Epstein-barr virus-associated malignancies: epidemiologic patterns and etiologic implications

Emerging roles of small Epstein-Barr virus derived non-coding RNAs in epithelial malignancy

Latent Epstein-Barr virus (EBV) infection is an etiological factor in the progression of several human epithelial malignancies such as nasopharyngeal carcinoma (NPC) and a subset of gastric carcinoma. Reports have shown that EBV produces several viral oncoproteins, yet their pathological roles in carcinogenesis are not fully elucidated. Studies on the recently discovered of EBV-encoded microRNAs (ebv-miRNAs) showed that these small molecules function as post-transcriptional gene regulators and may play a role in the carcinogenesis process. In NPC and EBV positive gastric carcinoma (EBVaGC), 22 viral miRNAs which are located in the long alternative splicing EBV transcripts, named BamH1 A rightward transcripts (BARTs), are abundantly expressed. The importance of several miR-BARTs in carcinogenesis has recently been demonstrated. These novel findings enhance our understanding of the oncogenic properties of EBV and may lead to a more effective design of therapeutic regimens to combat EBV-associated malignancies. This article will review the pathological roles of miR-BARTs in modulating the expression of cancer-related genes in both host and viral genomes. The expression of other small non-coding RNAs in NPC and the expression pattern of miR-BARTs in rare EBV-associated epithelial cancers will also be discussed.

Determining EBV load: current best practice and future requirements

EBV, a gammaherpesvirus and the pathogenic agent for infectious mononucleosis, is also associated with a broad spectrum of lymphoid and epithelial malignancies in immunocompetent and immunosuppressed individuals. EBV-DNA-load measurement by PCR has been shown to be a potential tool for the diagnosis of these diseases, a prognostic factor of their outcome and a successful method to monitor immunosuppressed patients. Since the end of 2011, there is an international WHO standard reference for EBV quantification available; however, many questions still remain; for instance about the optimal amplified region of the EBV genome, or the best-used specimen for EBV detection. Additionally, the optimal specimen and amplified region may vary in different malignancies. In this article, the authors review the different methods to measure EBV load, focus on the best-used specimen for the different EBV-associated malignancies and discuss future requirements and opportunities for EBV-load measurement.

Seroprevalence of Epstein-Barr virus infection in U.S. children ages 6-19, 2003-2010

BACKGROUND

Epstein-Barr virus (EBV) is a common herpesvirus linked to infectious mononucleosis and multiple cancers. There are no national estimates of EBV seroprevalence in the United States. Our objective was to estimate the overall prevalence and sociodemographic predictors of EBV among U.S. children and adolescents aged 6-19.

METHODS

We calculated prevalence estimates and prevalence ratios for EBV seroprevalence using data from the 2003-2010 U.S. National Health and Nutrition Examination Survey (NHANES) for children aged 6-19 (n = 8417). Poisson regression was used to calculate multivariable-adjusted prevalence ratios across subgroup categories (sex, race/ethnicity, parental education, household income, household size, foreign-born, BMI, and household smoking).

FINDINGS

Overall EBV seroprevalence was 66.5% (95% CI 64.3%-68.7%.). Seroprevalence increased with age, ranging from 54.1% (95% CI 50.2%-57.9%) for 6-8 year olds to 82.9% (95% CI 80.0%-85.9%) for 18-19 year olds. Females had slightly higher seroprevalence (68.9%, 95% CI 66.3%-71.6%) compared to males (64.2%, 95% CI 61.7%-66.8%). Seroprevalence was substantially higher for Mexican-Americans (85.4%, 95% CI 83.1%-87.8%) and Non-Hispanic Blacks (83.1%, 95% CI 81.1%-85.1%) than Non-Hispanic Whites (56.9%, 95% CI 54.1%-59.8%). Large differences were also seen by family income, with children in the lowest income quartile having 81.0% (95% CI 77.6%-84.5%) seroprevalence compared to 53.9% (95% CI 50.5%-57.3%) in the highest income quartile, with similar results for parental education level. These results were not explained by household size, BMI, or parental smoking. Among those who were seropositive, EBV antibody titers were significantly higher for females, Non-Hispanic Blacks and Mexican-Americans, with no association found for socioeconomic factors.

