Search

Supplementary Tables 1-4. Supplementary Table 1. Odds ratios (ORs) and 95% confidence intervals (CIs) of nasopharyngeal carcinoma (NPC) associated with oral health among ever smokers in southern China (2010-2014). Supplementary Table 2. Stratified odds ratios (ORs) and 95% confidence intervals (CIs) of nasopharyngeal carcinoma (NPC) associated with number of teeth lost after age 20 years.* Supplementary Table 3. Stratified odds ratios (ORs) and 95% confidence intervals (CIs)of nasopharyngeal carcinoma (NPC) associated with frequency of tooth brushing.* Supplementary Table 4. Odds ratios (ORs) and 95% confidence intervals (CIs) of nasopharyngeal carcinoma (NPC) associated with oral health in southern China - restricted to cases interviewed within 30 days of diagnosis (2010-2014).

Background: The association between oral health and risk of nasopharyngeal carcinoma (NPC) is largely unknown. Further understanding could shed light on potential pathogenic mechanisms and preventive measures.Methods: We conducted a population-based case–control study in southern China between 2010 and 2014. We enrolled 2,528 incident NPC cases, aged 20–74 years, and 2,596 controls, randomly selected from the total population registers, with frequency matching to the 5-year age and sex distribution of the cases by geographic region. We interviewed subjects using a structured questionnaire inquiring about oral health indicators and potential confounding factors. We used unconditional logistic regression to estimate multivariate-adjusted ORs with 95% confidence intervals (CI).Results: A higher number of filled teeth was associated with an elevated risk of NPC. Individuals with 1 to 3 and more than 3 teeth filled versus none had adjusted ORs of 1.25 (95% CI, 1.06–1.49) and 1.55 (95% CI, 1.13–2.12), respectively (Ptrend = 0.002). Conversely, the adjusted OR for those who brushed teeth twice or more per day versus once or less per day was 0.62 (95% CI, 0.55–0.70). We detected a borderline significant positive association with earlier age at first adult tooth loss.Conclusion: Our study suggested a positive association between some indicators of poor oral health and risk of NPC. Further studies are needed to confirm whether the findings are causal and, if so, to further explain the underlying mechanisms.Impact: Improvement of oral hygiene might contribute to reducing NPC risk. Cancer Epidemiol Biomarkers Prev; 25(8); 1201–7. ©2016 AACR.

Growth differentiation factor-10 (GDF10) belongs to a member of the transforming growth factor-β (TGF-β) superfamily. Dysfunction of the TGF-β pathway can lead to carcinoma progression. Previous studies have shown that GDF10 acts as a tumor suppressor gene in some cancers. However, the molecular mechanisms of the association between GDF10 and cell functions in nasopharyngeal carcinoma (NPC) remain unclear. In this study, the expression and methylation levels of GDF10 were studied in human subjects and cell lines. Furthermore, overexpression of GDF10 was used to explore its biological function and potential mechanism in NPC cell lines. GDF10 was downregulated in NPC owing to its aberrant promoter methylation. After treatment with 5-aza-2′-deoxycytidine, the expression of GDF10 in NPC cells was reversed. We also confirmed that the overexpression of GDF10 significantly inhibited cell proliferation and tumor growth both in vitro and in vivo, respectively. Additionally, GDF10 overexpression in NPC cells attenuated migration and invasion and inhibited epithelial-to-mesenchymal transition with a decrease in nuclear Smad2 and NF-κB protein accumulation. GDF10 was silenced owing to its promoter hypermethylation, and it might originally act as a functional tumor suppressor via TGF-β/Smad and NF-κB signaling pathways in NPC.

Background Dietary factors, such as consumption of preserved foods, fresh vegetables, and fruits, have been linked to the risk of nasopharyngeal carcinoma (NPC). However, little is known about associations between dietary patterns and the risk of NPC in NPC-endemic areas. Objectives We aimed to evaluate whether dietary patterns are associated with NPC risk. Methods We studied 2554 newly diagnosed NPC patients aged 20–74 y living in 3 endemic regions of southern China, and 2648 population-based controls frequency-matched to case patients by age, sex, and region, between 2010 and 2014. Dietary components were derived from food frequency data in adulthood and adolescence using principal component analysis. Four dietary components were identified and highly similar in adulthood and adolescence. We used multivariable unconditional logistic regression to calculate ORs with 95% CIs for the association between dietary patterns and NPC risk. Results Compared with the lowest quartile, individuals in the highest quartile of the “plant-based factor” in adulthood had a 52% (OR: 0.48; 95% CI: 0.38, 0.59) decreased risk of NPC, and those in the highest quartile of the “animal-based factor” had a >2-fold (OR: 2.26; 95% CI: 1.85, 2.77) increased risk, with a monotonic dose-response trend (P-trend

