Associations of dietary antioxidant intake with periodontal health among US adults: An exploratory mediation analysis via mitochondrial function.

AIM: To assess the relationship between dietary antioxidant intake and periodontal health in US adults and the potential role of mitochondrial function. MATERIALS AND METHODS: We performed a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Dietary antioxidant intake was evaluated using three diet-related indices: dietary oxidative balance score (DOBS), dietary total antioxidant capacity (DTAC) of antioxidant vitamins and composite dietary antioxidant index (CDAI). Periodontal parameters included attachment loss (AL) and probing pocket depth (PPD). Mitochondrial dysfunction was assessed using the methylmalonic acid (MMA) level. Weighted multivariable linear regression analyses were employed to investigate the association between dietary antioxidant intake and periodontal status. Additionally, exploratory mediation analyses were conducted to determine the mediating effect of MMA on the association. RESULTS: Totally, 5520 participants were included in our study. Participants with higher DOBS and DTAC scores had lower mean AL/PPD and MMA values. CDAI was negatively associated with mean AL and PPD. Furthermore, MMA mediated 9.4% and 4.9% of the associations between DOBS and mean AL and mean PPD, respectively. MMA also accounted for 7.2% and 3.3% of the association between DTAC and mean AL and PPD, respectively. CONCLUSIONS: The findings support that dietary antioxidant intake helps in improving periodontal health, possibly and partially by enhancing mitochondrial function.

Persistent infection with Porphyromonas gingivalis increases the tumorigenic potential of human immortalised oral epithelial cells through ZFP36 inhibition.

The association between Porphyromonas gingivalis infection and oral squamous cell carcinoma (OSCC) has been established by numerous epidemiological studies. However, the underlying mechanism specific to this connection remains unclear. By bioinformatical analysis, we identified ZFP36 as a potentially significant co-expressed gene in both the OSCC gene database and the persistent infection model of P. gingivalis. To further investigate the role of ZFP36, we established a cell model that human immortalized oral epithelial cells (HIOECs) that were sustainedly infected by P. gingivalis (MOI = 1) for a duration of 30 weeks. Our findings indicated that sustained infection with P. gingivalis inhibited the expression of ZFP36 protein and induced changes in the biological behaviour of HIOECs. The mechanism investigation demonstrated the potential role of ZFP36 in regulating the cancer-related biological behaviour of HIOECs. Subsequent studies revealed that highly expressed CCAT1 could serve as a molecular scaffold in the formation of the ZFP36/CCAT1/MK2 complex. This complex formation enhanced the binding abundance of MK2 and ZFP36, thereby promoting the inhibition of ZFP36 protein phosphorylation. To summarize, low expression of ZFP36 protein under persistent P. gingivalis infection enhances the cancer-related biological behaviour of HIOECs.

Association between ethylene oxide exposure and periodontitis: a cross-sectional study from NHANES 2013-2014.

BACKGROUND: Exposure to ethylene oxide (EO) induces inflammation and oxidative stress, which are the main mechanisms of periodontitis. However, the effect of EO on periodontal health is not unclear. In this study, we aimed to explore the relationship between EO exposure and the risk of periodontitis in general US adults. METHODS: Data used in our study from the National Health and Nutritional Examination Survey (NHANES) 2013-2014. The EO biomarker, hemoglobin adduct of EO (HbEO), was measured in blood samples utilizing high-performance liquid chromatography-tandem mass spectrometry. Periodontitis category was defined by the CDC/AAP according to clinical periodontal parameters. Natural cubic spline, weight multivariable logistic regression analyses and subgroup analysis were used to explore the association between EO exposure and the risk of periodontitis. RESULTS: A total of 1497 participants over the age of 30 were included in our study. A non-linear positive association with periodontitis was identified for HbEO levels. Participants in the highest tertile of HbEO levels were more likely to have poorer periodontal health compared to the lowest tertile (ORtertile3vs1 = 2.80, 95% CI: 1.85-4.24). Similar results were also found in different subgroups. CONCLUSIONS: HbEO levels are positively associated with poor periodontal health in US adults. Additional longitudinal studies are necessary to further enhance our comprehension of the impact of exposure to EO on periodontal status.

