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Andrographolide, a medicinal compound, exhibits several pharmacological activities, including antiviral and anticancer properties. Previously, we reported that andrographolide inhibits Epstein–Barr virus (EBV) lytic reactivation, which is associated with viral transmission and oncogenesis in epithelial cancers, including head-and-neck cancer (HNC) cells. However, the underlying mechanism through which andrographolide inhibits EBV lytic reactivation and affects HNC cells is poorly understood. Therefore, we investigated these mechanisms using EBV-positive HNC cells and the molecular modeling and docking simulation of protein. Based on the results, the expression of EBV lytic genes and viral production were significantly inhibited in andrographolide-treated EBV-positive HNC cells. Concurrently, there was a reduction in transcription factors (TFs), myocyte enhancer factor-2D (MEF2D), specificity protein (SP) 1, and SP3, which was significantly associated with a combination of andrographolide and sodium butyrate (NaB) treatment. Surprisingly, andrographolide treatment also significantly induced the expression of DNA Methyltransferase (DNMT) 1, DNMT3B, and histone deacetylase (HDAC) 5 in EBV-positive cells. Molecular modeling and docking simulation suggested that HDAC5 could directly interact with MEF2D, SP1, and SP3. In our in vitro study, andrographolide exhibited a stronger cytotoxic effect on EBV-positive cells than EBV-negative cells by inducing cell death. Interestingly, the proteome analysis revealed that the expression of RIPK1, RIPK3, and MLKL, the key molecules for necroptosis, was significantly greater in andrographolide-treated cells. Taken together, it seems that andrographolide exhibits concurrent activities in HNC cells; it inhibits EBV lytic reactivation by interrupting the expression of TFs and induces cell death, probably via necroptosis. [ABSTRACT FROM AUTHOR]

Epstein–Barr virus (EBV) is associated with various human malignancies. An association between EBV infection and oral squamous cell carcinoma (OSCC) has recently been reported. We established EBV-positive OSCC cells and demonstrated that EBV infection promoted OSCC progression. However, the mechanisms by which EBV promotes OSCC progression remain poorly understood. Therefore, we performed metabolic analyses of EBV-positive OSCC cells and established a xenograft model to investigate the viral contribution to OSCC progression. Here, we demonstrated that EBV infection induced mitochondrial stress by reducing the number of mitochondrial DNA (mtDNA) copies. Microarray data from EBV-positive OSCC cells showed altered expression of glycolysis-related genes, particularly the upregulation of key genes involved in the Warburg effect, including LDHA, GLUT1, and PDK1. Furthermore, lactate production and LDH activity were elevated in EBV-positive OSCC cells. EBV infection significantly upregulated the expression levels of cancer stem cell (CSC) markers such as CD44 and CD133 in the xenograft model. In this model, tumor growth was significantly increased in EBV-positive SCC25 cells compared with that in uninfected cells. Furthermore, tumorigenicity increased after serial passages of EBV-positive SCC25 tumors. This study revealed the oncogenic role of EBV in OSCC progression by inducing the Warburg effect and cancer stemness. [ABSTRACT FROM AUTHOR]

Water can contain pathogenic viruses. Many studies on RNA virus sources have shown that water can transmit them. However, there are few reports on pathogenic DNA virus transmission through water, such as adenovirus, which pose a widespread public health risk. Therefore, this study aimed to show waterborne viral transmission by detecting viruses in pooled human whole blood samples, tap water, and natural water from Mueang District, Phayao Province, Thailand, using a metagenomic approach. Viral prevalence in whole blood samples was measured by polymerase chain reaction (PCR) and quantitative PCR (qPCR), and environmental factors that affect viral infection were assessed. Metagenomics results showed that Epstein–Barr virus (EBV) members were among the prominent cancer-associated oncogenic DNA viruses detected in human blood and all water types similar to the EBV reference sequence (NC_007605). There were 59 out of 813 (7.26%) human whole blood samples that were positive for EBV DNA based on PCR and qPCR for the EBNA-1 and EBNA-2 genes. Water- and blood-borne human oncogenic EBV should be a concern in tap water treatment and blood transfusion in patients, respectively. Therefore, the detection of EBV in water suggests that transmission via water is possible and should be investigated further. [ABSTRACT FROM AUTHOR]