Background The potential role of occupational exposures in the development of nasopharyngeal carcinoma (NPC) remains unclear, particularly in high-incidence areas. Methods The authors conducted a population-based case-control study, consisting of 2514 incident NPC cases and 2586 randomly selected population controls, in southern China from 2010 to 2014. Occupational history and other covariates were self-reported using a questionnaire. Multivariate logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the risk of NPC associated with occupational exposures. Restricted cubic splines were used to evaluate potentially nonlinear duration-response relations. Results Individuals who had exposure to occupational dusts (OR, 1.45; 95% CI, 1.26-1.68), chemical vapors (OR, 1.37; 95% CI, 1.17-1.61), exhausts/smokes (OR, 1.42; 95% CI, 1.25-1.60), or acids/alkalis (OR, 1.56; 95% CI, 1.30-1.89) in the workplace had an increased NPC risk compared with those who were unexposed. Risk estimates for all 4 categories of occupational exposures appeared to linearly increase with increasing duration. Within these categories, occupational exposure to 14 subtypes of agents conferred significantly higher risks of NPC, with ORs ranging from 1.30 to 2.29, including dust from metals, textiles, cement, or coal; vapor from formaldehyde, organic solvents, or dyes; exhaust or smoke from diesel, firewood, asphalt/tar, vehicles, or welding; and sulfuric acid, hydrochloric acid, nitric acid, and concentrated alkali/ammonia. Conclusions Occupational exposures to dusts, chemical vapors, exhausts/smokes, or acids/alkalis are associated with an excess risk of NPC. If the current results are causal, then the amelioration of workplace conditions might alleviate the burden of NPC in endemic areas. Lay summary The role of occupational exposures in the development of nasopharyngeal carcinoma (NPC) remains unclear, particularly in high-incidence areas. The authors conducted a population-based study with 2514 incident NPC cases and 2586 population controls in southern China and observed that occupational exposures were associated with an increased risk of NPC. Duration-response trends were observed with increasing duration of exposure. These findings provide new evidence supporting an etiologic role of occupational exposures for NPC in a high-incidence region.

Background: The potential effect of alcohol or tea intake on the risk of nasopharyngeal carcinoma (NPC) remains controversial. Methods: In a population-based case–control study in southern China, we assessed alcohol or tea intake from 2,441 histopathologically confirmed NPC cases and 2,546 controls. We calculated mean daily ethanol (g/day) and tea intake (mL/day). Fully adjusted ORs with 95% confidence intervals (CI) were estimated using logistic regression; potential dose–response trends were evaluated using restricted cubic spline analysis. Results: Compared with nondrinkers, no significantly increased NPC risk in men was observed among current alcohol drinkers overall (OR, 1.08; 95% CI, 0.93–1.25), nor among current heavy drinkers (OR for ≥90 g/day ethanol vs. none, 1.32; 95% CI, 0.95–1.84) or former alcohol drinkers. Current tea drinking was associated with a decreased NPC risk (OR, 0.73; 95% CI, 0.64–0.84). Compared with never drinkers, those with the low first three quintiles of mean daily current intake of tea were at significantly lower NPC risk (OR, 0.53, 0.68, and 0.65, respectively), but not significant for the next two quintiles. Current daily tea intake had a significant nonlinear dose–response relation with NPC risk. Conclusions: Our study suggests no significant association between alcohol and NPC risk. Tea drinking may moderately reduce NPC risk, but the lack of a monotonic dose–response association complicates causal inference. Impact: Tea drinking might be a healthy habit for preventing NPC. More studies on biological mechanisms that may link tea with NPC risk are needed.

Background Epstein-Barr virus (EBV) reactivation from latent to lytic infection has been considered as a key step in nasopharyngeal carcinoma oncogenesis. However, epidemiological evidence regarding environmental risk factors for EBV reactivation on a population level remains largely lacking. Methods We enrolled 1916 randomly selected adults from the general population of Guangdong and Guangxi, China, from 2010 to 2014. Information on environmental factors was collected via a structured interview. Serum immunoglobulin A antibodies against EBV viral capsid antigen and nuclear antigen 1 were measured by enzyme-linked immunosorbent assay to evaluate EBV reactivation status. We used logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the associations of EBV reactivation with various environmental factors. Results No associations were observed between EBV reactivation and extensive environmental factors, including alcohol or tea drinking, a history of chronic ear/nose/throat diseases, use of medications or herbs, consumption of salted fish or preserved foods, oral hygiene, sibship structure, and various residential and occupational exposures. Only cigarette smoking was associated with EBV reactivation (current smokers vs never smokers; OR = 1.37; 95% CI = 1.02–1.83), with positive exposure-response trends with increasing intensity, duration, and pack-years of smoking. Conclusions Consistent with previous studies, we found an association between cigarette smoking and EBV reactivation. Other examined exposures were not associated with EBV reactivation. These null results could suggest either more complex interactions between exposures and EBV reactivation or a predominant role of host and/or viral genetic variation.