J-shaped association between systemic immune-inflammation index and periodontitis: Results from NHANES 2009-2014.

BACKGROUND: To examine the relationship between the systemic immune-inflammation index (SII) and periodontitis and to investigate possible effect modifiers. METHODS: Data used in the present cross-sectional study are from the National Health and Nutrition Examination Survey (NHANES) 2009-2014 (N = 10,301). The SII was calculated using the following formula: (neutrophils count × platelet count)/lymphocytes count. The category of periodontitis was defined by the Centers for Disease Control and Prevention and American Academy of Periodontology (CDC/AAP) classification. We employed natural cubic spline and multivariable logistic regression analyses to evaluate the associations of the SII with periodontitis. RESULTS: The associations between SII and periodontal health followed a J-shape (p < 0.001). The risk of periodontitis tended to reduce with the increment of log2 (SII) in participants with log2 (SII) ≤ 8.66 (odds radio [OR] = 0.83; 95% CI: 0.69-0.999), especially among non-Hispanic Whites (OR = 0.70; 95% CI: 0.52-0.95), and increased with the increment of log2 (SII) in participants with log2 (SII) > 8.66 (OR = 1.19; 95% CI: 1.02-1.38). A similar trend was also observed between the SII and the number of sites with probing pocket depth (PPD) ≥4 mm and clinical attachment loss (CAL) ≥ 3 or 5 mm. Furthermore, we found a significantly stronger correlation between lymphocytes and either neutrophils or platelets in individuals with log2 (SII) > 8.66, as opposed to those with log2 (SII) ≤ 8.66. CONCLUSIONS: There is a J-shaped association between SII and periodontitis in US adults, with an inflection point of log2 (SII) at 8.66, which may provide potential adjunctive treatment strategies for periodontitis with different immune response states. Further prospective trials are still required to confirm our findings.

Association between serum HE4 and poor periodontal health in adult women.

OBJECTIVES: The aim of this study is to explore the association between serum human epididymal protein (HE4) levels and poor periodontal health. MATERIALS AND METHODS: Data used in our study from the National Health and Nutrition Examination Survey (NHANES) 2001-2002 and Gene Expression Omnibus database (GSE10334 and GSE16134). Periodontitis category was defined by the 2017 classification scheme based on clinical periodontal parameters. Univariate and multivariate logistic regression analyses were used to explore the relationship between serum HE4 levels and the risk of periodontitis. GSEA analysis was performed to investigate the function of HE4. RESULTS: A total of 1715 adult women over the age of 30 were included in our study. Compared with the lowest tertile, individuals in the highest tertile of HE4 levels were more likely to be Stage III/IV periodontitis (ORtertile3vs1 = 2.35, 95% CI: 1.35-4.21). The association was still significant in populations who were less than 60 years old, non-Hispanic white, high school graduate, 1.3 < PI ≤ 3.5, non-smoker, current smoker, non-obese, obese, and who had not diabetes mellitus or had not hypertension. In addition, HE4 expression was upregulated in diseased gingival tissues and involved in cell proliferation and immunity. CONCLUSIONS: Serum HE4 is positively associated with poor periodontal health in adult women. CLINICAL RELEVANCE: Patients with high serum HE4 levels are more likely to have Stage III/IV periodontitis. HE4 has the potential to be used as a biomarker to predict the severity of periodontitis.

Association between retinol intake and periodontal health in US adults.

