC) patients. METHODS: The cancerous tissues, para-cancerous tissues and excised lymph nodes were collected from 20 operated patients with OSCC. The patients didn't receive radiotherapy and chemotherapy before hospitalization. The relative expression of CK19 mRNA in those tissues was detected by fluorescent quantitative polymerase chain reaction (FQ-PCR). RESULTS: The expression of CK19 mRNA in the cancerous tissues was 1.85 and 1.66 times higher than that in normal oral mucosa and in para-cancerous tissues, respectively. The expression of CK19 mRNA in lymph nodes from 9 patients with OSCC was positive and the positive rate was 45% (9/20). The positive rate of CK19 mRNA in all lymph nodes from 9 patients with OSCC was 81.8% (18/22), and the positive rate of CK19 mRNA in all lymph nodes from 20 patients with OSCC was 41.9%(18/43). CK19 mRNA level in the cancerous tissues relative to para-cancerous tissues and normal oral mucosa of the patients whose CK19 mRNA expression was positive was lower than that of the patients whose CK19 mRNA expression was negative in lymph nodes, respectively. CONCLUSION: The possible reason that the expression of CK19 mRNA in the cancerous tissues was higher than that in para-cancerous tissues and normal oral mucosa was that the CK19 synthesis in cancerous tissues increased obviously. The detection of CK19 mRNA in lymph nodes was regarded probably as one of the markers for detecting OSCC micrometastasis in lymph nodes. The detection of CK19 mRNA in lymph nodes by FQ-PCR was more sensitive than hematoxylin-eosin staining in diagnosing OSCC micrometastasis.

[Adhesion to buccal epithelial cells of Candida albicans isolates from oral lichen planus].

OBJECTIVE: To investigate the adhesion to buccal epithelial cells of Candida albicans isolates from erosive oral lichen planus (OLP) and nonerosive OLP, and its role in the development of OLP. METHODS: A total of 112 isolates, comprising healthy control (26), erosive OLP (62) and nonerosive OLP (24), were screened for the adhesion by using buccal epithelial cell (BEC) assay. RESULTS: The adhesion to buccal epithelial cells of the isolates from erosive OLP group was stronger than that of those from healthy control. CONCLUSION: Candida albicans, some isolates with a special virulence attribute may contribute to the occurrence and progression of erosive OLP.

[The relationship of Fas and Fas L protein expression in oral carcinogenesis].

OBJECTIVE: The purpose of the study is to investigate the mechanism of immune escape and the expression of Fas and Fas L in oral premalignant lesions (OPLs) and oral squamous cell carcinomas (OSCCs). METHODS: 64 samples, including normal oral mucosa(7), hyperkeratosis(9), premalignant lesions(24) and squamous cell carcinomas(24), were studied. The cells in the test specimens, which demonstrate granular staining, were considered as positive. The expression of Fas and Fas L was evaluated semi-quantitatively as follows: -, no expression; + (mild), < 5% positive cells; ++ (moderate), 6%-25% positive cells; +++ (intense), 26%-50% positive cells; or ++++ (very intense), > 50% positive cells. RESULTS: In the process of oral carcinogenesis, each stage had Fas expression. The positive staining appeared essentially on cell membrane. Various degrees of Fas expression were seen in the diseased tissues. The number of positively stained cells in the moderately and severely dysplastic tissues appeared higher than that in the normal control (P < 0.05). In the OSCC group, the level of expression of Fas antigen decreased significantly by comparison with the normal controls (P < 0.05). Fas L expression was discovered in each stage of the process of oral carcinogenesis. The positive staining appeared in cytoplasm. In hyperkeratotic tissues and OPLs, the number of Fas L expression cells was significantly higher than that in the normal controls. The number of Fas L expression cells of OSCCs increased by comparison with both normal controls and OPLs. CONCLUSION: The results indicate that the expression of Fas and Fas L is involved in oral carcinogenesis and this may be directly related to the mechanism by which the cancer cells evade the host immune assault. Perhaps, Fas/Fas L system may be used as a prognostic biomarker in predicting the behavior of oral premalignant lesions in the near future.

The changes of cytokeratin 19 during oral carcinogenesis.

OBJECTIVE: To investigate the changes of cytokeratin 19 during oral carcinogenesis. METHODS: 53 specimens including normal oral mucosa, oral epithelial hyperplasia, oral epithelial dysplasia and oral squamous cell carcinoma were investigated by immunohistochemistry, SDS-PAGE and Western blotting. RESULTS: CK19 was detectable in suprabasal cell layers in epithelial dysplasia and in oral cancer, especially in poor-differentiated cancerous cells. With the lesions getting worse, the positive rate, the intensity and the constituent ratio of CK19 raised significantly. CONCLUSIONS: The results suggest that the CK19 expression in suprabasal cell layers of oral mucosa can be used as a marker of diagnosis of oral precancerous lesions and CK19 expression is the initial events during oral carcinogenesis.