Epstein–Barr virus (EBV)‐associated nasopharyngeal carcinoma (NPC) cells display conspicuous lipid accumulation. Here, we show that EBV‐encoded membrane protein 2A (LMP2A) induces lipid accumulation in NPC cells by inhibition of lipolytic gene, adipocyte triacylglycerol lipase (ATGL). Inhibition of ATGL results in enhanced lipid accumulation and migratory capacity in NPC cells. Loss of ATGL in NPC cells correlates with poor overall survival., Epstein–Barr virus (EBV)‐associated nasopharyngeal carcinoma (NPC) is one of the most common human cancers in South‐East Asia exhibiting typical features of lipid accumulation. EBV‐encoded latent membrane protein 2A (LMP2A) is expressed in most NPCs enhancing migration and invasion. We recently showed an increased accumulation of lipid droplets in NPC, compared with normal nasopharyngeal epithelium. It is important to uncover the mechanism behind this lipid metabolic shift to better understand the pathogenesis of NPC and provide potential therapeutic targets. We show that LMP2A increased lipid accumulation in NPC cells. LMP2A could block lipid degradation by downregulating the lipolytic gene adipose triglycerol lipase (ATGL). This is in contrast to lipid accumulation due to enhanced lipid biosynthesis seen in many cancers. Suppression of ATGL resulted in enhanced migration in vitro, and ATGL was found downregulated in NPC biopsies. The reduced expression level of ATGL correlated with poor overall survival in NPC patients. Our findings reveal a new role of LMP2A in lipid metabolism, correlating with NPC patient survival depending on ATGL downregulation.

Nasopharyngeal carcinoma (NPC) is a prevalent malignancy in Southeast Asia, hence, identifying easily detectable biomarkers for NPC screening is essential for better diagnosis and prognosis. Using genome‐wide and targeted analyses based on next‐generation sequencing approaches, we previously showed that gene promoters are hypermethylated in NPC tissues. To confirm whether DNA methylation rates of genes could be used as biomarkers for NPC screening, 79 histologically diagnosed NPC patients and 29 noncancer patients were recruited. A convenient quantitative analysis of DNA methylation using real‐time PCR (qAMP) was carried out, involving pretreatment of tissue DNA, and circulating cell‐free DNA (ccfDNA) from nonhemolytic plasma, with methylation‐sensitive and/or methylation‐dependent restriction enzymes. The qAMP analyses revealed that methylation rates of RERG, ZNF671, ITGA4, and SHISA3 were significantly higher in NPC primary tumor tissues compared to noncancerous tissues, with sufficient diagnostic accuracy of the area under receiver operating characteristic curves (AUC). Interestingly, higher methylation rates of RERG in ccfDNA were statistically significant and yielded a very good AUC; however, those of ZNF671, ITGA4, and SHISA3 were not significant. Furthermore, the combination of methylation rates of RERG and ZNF671 in ccfDNA showed higher diagnostic accuracy than either of them individually. In conclusion, the methylation rates of specific genes in ccfDNA can serve as novel biomarkers for early detection and screening of NPC., The present study identified novel blood‐based noninvasive methylation biomarkers for nasopharyngeal carcinoma screening by a combination of RERG and ZNF671 methylation rates in circulating cell‐free DNA.

The human microbiome has been reported to mediate the response to anticancer therapies. However, research about the influence of the oral microbiome on nasopharyngeal carcinoma (NPC) survival is lacking. We aimed to explore the effect of oral microbiota on NPC prognosis.Four hundred eighty-two population-based NPC cases in southern China between 2010 and 2013 were followed for survival, and their saliva samples were profiled using 16s rRNA sequencing. We analyzed associations of the oral microbiome diversity with mortality from all causes and NPC.Within- and between-community diversities of saliva were associated with mortality with an average of 5.29 years follow-up. Lower Faith's phylogenetic diversity was related to higher all-cause mortality [adjusted hazard ratio (aHR), 1.52 (95% confidence interval (CI), 1.06-2.17)] and NPC-specific mortality [aHR, 1.57 (95% CI, 1.07-2.29)], compared with medium diversity, but higher phylogenetic diversity was not protective. The third principal coordinate (PC3) identified from principal coordinates analysis (PCoA) on Bray-Curtis distance was marginally associated with reduced all-cause mortality [aHR, 0.85 (95% CI, 0.73-1.00)], as was the first principal coordinate (PC1) from PCoA on weighted UniFrac [aHR, 0.86 (95% CI, 0.74-1.00)], but neither was associated with NPC-specific mortality. PC3 from robust principal components analysis was associated with lower all-cause and NPC-specific mortalities, with HRs of 0.72 (95% CI, 0.61-0.85) and 0.71 (95% CI, 0.60-0.85), respectively.Oral microbiome may be an explanatory factor for NPC prognosis. Lower within-community diversity was associated with higher mortality, and certain measures of between-community diversity were related to mortality. Specifically, candidate bacteria were not related to mortality, suggesting that observed associations may be due to global patterns rather than particular pathogens.

