Detection of Epstein-Barr virus genome and latent infection gene expression in normal epithelia, epithelial dysplasia, and squamous cell carcinoma of the oral cavity

Could MMP3 and MMP9 Serve as Biomarkers in EBV-Related Oropharyngeal Cancer

The high incidence of, and mortality from, head and neck cancers (HNCs), including those related to Epstein-Barr virus (EBV), constitute a major challenge for modern medicine, both in terms of diagnosis and treatment. Therefore, many researchers have made efforts to identify diagnostic and prognostic factors. The aim of this study was to evaluate the diagnostic usefulness of matrix metalloproteinase 3 (MMP 3) and matrix metalloproteinase 9 (MMP 9) in EBV positive oropharyngeal squamous cell carcinoma (OPSCC) patients. For this purpose, the level of these MMPs in the serum of patients with EBV-positive OPSCC was analyzed in relation to the degree of histological differentiation and TNM classification. Our research team's results indicate that the level of both MMPs is much higher in the EBV positive OPSCC patients compared to the EBV negative and control groups. Moreover, their levels were higher in more advanced clinical stages. Considering the possible correlation between the level of MMP 3, MMP 9 and anti-EBV antibodies, and also viral load, after statistical analysis using multiple linear regression, their high correlation was demonstrated. The obtained results confirm the diagnostic accuracy for MMP 3 and MMP 9. Both MMPs may be useful in the diagnosis of EBV positive OPSCC patients.

Distribution of Epstein-Barr virus in the oral cavity of Thais with various oral mucosal conditions

Objectives

We aimed to examine the presence of EBV, EBV strains, and variants among 3 oral conditions including normal oral mucosa (NOM), oral potentially malignant disorders/oral cancer (OPMDs/OC) and non-OPMDs/OC in a group of Thais.

Material and methods

Oral exfoliated cells were obtained from 315 participants living in the northeastern and central regions of Thailand. The participants were divided into 3 groups encompassing the NOM, the OPMDs/OC and the non-OPMDs/OC groups. The presence of EBV was first determined by PCR using primers for LMP1 gene. Subsequently, EBV strains of EBNA3c and variants based on LMP1 sequences were determined by real-time PCR.

Results

The prevalence of EBV in OPMDs/OC, non-OPMDs/OC and NOM were 72.0 %, 56.2 %, and 27.2 % respectively. EBV type A, B and AB were found in 52.1 %, 32.1 % and 15.8 % of all positive samples, respectively. The percentage of participants with EBV type A was more prominent in the NOM group (72.0 %) compared to the non-OPMDs/OC (54.8 %) and the OPMDs/OC group (41.8 %) whereas EBV type B was higher in the OPMDs/OC group (35.8 %) compared to the non-OPMDs/OC (31.5 %) and the NOM (24.0 %) groups. Regarding EBV variants, 30-bp deletion LMP1 variant (del-LMP1) which is more associated with malignant transformation was predominately found in the OPMDs/OC (32.8 %) and the non-OPMDs/OC (38.4 %) groups compared to the NOM group (20.0 %).

Conclusions

High frequency of EBV was demonstrated in the OPMDs/OC group. EBV type A was more predominant in the NOM group whereas EBV type B was more prevalent in the OPMDs/OC group. The del-LMP1 variant was more common in the OPMDs/OC and the non-OPMDs/OC groups.

Serum Anti-Zta and Anti-LMP1 Antibodies in Oropharyngeal Cancer Related to Epstein-Barr Virus-Diagnostic Usefulness

BACKGROUND

The role of the Epstein-Barr virus (EBV), the first known human oncogenic virus, in the development of nasopharyngeal cancer (NPC) is already well documented. There are few studies in the available scientific literature on oropharyngeal cancer associated with EBV infection. Due to the lack of an effective vaccine against EBV, it is necessary to search for new markers for the early diagnosis and prognosis of this disease. The aim of current study was to determine the usefulness of anti-Zta and anti-LMP1 antibodies as diagnostic and prognostic markers in EBV positive OPSCC patients.

METHODS

For this purpose, experiments were carried out to determine both the prevalence and level of EBVCA, EBNA1, EA, Zta, and LMP1 antibodies in serum patients depending on histological differentiation-grading and TNM classification (ELISA assay).

RESULTS

Based on the obtained results, we showed that OPSCC EBV positive patients are characterized by a higher level of anti-Zta antibodies than in the EBV negative group. Their level depended on the clinical stage. Moreover, a ROC analysis confirmed the diagnostic accuracy of anti-Zta antibodies.

CONCLUSIONS

Anti-Zta and anti-LMP1 antibodies may be useful in the diagnosis of OPSCC. It seems that combined antibody testing should be performed to increase diagnostic accuracy.

Can the Epstein-Barr Virus Play a Role in the Development of Prostate Cancer?