BACKGROUND: Inflammation and oxidative stress are two hallmarks of periodontitis. Retinol is an antioxidant and suppresses expression of pro-inflammatory factors. However, the evidence for an association between retinol intake and periodontitis is limited. Thus, the aim of this study is to assess the association between retinol intake and periodontal health. METHODS: Data used in this cross-sectional study from the National Health and Nutrition Examination Survey (NHANES) 2009-2014 (n = 9081). Dietary intake of retinol was measured based on two 24-h dietary recall interviews. The category of periodontitis was defined by the CDC/AAP according to clinical periodontal parameters. Univariate and multivariate logistic regression analyses were applied to investigate the relationship between retinol intake and the risk of periodontitis. RESULTS: Compared with the lowest tertile, individuals in the highest tertile of retinol intake were less likely to be periodontitis (ORtertile3vs1 = 0.79, 95% CI: 0.65-0.96). The association was still significant in populations who were less than 60 years old (ORtertile3vs1 = 0.80, 95% CI: 0.65-0.97), non-Hispanic black (ORtertile3vs1 = 0.62, 95% CI: 0.42-0.94), PI ≤ 1.3 (ORtertile3vs1 = 0.72, 95% CI: 0.55-0.93), 1.3 < PI ≤ 3.5 (ORtertile3vs1 = 0.70, 95% CI: 0.55-0.89), non-smoker (ORtertile3vs1 = 0.63, 95% CI: 0.48-0.81), obesity (ORtertile3vs1 = 0.68, 95% CI: 0.49-0.94) and who had not diabetes mellitus (ORtertile3vs1 = 0.79, 95% CI: 0.65-0.95) or had hypertension (ORtertile3vs1 = 0.63, 95% CI: 0.47-0.84). CONCLUSION: Retinol intake is inversely associated with poor periodontal health in US adults.

SESN1, negatively regulated by miR-377-3p, suppresses invasive growth of head and neck squamous cell carcinoma by interaction with SMAD3.

Sestrin 1 (SESN1) is a stress-inducible protein that suppresses tumors in numerous cancers. However, the function of SESN1 in head and neck squamous cell carcinoma (HNSCC) is not clear and needs to be elucidated. Here, SESN1 expression was downregulated in HNSCC tissues and cell lines, and low SESN1 expression was positively correlated with poor prognosis in patients with HNSCC. Moreover, SESN1 overexpression inhibited the proliferation, migration, and invasion of HSC-6 and CAL-33 cells. In addition, the binding relationship between miR-377-3p and SESN1 was confirmed using luciferase reporter and RNA immunoprecipitation assays. Downregulation of SESN1 expression was consistent with high levels of miR-377-3p in HNSCC tissues. Linear regression analysis of clinical HNSCC tissues revealed a negative correlation between miR-377-3p and SESN1 expression. Moreover, co-immunoprecipitation mass spectrometry analysis revealed that SESN1 interacted with SMAD3, and SMAD3 reversed the increased proliferation, migration, and invasion of HSC-6 and CAL-33 cells caused by SESN1 knockdown. In conclusion, these findings provide evidence that SESN1 functions as a tumor suppressor and reveal the miR-377-3p-SESN1-SMAD3 regulatory axis that contributes to proliferation, migration, and invasion in HNSCC development, which may represent an interventional target for HNSCC therapy.

Comprehensive Analysis of the PRDXs Family in Head and Neck Squamous Cell Carcinoma.

The peroxidase family of peroxiredoxins (PRDXs) plays a vital role in maintaining the intracellular balance of ROS. However, their function in head and neck squamous cell carcinoma (HNSCC) has not been investigated. We therefore explored the value of PRDXs in HNSCC. We found that the expression of PRDX1, PRDX4, and PRDX5 in HNSCC increased while the expression of PRDX2 decreased. Moreover, the high expression of PRDX4/5/6 indicated a poor prognosis. Lower expression of PRDX1/5 was linked to more immune cell infiltration, higher expression of immune-related molecules and a more likely response to anti-PD-1 treatment. Moreover, PRDX5 knockdown inhibited HNSCC cell proliferation, invasion and metastasis and it might promote apoptosis through its antioxidant property. Taken together, our study highlights the potential role of PRDXs in HNSCC. The function of PRDX5 in the development of HNSCC and the formation of the immune microenvironment makes it a promising potential therapeutic target.

Immune-related lncRNA classification of head and neck squamous cell carcinoma.