The dysregulation of epigenetic modification and energy metabolism cooperatively contribute to the tumorigenesis of nasopharyngeal carcinoma (NPC). However, the detailed mechanisms underlying their joint contribution to NPC development and progression remain unclear. Here, we investigate the role of Acy1 Coenzyme A Acyltransferases1 (ACAT1), a key enzyme in the metabolic pathway of ketone bodies, in the proliferation and metastasis of NPC and to elucidate the underlying molecular mechanisms. Ketogenesis, plays a critical role in tumorigenesis. Previously, we reported two enzymes involved in ketone body metabolism mediate epigenetic silencing and act as tumor suppressor genes in NPC. Here, we identify another key enzyme, Acetyl-CoA acetyltransferase 1 (ACAT1), and show that its transcriptional inactivation in NPC is due to promoter hypermethylation. Ectopic overexpression of ACAT1 significantly suppressed the proliferation and colony formation of NPC cells in vitro. The migratory and invasive capacity of NPC cells was inhibited by ACAT1. The tumorigenesis of NPC cells overexpressing ACAT1 was decreased in vivo. Elevated ACAT1 in NPC cells was accompanied by an elevated expression of CDH1 and a reduced expression of vimentin and SPARC, strongly indicating that ACAT1 is involved in regulating epithelial-mesenchymal transition (EMT). We also found that ACAT1 contributes to increased intracellular levels of β-hydroxybutyrate (β-HB). Exogenously supplied β-HB significantly inhibits the growth of NPC cells in a dose-dependent manner. In summary, ACAT1 may function as a tumor suppressor via modulation of ketogenesis and could thus serve as a potential therapeutic target in NPC. In summary, our data suggest that regulation of ketogenesis may serve as adjuvant therapy in NPC.

BACKGROUND Chemokines are important in inflammation, immunity, tumor progression, and metastasis. The purpose of this research was to find an integrated-RNA signature of chemokine family genes to predict the survival prognosis in head and neck squamous carcinoma (HNSC) patients. MATERIAL AND METHODS Relevant data of 504 HNSC patients were extracted from The Cancer Genome Atlas (TCGA) database. Through analyzing RNA sequencing data, the univariate Cox model was used to identify chemokine family genes associated with survival and then to develop a multiple-RNA signature in the training set. The prediction value of this multiple-RNA signature was further verified in the validation and entire sets. The receiver operating characteristic curves were used to assess the predictive value of this multiple-RNA signature. RESULTS Eleven chemokines were included in this prognostic signature. Based on this 11-chemokine signature, we further categorized patients as high or low risk. Compared with low-risk patients, high-risk patients had shorter overall survival (OS) time in the training set [hazard ratio (HR)=3.497, 95% confidence interval (CI)=2.142-5.711, p

Purpose: Caffeic acid phenethyl ester (CAPE) is the main polyphenol extracted from honeybee propolis, which inhibits the growth of several kinds of tumor. This study aimed to assess the inhibitory effect of CAPE in nasopharyngeal carcinoma (NPC), evaluate the synergistic action of CAPE in radiotherapy sensitivity of NPC cell lines and further elucidate the possible molecular mechanism involved. Materials and methods: CCK-8 assay was used to analyze cell proliferation ability. Colony formation assay was used to evaluate the clonogenic ability and radio-sensitiveness of NPC cells by CAPE treatment. Wound-healing and transwell assay were used to assess the motility of cells. The expression of key molecules of the epithelial-mesenchymal transition (EMT) was determined by western blot analysis and changes in radiation sensitivity were measured by colony-formation assay. cDNA microarray analysis was used to determine differentially expressed genes with and without CAPE treatment, with Gene Ontology enrichment of gene function and KEGG pathways determined. Cell cycle and apoptosis were detected by flow cytometry and western blot analysis. Results: CAPE suppressed the viability of NPC cell lines time- and dose-dependently. It induced apoptosis in NPC cells along with decreased expression of Bcl-XL and increased cleavage of PARP and expression of Bax. G1 phase arrest was induced by CAPE with ower expression of CDK4, CDK6, Rb and p-Rb. The migratory and invasive ability of NPC cells was decreased by the EMT pathway. The irradiation sensitivity of NPC cells was enhanced with CAPE treatment. CAPE specifically inhibited nuclear factor κB (NF-κB) signaling pathway by suppressing p65 subunit translocation from cytoplasm to nucleus. CAPE treatment was synergistic with chemotherapy and radiotherapy. Conclusion: CAPE may inhibit the proliferation and metastasis of NPC cells but enhance radiosensitivity in NPC therapy by inhibiting the NF-κB pathway. CAPE could be a potential therapeutic compound for NPC therapy.