Prostate cancer (PCa) is the fourth most frequently diagnosed cancer worldwide, accounting for 7.3% of all cancers. PCa mortality is the fifth most common cause of cancer death. Despite well-known factors influencing the development of PCa, such as age, race/ethnicity and family history, many researchers have raised the possibility of persistent infections with oncogenic viruses. Therefore, we aimed to assess the frequency of Epstein-Barr virus (EBV) DNA in tissue collected from PCa patients. Next, the frequency and the level of Epstein-Barr virus capsid antigen (EBVCA) and Epstein-Barr nuclear antigen 1 (EBNA1) antibodies in both IgA and IgG classes were measured. The antibody titer was also analyzed depending on the risk group, Gleason score (GS) and tumor, node, metastasis (TNM) classification. Serum samples were analyzed using the Microblot-Array EBV IgM, IgA and IgG test kits. The study group consisted of 115 patients diagnosed and histopathologically confirmed with PCa. In 49% of patients included in the study, EBV DNA was detected in the tumor tissue. The studies showed both higher seroprevalence and higher antibody titers in patients with EBV-positive PCa compared to patients with EBV-negative PCa. We also observed a dependence of antibody titer on pathological features, such as GS, risk group and T stage.

Is Systemic Immunosuppression a Risk Factor for Oral Cancer? A Systematic Review and Meta-Analysis

Even if the relationship between immunosuppression and increased incidence of systemic cancers is well known, there is less awareness about the risk of developing oral cancer in immunosuppressed patients. The aim of this review was to evaluate the association between immunosuppression and the development of oral cancer. Two authors independently and, in duplicate, conducted a systematic literature review of international journals and electronic databases (MEDLINE via OVID, Scopus, and Web of Science) from their inception to 28 April 2023. The assessment of risk of bias and overall quality of evidence was performed using the Newcastle-Ottawa Scale and GRADE system. A total of 2843 articles was identified, of which 44 met the inclusion criteria and were included in either the qualitative or quantitative analysis. The methodological quality of the included studies was generally high or moderate. The quantitative analysis of the studies revealed that immunosuppression should be considered a risk factor for the development of oral cancer, with a percentage of increased risk ranging from 0.2% to 1% (95% CI: 0.2% to 1.4%). In conclusion, the results suggest that a constant and accurate follow-up should be reserved for all immunosuppressed patients as a crucial strategy to intercept lesions that have an increased potential to evolve into oral cancer.

Analysis of Epstein-Barr Virus Infection in Oral Potentially Malignant Disorders and Oral Cancer: A Cross-Sectional Study

Aims and Objectives

The primary objective of this study is to determine the prevalence of Epstein-Barr virus (EBV) in oral potentially malignant disorders (OPMDs) and oral cancer (OC) in a group of Thais using polymerase chain reaction (PCR) and Epstein-Barr encoding regions (EBERs) in situ hybridization (ISH). The secondary objective is to investigate the risk factors of OC and the association between the presence of EBV and risk factors of OC/site of oral lesions.

Materials and Methods

Sixty-one participants attending the screening project for OC and OPMDs at the Northeastern district hospitals of Thailand were recruited. Information related to risk factors and biopsy tissues for histopathological diagnosis was collected. Sixty-seven paraffin tissue blocks, including 52 OPMDs and 15 OC specimens, were investigated for EBV infection, using PCR analysis with latent membrane protein-1 (LMP-1) primer and EBERs ISH. Pearson's Chi-square or Fisher's exact test was used to analyze the differences in variables between participants with OPMDs and OC, as appropriate. The association between EBV infection and related risk factors was analyzed using logistic regression with a significant level at 0.05.

Results

Using PCR analysis, 8 of 67 specimens (11.94%) were positive for LMP-1. Three cases of OPMDs were positive for both LMP-1 PCR and EBERs ISH. Regarding risk factors of OC, the two most common risk factors were betel nut chewing (52.46%) and working in sunlight (42.62%). The habit of taking alcohol was significantly different between the OC and the OPMDs groups (p = 0.009). The association between LMP-1 and the lesion at the tongue was statistically significant, with odds ratio = 4.900 (95% confidence interval = 1.046-22.943; p = 0.044).

Conclusions

The prevalence of EBV infection in this group of participants was low. However, OPMDs at the tongue exhibited a significant association with EBV infection.

Epstein-Barr Virus Detection and LMP-1 Expression in Thai Patients with Oral Squamous Cell Carcinoma

BACKGROUND

To date, high-risk human papillomavirus (HPV) is primarily linked to oropharyngeal carcinoma, but only a small subset of oral squamous cell carcinoma (OSCC) is truly driven by high-risk HPV. In addition, Epstein-Barr virus (EBV) is another potential oncogenic virus for OSCC development. This study aims to investigate the role of EBV infection in Thai patients with OSCC.

METHODS

Forty-seven formalin-fixed paraffin-embedded specimens of OSCC were obtained. EBV DNA was detected by polymerase chain reaction analysis using primers for LMP-1 region of EBV. EBV-positive OSCC cases were subjected to LMP-1 immunohistochemical analysis and EBV-encoded small RNA (EBER) in situ hybridization to determine EBV cellular localization in OSCC. LMP-1 immunohistochemical analysis was also performed in all EBV-negative OSCC cases.

RESULTS

Of the 47 OSCC specimens, ten (21%) exhibited EBV DNA by PCR analysis. Seven of ten (70%) EBV-positive specimens showed high-grade LMP-1 expression by immunohistochemistry. However, no EBER expression was detected in all EBV-positive OSCC specimens. In EBV-negative specimens, LMP-1 was also negative except in 3 specimens which showed low grade expression of LMP-1.

CONCLUSION

The prevalence of EBV infection in OSCC in this group of Thai patients was 21%. Most of EBV-positive OSCC cases showed LMP-1 expression but a lack of EBER expression. From our findings, we presume that EBV may take some roles in OSCC development in this group of participants.