CONCLUSIONS

In the first nationally representative U.S. estimates, we found substantial socioeconomic and race/ethnic differences in the seroprevalence of EBV across all ages for U.S. children and adolescents. These estimates can help researchers and clinicians identify groups most at risk, inform research on EBV-cancer etiology, and motivate potential vaccine development.

Variations of Epstein-Barr virus nuclear antigen 1 in Epstein-Barr virus-associated gastric carcinomas from Guangzhou, southern China

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is the only viral protein consistently expressed in all EBV-associated malignancies, and play a critical role in the onset, progression, and/or maintenance of these tumors. Based on the signature changes at amino acid residue 487, EBNA1 is classified into five distinct subtypes: P-ala, P-thr, V-leu, V-val and V-pro. In the present study, the sequence variations of EBNA1 in EBV-associated gastric carcinoma (EBVaGC) and throat washing (TW) samples of healthy EBV carriers in Guangzhou, southern China, where nasopharyngeal carcinoma (NPC) is endemic, were analyzed by PCR and DNA sequencing. V-val subtype was the most predominant (53.6%, 15/28) in EBVaGC, followed by P-ala (42.9%, 12/28) and V-leu (32.1%, 9/28) subtypes. In TWs of healthy EBV carriers, V-val subtype was also predominant (85.7%, 18/21). The sequence variations of EBNA1 in EBVaGC were similar to those in TW of healthy EBV carriers (p>0.05), suggesting that the EBV strains in EBVaGC might originate from the viral strains prevalent within the background population. The predominance of V-val subtype in EBVaGC in Guangzhou was similar to that in EBVaGC in northern China and Japan, but was different from that in EBVaGC in America, suggesting that the variations of EBNA1 in EBVaGC represent geographic-associated polymorphisms rather than tumor-specific mutations. In addition, the EBNA1 variations in EBVaGC in gastric remnant carcinoma were also determined. V-leu subtype was detected in all 4 (100%) cases, although 2 cases occurred as mixed infection with P-ala subtype. This is different from the predominant V-val subtype in EBVaGC in conventional gastric carcinoma, suggesting that V-leu might be a subtype that adapts particularly well to the microenvironment within the gastric stump and enters the remnant gastric mucosa epithelia easily. This, to our best knowledge, is the first investigation of EBNA1 polymorphisms in EBVaGC from endemic area of NPC.

Epstein-Barr virus presence in pediatric diffuse large B-cell lymphoma reveals a particular association and latency patterns: analysis of viral role in tumor microenvironment

Non-Hodgkin's lymphoma represents 6-10% of pediatric malignancies, and diffuse large B-cell lymphoma (DLBCL) is one of the three major subtypes. The 2008 WHO classification included a new entity, Epstein-Barr virus (EBV)-positive DLBCL of the elderly, affecting patients >50 years. It has been demonstrated that EBV may play a role in tumor microenvironment composition, disturbing antitumor immune response and disease progression. As most studies were performed in adults, our aim was to assess EBV presence and latency pattern, as well as T-cell microenvironment in a pediatric DLBCL series of Argentina. The study was conducted on formalin-fixed paraffin-embedded biopsies from 25 DLBCL patients. EBV-encoded small nuclear early regions (EBERs) expression was performed by in situ hybridization, whereas EBV gene expression was analyzed using real-time PCR. Epstein-Barr virus latent membrane proteins (LMP)1, LMP2A, CD3, CD4, CD8 and Foxp3 expression were assessed by immunohistochemistry (IHC). Forty percent of cases showed EBV expression, with a significantly higher incidence among patients <10 years (p = 0.018), and with immunosuppressed (p = 0.023). T-cell subsets were not altered by EBV presence. Full EBV latency antigen expression (latency type III) was the most frequently pattern observed, together with BZLF1 lytic gene expression. One patient showed II-like pattern (LMP1 without LMP2A expression). Based exclusively on IHC, some patients showed latency II/III (EBERs and LMP1 expression) or I (EBERs only). These findings suggest that EBV association in our series was higher than the previously demonstrated for elderly DLBCL and that EBV latency pattern could be more complex from those previously observed. Therefore, EBV could be an important cofactor in pediatric DLBCL lymphomagenesis.