Reactivation of Epstein–Barr virus (EBV) is associated with EBV-associated malignancies and is considered to be a benefit target for treatment. Andrographolide is claimed to have antiviral and anti-tumor activities. Therefore, this study aimed to investigate the effect of andrographolide on the inhibition of EBV lytic reactivation in EBV-positive cancer cells. The cytotoxicity of andrographolide was firstly evaluated in EBV-positive cancer cells; P3HR1, AGS-EBV and HONE1-EBV cells, using an MTT assay. Herein, the spontaneous expression of EBV lytic genes; BALF5, BRLF1 and BZLF1, was significantly inhibited in andrographolide-treated cells. Accordingly, andrographolide inhibited the expression of Zta and viral production in sodium butyrate (NaB)-induced EBV lytic reactivation. Additionally, proteomics and bioinformatics analysis revealed the differentially expressed proteins that inhibit EBV lytic reactivation in all treated cell lines were functionally related with the histone modifications and chromatin organization, such as histone H3-K9 modification and histone H3-K27 methylation. Taken together, andrographolide inhibits EBV reactivation in EBV-positive cancer cells by inhibiting EBV lytic genes, probably, through the histone modifications. [ABSTRACT FROM AUTHOR]

The etiology of oral carcinogenesis appears to be multifactorial. There is emerging evidence of the presence of Epstein-Barr virus (EBV) in epithelial oral squamous cell carcinoma (OSCC), but an association of EBV with oral carcinogenesis has not yet been established. Although epigenetic alterations, such as aberrant DNA methylation, are known to contribute to the pathogenesis of oral cancer, the relationship of such alterations with EBV infection is little known. This study aimed to investigate the association between EBV infection and promoter methylation patterns of tumor-associated genes in OSCC tissues. A total of 165 of formalin-fixed paraffin-embedded OSCC tissues were studied (68 of EBV positive and 97 of EBV negative). The promoter methylation patterns were investigated for four tumor-associated genes, E-cadherin, p16 INK4a , p14 ARF , and MGMT, by using methylation-specific polymerase chain reaction (MSP). The frequencies of gene promoter hypermethylation in all cases were 47.3% for E-cadherin, 92.7% for p16 INK4a , 74.5% for p14 ARF , and 35.8% for MGMT. Interestingly, most of the analyzed gene promoters were more frequently hypermethylated in EBV-positive than EBV-negative cases, in particular the E-cadherin (56/22) and MGMT (38/21) gene promoters (p < 0.05). Concomitantly, hypermethylation of multiple gene promoters (≥3) was encountered more frequently in EBV-positive samples. Hypermethylation of the E-cadherin promoter associated with EBV was more frequently observed in moderately and poorly differentiated OSCC tissues. These results indicate that epigenetic changes frequently occur in OSCCs and may partly be induced by EBV infection, therefore, EBV may involve in development and progression of the OSCCs. [ABSTRACT FROM AUTHOR]

Different types of cells infected with Epstein-Barr virus (EBV) can release exosomes containing viral components that functionally affect neighboring cells. Previously, we found that EBV was localized mostly in infiltrating lymphocytes within the stromal layer of cervical lesions. In this study, we aimed to determine effects of exosome-transferred EBV-encoded RNAs (EBERs) on keratinocytes expressing human papillomavirus (HPV) 16 E6/E7 (DonorI-HPV16 HFKs). Lipid transfection of in vitro-transcribed EBER1 molecules (ivt EBER1) into DonorI-HPV16 HFKs caused strong induction of interferon (IFN)-related genes and interleukin 6 (IL-6). To gain insights into the physiological situation, monocyte-derived dendritic cells (moDCs), low passage DonorI-HPV16 HFKs and primary keratinocytes were used as recipient cells for internalization of exosomes from wild-type EBV (wt EBV) or B95-8 EBV-infected lymphoblastoid cell lines (LCLs). qRT-PCR was used to determine the expression of EBER1, HPV16 E6/E7, IFN-related genes and IL-6 in recipient cells. The secretion of inflammatory cytokines was investigated using cytometric bead array. Wt EBV-modified exosomes induced both IFN-related genes and IL-6 upon uptake into moDCs, while exosomes from B95-8 EBV LCLs induced only IL-6 in moDCs. Internalization of EBV–modified exosomes was demonstrated in DonorI-HPV16 HFKs, yielding only EBER1 but not EBER2. However, EBER1 transferred by exosomes did not induce IFN-related genes or IL-6 expression and inflammatory cytokine secretion in DonorI-HPV16 HFKs and primary keratinocytes. EBER1 copy numbers in exosomes from wt EBV-infected LCLs were 10-fold higher than in exosomes from B95-8 LCLs (equal cell equivalent), whereas ivt EBER1 was used at approximately 100-fold higher concentration than in exosomes. These results demonstrated that the induction of IFN-related genes and IL-6 by EBER1 depends on quantity of EBER1 and type of recipient cells. High levels of EBER1 in cervical cells or infiltrating dendritic cells may play a role in the inflammation-to-oncogenesis transition of HPV-associated cervical cancer through modulation of innate immune signals. [ABSTRACT FROM AUTHOR]

