Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. This study evaluated whether the VEGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could be a biomarker to predict the progression and prognosis of OSCCs... more
Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. This study evaluated whether the VEGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could be a biomarker to predict the progression and prognosis of OSCCs in Taiwan. This study used quantitative real-time reverse transcription-polymerase chain reaction (quantitative RT-PCR) to detect the VEGF mRNA levels in 60 OSCC specimens. Threshold cycle (CT) was defined as the PCR cycle number needed to generate a predetermined amount of DNA (threshold). The relative amount of tissue VEGF mRNA, standardized against the amount of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, was expressed as ΔCT = (VEGF CT - GAPDH CT). For a chosen threshold, a smaller starting copy number of mRNA results in a higher CT value. Thus, the lower the ΔCT, the greater the copy number of VEGF mRNA in tissues. The lower mean VEGF mRNA ΔCT value was significantly associated with OSCCs with larger tumor size (p = 0.040), positive...
The aim of this prospective clinical study was to assess the risk factors associated with failure of mini-implants used for orthodontic anchorage. A total of 140 mini-implants in 44 patients, including 48 miniplates and 92 freestanding... more
The aim of this prospective clinical study was to assess the risk factors associated with failure of mini-implants used for orthodontic anchorage. A total of 140 mini-implants in 44 patients, including 48 miniplates and 92 freestanding miniscrews, were examined in the study. A variety of orthodontic loads were applied. The majority of implants were placed in the posterior maxilla (104/140), and the next most common location was the posterior mandible (34/140). A cumulative survival rate of 89% (125/140) was found by Kaplan-Meier analysis. There was no significant difference in the survival rate between miniplates and freestanding miniscrews, but miniplates were used in more hazardous situations. The Cox proportional-hazards regression model identified anatomic location and peri-implant soft tissue character as 2 independent prognostic indicators. The estimated relative risk of implant failure in the posterior mandible was 1.101 (95% confidence interval, 0.942 to 1.301; P = .046). Th...
Research Interests: Dentistry, Biomedical Engineering, Survival Analysis, Adolescent, Dental Implants, and 16 moreProspective studies, Humans, Female, Male, The, Risk factors, Oral, Middle Aged, Adult, ORTHODONTIC appliances, Periodontitis, Risk Factors, Dental Stress Analysis, Proportional Hazards Models, Bone Plates, and Bone screws
Research Interests:
Research Interests: Dentistry, Flow Cytometry, Multivariate Analysis, Oral and Maxillofacial Surgery, Humans, and 19 moreTaiwan, Female, Male, Young Adult, Oral Cancer, Aged, Middle Aged, Peripheral blood lymphocyte, Oral Squamous Cell Carcinoma (OSCC), Betel Quid, Mouth Neoplasms, Precancerous Conditions, Adult, Analysis of Variance, Oral Squamous Cell Carcinoma, Reference Values, NK Cell, Logistic Models, and Case Control Studies
Research Interests:
The aim of the study was to examine the expressions of p53 and proliferating cell nuclear antigen (PCNA) in oral lichen planus (OLP) in relation to its clinical behavior and the... more
The aim of the study was to examine the expressions of p53 and proliferating cell nuclear antigen (PCNA) in oral lichen planus (OLP) in relation to its clinical behavior and the patients' oral habits. Immunohistochemical study was carried out to investigate the expressions of p53 and PCNA in 56 OLP specimens. The results were correlated with the clinical behavior of the disease and the patients' oral habits. The expression rates were further compared with those of normal oral mucosa (NOM), epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinoma (SCC). The staining rate of p53 (28.6%) and PCNA labeling index (LI) (27.6 +/- 8.8%) in OLP were similar to those in EH ( P = .868, .074, respectively), but higher than those of NOM and lower than those of ED and SCC (all P < .05). In OLP, no significant correlations were found between p53 or PCNA expression and the patients' age, gender, lesion duration, location, size, number of site, presence of pain, presence of local irritant, and the habits of alcohol drinking and cigarette smoking (all P > .05). In addition, the mean PCNA LI of p53+ cases was close to that of p53- cases (P = .38). However, the staining rate of p53 in OLP was higher in areca quid (AQ) chewers compared to abstainers (P = .001), and the mean PCNA LI in atrophic cases was higher than that in hypertrophic cases (P = .029). Interestingly, the staining rate of p53 and mean PCNA LI were significantly increased in AQ chewers with atrophic OLP (100%, 36.7% +/- 9.0%, respectively), which were similar to those in ED and SCC (all P > .05). Although this study could not confirm the precancerous nature of OLP by the relatively low p53 and PCNA expression, the results do suggest that atrophic form OLP and patients with AQ chewing habit may have a higher disease activity in view of higher expression rates of p53 and PCNA in the lesions.