Somatic genomic imbalances in 'tumour-free' surgical margins of oral cancer

Up to 30% of oral squamous cell carcinoma (OSCC) patients develop local recurrence and distant metastasis. The molecular status of histologically cancer-free tumour margins could be a critical factor in predicting tumour behaviour. The aim of this study was to detect somatic genomic imbalances in OSCC with emphasis on the surgical margins. DNA was isolated from tumour tissues, margin tissues, and blood samples (used as control) obtained from 11 OSCC patients, and genome-wide array comparative genomic hybridization was performed. Imbalances were present in both tumours and margins, although, as expected, they were more prevalent in tumours (duplications, P = 0.0002; deletions, P = 0.0001). Duplications were more frequent than deletions in both tumours and margins, but without statistical significance. Fifteen imbalances in tumour tissues were recurrent and all of them were duplications. Four of these were found both in tumours and margins and involved chromosomes 1q, 8p, Xp, Yp, and Yq. Four imbalances were recurrent in margin tissue and all of them were duplications (autosomes 8 and 17 and both sex chromosomes). Histologically 'cancer-free' margins hide genomic alterations consistent with unexplained OSCC recurrences. Establishing the molecular status of the margins could improve outcome prediction.

EBV Association with Lymphomas and Carcinomas in the Oral Compartment

Epstein-Barr virus (EBV) is an oncogenic human herpesvirus infecting approximately 90% of the world's population. The oral cavity serves a central role in the life cycle, transmission, and pathogenesis of EBV. Transmitted to a new host via saliva, EBV circulates between cellular compartments within oral lymphoid tissues. Epithelial cells primarily support productive viral replication, while B lymphocytes support viral latency and reactivation. EBV infections are typically asymptomatic and benign; however, the latent virus is associated with multiple lymphomas and carcinomas arising in the oral cavity. EBV association with cancer is complex as histologically similar cancers often test negative for the virus. However, the presence of EBV is associated with distinct features in certain cancers. The intrinsic ability of EBV to immortalize B-lymphocytes, via manipulation of survival and growth signaling, further implicates the virus as an oncogenic cofactor. A distinct mutational profile and burden have been observed in EBV-positive compared to EBV-negative tumors, suggesting that viral infection can drive alternative pathways that converge on oncogenesis. Taken together, EBV is also an important prognostic biomarker that can direct alternative therapeutic approaches. Here, we discuss the prevalence of EBV in oral malignancies and the EBV-dependent mechanisms associated with tumorigenesis.

PCR Detection of Epstein-Barr Virus (EBV) DNA in Patients with Head and Neck Squamous Cell Carcinoma, in Patients with Chronic Tonsillitis, and in Healthy Individuals

Epstein-Barr virus (EBV) is a common virus worldwide that is an etiologic agent in the development of many diseases, including cancer. Recent reports have shown the association of EBV with tumorigenesis in head and neck squamous cell carcinoma (HNSCC). Moreover, EBV has been reported to be present in tonsillar tissues, which suggests a close relationship between viral infections and tonsillar diseases, including chronic tonsillitis. The aim of the study was to analyze the prevalence of EBV DNA in 86 patients with HNSCC, in 70 patients with chronic tonsillitis, and in 144 healthy individuals (control group) and the associations between EBV infection and clinicopathological and demographic characteristics and the use of stimulants in all study groups. The objective of this study was also to analyze the prevalence of coinfection with human papillomavirus (HPV). After prior DNA isolation, EBV detection was performed using an EBV kit by real-time polymerase chain reaction. The prevalence of EBV infection in patients with HNSCC, patients with chronic tonsillitis, and the control group was 47.7%, 60%, and 24.3%, respectively. Compared to controls, a significantly higher prevalence of EBV in patients with chronic tonsillitis and HNSCC may suggest that EBV is a potential risk factor. No association was found between EBV infection and demographic or clinical data. Further studies are warranted due to inconclusive reports that were mainly related to geographic distribution, sample type, and detection technique. Considering the prevalence of the virus and the risk of serious diseases, attention should be paid to screening diagnosis and prevention of the infection.

Potential Role of Epstein–Barr Virus in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Scoping Review

Though the oral cavity is anatomically proximate to the nasal cavity and acts as a key reservoir of EBV habitation and transmission, it is still unclear whether EBV plays a significant role in oral carcinogenesis. Many studies have detected EBV DNA in tissues and exfoliated cells from OSCC patients. However, very few studies have investigated the expression of functional EBV proteins implicated in its oncogenicity. The most studied are latent membrane protein 1 (LMP-1), a protein associated with the activation of signalling pathways; EBV determined nuclear antigen (EBNA)-1, a protein involved in the regulation of gene expression; and EBV-encoded small non-polyadenylated RNA (EBER)-2. LMP-1 is considered the major oncoprotein, and overexpression of LMP-1 observed in OSCC indicates that this molecule might play a significant role in oral carcinogenesis. Although numerous studies have detected EBV DNA and proteins from OSCC and oral potentially malignant disorders, heterogeneity in methodologies has led to discrepant results, hindering interpretation. Elucidating the exact functions of EBV and its proteins when expressed is vital in establishing the role of viruses in oral oncogenesis. This review summarises the current evidence on the potential role of EBV in oral oncogenesis and discusses the implications as well as recommendations for future research.