BACKGROUND: Long noncoding RNAs (lncRNAs) play a critical role in innate and adaptive immune responses. Thus, we aimed to identify ideal subtypes for head and neck squamous cell carcinoma (HNSCC) based on immune-related lncRNAs. METHODS: TCGA HNSCC cohort was divided into two datasets (training and validation dataset), and 960 previously characterized immune-related lncRNAs were extracted for non-negative matrix factorization analysis. We characterized our HNSCC subtypes based on biological behaviors, immune landscape and response to immunotherapy in both training and validation cohort. A lncRNA-signature was generated to predict our HNSCC subtypes, and essential lncRNAs involved in tumor microenvironment (TME) were identified. RESULTS: We developed and validated two HNSCC subtypes (C1 and C2) based on the 70 lncRNAs in the training and validation cohort. C2 subtype displayed good prognosis, high immune cell infiltration, immune-related genes expression and sensitivity to PD-1 blockade. C1 subtype was associated with high activity of mTORC1 signaling and glycolysis as well as high fraction of inactive immune cells. Finally, we generated a 31-lncRNA signature that could predict our above subtypes with high accurate. Additionally, TRG-AS1 was identified as the essential lncRNA involving TME formation. Knockdown of TRG-AS1 inhibited the expression of HLA-A, HLA-B, HLA-C, CXCL9, CXCL10 and CXCL11. High expression of TRG-AS1 indicated a favorable prognosis in HNSCC and anti-PD-L1 cohort (IMvigor210). CONCLUSIONS: Our study establishes a novel HNSCC classification on the basis of 31-lncRNA, helping to identify beneficiaries for anti-PD-1 treatment. In addition, a critical lncRNA TRG-AS1 is identified as a new potential prognosis biomarker as well as therapeutic target.

Survival Rates of Splinted and Nonsplinted Prostheses Supported by Short Dental Implants (≤8.5 mm): A Systematic Review and Meta-Analysis.

PURPOSE: To evaluate and compare the implant survival rates, marginal bone loss, and mechanical complications of prostheses supported by splinted and nonsplinted short implants (≤8.5 mm). MATERIAL AND METHODS: Electronic database (MEDLINE, CENTRAL, Web of Science, and EMBASE) and manual searches up to May 2021 were conducted to identify studies comparing splinted and nonsplinted short implants (≤8.5 mm). The primary outcome was implant survival rate. Secondary outcomes were marginal bone loss and mechanical complications. The quality of included studies and risk-of-bias were assessed according to the Newcastle-Ottawa Scale. A random-effects model was used to analyze the data. RESULTS: Twelve studies fulfilled the inclusion criteria and featured 1506 short implants (596 nonsplinted and 910 splinted) with a follow-up time ranging from 1 to 16 years. Quantitative analysis found no statistically significant differences between splinted and nonsplinted short implants (≤8.5 mm) for survival rate (RR = 0.98; 95% CI 0.96, 1.01; p = 0.26)) and marginal bone loss (SMD = -0.08; 95% CI - 0.23, 0.07; p = 0.28). Veneer chipping, abutment screw breakage, screw loosening, and loss of retention were reported in the selected studies as common complications. However, no statistically significant difference was found between splinted and nonsplinted short implants (RR = 0.56; 95% CI 0.20, 1.54; p = 0.26). CONCLUSIONS: Within the limitations of the present meta-analysis, it might be concluded that splinted short implants (≤8.5 mm) do not present superior performance in survival rate, marginal bone maintenance and prevention of mechanical complications compared with single-unit prostheses.

SPDEF suppresses head and neck squamous cell carcinoma progression by transcriptionally activating NR4A1.