Research Interests: Dentistry, Immunohistochemistry, Adolescent, Linear models, Humans, and 14 moreFemale, Oral Surgery, Male, Oral Lichen Planus, Aged, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Areca Nut, Mouth Neoplasms, Precancerous Conditions, Adult, Mouth mucosa, Analysis of Variance, and Substance-Related Disorders
Research Interests:
Research Interests:
Research Interests: Dentistry, Free Radical, DNA, Antioxidants, South Africa, and 20 moreHumans, Keratinocytes, Copper, Reactive Oxygen Species, vitamin C, Glutathione, Catalase, Oral Oncology, Iron, Oral Cancer, Superoxide Dismutase, Ascorbic Acid, Plant extracts, Betel Quid, Areca Nut, Gingiva, Mouth Neoplasms, Public health systems and services research, Chelating Agents, and Deferoxamine
Esculetin has been shown to selectively induce tumor apoptosis in several types of cancers and is regarded as a promising chemotherapeutic agent. In this study, we showed that esculetin significantly suppressed the growth of oral cancer... more
Esculetin has been shown to selectively induce tumor apoptosis in several types of cancers and is regarded as a promising chemotherapeutic agent. In this study, we showed that esculetin significantly suppressed the growth of oral cancer SAS cells in a dose-dependent manner. DNA content flow cytometry and TUNEL assay revealed that esculetin induced cell cycle arrest and apoptosis. Western blotting showed esculetin increased DR5 protein expression and activated caspase-8, which differed from previous studies conducted in other cell types. Furthermore, treatment with esculetin significantly increased TRAIL-induced apoptosis in SAS cells and the TRAIL-sensitizing effect was blocked by DR5/Fc chimera protein. Our results indicate that esculetin enhances TRAIL-induced apoptosis primarily through upregulation of DR5. Combination of esculetin and TRAIL may be a novel treatment strategy for oral cancers.
Research Interests:
Research Interests: Surgical Oncology, Multivariate Analysis, Humans, Liver Cirrhosis, Smoking, and 22 moreFemale, Alcohol Drinking, Male, Hepatocellular Carcinoma, Squamous Cell Carcinoma, Risk factors, Clinical Sciences, Aged, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Betel Quid, Areca Nut, Mouth Neoplasms, Adult, Mouth mucosa, Mastication, Survival Rate, Prognosis, Risk Factors, Surgical, Predictive value of tests, and Cohort Studies
Research Interests: Dentistry, Tobacco, Humans, Mutation, Smoking, and 16 moreTaiwan, Female, Male, Polymerase Chain Reaction, Aged, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Areca Nut, Mouth Neoplasms, Adult, Oral Squamous Cell Carcinoma, Chi Square Distribution, Adenomatous Polyposis-coli, Codon, Amino Acid Substitution Rates, and Statistics as Topic
Research Interests:
Loss of heterozygosity (LOH) at adenomatous polyposis coli (APC) and mutated in colon cancer (MCC) genes was investigated in 37 untreated human primary oral squamous cell carcinomas (SCCs) using the polymerase chain reaction. LOH was... more
Loss of heterozygosity (LOH) at adenomatous polyposis coli (APC) and mutated in colon cancer (MCC) genes was investigated in 37 untreated human primary oral squamous cell carcinomas (SCCs) using the polymerase chain reaction. LOH was observed in 14 of 26 (53.8%) ...