General Features and Novel Gene Signatures That Identify Epstein-Barr Virus-Associated Epithelial Cancers

Epstein-Barr virus (EBV) is associated with various types of human malignancies, including nasopharyngeal carcinoma (NPC), EBV-associated gastric carcinoma (EBVaGC), and oral squamous cell carcinoma (OSCC). The present study aimed to identify gene signatures and common signaling pathways that can be used to predict the prognosis of EBV-associated epithelial cancers (EBVaCAs) by performing an integrated bioinformatics analysis of cell lines and tumor tissues. We identified 12 differentially expressed genes (DEGs) in the EBVaCA cell lines. Among them, only four DEGs, including BAMBI, SLC26A9, SGPP2, and TMC8, were significantly upregulated. However, SLC26A9 and TMC8, but not BAMBI and SGPP2, were significantly upregulated in EBV-positive tumor tissues compared to EBV-negative tumor tissues. Next, we identified IL6/JAK/STAT3 and TNF-α/NF-κB signaling pathways as common hallmarks of EBVaCAs. The expression of key genes related to the two hallmarks was upregulated in both EBV-infected cell lines and EBV-positive tumor tissues. These results suggest that SLC26A9 and TMC8 might be gene signatures that can effectively predict the prognosis of EBVaCAs and provide new insights into the molecular mechanisms of EBV-driven epithelial cancers.

High-Risk Human Papillomavirus and Epstein-Barr Virus Coinfection: A Potential Role in Head and Neck Carcinogenesis

Simple Summary

A subset of carcinomas that arise in the head and neck region show a viral etiology. In fact, a subgroup of oropharyngeal cancers are caused by some types of human papillomavirus (HPV), so-called high-risk (HR)-HPVs, whereas undifferentiated nasopharyngeal carcinomas are etiologically related to Epstein–Barr virus (EBV). However, studies have reported the presence of both HR-HPV and EBV in some types of head and neck cancers. In this review, we discuss the potential contribution and role of HR-HPV/EBV coinfection in head and neck carcinogenesis, as well as the mechanisms that are potentially involved. In addition, HR-HPV/EBV interaction models are proposed.

Abstract

High-risk human papillomaviruses (HR-HPVs) and Epstein–Barr virus (EBV) are recognized oncogenic viruses involved in the development of a subset of head and neck cancers (HNCs). HR-HPVs are etiologically associated with a subset of oropharyngeal carcinomas (OPCs), whereas EBV is a recognized etiological agent of undifferentiated nasopharyngeal carcinomas (NPCs). In this review, we address epidemiological and mechanistic evidence regarding a potential cooperation between HR-HPV and EBV for HNC development. Considering that: (1) both HR-HPV and EBV infections require cofactors for carcinogenesis; and (2) both oropharyngeal and oral epithelium can be directly exposed to carcinogens, such as alcohol or tobacco smoke, we hypothesize possible interaction mechanisms. The epidemiological and experimental evidence suggests that HR-HPV/EBV cooperation for developing a subset of HNCs is plausible and warrants further investigation.

Simultaneous occurrence of Epstein-Barr virus (EBV) in periodontal pockets and in oral squamous cell carcinoma: a cross-sectional study

OBJECTIVES

This study aimed to investigate the detection of Epstein-Barr virus (EBV) in oral squamous cell carcinoma (OSCC) and to verify the concordance of EBV-DNA frequency in subgingival sites and in the OSCC.

METHODS

A cross-sectional study with 30 OSCC patients, aged from 44 to 88 years old, was conducted. Samples were collected in subgingival sites and at the OSCC, then submitted to DNA isolation, qPCR, and genotyping. Descriptive statistic was performed to report the frequency of EBV-DNA in all samples, and McNemar test was applied to verify the concordance among the EBV-DNA frequency in both sites.

RESULTS

The individuals presented 62 years old in average, and the majority were male (66.6%). EBV-DNA was detected in 56.7% OSCC lesions. Among the subgroup of 19 dentate individuals, high concordance (73.7%) in both EBV-DNA detection and the absence in subgingival sites and OSCC was observed, and it was statistically significant (p < 0.05).

CONCLUSIONS

We report the notable occurrence of EBV-DNA in OSCC; also, the presence of EBV in periodontal sites may contribute to find it in OSCC, although the possible contribution of EBV in the OSCC remains to be investigated.

CLINICAL RELEVANCE

The identification of this easily accessible site of EBV latent infection may help to improve the patient's quality of life by maintenance of oral/periodontal health condition and preventing further possible disorders related to the virus, and also encourages new approaches for investigating EBV, periodontitis, and OSCC.

The Role of Coinfections in the EBV-Host Broken Equilibrium

The Epstein–Barr virus (EBV) is a well-adapted human virus, and its infection is exclusive to our species, generally beginning in the childhood and then persisting throughout the life of most of the affected adults. Although this infection generally remains asymptomatic, EBV can trigger life-threatening conditions under unclear circumstances. The EBV lifecycle is characterized by interactions with other viruses or bacteria, which increases the probability of awakening its pathobiont capacity. For instance, EBV infects B cells with the potential to alter the germinal center reaction (GCR)—an adaptive immune structure wherein mutagenic-driven processes take place. HIV- and Plasmodium falciparum-induced B cell hyperactivation also feeds the GCR. These agents, along with the B cell tropic KSHV, converge in the ontogeny of germinal center (GC) or post-GC lymphomas. EBV oral transmission facilitates interactions with local bacteria and HPV, thereby increasing the risk of periodontal diseases and head and neck carcinomas. It is less clear as to how EBV is localized in the stomach, but together with Helicobacter pylori, they are known to be responsible for gastric cancer. Perhaps this mechanism is reminiscent of the local inflammation that attracts different herpesviruses and enhances graft damage and chances of rejection in transplanted patients. In this review, we discussed the existing evidence suggestive of EBV possessing the potential to synergize or cooperate with these agents to trigger or worsen the disease.