Background To assess the effects of Epstein–Barr virus (EBV) and human papillomavirus (HPV) infection on the tumor microenvironment, we examined the relationship between viral infection status, macrophage migration inhibitory factor (MIF), and tumor-associated macrophages in nasopharyngeal carcinoma (NPC). Methods A tissue microarray containing 150 cores from 90 patients with NPC and six with chronic inflammation was used. EBV and HPV status were detected using in situ hybridization with commercial EBER1 and HPV16/18 probes. Immunofluorescence double staining of MIF, pan-macrophage marker CD68, M1 macrophage marker CD11c, and M2 macrophage marker CD163 were analyzed using the same tissue microarray. The levels of these markers between NPC and inflammation cases and between tumor nests and stroma were compared. Correlations among these markers were analyzed. Results We found EBER1(+) cases in 90% of NPC patients, including 10% EBV/HPV co-infection. M1 macrophages mainly infiltrated the tumor nest, while M2 macrophages infiltrated the tumor stroma. We found a significant positive correlation between EBER1 levels and MIF levels in tumor nests and a significant positive correlation between HPV16/18 and CD11c(+) cell levels in NPC tissues. Conclusions It is suggested that MIF is associated with EBV, and M1 macrophage infiltration is affected by HPV status in NPC.

Background: Nasopharyngeal carcinoma (NPC) is a common tumor in head and neck and is prevailing in China. Although treatment methods continue to improve, the prognosis of advanced patients is still unsatisfactory. Kinesin family member 15 (KIF15) is a kind of protein, which regulates the process of cell mitosis and plays an important role in several types of human cancers. This study aims to investigate the role of KIF15 in NPC.Methods: First, the differential expression of KIF15 in NPC and para-carcinoma tissues was evaluated based on both data collected from Gene Expression Omnibus (GEO) database and immunohistochemical analysis on clinical specimens collected from in-house cohort. Next, cell lines C666-1 and CNE-2Z were selected for the construction of KIF15‑knockdown cell models. Then, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, wound healing, Transwell and clone formation assays were used to detect the proliferation, apoptosis, migration, invasion and colony formation of nasopharyngeal carcinoma cells in vitro. A mouse xenograft model was constructed for in vivo study. Furthermore, Human Apoptosis Antibody Array kit was used to screen possible targets of KIF15 in NPC. In the end, the potential molecular mechanisms underlying the effects of KIF15 was explored through western blot analysis.Results: The results showed that the expression of KIF15 in NPC tissues is higher than that in para-carcinoma tissues, and high levels of KIF15 expression are associated with low survival rates. In addition, knockdown of KIF15 inhibited cell proliferation, migration, invasion and colony formation ability, and promoted cell apoptosis. What’s more, in vivo xenograft experiments showed that down-regulation of KIF15 can inhibit NPC tumor growth. Moreover, the mechanism study demonstrated a variety of apoptosis-related proteins as well as PI3K/AKT and MAPK signaling pathways may be involved in KIF15-induced regulation of NPC.Conclusions: In short, we demonstrated that KIF15 is overexpressed and accelerated the progression of nasopharyngeal carcinoma. It can be used as a new prognostic indicator as well as a potential drug target for the treatment of NPC.

Polygenic risk scores (PRS) have the potential to identify individuals at risk of diseases, optimizing treatment, and predicting survival outcomes. Here, we construct and validate a genome-wide association study (GWAS) derived PRS for nasopharyngeal carcinoma (NPC), using a multi-center study of six populations (6 059 NPC cases and 7 582 controls), and evaluate its utility in a nested case-control study. We show that the PRS enables effective identification of NPC high-risk individuals (AUC = 0.65) and improves the risk prediction with the PRS incremental deciles in each population (Ptrend ranging from 2.79 × 10−7 to 4.79 × 10−44). By incorporating the PRS into EBV-serology-based NPC screening, the test’s positive predictive value (PPV) is increased from an average of 4.84% to 8.38% and 11.91% in the top 10% and 5% PRS, respectively. In summary, the GWAS-derived PRS, together with the EBV test, significantly improves NPC risk stratification and informs personalized screening.