Research Interests:
Research Interests: Dentistry, Cell Adhesion, Medicinal Plants, Oral and Maxillofacial Surgery, Humans, and 20 moreSmoking, Taiwan, Female, Male, Squamous Cell Carcinoma, Glycoproteins, Oral, Aged, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Neoplasm Invasiveness, Betel Quid, Areca Nut, Mouth Neoplasms, Precancerous Conditions, Epithelial cells, Adult, Mouth mucosa, Survival Rate, and Prognosis
To develop a clinical staging system for maxillary osteoradionecrosis (ORN) in irradiated nasopharyngeal carcinoma (NPC) patients. The data of maxillary ORN cases among 1,758 irradiated NPC patients were analyzed. A staging system based... more
To develop a clinical staging system for maxillary osteoradionecrosis (ORN) in irradiated nasopharyngeal carcinoma (NPC) patients. The data of maxillary ORN cases among 1,758 irradiated NPC patients were analyzed. A staging system based on the degrees of bone exposure (E), infection (I), and bleeding (B) was developed. Correlations between various clinical parameters and stages of maxillary ORN and relationships between treatment modalities and outcomes at each stage were evaluated. Cumulative success of treatment and risk factors that affect treatment outcomes were analyzed. The incidence of maxillary ORN was 2.7% (48/1,758). TNM stage of NPC (p < 0.001), radiation dose (p = 0.029), and tooth extraction (p < 0.001) appeared to have significant influences on disease severity. Success rates between conservative therapy and surgical treatment were not significantly different for Stage I ORN but differed significantly for Stage II (p = 0.013) and Stage III (p = 0.008) lesions. Grade 3 infection and bleeding significantly jeopardized treatment success (p = 0.043 and 0.015, respectively). The risk ratios of treatment failure for Grade 3 infection and bleeding were 2.523 (p = 0.034) and 3.141 (p = 0.027), respectively. More serious maxillary ORN tended to occur in cases with more advanced NPC, higher radiation dose, and history of tooth extraction. Surgical treatment was usually required in Stage II and III ORN. The grades of infection and bleeding are important factors in guidance of treatment and prediction of outcomes.
Research Interests:
Research Interests:
The management of bisphosphonate-related osteonecrosis of the jaws (BRONJ) is challenging and controversial. At present, there is no established medication treatment for the disease. A 78-year-old osteoporotic woman with osteonecrosis of... more
The management of bisphosphonate-related osteonecrosis of the jaws (BRONJ) is challenging and controversial. At present, there is no established medication treatment for the disease. A 78-year-old osteoporotic woman with osteonecrosis of the mandible related to alendronate therapy was referred for treatment. The disease was unresponsive to conservative therapy, including antibacterial mouth rinse, antibiotics, and minor surgical debridement. Teriparatide, a human recombinant pararthyroid hormone peptide 1-34, was then used for treatment. The oral mucosa completely regrew, and pain subsided 4 weeks after the initiation of teriparatide administration. Progressive bone regeneration was found during and after the 6-month period of teriparatide therapy. Our case demonstrated that teriparatide can be an important adjuvant in the management of advanced BRONJ and should be considered prior to major resection with reconstruction. Its true value in the treatment of BRONJ for noncancer patients with osteoporosis warrants future studies.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Biomaterials, Carbon Dioxide, Photochemistry, Glass, Scanning Electron Microscopy, and 13 moreMultidisciplinary, Lasers, Weight Loss, Temperature, Enamel, Phase Transformation, X ray diffraction, Fourier transform infrared spectroscopy, Microstructures, Functional Group, Bioactive Glass, Dental Enamel, and Continuous Wave
Research Interests:
To verify the inhibitory effects of epigallocatechin-3-gallate (EGCG) on the synthesis of hypoxia-induced vascular endothelial growth factor (VEGF) in nasal polyp fibroblasts (NPFs). Eight primary cultures of NPFs were established from... more
To verify the inhibitory effects of epigallocatechin-3-gallate (EGCG) on the synthesis of hypoxia-induced vascular endothelial growth factor (VEGF) in nasal polyp fibroblasts (NPFs). Eight primary cultures of NPFs were established from nasal polyps. Effects of EGCG on the production of hypoxia-inducible factor (HIF)-1 alpha (the most potent VEGF stimulant) and VEGF by NPFs under hypoxic conditions were measured by Western blot analysis. Immunohistochemical staining was used to examine the in vivo expressions of HIF-1 alpha and VEGF in 20 sections of nasal polyps. Western blot analysis showed that cobalt chloride induced HIF-1 alpha and VEGF synthesis in NPFs in a time-dependent manner, reaching a plateau at 4 and 8 hours, respectively, following treatment. Epigallocatechin-3-gallate attenuated the level of HIF-1 alpha induced by cobalt chloride and also reduced cobalt chloride-stimulated VEGF production by suppressing HIF-1 alpha synthesis. Furthermore, oligomycin (a specific HIF-1 alpha inhibitor) combined with EGCG resulted in a more profound inhibition of VEGF synthesis compared with oligomycin or EGCG treatment alone. Nevertheless, the synergistic effect seemed smaller than the sum of their individual actions. Immunohistochemical analysis revealed the presence of HIF-1 alpha and VEGF in NPFs and mononuclear round cells. Intimate alignment of VEGF-positive fibroblasts and proliferating small capillaries was frequently found. Nasal polyp fibroblasts contribute to the pathogenesis of nasal polyps by producing VEGF to promote angiogenesis under hypoxic conditions. Epigallocatechin-3-gallate substantially diminishes HIF-1 alpha and VEGF synthesis in NPFs.
