Interactive effects of CDKN2B-AS1 gene polymorphism and habitual risk factors on oral cancer.

Oral squamous cell carcinoma (OSCC) is a common malignant disease associated with a high mortality rate and heterogeneous disease aetiology. Cyclin dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1), is a long noncoding RNA that has been shown to act as a scaffold, sponge, or signal hub to promote carcinogenesis. Here, we attempted to assess the effect of CDKN2B-AS1 single-nucleotide polymorphisms (SNPs) on the susceptibility to OSCC. Five CDKN2B-AS1 SNPs, including rs564398, rs1333048, rs1537373, rs2151280 and rs8181047, were analysed in 1060 OSCC cases and 1183 cancer-free controls. No significant association of these five SNPs with the risk of developing OSCC was detected between the case and control group. However, while examining the clinical characteristics, patients bearing at least one minor allele of rs1333048 (CA and CC) were more inclined to develop late-stage (stage III/IV, adjusted OR, 1.480; 95% CI, 1.129-1.940; p = 0.005) and large-size (greater than 2 cm in the greatest dimension, adjusted OR, 1.347; 95% CI, 1.028-1.765; p = 0.031) tumours, as compared with those homologous for the major allele (AA). Further stratification analyses demonstrated that this genetic correlation with the advanced stage of disease was observed only in habitual betel quid chewers (adjusted OR, 1.480; 95% CI, 1.076-2.035; p = 0.016) or cigarette smokers (adjusted OR, 1.531; 95% CI, 1.136-2.063; p = 0.005) but not in patients who were not exposed to these major habitual risks. These data reveal an interactive effect of CDKN2B-AS1 rs1333048 with habitual exposure to behavioural risks on the progression of oral cancer.

Potential impact of ADAM-10 genetic variants with the clinical features of oral squamous cell carcinoma.

A disintegrin and metalloproteinase domain-containing protein 10 (ADAM-10) involves in the tumour progression, but the impacts of single-nucleotide polymorphism (SNP) of ADAM-10 on oral squamous cell carcinoma (OSCC) remain unclear. The aim of this study was to investigate the influence of SNP of ADAM-10 on the clinical features of OSCC in male Taiwanese. Five loci of ADAM-10 SNPs including rs653765 (C/T), rs2305421 (A/G), rs514049 (A/C), rs383902 (T/C) and rs2054096 (A/T) were genotyped by TaqMan allelic discrimination in 1138 OSCC patients and 1199 non-OSCC individuals. The ADAM-10 SNP rs2305421 GG (AOR: 1.399, 95% CI: 1.045-1.874, p = 0.024) and G allele (AOR: 1.170, 95% CI: 1.012-1.351, p = 0.034) illustrated a significantly higher genotypic frequencies in the OSCC group compared to the distribution of the ADAM-10 SNP rs2305421 AA wild type. In the subgroup analysis, the ADAM-10 SNP rs383902 TC+CC was significantly correlated to tumour size larger than T2 in betel quid chewer (AOR: 1.375, 95% CI: 1.010-1.872, p = 0.043), while the ADAM-10 SNP rs653765 CT+TT was significantly associated with tumour size larger than T2 in cigarette smoker (AOR: 1.346, 95% CI: 1.023-1.772, p = 0.034). The results from The Cancer Genome Atlas revealed highest ADAM-10 mRNA level in T2 stage of current smokers with head and neck squamous cell carcinoma (HNSCC). In conclusions, the ADAM-10 SNP rs2305421 G allele is associated with the presence of OSCC, and the ADAM-10 SNP rs383902 TC+CC and ADAM-10 SNP rs653765 CT+TT correlates to large tumour size in specific conditions.

Hispolon induces apoptosis in oral squamous cell carcinoma cells through JNK/HO-1 pathway activation.