Interplay between Epstein-Barr virus infection and environmental xenobiotic exposure in cancer

Epstein-Barr virus (EBV) is a herpesvirus associated with lymphoid and epithelial malignancies. Both B cells and epithelial cells are susceptible and permissive to EBV infection. However, considering that 90% of the human population is persistently EBV-infected, with a minority of them developing cancer, additional factors are necessary for tumor development. Xenobiotics such as tobacco smoke (TS) components, pollutants, pesticides, and food chemicals have been suggested as cofactors involved in EBV-associated cancers. In this review, the suggested mechanisms by which xenobiotics cooperate with EBV for carcinogenesis are discussed. Additionally, a model is proposed in which xenobiotics, which promote oxidative stress (OS) and DNA damage, regulate EBV replication, promoting either the maintenance of viral genomes or lytic activation, ultimately leading to cancer. Interactions between EBV and xenobiotics represent an opportunity to identify mechanisms by which this virus is involved in carcinogenesis and may, in turn, suggest both prevention and control strategies for EBV-associated cancers.

Human papillomavirus, Epstein-Barr virus, and Candida albicans co-infection in oral leukoplakia with different degrees of dysplasia

OBJECTIVES

To identify human papillomavirus (HPV), Epstein-Barr virus (EBV), and Candida albicans in oral leukoplakia with different degrees of dysplasia.

MATERIALS AND METHODS

An observational, cross-sectional, descriptive study was performed using 30 formalin-fixed and paraffin-embedded tissues from patients with clinical suspicion of leukoplakia and confirmed diagnosis of oral dysplasia. Histological analyses were performed by two pathologists (interobserver) and dysplasias were classified as mild, moderate, or severe. Conventional PCR was used to detect HPV and EBV viruses and C. albicans. To determine the association between each microorganism with different degrees of dysplasia a Chi-square test was employed.

RESULTS

The tongue was the most common site for leukoplakias (71.4%) in females with a mean age of 50 years (ranging between 30 to 50 years old; 57.1%). EBV was the most frequently detected (73.3%), followed by HPV (43.3%), mainly of type 16 (40%), and C. albicans (23.3%). Significant differences were observed between degrees of dysplasia and HPV presence (p = 0.005). In lesions positive for HPV, EBV, and C. albicans the most frequent histological changes were hyperkeratosis, irregular interpapillary ridges, and loss of basal stratum cell polarity.

CONCLUSION

Co-infection with human papillomavirus, Epstein Barr virus, and Candida albicans in oral leukoplakia could be associated with dysplastic changes.

Clinical Manifestations and Epigenetic Regulation of Oral Herpesvirus Infections

The oral cavity is often the first site where viruses interact with the human body. The oral epithelium is a major site of viral entry, replication and spread to other cell types, where chronic infection can be established. In addition, saliva has been shown as a primary route of person-to-person transmission for many viruses. From a clinical perspective, viral infection can lead to several oral manifestations, ranging from common intraoral lesions to tumors. Despite the clinical and biological relevance of initial oral infection, little is known about the mechanism of regulation of the viral life cycle in the oral cavity. Several viruses utilize host epigenetic machinery to promote their own life cycle. Importantly, viral hijacking of host chromatin-modifying enzymes can also lead to the dysregulation of host factors and in the case of oncogenic viruses may ultimately play a role in promoting tumorigenesis. Given the known roles of epigenetic regulation of viral infection, epigenetic-targeted antiviral therapy has been recently explored as a therapeutic option for chronic viral infection. In this review, we highlight three herpesviruses with known roles in oral infection, including herpes simplex virus type 1, Epstein–Barr virus and Kaposi’s sarcoma-associated herpesvirus. We focus on the respective oral clinical manifestations of these viruses and their epigenetic regulation, with a specific emphasis on the viral life cycle in the oral epithelium.

Oral and Maxillo-Facial Manifestations of Systemic Diseases: An Overview

Many systemic (infective, genetic, autoimmune, neoplastic) diseases may involve the oral cavity and, more generally, the soft and hard tissues of the head and neck as primary or secondary localization. Primary onset in the oral cavity of both pediatric and adult diseases usually represents a true challenge for clinicians; their precocious detection is often difficult and requires a wide knowledge but surely results in the early diagnosis and therapy onset with an overall better prognosis and clinical outcomes. In the current paper, as for the topic of the current Special Issue, the authors present an overview on the most frequent clinical manifestations at the oral and maxillo-facial district of systemic disease.

Can Epstein-Barr virus play a role in upper urinary tract urothelial carcinomas?

INTRODUCTION

Upper urinary tract urothelial carcinomas are very rare tumours with different biological behaviours. The Epstein-Barr virus, which is the first known oncogenic virus, is being investigated for various malignant tumours. It is known that this virus is associated with nasopharyngeal carcinoma, as well as multiple haematological malignancies, head and neck and gastric cancers. We aimed to determine the presence of the Epstein-Barr virus in upper urinary tract urothelial carcinomas using chromogenic in situ hybridisation (CISH).