Research Interests:
Although second primary tumors are common in patients with oral squamous cell carcinoma (OSCC), their predisposing factors and treatment guideline remain uncertain. Three hundred ninety-four patients with OSCC who received radical surgery... more
Although second primary tumors are common in patients with oral squamous cell carcinoma (OSCC), their predisposing factors and treatment guideline remain uncertain. Three hundred ninety-four patients with OSCC who received radical surgery from January 2002 to December 2009 were retrospectively reviewed. Forty-five patients developed oral second primary tumors. Areca quid chewing, tongue tumors, and nodal metastasis were risk factors for second primary tumors. Multivariate analyses revealed that no second primary tumor (hazard ratio [HR] = 5.046; 95% confidence interval [CI] = 3.704-12.246; p = .003), contralateral neck dissection for ipsilateral second primary tumors (HR = 6.254; 95% CI = 3.027-13.365; p = .007), and postoperative radiotherapy (RT; HR = 3.987; 95% CI = 1.099-10.381; p = .040) were independent favorable prognostic factors. Areca quid chewing, tongue tumors, and nodal metastasis predisposed patients with OSCC to second primary tumor development. Elective dissection of...
Osteoblast apoptosis is important in the regulation of inflammatory bone resorption. Hypoxia resulting from inflammation enhances glycolysis and apoptosis. Sirtuin 6 (SIRT6) is a modulator of glucose metabolism and apoptosis. In the study... more
Osteoblast apoptosis is important in the regulation of inflammatory bone resorption. Hypoxia resulting from inflammation enhances glycolysis and apoptosis. Sirtuin 6 (SIRT6) is a modulator of glucose metabolism and apoptosis. In the study we assessed the role of SIRT6 in hypoxia-induced glycolysis and apoptosis in osteoblasts, with special attention on the significance of these cellular processes in periapical lesions. Human bone marrow-derived osteoblasts were cultured under hypoxia. Expression of lactate dehydrogenase A was examined by Western blot, and production of lactate was measured by colorimetric assay. Cleavage of poly (adenosine diphosphate ribose) polymerase was used as an apoptosis marker and assessed by Western blot. SIRT6 was overexpressed in osteoblasts by lentiviral gene transduction, and then glycolytic and apoptotic responses were studied. In a rat model of bacteria-induced periapical lesions, expressions of SIRT6 and markers of glycolysis and apoptosis in osteobl...
Research Interests:
The appropriate surface composition and topography are crucial for osseointegration of titanium dental implants, and surface properties are known to enhance cell adhesion and promote expression of specific osteoblastic genes. In this... more
The appropriate surface composition and topography are crucial for osseointegration of titanium dental implants, and surface properties are known to enhance cell adhesion and promote expression of specific osteoblastic genes. In this study, a translucent titanium coating on glass coverslip (TiGlass) was introduced as a potential tool for direct observation of cell behavior on a titanium surface. Scanning electron microscopy, energy-dispersive x-ray analysis, and atomic force microscopy were performed on TiGlass to provide information about its physical properties. Random migration, osteoblastic gene expression, and immunofluorescence cell staining on TiGlass were also examined and analyzed. The translucent titanium surface offered excellent optical characteristics that facilitated transmitted light observations under an optical microscope, transforming the opaque metal into an observable titanium matrix. Random migration analysis of the primary osteoblasts on TiGlass revealed that t...