SAM pointed domain containing E26 transformation-specific transcription factor (SPDEF) plays dual roles in the initiation and development of human malignancies. However, the biological role of SPDEF in head and neck squamous cell carcinoma (HNSCC) remains unclear. In this study, the expression level of SPDEF and its correlation with the clinical parameters of patients with HNSCC were determined using TCGA-HNSC, GSE65858, and our own clinical cohorts. CCK8, colony formation, cell cycle analysis, and a xenograft tumor growth model were used to determine the molecular functions of SPDEF in HNSCC. ChIP-qPCR, dual luciferase reporter assay, and rescue experiments were conducted to explore the potential molecular mechanism of SPDEF in HNSCC. Compared with normal epithelial tissues, SPDEF was significantly downregulated in HNSCC tissues. Patients with HNSCC with low SPDEF mRNA levels exhibited poor clinical outcomes. Restoring SPDEF inhibited HNSCC cell viability and colony formation and induced G0/G1 cell cycle arrest, while silencing SPDEF promoted cell proliferation in vitro. The xenograft tumor growth model showed that tumors with SPDEF overexpression had slower growth rates, smaller volumes, and lower weights. SPDEF could directly bind to the promoter region of NR4A1 and promoted its transcription, inducing the suppression of AKT, MAPK, and NF-κB signaling pathways. Moreover, silencing NR4A1 blocked the suppressive effect of SPDEF in HNSCC cells. Here, we demonstrate that SPDEF acts as a tumor suppressor by transcriptionally activating NR4A1 in HNSCC. Our findings provide novel insights into the molecular mechanism of SPDEF in tumorigenesis and a novel potential therapeutic target for HNSCC.

Comprehensive Characterization of Immune Landscape Based on Epithelial-Mesenchymal Transition Signature in OSCC: Implication for Prognosis and Immunotherapy.

Current anatomic TNM stage classification fails to capture the immune heterogeneity of oral squamous cell carcinoma (OSCC). Increasing evidence indicates the strong association between epithelial-mesenchymal transition (EMT) and tumor immune response. In this study, we employed an EMT signature to classify OSCC patients into epithelial- (E-) and mesenchymal- (M-) phenotypes using TCGA and GSE41613 transcriptome data. The ESTIMATE and CIRBERSORT analyses implied that the EMT signature genes originated from the stroma of the bulk tissue. The M-subtype tumors were characterized as "immune-hot" with more immune cell infiltration than the E-subtype ones. The low infiltration of active immune cells, the high infiltration of inactive immune cells, and the high expressions of immune checkpoints demonstrated an immunosuppressive characteristic of the M-subtype tumors. Moreover, we developed and validated a novel prognostic classifier based on the EMT score, the expressions of seven immune checkpoints, and the TNM stages, which could improve the prediction efficiency of the current clinical parameter. Together, our findings provide a better understanding of the tumor immune heterogeneity and may aid guiding immunotherapy in OSCC.

Derivation and Validation of a Prognostic Scoring Model Based on Clinical and Pathological Features for Risk Stratification in Oral Squamous Cell Carcinoma Patients: A Retrospective Multicenter Study.

OBJECTIVE: To develop and validate a simple-to-use prognostic scoring model based on clinical and pathological features which can predict overall survival (OS) of patients with oral squamous cell carcinoma (OSCC) and facilitate personalized treatment planning. MATERIALS AND METHODS: OSCC patients (n = 404) from a public hospital were divided into a training cohort (n = 282) and an internal validation cohort (n = 122). A total of 12 clinical and pathological features were included in Kaplan-Meier analysis to identify the factors associated with OS. Multivariable Cox proportional hazards regression analysis was performed to further identify important variables and establish prognostic models. Nomogram was generated to predict the individual's 1-, 3- and 5-year OS rates. The performance of the prognostic scoring model was compared with that of the pathological one and the AJCC TNM staging system by the receiver operating characteristic curve (ROC), concordance index (C-index), calibration curve, and decision curve analysis (DCA). Patients were classified into high- and low-risk groups according to the risk scores of the nomogram. The nomogram-illustrated model was independently tested in an external validation cohort of 95 patients. RESULTS: Four significant variables (physical examination-tumor size, imaging examination-tumor size, pathological nodal involvement stage, and histologic grade) were included into the nomogram-illustrated model (clinical-pathological model). The area under the ROC curve (AUC) of the clinical-pathological model was 0.687, 0.719, and 0.722 for 1-, 3- and 5-year survival, respectively, which was superior to that of the pathological model (AUC = 0.649, 0.707, 0.717, respectively) and AJCC TNM staging system (AUC = 0.628, 0.668, 0.677, respectively). The clinical-pathological model exhibited improved discriminative power compared with pathological model and AJCC TNM staging system (C-index = 0.755, 0.702, 0.642, respectively) in the external validation cohort. The calibration curves and DCA also displayed excellent predictive performances. CONCLUSION: This clinical and pathological feature based prognostic scoring model showed better predictive ability compared with the pathological one, which would be a useful tool of personalized accurate risk stratification and precision therapy planning for OSCC patients.