Background Besides the well-known risk factors, Epstein-Barr virus ( EBV) might play a significant role in oral squamous cell carcinoma ( OSCC). To explore the role of EBV in OSCC, the prevalence of EBV infection in oral exfoliated cells of OSCC cases and controls in northeastern Thailand was investigated, and the association of EBV in tumor lesion cells was further confirmed. Methods Oral exfoliated cells were collected from OSCC cases and non-cancer controls. Cells from tumor lesions were taken from OSCC patients for further strong confirmation of the association of EBV with OSCC. EBV DNA was detected by polymerase chain reaction ( PCR) using primers specific for EBV DNA polymerase. The EBV DNA positive samples were confirmed further by nested PCR. Results Epstein-Barr virus was detected in the oral exfoliated cells of 45.05% of OSCC patients and 18.08% of the non-cancer control ( P < 0.001). Similarly, EBV was detected in 32.5% of the tumor lesions. Betel quid chewing was statistically significantly associated with EBV prevalence ( OR = 2.08), whereas no association with tobacco smoking and alcohol consumption. Alcohol consumption and betel quid chewing were significantly associated with OSCC ( OR = 3.05 and OR = 5.05, respectively), but tobacco smoking was not associated. Interestingly, EBV was significantly associated with OSCC ( OR = 3.76). Conclusions Epstein-Barr virus prevalence is associated with OSCC and seems to be enhanced by betel quid chewing, suggesting that EBV may, together with betel quid chewing, act as an important etiological risk factor of OSCC. [ABSTRACT FROM AUTHOR]

Andrographolide is the principal bioactive chemical constituent of Andrographis paniculata and exhibits activity against several viruses, including Epstein–Barr virus (EBV). However, the particular mechanism by which andrographolide exerts an anti-EBV effect in EBV-associated gastric cancer (EBVaGC) cells remains unclear. We investigated the molecular mechanism by which andrographolide inhibits lytic reactivation of EBV in EBVaGC cells (AGS-EBV cell line) using proteomics and bioinformatics approaches. An andrographolide treatment altered EBV protein-expression patterns in AGS-EBV cells by suppressing the expression of EBV lytic protein. Interestingly cellular transcription factors (TFs), activators for EBV lytic reactivation, such as MEF2D and SP1, were significantly abolished in AGS-EBV cells treated with andrographolide and sodium butyrate (NaB) compared with NaB-treated cells. In contrast, the suppressors of EBV lytic reactivation, such as EZH2 and HDAC6, were significantly up-regulated in cells treated with both andrographolide and NaB compared with NaB treatment alone. In addition, bioinformatics predicted that HDAC6 could interact directly with MEF2D and SP1. Furthermore, andrographolide significantly induced cell cytotoxicity and apoptosis of AGS-EBV cells by induction of apoptosis-related protein expression. Our results suggest that andrographolide inhibits EBV lytic reactivation by inhibition of host TFs, partially through the interaction of HDAC6 with TFs, and induces apoptosis of EBVaGC cells. [ABSTRACT FROM AUTHOR]