Research Interests: Dentistry, Biomedical Engineering, Glass, Cell Adhesion, Scanning Electron Microscopy, and 14 moreTitanium, Fluorescent Dyes and Reagents, Atomic Force Microscopy, Dental Materials, Animals, Osteopontin, Alkaline phosphatase, Fluorescent Antibody Technique, Rats, Surface Properties, Wistar Rats, Osteoblasts, Materials Testing, and Vinculin
Overeruption of maxillary molar(s) because of loss of the opposing teeth creates occlusal interference and functional disturbances. To restore proper occlusion, intrusion of the overerupted molars becomes essential before reconstruction... more
Overeruption of maxillary molar(s) because of loss of the opposing teeth creates occlusal interference and functional disturbances. To restore proper occlusion, intrusion of the overerupted molars becomes essential before reconstruction can be initiated. A plausible procedure is orthodontic intrusion, which demands calibrated anchorage support from intraoral multiunit teeth and from headgear wear. In this report, we present a simplified and localized version of the orthodontic appliances in conjunction with mini-implants to intrude the overerupted molars. The purpose of using implants as skeletal anchorage was to eliminate the need for patient compliance for headgear wear and to overcome the difficulty resulting from the shortage of anchor teeth. The results showed that the biological responses of the teeth and the surrounding bony structures to the intrusion appeared normal and acceptable. Furthermore, the periodontal health and vitality of the teeth were well maintained even after...
Research Interests:
Recruitment of macrophages is essential to the pathogenesis of nasal polyps (NP), since this disease is inflammation-related. In this study, the effects of tumor necrosis factor alpha (TNF-alpha) on the expression of C-C chemokine ligand... more
Recruitment of macrophages is essential to the pathogenesis of nasal polyps (NP), since this disease is inflammation-related. In this study, the effects of tumor necrosis factor alpha (TNF-alpha) on the expression of C-C chemokine ligand 2 (CCL2) in fibroblasts derived from nasal polyps (NPFs) were investigated. The roles of cyclooxygenase (COX) 2 and prostaglandins in the mediation of TNF-alpha-stimulated CCL2 gene expression were also investigated. Northern blot analysis was used to study the expression of CCL2 and c-Fos in cultured NPFs. An electrophoretic mobility shift assay was used to explore the interactions between activator protein 1 (AP- 1) and DNA. Immunohistochemistry was used to explore the in vivo expressions of COX-2, CCL2, and CD68 in NPs. The Northern blot analysis showed that TNF-alpha stimulated the expression of CCL2 and COX-2 genes, and the synthesis of CCL2 messenger RNA was COX-2-dependent. A transient elevation of c-Fos and c-Jun messenger RNAs was induced b...
Research Interests:
Recruitment of macrophages is crucial to the pathogenesis of the nasal polyp (NP) because this disease is believed to be inflammation related. Information regarding the expression of C-C chemokine ligand 2 (CCL2), an essential modulator... more
Recruitment of macrophages is crucial to the pathogenesis of the nasal polyp (NP) because this disease is believed to be inflammation related. Information regarding the expression of C-C chemokine ligand 2 (CCL2), an essential modulator of monocyte chemotaxis in nasal polyp fibroblasts (NPFs), remains unavailable. In this study, the effects of tumor necrosis factor (TNF)-a on CCL2 expression in NPFs and the signaling pathway involved were investigated. Primary cultures of NPFs were established from NPs. The expressions of CCL2, c-Fos, and c-Jun mRNAs in NPF after TNF-a stimulation were detected by Northern blot. Western blot was used to examine the activation of mitogen-activated protein kinase (MAPK) signaling pathways. Activator protein (AP) 1/DNA interactions were evaluated by electrophoretic mobility shift assay (EMSA). Northern blot showed that TNF-alpha stimulated CCL2 gene expression in NPFs. Significant increase of B-Raf, phosphorated MAPK including mitogen-activated ERK-act...