MATERIALS AND METHODS

A total of 44 upper urinary tract urothelial carcinomas from two different centres were included. Demographic data and survival rates were obtained from hospital records. One demonstrative paraffin block from each case was stained using Epstein-Barr encoded RNA (EBER) with an automated CISH procedure. The positivity of EBER was statistically analysed for prognostic factors.

RESULTS

Among all patients, 38 were male and 6 were female. The mean age of the patients was 65.93 years. At the time of the study, 15 patients had died and 29 were alive. EBER-CISH positivity was found in 13 patients. Four showed strong EBER-CISH expression and nine showed weak expression. EBER-CISH positivity was not statistically related to any of the prognostic factors or to overall survival.

DISCUSSION

Although EBER-CISH positivity showed no significant relation with prognostic factors, it was observed in one-third of all cases. Therefore, we think that the Epstein-Barr virus may have a role in the pathogenesis of upper urinary tract urothelial carcinomas. This finding needs to be supported by larger studies.

Epstein-Barr virus (EBV) and polyomaviruses are detectable in oropharyngeal cancer and EBV may have prognostic impact

BACKGROUND

The etiological role of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (OPSCC) is confirmed. However, the role of other oncoviruses in OPSCC is unknown.

MATERIALS AND METHODS

A total of 158 consecutive OPSCC patients treated with curative intent were included. DNA extracted from tumor sections was used to detect Epstein-Barr virus (EBV), HPV, and the following polyomaviruses: John Cunningham virus (JCV), Simian virus 40 (SV40), and BK virus (BKV) with PCR. In addition, p16 expression was studied by immunohistochemistry, and EBV-encoded small RNA (EBER) transcripts were localized by in situ hybridization. The effect of viral status on overall survival (OS) and disease-free survival (DFS) was analyzed.

RESULTS

A total of 94/158 samples (59.5%) were HPV-positive, 29.1% contained BKV DNA, 20.3% EBV DNA, 13.9% JCV DNA, and 0.6% SV40 DNA. EBER was expressed only in stromal lymphocytes adjacent to the tumor and correlated with HPV positivity (p = 0.026). p16 expression associated only with HPV. None of the three polyomaviruses had an impact on survival. Patients with EBER-positive but HPV-negative OPSCC had significantly poorer OS and DFS than those with HPV-positive OPSCC and slightly worse prognosis compared with the patients with EBER-negative and HPV-negative OPSCC.

CONCLUSION

Polyomaviruses are detectable in OPSCC but seem to have no impact on survival, whereas HPV was the strongest viral prognostic factor. EBER expression, as a sign of latent EBV infection, may have prognostic impact among patients with HPV-negative OPSCC. EBER analysis may identify a new subgroup of OPSCCs unrelated to HPV.

Epstein-Barr Virus Infection of Oral Squamous Cells

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.

Overexpression of Epstein-Barr virus-encoded latent membrane protein-1 (LMP-1) in oral squamous cell carcinoma

Background

As oral cavity is the main location of Epstein-Barr virus (EBV) latency and shedding, and as EBV-encoded latent membrane protein-1 (LMP-1) has a crucial role in cell transformation, association between EBV infection, LMP-1 expression and oral malignancy is of interest. Although EBV DNA has been detected in oral squamous cell carcinoma (OSCC), studies on LMP-1 expression in OSCC and oral potentially malignant disorders are scarce and still controversial. This study aimed to evaluate the expression of LMP-1 in OSCC and oral leukoplakia (OL).

Methods

Biopsy specimens of 36 OSCC, 69 OL with and without dysplasia and 10 normal oral mucosa were assessed for the expression of LMP-1 using immunohistochemistry. In each case, at least 1000 cells were counted. Cells with staining were considered positive, classified by location as nuclear, cytoplasmic and nuclear plus cytoplasmic staining. Percentage of positive cells at different locations and of total positive cells were determined. For statistical analysis, SPSS version 21 was used. Statistical significance was considered at p < 0.05.

Results

LMP-1 was expressed in all studied specimens. In terms of percentage of total positive cells, LMP-1 expression was higher from normal mucosa (26.36%), OL without dysplasia (28.03%), OL with dysplasia (34.15%), to the significantly highest, (59.67%) in OSCC. In addition, cells with nuclear staining alone, cytoplasmic staining alone and cells with nuclear plus cytoplasmic staining were significantly higher in OSCC compared to those of normal mucosa, OL with and without dysplasia.

Conclusions

LMP-1 was overexpressed in OSCC. Our analysis on subcellular localization of LMP-1 in OSCC revealed prominent distinguished pattern, cytoplasmic distribution. Further studies in cell lines and animals are required to clarify the association between this EBV-encoded proteins and oral carcinogenesis.