Oral squamous cell carcinoma (OSCC) has a high recurrence rate and poor prognosis. Hispolon, a polyphenolic compound with antiviral, antioxidant, and anticancer activities, is a potential chemotherapy agent. However, few studies have investigated the anti-cancer mechanism of hispolon in oral cancer. This present study used the cell viability assay, clonogenic assay, fluorescent nuclear staining, and flow cytometry assay to analyse the apoptosis-inducing effects of hispolon in OSCC cells. After hispolon treatment, the apoptotic initiators, cleaved caspase-3, -8, and - 9, were upregulated, whereas the cellular inhibitor of apoptosis protein-1 (cIAP1) was downregulated. Furthermore, a proteome profile analysis using a human apoptosis array revealed the overexpression of heme oxygenase-1 (HO-1) by hispolon, which was determined to be involved in caspase-dependent apoptosis. Moreover, cotreatment with hispolon and mitogen-activated protein kinase (MAPK) inhibitors revealed that hispolon induces apoptosis in OSCC cells through activation of the c-Jun N-terminal kinase (JNK) pathway and not the extracellular signal-regulated kinase (ERK) or p38 pathway. These findings indicate that hispolon may exert an anticancer effect on oral cancer cells by upregulating HO-1 and inducing caspase-dependent apoptosis by activating the JNK pathway.

Is OLP potentially malignant? A clue from ZNF582 methylation.

OBJECTIVE: Whether oral lichen planus (OLP) was potentially malignant remains controversial. Here, we examined associations of ZNF582 methylation (ZNF582m ) with OLP lesions, dysplastic features and squamous cell carcinoma (OSCC). MATERIALS AND METHODS: This is a case-control study. ZNF582m was evaluated in both lesion and adjacent normal sites of 42 dysplasia, 90 OSCC and 43 OLP patients, whereas ZNF582m was evaluated only in one mucosal site of 45 normal controls. High-risk habits affecting ZNF582m such as betel nut chewing and cigarette smoking were also compared in those groups. RESULTS: OLP lesions showed significantly lower ZNF582m than those of dysplasia and OSCC. At adjacent normal mucosa, ZNF582m increased from patients of OLP, dysplasia, to OSCC. In addition, ZNF582m at adjacent normal sites in OLP patients was comparable to normal mucosa in control group. Dysplasia/OSCC patients with high-risk habits exhibited significantly higher ZNF582m than those without high-risk habits. However, ZNF582m in OLP patients was not affected by those high-risk habits. CONCLUSIONS: OLP is unlikely to be potentially malignant based on ZNF582m levels. ZNF582m may also be a potential biomarker for distinguishing OLP from true dysplastic features and OSCC, and for monitoring the malignant transformation of OLP, potentially malignant disorders with dysplastic features and OSCC.

Complement C1q mediates the expansion of periportal hepatic progenitor cells in senescence-associated inflammatory liver.

Most hepatocellular carcinomas (HCCs) develop in patients with chronic hepatitis, which creates a microenvironment for the growth of hepatic progenitor cells (HPCs) at the periportal area and subsequent development of HCCs. We investigated the signal from the inflammatory liver for this pathogenic process in the hepatic conditional ß-catenin knockout mouse model. Senescent ß-catenin-depleted hepatocytes in aged mice create an inflammatory microenvironment that stimulates periportal HPC expansion but arrests differentiation, which predisposes mice to the development of liver tumors. The release of complement C1q from macrophages in the inflammatory niche was identified as the unorthodox signal that activated the ß-catenin pathway in periportal HPCs and was responsible for their expansion and de-differentiation. C1q inhibitors blocked the ß-catenin pathway in both the expanding HPCs and the liver tumors but spared its orthodox pathway in pericentral normal hepatocytes. This mechanism has been validated in human liver specimens from patients with chronic hepatitis. Taken together, these results demonstrate that C1q- mediated activation of ß-catenin pathway in periportal HPCs is a previously unrecognized mechanism for replenishing hepatocytes in the inflammatory liver and, if unchecked, for promoting hepatocarcinogenesis. C1q may become a new target for blocking carcinogenesis in patients with chronic hepatitis.

Lozenges with probiotic strains enhance oral immune response and health.