Integrative Analysis of TP53INP2 in Head and Neck Squamous Cell Carcinoma.

TP53INP2 plays an important role in regulating gene transcription and starvation-induced autophagy, however, its function in head and neck squamous cell carcinoma (HNSCC) remains unclear. Therefore, we assessed the expression and prognostic value of TP53INP2. In addition, RNAseq, miRNAseq, copy number variation, and mutation profiles from The Cancer Genome Atlas (TCGA) dataset were applied to evaluate the distinctive genomic patterns related to TP53INP2 expression. We found that TP53INP2 expression was lower in HNSCC compared with normal controls. Patients with higher TP53INP2 expression had longer survival time. Knockdown of TP53INP2 promoted cell viability. Functional analysis exhibited that TP53INP2 was linked to DNA replication, DNA repair, cell cycle, and multiple metabolic pathways. Moreover, TP53INP2 might affect the expression of multiple genes via enhancing the transcriptional activity of nuclear hormone receptors. A competing endogenous RNA (ceRNA) network consisting of 33 lncRNAs, eight miRNAs, and 13 mRNAs was constructed based on the expression of TP53INP2. Taken together, our study highlights the potential value of TP53INP2 in predicting the survival of HNSCC and its important role in the genesis and development of HNSCC.

Targeting methyltransferase PRMT5 retards the carcinogenesis and metastasis of HNSCC via epigenetically inhibiting Twist1 transcription.

Protein arginine methyltransferase 5 (PRMT5) is an important type II arginine methyltransferase that can play roles in cancers in a highly tissue-specific manner, but its role in the carcinogenesis and metastasis of head and neck squamous cell carcinoma (HNSCC) remains unclear. Here, we detected PRMT5 expression in HNSCC tissues and performed series of in vivo and in vitro assays to investigate the function and mechanism of PRMT5 in HNSCC. We found that PRMT5 was overexpressed in dysplastic and cancer tissues, and associated with lymph node metastasis and worse patient survival. PRMT5 knockdown repressed the malignant phenotype of HNSCC cells in vitro and in vivo. PRMT5 specific inhibitor blocked the formation of precancerous lesion and HNSCC in 4NQO-induced tongue carcinogenesis model, prevented lymph node metastasis in tongue orthotopic xenograft model and inhibited cancer development in subcutaneous xenograft model and Patient-Derived tumor Xenograft (PDX) model. Mechanistically, PRMT5-catalyzed H3R2me2s promotes the enrichment of H3K4me3 in the Twist1 promoter region by recruiting WDR5, and subsequently activates the transcription of Twist1. The rescue experiments indicated that overexpressed Twist1 abrogated the inhibition of cell invasion induced by PRMT5 inhibitor. In summary, this study elucidates that PRMT5 inhibition could reduce H3K4me3-mediated Twist1 transcription and retard the carcinogenesis and metastasis of HNSCC.

Comprehensive Analysis of Prognostic Alternative Splicing Signatures in Oral Squamous Cell Carcinoma.