Total Antioxidant Status (TAS), Superoxide Dismutase (SOD), and Glutathione Peroxidase (GPx) in Oropharyngeal Cancer Associated with EBV Infection

A growing number of studies reveal that oxidative stress is associated with viral infections or cancer development. However, there are few reports assessing the relationships between oxidative stress, viral infection, and carcinogenesis. The present study analyzed the level of total antioxidant status (TAS) as well as the activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) in patients with oropharyngeal cancer both Epstein-Barr virus (EBV)-positive and EBV-negative in comparison with the control group. The correlations between these parameters and EBV type (wild-type LMP1 (wt-LMP1) or LMP1 with deletion (del-LMP1)), level of antibodies against EBV, the degree of tumor differentiation, and TNM classification were also investigated. Fresh frozen tumor tissue samples collected from 66 patients with oropharyngeal squamous cell carcinoma were tested using nested PCR assay for EBV DNA detection. Spectrophotometric methods were used to measure TAS values as well as SOD and GPx activities in homogenates of tissue, using diagnostic kits produced by Randox Laboratories. Sera from all individuals were investigated using ELISA method to detect the presence of Epstein-Barr virus capsid antigen (EBVCA) IgM and IgG, Epstein-Barr virus nuclear antigen (EBNA) IgG, and early antigen (EA) IgG antibodies. The level of TAS and activities of antioxidant enzymes (GPx and SOD) were significantly decreased in tissues with oropharyngeal cancer, particularly in EBV-positive cases. In 82.3% of patients, wt-LMP1 was detected. Significantly lower TAS, GPx, and SOD values were stated in patients infected with wild-type EBV. The presence of antibodies against early antigen (anti-EA) was detected in over 80% of patients, which suggests reactivation of EBV infection. The correlation between the degree of tumor differentiation and TN classification, especially in EBV-positive patients, was also observed. Determination of these parameters may be useful in evaluating tumor burden in patients with various stages of oropharyngeal cancer and could be an important prognostic factor. Future studies are needed to understand the role of EBV lytic reactivation induced by oxidative stress.

Epstein-Barr virus in the pathogenesis of oral cancers

Epstein-Barr virus (EBV) is a ubiquitous gamma-herpesvirus that establishes a lifelong persistent infection in the oral cavity and is intermittently shed in the saliva. EBV exhibits a biphasic life cycle, supported by its dual tropism for B lymphocytes and epithelial cells, which allows the virus to be transmitted within oral lymphoid tissues. While infection is often benign, EBV is associated with a number of lymphomas and carcinomas that arise in the oral cavity and at other anatomical sites. Incomplete association of EBV in cancer has questioned if EBV is merely a passenger or a driver of the tumorigenic process. However, the ability of EBV to immortalize B cells and its prevalence in a subset of cancers has implicated EBV as a carcinogenic cofactor in cellular contexts where the viral life cycle is altered. In many cases, EBV likely acts as an agent of tumor progression rather than tumor initiation, conferring malignant phenotypes observed in EBV-positive cancers. Given that the oral cavity serves as the main site of EBV residence and transmission, here we review the prevalence of EBV in oral malignancies and the mechanisms by which EBV acts as an agent of tumor progression.

Epstein-Barr virus infection and oral squamous cell carcinoma risk: A meta-analysis

Background

The evidence for association between Epstein-Barr virus (EBV) infection and risk of oral squamous cell carcinoma (OSCC) is inconsistent in the literature. Therefore, this meta-analysis was conducted to clarify this association.

Methods

A literature search was conducted in electronic databases for English- and Chinese-language publications until March 31, 2017 to include eligible case-control studies. The pooled odds ratio (OR) and 95% confidence interval (95% CI) were estimated to determine the association between EBV infection and OSCC risk using a fixed- or random-effects model based on heterogeneity. Publication bias was assessed using funnel plot analysis.

Results

A total of 13 case-control studies with 686 OSCC patients and 433 controls were included based on predetermined inclusion and exclusion criteria. The pooled OR with 95% CI between EBV infection and OSCC risk was 5.03 (1.80–14.01) with significant heterogeneity observed (I² = 87%). The subgroup analysis indicates that the year of publication, study location, economic level, sample size, tissue type, detection method and marker, control type, and language might explain potential sources of heterogeneity. Publication bias was not observed, and sensitivity analysis showed stable results.

Conclusions

The results of the current meta-analysis suggest that EBV infection is statistically associated with increased risk of OSCC. However, additional high-quality studies with larger sample sizes are needed to further confirm the relationship between EBV and OSCC.

No evidence for the presence of Epstein-Barr virus in squamous cell carcinoma of the mobile tongue

Squamous cell carcinoma of the head and neck (SCCHN) comprises a large group of cancers in the oral cavity and nasopharyngeal area that typically arise in older males in association with alcohol/tobacco usage. Within the oral cavity, the mobile tongue is the most common site for tumour development. The incidence of tongue squamous cell carcinoma (TSCC) is increasing in younger people, which has been suggested to associate with a viral aetiology. Two common human oncogenic viruses, human papilloma virus (HPV) and Epstein-Barr virus (EBV) are known causes of certain types of SCCHN, namely the oropharynx and nasopharynx, respectively. EBV infects most adults worldwide through oral transmission and establishes a latent infection, with sporadic productive viral replication and release of virus in the oral cavity throughout life. In view of the prevalence of EBV in the oral cavity and recent data indicating that it infects tongue epithelial cells and establishes latency, we examined 98 cases of primary squamous cell carcinoma of the mobile tongue and 15 cases of tonsillar squamous cell carcinoma for the presence of EBV-encoded RNAs (EBERs), EBV DNA and an EBV-encoded protein, EBNA-1. A commercially available in situ hybridisation kit targeting EBER transcripts (EBER-ISH) showed a positive signal in the cytoplasm and/or nuclei of tumour cells in 43% of TSCCs. However, application of control probes and RNase A digestion using in-house developed EBER-ISH showed identical EBER staining patterns, indicating non-specific signals. PCR analysis of the BamH1 W repeat sequences did not identify EBV genomes in tumour samples. Immunohistochemistry for EBNA-1 was also negative. These data exclude EBV as a potential player in TSCC in both old and young patients and highlight the importance of appropriate controls for EBER-ISH in investigating EBV in human diseases.