OBJECTIVE: Probiotics participate in regulating oral microbiota and reducing the prevalence of oral diseases; however, clinical research on probiotics is insufficient. Therefore, in this study, we performed in vitro screening of potential oral protective probiotic strains and then evaluated the clinical efficacy of the selected strains on maintaining oral health. MATERIALS AND METHODS: Fifty healthy individuals were recruited and randomly assigned into the placebo group and probiotics group, which included three strains of probiotics, Lactobacillus salivarius subs. salicinius AP-32, Lactobacillus paracasei ET-66, and Lactobacillus plantarum LPL28. Each group was blindly administered placebo or probiotics for four weeks. RESULTS: Next-generation sequencing results showed that the oral microbiota of Lactobacillus salivarius in the oral cavity were significantly increased in subjects supplemented with mixed probiotic lozenges. The anti-bacterial activities of viable probiotics were observed within two weeks. Both IgA levels and Lactobacillus and Bifidobacterium abundances in the oral cavity were significantly increased in the experimental groups, along with a reduced formation of plaque. Most participants reported that their oral health conditions and intestinal symptoms had improved. CONCLUSIONS: Overall, our clinical study suggests that oral probiotic lozenges may enhance oral immunity, modulate oral microbiota, and improve oral health.

Deoxyshikonin Mediates Heme Oxygenase-1 Induction and Apoptotic Response via p38 Signaling in Tongue Cancer Cell Lines.

Deoxyshikonin (DSK), a phytochemical constituent, has been documented to elicit various oncostatic properties alone or in combination with established therapeutics. However, its role in restraining oral squamous cell carcinoma (OSCC) is mostly unclear. Here, we examined the tumor-suppressive effect of DSK and explored the molecular mechanisms underlying DSK's activities on controlling oral cancer. Our results showed that DSK dose-dependently lessened the cell viability of tongue cancer cell lines, involving induction of cell cycle arrest at the sub-G1 phase and apoptotic cell death. Moreover, a unique signature of apoptosis-related proteins, including augmented nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) expression and caspase activation, was observed in DSK-treated tongue cancer cell lines. Furthermore, DSK-mediated upregulation of HO-1 and cleavage of caspase-9 and -3 were significantly inhibited by pharmacological blockage of p38 kinase. Collectively, these data revealed that DSK halted cell cycle progression and elicited cell apoptosis in tongue cancer cell lines, reshaping a p38-dependent profile of apoptotic proteome. Our findings provided novel insights into the therapeutic implications of a natural compound on the management of OSCC.

Oral microbial dysbiosis and its performance in predicting oral cancer.

Dysbiosis of oral microbiome may dictate the progression of oral squamous cell carcinoma (OSCC). Yet, the composition of oral microbiome fluctuates by saliva and distinct sites of oral cavity and is affected by risky behaviors (smoking, drinking and betel quid chewing) and individuals' oral health condition. To characterize the disturbances in the oral microbial population mainly due to oral tumorigenicity, we profiled the bacteria within the surface of OSCC lesion and its contralateral normal tissue from discovery (n = 74) and validation (n = 42) cohorts of male patients with cancers of the buccal mucosa. Significant alterations in the bacterial diversity and relative abundance of specific oral microbiota (most profoundly, an enrichment for genus Fusobacterium and the loss of genus Streptococcus in the tumor sites) were identified. Functional prediction of oral microbiome shown that microbial genes related to the metabolism of terpenoids and polyketides were differentially enriched between the control and tumor groups, indicating a functional role of oral microbiome in formulating a tumor microenvironment via attenuated biosynthesis of secondary metabolites with anti-cancer effects. Furthermore, the vast majority of microbial signatures detected in the discovery cohort was generalized well to the independent validation cohort, and the clinical validity of these OSCC-associated microbes was observed and successfully replicated. Overall, our analyses reveal signatures (a profusion of Fusobacterium nucleatum CTI-2 and a decrease in Streptococcus pneumoniae) and functions (decreased production of tumor-suppressive metabolites) of oral microbiota related to oral cancer.

Initiating narrative medicine into dental education: Opportunity, change, and challenge.

Recently, the patient-centered and comprehensive dental treatment are emphasized as the same important competency as traditional clinical skill training in dental education. It is a silver lining to reorganize current dental education and redefine the role of dentistry to dentist, patient, and society. Narrative medicine has emerged as a variant from medical humanities and takes inspiration from philosophy, literature, poetry, art, ethics, and social sciences. Narrative medicine adds humanistic care with empathy and listening to patients in daily care. In this article, we introduce the definition of narrative medicine, the concept of narrative dentistry, implementation of narrative medicine into dental education, and challenges in initiating narrative dentistry. During the current COVID-19 pandemic, it also affords the opportunity to initiate narrative medicine into dental education, dentist could emerge to heal patient holistically, but not simply eliminate oral diseases.