Background Acy1 Coenzyme A Acyltransferases1 (ACAT1) is a key enzyme in the metabolism of ketone bodies, but its expression and biological function in the pathogenesis of NPC remains underexplored. Methods The mRNA and protein expression levels of ACAT1 in NPC and normal control tissues were analyzed by qPCR and immunohistochemistry staining, respectively. GEO database was applied for meta-analysis of ACAT1 mRNA expression and DNA promoter methylation. The role of ACAT1 in NPC proliferation was examined by CCK8 and colony formation assays in vitro and tumorigenicity in vivo. The wound healing and transwell assays were used for analyzing the migratory and invasive ability. cDNA microarray analysis was performed to identify the genes involved in epithelial-mesenchymal transition and dysregulated by ACAT1. These changes were further confirmed by western blot. Results We found that ACAT1 is inactivated in NPC cell lines and primary tissues. DNA microarray data showed higher methylation in the CpG island region of ACAT1 in NPC than normal tissues. The demethylating reagent 5-aza-dC significantly restored the transcription of ACAT1 in NPC cell lines, suggesting that ACAT1 was inactivated by DNA promoter hypermethylation. Ectopic overexpression of ACAT1 remarkably suppressed the proliferation and colony formation of NPC cells in vitro. As well, the tumorigenesis of NPC cells overexpressing ACAT1 was decreased in vivo. In addition, the migratory and invasive capacities of NPC cells was inhibited by ACAT1 overexpression. Importantly, the higher level of ACAT1 was accompanied by an increased expression of CDH1, EPCAM, and a decreased expression of vimentin and SPARC. This strongly indicates that ACAT1 is able to affect the epithelial-mesenchymal transition in NPC, thereby controlling cellular motility. In addition, we found that ACAT1 expression increases the intracellular level of β-HB. Moreover, exogenous β-HB remarkably inhibits the growth of NPC cells in a dose-dependent manner. Conclusions We have discovered that the ketone body metabolism enzyme ACAT1 is epigenetically downregulated in NPC and acts as a potential tumor suppressor in NPC. Our findings highlight the possibility of using the modulation of ketone body metabolism as effective adjuvant therapy for NPC.

The relationship between oral health and the risk of nasopharyngeal carcinoma (NPC) was previously established. However, the role of oral microbiome has not been evaluated in the disease in a large epidemiological study. This paper clearly establishes a difference in the oral microbiomes between NPC patients and healthy controls which cannot be explained by other confounding factors. It furthermore identifies a pair of closely related coexcluding organisms associated with the disease, highlighting the importance of modern methods for single-nucleotide resolution in 16S rRNA sequence characterization. To the best of our knowledge, this is one of the first examples of cancer-associated niche specialization of the oral microbiome., Oral health and changes in the oral microbiome have been associated with both local and systemic cancer. Poor oral hygiene is a known risk factor for nasopharyngeal carcinoma (NPC), a virally associated head and neck cancer endemic to southern China. We explored the relationship between NPC and the oral microbiome using 16S rRNA sequencing in a study of 499 NPC patients and 495 population-based age and sex frequency-matched controls from an area of endemicity of Southern China. We found a significant reduction in community richness in cases compared to that in controls. Differences in the overall microbial community structure between cases and controls could not be explained by other potential confounders; disease status explained 5 times more variation in the unweighted UniFrac distance than the next most explanatory variable. In feature-based analyses, we identified a pair of coexcluding Granulicatella adiacens amplicon sequence variants (ASVs) which were strongly associated with NPC status and differed by a single nucleotide. The G. adiacens variant an individual carried was also associated with the overall microbial community based on beta diversity. Co-occurrence analysis suggested the two G. adiacens ASVs sit at the center of two coexcluding clusters of closely related organisms. Our results suggest there are differences in the oral microbiomes between NPC patients and healthy controls, and these may be associated with both a loss of microbial diversity and niche specialization among closely related commensals. IMPORTANCE The relationship between oral health and the risk of nasopharyngeal carcinoma (NPC) was previously established. However, the role of oral microbiome has not been evaluated in the disease in a large epidemiological study. This paper clearly establishes a difference in the oral microbiomes between NPC patients and healthy controls which cannot be explained by other confounding factors. It furthermore identifies a pair of closely related coexcluding organisms associated with the disease, highlighting the importance of modern methods for single-nucleotide resolution in 16S rRNA sequence characterization. To the best of our knowledge, this is one of the first examples of cancer-associated niche specialization of the oral microbiome.

In order to improve the mechanical strength of micro-booster based on 3,4-dinitrofurazanofuroxan (DNTF), 2,4-toluene diisocyanate (TDI) was introduced into the composite binder of nitrocotton (NC) and glycidyl azide polymer (GAP). A full-liquid explosive ink containing DNTF, binder and solvent was printed layer by layer. By the polymer cross-linking technology, the inkjet printed sample with three-dimensional network structure was obtained. The morphology, crystal form, density, mechanical strength, thermal decomposition and micro scale detonation properties of the printed samples were tested and analyzed. The results show that the printed sample has a smooth surface and a dense internal microstructure, and the thickness of the single layer printing is less than 10 &mu, m. Compared with the raw material DNTF, the thermal decomposition temperature and activation energy of the printed samples do not change significantly, indicating better thermal stability. The addition of curing agent TDI increases the mechanical properties and charge density of the energetic composites. The elastic modulus and hardness are increased by more than 20%. The charge density can attain 1.773 g&middot, cm&minus, 3, which can reach 95.5% of the theoretical density. The critical detonation size of the sample can reach 1 mm &times, 0.01 mm or less and the detonation velocity can achieve 8686 m&middot, s&minus, 1, which exhibits excellent micro-scale detonation ability.