The Epstein–Barr virus (EBV) is a human herpesvirus associated with various cancers. The number of reports that describe infection of EBV in oral squamous carcinoma cells is increasing. However, there is no available in vitro model to study the possible role of EBV in the development of oral squamous cell carcinoma. Herein, we report establishment of a latent EBV infection of well-differentiated HSC1 cells and poorly differentiated SCC25 cells. Viral copy numbers per cell in EBV-infected HSC1 and SCC25 cells are 2 and 5, respectively. Although the EBV copy number was small, spontaneous viral replication was observed in EBV-infected HSC1 cells. Contrarily, infectious viral production was not observed in EBV-infected SCC25 cells, despite containing larger number of EBV genomes. Chemical activation of cells induced expression of viral lytic BZLF1 gene in EBV-infected HSC1 cells, but not in EBV-infected SCC25 cells. EBV infection activated proliferation and migration of HSC1 cells. However, EBV-infection activated migration but not proliferation in SCC25 cells. In conclusion, EBV can infect squamous cells and establish latent infection, but promotion of cell proliferation and of lytic EBV replication may vary depending on stages of cell differentiation. Our model can be used to study the role of EBV in the development of EBV-associated oral squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

No effective screening method is available for oral squamous cell carcinoma (OSCC) that is recognized to influence by environmental factors as well as human papillomavirus (HPV) and Epstein-Barr virus (EBV). Therefore, we sought to identify salivary biomarkers for screening of OSCC with or without HPV and/or EBV infection. Saliva, lesion and oral exfoliated cells were collected from OSCC patients and cancer-free controls (CFCs) and grouped depending on their HPV- and EBV-infection status. Salivary protein was precipitated and subjected to 2-dimensional gel electrophoresis. Differential expression of proteins was identified by mass spectrometry and validated by Western blotting. Distinctive expression patterns of salivary proteins were detected in OSCC as compared with CFCs. Levels of peroxiredoxin-2 (PRDX-2) and zinc-alpha-2-glycoprotein (ZAG) were significantly up-regulated in OSCC cases (p < 0.001) relative to CFCs. Similarly, these proteins were also up-regulated in lesion cells compared with oral exfoliated cells (p < 0.001). However, the expression patterns of these proteins were not significantly influenced by patient histories (risk factors). In combination, these proteins yielded the highest discriminatory power (AUC = 0.999), sensitivity (100%), and specificity (98.77%) in distinguishing the early stages of OSCC. The detection of PRDX-2 combining with ZAG protein could potentially be used as salivary biomarkers for early screening of OSCC. Significance Our findings demonstrate a useful of combined detection of PRDX-2 and ZAG as a salivary biomarker for the early detection of OSCC. [ABSTRACT FROM AUTHOR]

Background Persistent infection with EBV has been linked to the development of malignancies including HPV-associated cervical carcinoma. However, the role of EBV in HPV-associated cervical cancer is still poorly understood. Objective To determine the possible contributing role of EBV in HPV-associated cervical carcinogenesis according to HPV genotypes, HPV genome status and EBV localization. Study design Cervical tissues, including 82 with no squamous intraepithelial lesions (noSILs), 85 low-grade SILs (LSILs), 85 high grade SILs (HSILs) and 40 squamous cell carcinoma samples (SCC) were investigated using PCR and dot blot hybridization for EBV detection and PCR and reverse line blot hybridization for HPV genotyping. The amplification of papillomavirus oncogene transcripts assay and in situ hybridization were used to determine HPV physical status and EBV EBER localization, respectively. Results EBV was detected increasingly from noSIL (13.4%), LSIL (29.4%) to HSIL (49.4%) samples. The prevalence of HPV–EBV co-infection was significantly higher in any grade of lesion than in noSIL samples ( p < 0.05) including noSIL (1.2%; 95% confidence intervals [CI] = 0.0–3.6%, relative risk [RR] = 1), LSIL (18.8%, 95% CI = 10.5–27.1%, RR = 15.4), HSIL (41.2%, 95% CI = 30.7–51.6%, RR = 33.8) and SCC (30.0%, 95% CI = 15.8–44.2%, RR = 24.6). Interestingly, HPV–EBV co-infection was more common in cases with episomal forms of high-risk (HR) HPV whereas HPV alone was more common in cases with integrated HR-HPV. In addition, EBER staining demonstrated that EBV was mainly present in infiltrating lymphocytes. Conclusion Infiltrating EBV-infected lymphocytes may play a role in cancer progression of cervical lesion containing episomal HR-HPV. [ABSTRACT FROM AUTHOR]