FLLL32 Triggers Caspase-Mediated Apoptotic Cell Death in Human Oral Cancer Cells by Regulating the p38 Pathway.

Oral cancer is the most common oral malignant tumor in Taiwan. Although there exist several methods for treatment, oral cancer still has a poor prognosis and high recurrence. FLLL32, a synthetic analog of curcumin with antitumor activity, is currently known to induce melanoma apoptosis and inhibit tumor growth in various cancers. However, few studies have examined the mechanisms of FLLL32 in oral cancer. In this study, we explore whether FLLL32 induces apoptosis in oral cancer. We determined that FLLL32 can inhibit the cell viability of oral cancer. Next, we analyzed the effect of FLLL32 on the cell cycle of oral cancer cells and observed that the proportion of cells in the G2/M phase was increased. Additionally, annexin-V/PI double staining revealed that FLLL32 induced apoptosis in oral cancer cells. Data from the Human Apoptosis Array revealed that FLLL32 increases the expression of cleaved caspase-3 and heme oxygenase-1 (HO-1). FLLL32 activates proteins such as caspase-8, caspase-9, caspase-3, PARP, and mitogen-activated protein kinases (MAPKs) in apoptosis-related molecular mechanisms. Moreover, by using MAPK inhibitors, we suggest that FLLL32 induces the apoptosis of oral cancer cells through the p38 MAPK signaling pathway. In conclusion, our findings suggest that FLLL32 is a potential therapeutic agent for oral cancer by inducing caspase-dependent apoptosis and HO-1 activation through the p38 pathway. We believe that the activation of HO-1 and the p38 pathway by FLLL32 represent potential targets for further research in oral cancer.

Glabridin induces apoptosis and cell cycle arrest in oral cancer cells through the JNK1/2 signaling pathway.

Glabridin, a flavonoid extracted from licorice (Glycyrrhiza glabra), possesses various biological properties, including anticancer activities. However, the effect of glabridin on oral cancer cell apoptosis and the underlying molecular mechanisms has not been elucidated. In this study, we demonstrated that glabridin treatment significantly inhibits cell proliferation in human oral cancer SCC-9 and SAS cell lines. Flow cytometric assays demonstrated that glabridin induced several features of apoptosis, such as sub-G1 phase cell increase and phosphatidylserine externalization. Furthermore, glabridin induced apoptosis dose-dependently in SCC-9 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. Moreover, glabridin increased the phosphorylation of the extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase (JNK) pathways in a dose-dependent manner. Moreover, the inhibition of the JNK1/2 inhibitor significantly reversed the glabridin-induced activation of the caspase pathway. In conclusion, our findings suggest that glabridin induces oral cancer cell apoptosis through the JNK1/2 pathway and is a potential therapeutic agent for oral cancer.

Malignant transformation of Taiwanese patients with oral leukoplakia: A nationwide population-based retrospective cohort study.

BACKGROUND/PURPOSE: Oral leukoplakia (OL) is one of the clinically diagnosed oral potentially malignant disorders (OPMDs) with an increased risk of oral cancer development. In this study, we investigated the malignant transformation of OL in Taiwanese population. METHODS: A retrospective cohort study was analyzed from Taiwan's National Health Insurance Research Database. A comparison cohort was randomly frequency-matched with the OL cohort according to age, sex, and index year. Oral submucous fibrosis (OSF) and oral lichen planus (OLP) were further stratified to evaluate the possible synergistic effects for OL-associated malignant transformation. RESULTS: In this cohort, 102 (5.374%) of 1898 OL patients were observed to transform into oral cancer. The malignant transformation rate was 26.40-fold in the OL cohort than in the comparison cohort after adjustment (95% confidence intervals 18.46-37.77). To further stratify with OSF and OLP, OL with OSF (58.38; 95% confidence intervals 34.61-98.50) and OL with OLP (36.88; 95% confidence intervals 8.90-152.78) had higher risk of malignant transformation rate than OL alone (27.01; 95% confidence intervals 18.91-38.59). The Kaplan-Meier plot revealed the free of malignant transformation rate was significant over the 13 years follow-up period (log-rank test, p < 0.001). CONCLUSION: OL patients exhibited a significantly higher risk of malignant transformation than those without OL. In addition, both OSF and OLP could enhance malignant transformation in patients with OL. However, further studies are required to identify the histopathological and clinical parameters in the pathogenesis of malignant transformation among OPMDs.