Objectives Given the role of exposures related to residence in the development of nasopharyngeal carcinoma (NPC) has not been well explored, present study aims to investigate the magnitude and pattern of associations for NPC with lifelong residential exposures. Materials and Methods We carried out a multi-center, population-based case-control study with 2533 incident NPC cases and 2597 randomly selected population controls in southern China between 2010 and 2014. We performed multivariate logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the risk of NPC associated with residential exposures. Results Compared with those living in a building over lifetime, risk of NPC was higher for individuals living in a cottage (OR: 1.56; 95% CI: 1.34–1.81) or in a boat (3.87; 2.07–7.21). NPC risk was also increased in individuals using wood (1.34; 1.03–1.75), coal (1.70; 1.17–2.47), or kerosene (3.58; 1.75–7.36) vs. using gas/electricity as cooking fuel; using well water (1.57; 1.34–1.83), river water (1.80; 1.47–2.21), or spring/pond/stream water (2.03; 1.70–2.41) vs. tap water for source of drinking water; living in houses with smaller-sized vs. larger windows in the bedroom (3.08; 2.46–3.86), hall (1.89; 1.55–2.31) or kitchen (1.67; 1.34–2.08); and increasing exposure to cooking smoke [(1.53; 1.20–1.94) for high exposure)] or burned incense [(1.59; 1.31–1.95) for daily use)]. Weighted Cox regression analysis corroborated these results. Conclusion Poorer residential conditions and household air pollution are associated with an increased risk of NPC. Large-scale studies in other populations or longitudinal studies are warranted to further corroborate these findings.

The aim of this study was to investigate the inactivation of the MutS homolog human 3 (MSH3) gene by promoter methylation in nasopharyngeal carcinoma (NPC). Methylation-specific PCR, semi-quantitative reverse transcription PCR and immunohistochemical analysis were used to detect methylation and the mRNA and protein expression levels of MSH3 in 54 cases of NPC tissues and 16 cases of normal nasopharyngeal epithelial (NNE) tissues. The association between promoter methylation and mRNA expression, and the mRNA and protein expression of the gene and clinical factors was analyzed. The promoter methylation of MSH3 was detected in 50% (27/54) of the primary tumors, but not in the 16 NNE tissues. The mRNA and protein expression levels were significantly decreased in the 54 cases of human NPC as compared to the 16 NNE tissues (P0.05). On the whole, MSH3 was frequently inactivated by promoter methylation and its mRNA and protein expression correlated with the primary tumor stage in NPC.

Epstein-Barr virus (EBV)-encoded latent membrane protein 2A (LMP2A) promotes the motility of nasopharyngeal carcinoma (NPC) cells. Previously, we have shown that the localization of integrin β4 (ITGβ4) is regulated by LMP2A, with ITGβ4 concentrated at the cellular protrusions in LMP2A-expressing NPC cells. In the present study, we aim to further investigate mechanisms involved in this process and its contribution to cell motility. We show that expression of LMP2A was correlated with increased epidermal growth factor receptor (EGFR) activation, elevated levels of intracellular Ca2+, calpain activation and accelerated cleavage of ITGβ4. Activation of EGFR and calpain activity was responsible for a redistribution of ITGβ4 from the basal layer of NPC cells to peripheral membrane structures, which correlated with an increased migratory capacity of NPC cells. Furthermore, we demonstrated that the calpain inhibitor calpastatin was downregulated in NPC primary tumors. In conclusion, our results point to LMP2A-mediated targeting of the EGFR/Ca2+/calpain/ITGβ4 signaling system as a mechanism underlying the increased motility of NPC cells. We suggest that calpain-facilitated cleavage of ITGβ4 contributes to the malignant phenotype of NPC cells., Summary: LMP2A expression in nasopharyngeal carcinoma cells increases EGFR activation and cytosolic Ca2+, subsequently stimulates calpain-dependent cleavage of ITGβ4 and enhances cell motility.