BACKGROUND: Alternative splicing (AS) plays an essential role in tumorigenesis and progression. This study aimed to develop a novel prognostic model based on the AS events to obtain more accurate survival prediction and search for potential therapeutic targets in oral squamous cell carcinoma (OSCC). METHODS: Seven types of AS events in 326 OSCC patients with RNA-seq were obtained from the TCGA SpliceSeq tool and the TCGA database. Cox analysis, the least absolute shrinkage and selection operator Cox regression and random forest were employed to establish prognostic models. Genomics of Drug Sensitivity in Cancer (GDSC) was adopted to estimate the possible drug sensiticity. Prognostic splicing factor (SF)-AS network was constructed by Cytoscape. RESULTS: The final model included 12 AS events, showing satisfactory performance. The area under the curve for 3- and 5-year survival in the training cohort was 0.83 and 0.82, respectively while that in internal validation was 0.83 and 0.82 accordingly. The calibration curve also indicated a satisfactory agreement between the observation and the predictive values. Low-risk patients stratified by the final model presented higher sensitivity to three chemo drugs. Besides, the prognostic SF-AS regulatory network contained five key SFs and 62 AS events. CONCLUSIONS: We developed a powerful prognostic AS signature for OSCC and deepened the understanding of SF-AS network regulatory mechanisms. Low-risk patients tended to be more sensitive to the three chemo drugs while five key SFs including CELF2, TIA1, HNRNPC, HNRNPK, and SRSF9 were identified as potential prognostic biomarkers, which may offer new prospects for effective therapies of OSCC.

Association between APOBEC3H-Mediated Demethylation and Immune Landscape in Head and Neck Squamous Carcinoma.

Immunotherapy has been demonstrated as a promising strategy in controlling head and neck squamous cell carcinoma (HNSC). The AID/APOBEC family is well characterized as DNA mutator and considered to play critical roles in immune responses in HNSC. However, the expression pattern and deamination-dependent demethylation roles of AID/APOBECs in HNSC are unclear. In this study, the RNA-seq and DNA methylation profiles of HNSC from TCGA database and cell-based experiments were applied to analyze the relationships between AID/APOBEC expression levels, patients' clinical outcomes, methylation alterations, and immune responses. Here, we found that APOBEC3H was abnormally upregulated in HNSC patients. HPV+ patients tended to have higher APOBEC3H levels than HPV- patients. Remarkably, patients with high APOBEC3H levels showed a favorable overall survival. Furthermore, tumors with high APOBEC3H levels exhibited a genome-wide DNA hypomethylation pattern. APOBEC3H was identified to demethylate and upregulate CXCL10 and improve CD8+ T cell tumor infiltration in the tumor microenvironment. Collectively, APOBEC3H plays critical roles in CD8+ T cell immune infiltration and activation in HNSC, which may be a potential biomarker for oncoimmunotherapy in HNSC.

Role of the arecoline/YAP1/BMP4 pathway in promoting endothelial-mesenchymal transition in oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSF) is a potentially malignant lesion characterized by epithelial-mesenchymal transition (EMT). Bone morphogenetic protein 4 (BMP4) promotes EMT in fibrotic diseases, but the underlying mechanisms and its potential role in OSF are unclear. This study investigates whether BMP4 plays a role in the pathogenesis of OSF and explores the underlying mechanisms. METHODS: The expression of BMP4 and the EMT proteins E-cadherin and vimentin was investigated in OSF specimens by immunohistochemical staining. Pearson's correlation analysis was conducted to explore the correlation between BMP4 and the EMT markers. Western blotting and RT-PCR assays were used to analyze the effect of arecoline (a known EMT-promoting pathogenic factor in OSF) on BMP4 and identify the transcription factor involved. Confocal microscopy was used to observe the intracellular sublocalization of the identified transcription factor, Yes-associated protein 1 (YAP1). Finally, siRNA silencing of BMP4 was used to determine its effect on YAP1 activation and arecoline-induced EMT. RESULTS: BMP4 is overexpressed in OSF and plays a role in EMT, as its expression correlates with the expression of E-cadherin and vimentin. Arecoline induces BMP4 expression via the activation of YAP1 (through its nuclear translocation). Furthermore, the YAP1/BMP4 mechanism is the main molecular event in arecoline-induced EMT, as knockdown of BMP4 expression affects expression of the EMT markers and inhibits extracellular matrix accumulation. CONCLUSIONS: Arecoline induces EMT in OSF via the YAP1/BMP4 pathway. Thus, BMP4 could be considered as a potential therapeutic target for the treatment of OSF.