Malignant transformation of oral submucous fibrosis in Taiwan: A nationwide population-based retrospective cohort study.

BACKGROUND: Oral submucous fibrosis (OSF) is one of the well-recognized oral potentially malignant disorders. In this study, we investigated the malignant transformation of OSF in a Taiwanese population. METHODS: A retrospective cohort study was analyzed from Taiwan's National Health Insurance Research Database. A comparison cohort was randomly frequency-matched with the OSF cohort according to age, sex, and index year. Oral leukoplakia (OL) was further stratified to evaluate for the possible synergistic effects of OSF-associated malignant transformation. RESULTS: In this cohort, 71 (9.13%) of 778 cases of OSF were observed to transform into oral cancer. The malignant transformation rate was 29.26-fold in the OSF cohort than in the comparison cohort after adjustment (95% confidence intervals 20.55-41.67). To further stratify with OL, OSF with OL (52.46%; 95% confidence intervals 34.88-78.91) had higher risk of malignant transformation rate than OSF alone (29.84%; 95% confidence intervals 20.99-42.42). The Kaplan-Meier plot revealed the rate free of malignant transformation was significant over the 13-year follow-up period (log-rank test, P<.001). The mean duration of malignant transformation was 5.1, 2.7, and 2.2 years for non-OSF, OSF alone, and OSF with OL, respectively. CONCLUSION: Oral submucous fibrosis patients exhibited a significantly higher risk of malignant transformation than those without OSF. OL could enhance malignant transformation in patients with OSF.

Flipped classroom teaching model with video instruction improves skills in local anesthesia training.

Background/purpose: Local anesthesia (LA) training is an essential clinical skill in dental education. However, the traditional teaching method of student-to-student injection has ethical concerns. This study investigated whether a flipped classroom (FC) teaching model with instructional videos improves students' skills in administering LA. Materials and methods: Fourth-year dental students in 2017 (traditional teaching, n = 70) and 2018 (FC model, n = 79) were assessed for their ability to perform an inferior alveolar nerve block and lingual nerve block. The FC group watched pre-recorded videos prior to a hands-on training session. Skills were evaluated using a 24-item checklist converted to letter grades. Perceptions of the FC approach were also surveyed. Results: The FC group showed statistically significantly higher final grades than the traditional teaching group (P < 0.05). Most FC students agreed that the videos improved clarity and learning objectives. Conclusion: The FC teaching model with procedural video instruction improved skills and confidence in administering LA over traditional teaching methods. Videos can be a beneficial supplement in pre-clinical dental training.

Analysis of approved dental teaching projects in the teaching practice research program in 8 dental schools of Taiwan from 2018 to 2023.

Background/purpose: The teaching practice research program was initiated by Taiwan's Ministry of Education in 2018 to improve medical teaching quality. This study analyzed dental teaching projects conducted under this program from 2018 to 2023. Materials and methods: Data of submitted and approved medical (including dental) teaching projects from 2018 to 2023 were obtained from the annual reports released by the program committee. The annual passing rates were calculated by dividing the number of approved dental teaching projects by the total number of approved medical teaching projects in the category of medical and healthcare sciences in a particular year. The 24 approved dental teaching projects were reviewed, classified into different topics in the dental field, and then reported. Results: There were 24 approved dental teaching projects out of a total of 822 approved medical teaching projects from 2018 to 2023. The annual passing rates increased gradually from 2018 (1.4 %) to 2022 (3.9 %) and 2023 (3.8 %) with an overall mean passing rate of 2.9 % over a period of 6 years. Of the 24 approved dental teaching projects, digital dentistry was the most common teaching research topic (9 projects), followed by new teaching models (7 projects), 3D technology (3 projects), endodontics (3 projects), dental histology (one project), and evidence-based method (one project). Conclusion: Digital dentistry and new teaching models were the two predominant dental teaching research topics, suggesting that both are the modern trends in the dental education. However, the dental teaching research projects are still very limited in 8 Taiwanese dental schools.