Research Interests:
Research Interests: Dentistry, Epidemiology, Medicinal Plants, Gene expression, Cell Culture, and 18 moreCell line, Humans, Taiwan, Glutathione, Oral Oncology, Oral Cancer, Chewing, mRna expression levels, Oral Squamous Cell Carcinoma (OSCC), Areca Nut, Arecoline, Mouth Neoplasms, Mouth mucosa, Public health systems and services research, Mastication, Oral Squamous Cell Carcinoma, Oral mucositis, and Carcinogen
Norcantharidin (NCTD) is the demethylated analogue of cantharidin. In this study, multi-parameter assessments of morphological alterations, clonogenic efficiency, cell growth curves, DNA synthesis, and DNA strand break were employed to... more
Norcantharidin (NCTD) is the demethylated analogue of cantharidin. In this study, multi-parameter assessments of morphological alterations, clonogenic efficiency, cell growth curves, DNA synthesis, and DNA strand break were employed to determine and compare the cytotoxic effects of NCTD on oral cancer KB cell line and normal buccal keratinocytes. The results showed NCTD induced significant cytotoxicity in KB cells after 24 h of exposure. Normal buccal keratinocytes were more resistant to NCTD induced cytotoxicity. The IC(50) of 24 h NCTD treatment for KB and keratinocytes were 15.06 and 216.29 microg/ml, respectively with a keratinocyte/KB selective index of 14.36. Anoikis and membrane blebbing, morphological characterization of apoptosis, were observed in about 90% of KB cells after exposure to 100 microg/ml of NCTD for 24 h compared to about 30% in keratinocytes. In addition, inhibition of colony formation was noted in KB cells even when exposed to low concentration of drug (5 microg/ml) for a short period of time (6 h). NCTD inhibited subsequent cell proliferation in KB but growth of normal keratinocytes was retarded only temporarily. NCTD inhibited DNA synthesis in both KB and normal keratinocytes. However, keratinocytes were more sensitive to DNA synthesis inhibition by low dose of NCTD. Significant DNA strand break was noted in KB cells only after cell viability was reduced to less than 60% of the control. In comparison, normal keratinocytes were resistant to NCTD induced DNA strand break. These results indicated KB cells were more sensitive to NCTD induced cytotoxicity compared to normal keratinocytes. NCTD may be of value in treating oral cancers. The underlying mechanisms of the differential actions of NCTD on these two cell types are worthy of further investigations.
Research Interests:
Research Interests: Dentistry, Immunohistochemistry, Macrophages, Western blotting, Cell line, and 15 moreHumans, Animals, Chemotaxis, Bone Disease, Endodontics, Rats, Western blot, Tumor necrosis factor-alpha, Disease Progression, Anti Inflammatory Activity, Osteoblasts, Somatic Cell Count, Tumor Necrosis Factor–α (TNF), Enzyme Linked Immunosorbent Assay, and Simvastatin
Research Interests:
Research Interests:
Autophagy is a process for recycling intracellular organelles as a survival mechanism. Apoptosis has important biological roles in the pathogenesis of many diseases. This study elucidated the effect of simvastatin on autophagy/apoptosis... more
Autophagy is a process for recycling intracellular organelles as a survival mechanism. Apoptosis has important biological roles in the pathogenesis of many diseases. This study elucidated the effect of simvastatin on autophagy/apoptosis in MC3T3E1 murine osteoblastic cells and also the significance of this action on the progression of induced rat apical periodontitis. We examined the H2O2-stimulated expression of LC3-II (an autophagy marker) and poly (adenosine phosphate ribose) polymerase (PARP) fragmentation (an apoptosis marker) in MC3T3E1 by Western analysis. In a rat model of induced apical periodontitis, the relation between disease progression and osteoblastic expression of Beclin-1 (an autophagy marker) and terminal deoxyuridine triphosphate nick end-labeling (an apoptosis marker) was studied by radiographic and immunohistochemistry analyses. Western blot showed elevated levels of LC3-II and PARP cleavage after H2O2 treatment. An autophagy inhibitor 3-methyladenine promoted whereas rapamycin (an autophagy enhancer) diminished H2O2-induced PARP cleavage. Simvastatin enhanced H2O2-induced LC3-II formation and simultaneously decreased PARP fragmentation. Radiography and immunohistopathology demonstrated that simvastatin reduced the number of apoptotic osteoblasts and the extension of periapical lesions in rats. The number of Beclin-1-synthesizing osteoblasts also increased markedly after simvastatin treatment. We found a negative relation between autophagy and apoptosis in osteoblastic cells. In addition, simvastatin suppressed apoptosis and enhanced autophagy both in vitro and in vivo. Our data implied that simvastain might alleviate the progression of apical periodontitis by promoting autophagy to protect osteoblasts from turning apoptotic.