Screening and identification of biomarkers associated with clinicopathological parameters and prognosis in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a major type of malignant tumor of the oral cavity. Despite marked advances in the management and diagnosis of OSCC, the associated overall survival ratio has only exhibited a modest increase in recent years. The present study aimed to identify potential crucial genes associated with clinical features and prognosis for OSCC, and to provide a basis for further investigation. RNA-sequencing data and corresponding clinical information were downloaded from The Cancer Genome Atlas database and differentially expressed mRNAs (DEmRNAs) were identified using the edgeR package. Bioinformatics analysis was performed to identify differentially expressed clinical features-associated mRNAs (CFmRNAs) and enhance the current knowledge of the function of them. Functional enrichment analysis and protein-protein interplay (PPI) network analysis were then performed to better understand CFmRNAs. Survival-associated genes were analyzed with Kaplan-Meier survival curves and the log-rank test. A total of 2,013 DEmRNAs between OSCC samples and normal tissues were identified, 180 of which were associated with clinical features. A total of 17 GO terms and 4 KEGG pathways were significantly enriched in functional enrichment analysis. A total of 4 hub genes (albumin, statherin, neurotensin and mucin 7) were identified in the PPI network analysis. A total of 6 genes (DDB1 and CUL4 associated factor 4 like 2, opiorphin prepropeptide, R3H domain containing like, transmembrane phosphatase with tensin homology, actin like 8 and protocadherin α 11) were observed to have an influence on survival. The DEmRNAs identified may have a crucial role in the genesis and development of OSCC and may be further developed for diagnostic, therapeutic and prognostic applications for OSCC in the future.

A 3-mRNA-based prognostic signature of survival in oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the most common type of head and neck squamous cell carcinoma with an unsatisfactory prognosis. The aim of this study was to identify potential prognostic mRNA biomarkers of OSCC based on analysis of The Cancer Genome Atlas (TCGA). METHODS: Expression profiles and clinical data of OSCC patients were collected from TCGA database. Univariate Cox analysis and the least absolute shrinkage and selection operator Cox (LASSO Cox) regression were used to primarily screen prognostic biomarkers. Then multivariate Cox analysis was performed to build a prognostic model based on the selected prognostic mRNAs. Nomograms were generated to predict the individual's overall survival at 3 and 5 years. The model performance was assessed by the time-dependent receiver operating characteristic (ROC) curve and calibration plot in both training cohort and validation cohort (GSE41613 from NCBI GEO databases). In addition, machine learning was used to assess the importance of risk factors of OSCC. Finally, in order to explore the potential mechanisms of OSCC, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was completed. RESULTS: Three mRNAs (CLEC3B, C6 and CLCN1) were finally identified as a prognostic biomarker pattern. The risk score was imputed as: (-0.38602 × expression level of CLEC3B) + (-0.20632 × expression level of CLCN1) + (0.31541 × expression level of C6). In the TCGA training cohort, the area under the curve (AUC) was 0.705 and 0.711 for 3- and 5-year survival, respectively. In the validation cohort, AUC was 0.718 and 0.717 for 3- and 5-year survival. A satisfactory agreement between predictive values and observation values was demonstrated by the calibration curve in the probabilities of 3- and 5- year survival in both cohorts. Furthermore, machine learning identified the 3-mRNA signature as the most important risk factor to survival of OSCC. Neuroactive ligand-receptor interaction was most enriched mostly in KEGG pathway analysis. CONCLUSION: A 3-mRNA signature (CLEC3B, C6 and CLCN1) successfully predicted the survival of OSCC patients in both training and test cohort. In addition, this signature was an independent and the most important risk factor of OSCC.