BACKGROUND To the authors' knowledge, no studies to date have explored familial risks of nasopharyngeal carcinoma (NPC) in detail and quantified its lifetime risk in high-incidence populations. METHODS The authors conducted a population-based case-control study of 2499 NPC cases and 2576 controls randomly selected in southern China from 2010 through 2014. Unconditional logistic regression was used to estimate multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) associated with a family history of NPC. In addition, the authors compiled a reconstructed cohort comprising 40,781 first-degree relatives of cases and controls to calculate the lifetime cumulative risk of NPC. RESULTS Individuals with a first-degree family history of NPC were found to be at a >4-fold risk of NPC (OR, 4.6; 95% CI, 3.5-6.1) compared with those without such a history, but had no excess risk of other malignancies. The excess risk was higher for a maternal than a paternal history and was slightly stronger for a sibling compared with a parental history, and for a sororal than a fraternal history. Among relatives of cases, the cumulative risk of NPC up to age 74 years was 3.7% (95% CI, 3.3%-4.2%), whereas that among relatives of controls was 0.9% (95% CI, 0.7%-1.2%). Cumulative risk was higher in siblings than in parents among relatives of cases, whereas no such difference was noted among relatives of controls. CONCLUSIONS Individuals with a family history of NPC have a substantially higher risk of NPC. These relative and cumulative risk estimates can guide the development of strategies for early detection and clinical consultation in populations with a high incidence of NPC. Cancer 2017;123:2716-25. © 2017 American Cancer Society.

Background An association between a nonmedicinal herbal diet and nasopharyngeal carcinoma (NPC) has often been hypothesized but never thoroughly investigated. Methods This study enrolled a total of 2469 patients with incident NPC and 2559 population controls from parts of Guangdong and Guangxi Provinces in southern China between 2010 and 2014. Questionnaire information was collected on the intake of traditional herbal tea and herbal soup as well as the specific herbal plants used in soups and other potentially confounding lifestyle factors. Multivariate logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the NPC risk in association with herbal tea and soup intake. Results Ever consumption of herbal tea was not associated with NPC risk (OR, 1.03; 95% CI, 0.91-1.17). An inverse association was observed for NPC among ever drinkers of herbal soup (OR, 0.78; 95% CI, 0.67-0.90) but without any monotonic trend with an increasing frequency or duration of herbal soup consumption. Inverse associations with NPC risk were detected with 9 herbal plants used in herbal soup, including Ziziphus jujuba, Fructus lycii, Codonopsis pilosula, Astragalus membranaceus, Semen coicis, Smilax glabra, Phaseolus calcaratus, Morinda officinalis, and Atractylodes macrocephala (OR range, 0.31-0.79). Conclusions Consuming herbal soups including specific plants, but not herbal tea, was inversely associated with NPC. If replicated, these results might provide potential for NPC prevention in endemic areas.

Background 3-Hydroxybutyrate dehydrogenase type 2 (BDH2) is known to catalyse a rate-limiting step in the biogenesis of the mammalian siderophore and regulate intracellular iron metabolism. Here we aim to explore the expression and possible function of BDH2 in nasopharyngeal carcinoma (NPC). Methods The transcription and protein expression of BDH2 in NPC were determined by both real-time RT-PCR and immunohistochemistry staining assays. Cell proliferation, migration and invasion were evaluated by MTT assay, wound-healing assay and Transwell assay, respectively. The profile of genes regulated by restoring BDH2 expression in NPC cells was analysed by cDNA microarray. The level of iron in NPC cells was detected by iron colorimetric assay. Results The expression of BDH2 was significantly downregulated in NPC. Ectopic expression of BDH2 inhibited NPC cell proliferation and colony formation. Meanwhile, BDH2 suppressed the migration and invasion of NPC cells by reversing the epithelial–mesenchymal transition (EMT). In addition, a higher level of BDH2 decreased the growth and metastasis of NPC cells via reducing intracellular iron level. Conclusions Our findings suggest that BDH2 may be a candidate tumour-suppressor gene in NPC. Decreasing intracellular iron could be an effective therapeutic approach for NPC.

Rab11 family interacting protein 2 (Rab11-FIP2) is a conserved protein and effector molecule for the small GTPase Rab11. By interacting with Rab11 and MYO5B, Rab11-FIP2 regulates endosome trafficking of plasma membrane proteins, promoting cellular motility. The endosomal trafficking system in nasopharyngeal carcinoma (NPC) remains unclear. Here, an outlier analysis using the Oncomine database suggested that Rab11-FIP2 but not Rab11 and MYO5B was overexpressed in NPC. We confirmed that the transcription of Rab11-FIP2 was upregulated in NPC cell lines and primary tumor tissues as compared with a normal nasopharyngeal epithelial cell line and normal nasopharynx tissues. We further confirmed the elevated protein expression level of Rab11-FIP2 in NPC biopsies. Instead of regulating the epithelial-mesenchymal transition or Akt signaling pathway, knockdown of Rab11-FIP2 inhibited the migration and invasion ability of NPC cell lines by decreasing the expression of Rac and Cdc42. In summary, Rab11-FIP2 could be an oncogene in NPC, mainly contributing to metastatic capacity by activating Rho GTPase signaling.