Research Interests:
Research Interests: Dentistry, Humans, Sex ratio, Taiwan, Female, and 17 moreOral Surgery, Male, Risk factors, Aged, Prevalence, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Questionnaires, Areca Nut, Mouth Neoplasms, Precancerous Conditions, Adult, Mouth mucosa, Analysis of Variance, Odds ratio, Risk Factors, and Logistic Models
Research Interests:
Research Interests:
We recently found that the expression of placenta growth factor (PlGF) in oral squamous cell carcinoma (OSCC) specimens is correlated with the progression and prognosis of OSCC. In this study, serum samples were obtained from 72 OSCC... more
We recently found that the expression of placenta growth factor (PlGF) in oral squamous cell carcinoma (OSCC) specimens is correlated with the progression and prognosis of OSCC. In this study, serum samples were obtained from 72 OSCC patients before and 3 months after surgical cancer excision and from 30 normal controls. Serum PlGF levels were determined by enzyme-linked immunosorbent assay (ELISA). The mean serum PlGF levels were significantly higher in pre-surgery OSCC patients than in normal controls (19.1±10.7 vs. 10.1±4.5, P<0.001). Serum PlGF levels dropped to near the normal control levels after surgical cancer removal. Higher pre-surgery serum PlGF levels were significantly associated with larger tumor size (P=0.015), positive lymph node metastasis (P=0.001), more advanced clinical stages (P=0.002), and loco-regional recurrence (P=0.037). The serum PlGF level was identified as an independent unfavorable prognosis factor by multivariate Cox regression analyses (P=0.014). Kaplan-Meier curve showed that OSCC patients with a higher serum PlGF level had a significantly poorer cumulative recurrence-free survival than those with a lower serum PlGF level (log-rank test, P=0.009). When we used the serum PlGF level of 19.1 pg/ml (mean normal control value plus 2 standard deviations) as a cutoff point, the sensitivity, specificity, and positive predictive value for tumor recurrence was 80%, 56% and 78%, respectively. We conclude that the serum PlGF level may be a valuable biomarker for prediction of therapeutic effect, progression, recurrence and prognosis of OSCC.
Research Interests: Dentistry, Humans, Female, Male, Oral Oncology, and 11 moreAged, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Mouth Neoplasms, Adult, Public health systems and services research, Prognosis, Disease Progression, Enzyme Linked Immunosorbent Assay, Predictive value of tests, and Case Control Studies
Research Interests: Dentistry, Cell Cycle, Enzyme Inhibitors, Multivariate Analysis, Humans, and 24 moreFemale, Male, Oral Oncology, Oral Cancer, Risk factors, Oral Mucosa, Aged, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Kaplan-Meier, Areca Nut, Tumor Suppressor Gene, Mouth Neoplasms, Precancerous Conditions, Adult, Mouth mucosa, Public health systems and services research, Survival Rate, Prognosis, Protein Expression, Oral Squamous Cell Carcinoma, Risk Factors, Cell Cycle Proteins, and Overall Survival
A cell line, TW2.6, has been established from the surgically resected specimen of an untreated primary squamous cell carcinoma of the buccal mucosa from a 48-year-old man who was an areca quid chewer and tobacco smoker. TW2.6 cells... more
A cell line, TW2.6, has been established from the surgically resected specimen of an untreated primary squamous cell carcinoma of the buccal mucosa from a 48-year-old man who was an areca quid chewer and tobacco smoker. TW2.6 cells exhibited morphological features of keratinocytes and replicated rapidly in culture with a doubling time of 24h. The karyotype showed human chromosomes with high hyperdiploidy and complex rearrangements. Western blotting showed pronounced expression of p53 and moderate expression of p21(CIP1). The baseline expressions of p27(KIP1) and p16(INK4a) were barely detectable. Low levels of Bax and Fas were found in TW2.6 cells but Bcl-2 expression was more readily observed. Mutational analysis of p53 gene revealed an A-->G transition at the second base of codon 220, resulting in amino acid substitution from tyrosine to cysteine in the protein. Functional analysis showed that TW2.6 was unable to activate the p53-specific PUMA promoter. Lipofectamine 2000 and calcium phosphate precipitation technique offer good transfection efficiencies for TW2.6 cells and may be used in future transfection experiments. A xenograft-SCID mouse tumor model was established for TW2.6. Histological examination demonstrated that the engrafted tumors maintained the morphological features of a squamous cell carcinoma. It is thought that the establishment of tumorigenic TW2.6 cell line provides a valuable model for AQ and tobacco smoke-associated buccal carcinoma.