Serum EBV antibodies and LMP-1 in Polish patients with oropharyngeal and laryngeal cancer

Background

The association between Epstein-Barr virus (EBV) and the development of head and neck cancer was reported by many researchers. The aim of the present study was to detect EBV DNA and EBV antibodies in 110 Polish patients with oropharyngeal and laryngeal cancer compared to 40 healthy individuals.

Methods

Frozen tumor tissue fragments were tested using nested PCR assay for EBV DNA detection. Sera from all individuals were investigated using ELISA tests to detect the presence of VCA IgM and IgG, EBNA IgG, EA IgG.

Results

EBV DNA was detected in 52.7% of the patients (25% in controls). EBVCA were detected in 94.5%, EBNA in 96.4% and EA in 94.5% of patients. The significantly higher level of EA in the patients suggests EBV reactivation. The majority of patients (83%) were infected with wild-type EBV.

Conclusion

Our study showed that this variant seems to be associated with oropharyngeal and laryngeal cancer in the Polish population.

Epstein-Barr virus (EBV)-associated epithelial and non-epithelial lesions of the oral cavity

Epstein–Barr virus (EBV) is known to be associated with the development of malignant lymphoma and lymphoproliferative disorders (LPDs) in immunocompromised patients. EBV, a B-lymphotropic gamma-herpesvirus, causes infectious mononucleosis and oral hairy leukoplakia, as well as various pathological types of lymphoid malignancy. Furthermore, EBV is associated with epithelial malignancies such as nasopharyngeal carcinoma (NPC), salivary gland tumor, gastric carcinoma and breast carcinoma. In terms of oral disease, there have been several reports of EBV-related oral squamous cell carcinoma (OSCC) worldwide. However, the role of EBV in tumorigenesis of human oral epithelial or lymphoid tissue is unclear. This review summarizes EBV-related epithelial and non-epithelial tumors or tumor-like lesions of the oral cavity. In addition, we describe EBV latent genes and their expression in normal epithelium, inflamed gingiva, epithelial dysplasia and SCC, as well as considering LPDs (MTX- and age-related) and DLBCLs of the oral cavity.

Wogonin as a targeted therapeutic agent for EBV (+) lymphoma cells involved in LMP1/NF-κB/miR-155/PU.1 pathway

Background

Wogonin is an encouraging choice for clinical use owing to its potent anti-tumor and anti-inflammatory effects with the high safety profile. However, wogonin for targeted therapy of lymphoma was not well addressed. In this study, we focused on its anticancer effect alongside with the underlying mechanisms for targeted therapy in EBV-positive lymphoma. This will facilitate its introduction to clinical use, which is planned in the near future.

Methods

Cell proliferation was studied by CCK8. Flow cytometry was used to analyze the apoptosis and the cycle arrest of cells. Further, we also used immunofluorescent staining to detect the morphologic changes of the apoptotic cells. The expression of LMP1/miR-155/p65/pp65/PU.1 was evaluated by quantitative real-time PCR (qRT-PCR) and western blot, while that of NF-κB was analyzed by EMSA. At last, immunohistochemical staining was applied to assess the expression of target proteins and relevant molecules.

Results

In vitro, wogonin induced the apoptosis of Raji cells by downregulating the expression of NF-κB through LMP1/miR-155/NF-κB/PU.1 pathway, which was in a dose and time-dependent manner. In vivo, wogonin could suppress tumor growth, associated with the downregulation of ki67, p65 and upregulation of PU.1.

Conclusions

Wogonin could suppress tumor growth and induce cell apoptosis by inhibiting the expression of NF-κB. Taken these findings, we concluded that wogonin could be a potential targeted therapeutic agent for EBV-positive lymphoma with the expression of LMP1 through the pathway of LMP1/NF-κB/miR-155/PU.1.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3145-4) contains supplementary material, which is available to authorized users.

The interaction between human papillomavirus and other viruses

The etiological role of human papillomavirus (HPV) in anogenital tract and head and neck cancers is well established. However, only a low percentage of HPV-positive women develop cancer, indicating that HPV is necessary but not sufficient in carcinogenesis. Several biological and environmental cofactors have been implicated in the development of HPV-associated carcinoma that include immune status, hormonal changes, parity, dietary habits, tobacco usage, and co-infection with other sexually transmissible agents. Such cofactors likely contribute to HPV persistent infection through diverse mechanisms related to immune control, efficiency of HPV infection, and influences on tumor initiation and progression. Conversely, HPV co-infection with other factors may also harbor anti-tumor effects. Here, we review epidemiological and experimental studies investigating human immunodeficiency virus (HIV), herpes simplex virus (HSV) 1 and 2, human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), BK virus (BKV), JC virus (JCV), and adeno-associated virus (AAV) as viral cofactors in or therapeutic factors against the development of genital and oral HPV-associated carcinomas.