Research Interests: Dentistry, Western blotting, Cell line, Humans, Smoking, and 13 moreMale, Oral Oncology, ENT, Middle Aged, Oral Squamous Cell Carcinoma (OSCC), Areca Nut, Mouth Neoplasms, Mouth mucosa, Public health systems and services research, Oral Squamous Cell Carcinoma, Tobacco Smoke, Cheek, and DNA mutational analysis
Research Interests:
Research Interests:
Research Interests: Adolescent, Humans, Female, Male, Mandible, and 4 moreMiddle Aged, Adult, Spinal Osteotomy, and Prognathism
Expression of placenta growth factor (PlGF) mRNA is shown to correlate with the progression and prognosis of several human cancers. In this study, we assessed whether the PlGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could... more
Expression of placenta growth factor (PlGF) mRNA is shown to correlate with the progression and prognosis of several human cancers. In this study, we assessed whether the PlGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could be used to predict the progression and prognosis of OSCCs in Taiwan. This study used quantitative real-time reverse transcription-polymerase chain reaction (quantitative RT-PCR) to detect the PlGF mRNA levels in 63 paired OSCC and adjacent normal-looking oral mucosa (non-OSCC) tissues. Threshold cycle (CT) was defined as the PCR cycle number needed to generate a pre-determined amount of DNA (threshold). For a chosen threshold, a smaller starting copy number of mRNA results in a higher CT value. In this study, the relative expression level of tissue PlGF mRNA in each OSCC patients was expressed as -ΔCT = -(OSCC CT - non-OSCC CT). Thus, the higher the -ΔCT, the greater the copy number of PlGF mRNA in tissues. We found that the higher mean PlGF mRNA -ΔCT value was significantly associated with OSCCs with larger tumor size (p = 0.03), positive lymph node metastasis (p = 0.003), more advanced clinical stages (p = 0.013) or the presence of loco-regional recurrence (p = 0.039). Positive lymph node metastasis (p = 0.019) and PlGF mRNA -ΔCT value >2 (p = 0.016) were identified as two independent unfavorable prognosis factors by multivariate analyses with Cox regression model. Moreover, Kaplan-Meier curve showed that OSCC patients with a PlGF mRNA -ΔCT value >2 had a significantly poorer recurrence-free survival than those with a PlGF mRNA -ΔCT value ≤2 (log-rank test, p = 0.017). The OSCC tissue PlGF mRNA level can be used to predict the progression and prognosis of OSCCs in Taiwan.
Research Interests:
Although intrusion of natural tooth abutments in tooth-implant connected fixed prostheses has been reported, it can also occur to a free-standing natural tooth bounded by implant prostheses. For the patient described in this article,... more
Although intrusion of natural tooth abutments in tooth-implant connected fixed prostheses has been reported, it can also occur to a free-standing natural tooth bounded by implant prostheses. For the patient described in this article, intrusion was noted with a natural tooth bounded by 2 implant-supported prostheses 5 months after insertion of the prostheses. The intrusion was reversed completely after 5 months with appropriate management. The course of treatment and possible mechanisms of intrusion are provided.