Relationship of Epstein-Barr virus and interleukin 10 promoter polymorphisms with the risk and clinical outcome of childhood Burkitt lymphoma

Epstein-Barr virus (EBV) is an important environmental factor associated to the development of Burkitt lymphoma (BL) in endemic and intermediate risk regions. However, little is known about the contribution of genetic constitution to the development and clinical response of the disease. The aim of this work was to investigate the role of EBV and Interleukin 10 (IL10) single nucleotide polymorphisms (-1082A/G, -819C/T, -592C/A) and microsatellites (IL10.R and IL10.G) in susceptibility and clinical outcome in pediatric BL patients, in a region with intermediate EBV association frequency. The frequencies of IL10 promoter Single nucleotide polymorphisms -1082A/G, -819C/T, -592C/A, and IL10.R and IL10.G microsatellites were compared in 62 pediatric patients and 216 healthy donors. IL10 -1082GG and GCC/GCC genotypes were more frequent in patients than in controls, and associated to a higher risk of BL development (GG genotype OR 2.62, 95% CI, 1.25-5.51; P = 0.008; Pc = 0.024). EBV was detected in tumor samples by EBER-ISH in 54.1% of cases. EBV+ patients exhibited a better event free survival (EFS) (P = 0.019) than EBV- patients. Carriers of IL10 R3-GCC had worse EFS (P = 0.028). Our results suggest a risk effect and an independent prognostic value of IL10 polymorphisms and EBV in childhood BL patients.

Epstein-Barr virus and breast cancer: epidemiological and molecular study on Egyptian and Iraqi women

BACKGROUND AND PURPOSE

The role of Epstein-Barr virus (EBV) in breast carcinogenesis is still controversial. Unraveling this relationship is potentially important for better understanding of breast cancer etiology, early detection and possibly prevention of breast cancer. The aim of the current study is to unravel the association between EBV and primary invasive breast cancer (PIBC) in two different Arab populations (Egyptian and Iraqi women).

PATIENTS AND METHODS

The study was done on paraffin-embedded tissues of 40 Egyptian and 50 Iraqi patients with PIBC in addition to 20 normal breast tissues as controls for each group. Both controls and neoplastic tissues were assessed for the expression of EBV genes and proteins (EBNA-1, LMP-1, and EBER) as well as CD21 marker by immunohistochemistry (IHC), in situ hybridization (ISH) and PCR techniques.

RESULTS

Our gold standard for EBV reactivity in breast cancer cases was positivity of both EBNA1 by PCR and EBER by in situ hybridization. EBV was detected in 18/40 (45%) and 14/50 (28%) of Egyptian and Iraqi women; respectively where p=0.073, compared to 0/20 (0%) of their control groups (p<0.05). Regarding the association between EBV positivity and tumor grade, there was not any statistical significant difference between EBV presence and tumor grade in both populations where p=0.860 and p=0.976 and the calculated rank biserial correlation coefficient was 0.114 and 0.269 for Egyptian and Iraqi women respectively.

CONCLUSION

Our findings show that EBV might act as a promoter for the development of PIBC and it might contribute to increased tumor aggressiveness in Egyptian and Iraqi patients.

Leiomyosarcoma of the sigmoid colon with multiple liver metastases and gastric cancer: a case report

Background

Leiomyosarcoma (LMS) of the gastrointestinal tract is an extremely rare high-grade neoplasm with poor prognosis. For advanced LMS with distant metastasis, the decision as to the choice of the most appropriate therapeutic strategy, including chemotherapy and surgery, is difficult. Here, we present an unusual case of LMS of the sigmoid colon with liver metastases and gastric cancer. The survival of this patient was prolonged by a combined modality therapy involving chemotherapy and surgery.

Case presentation

A 66-year-old woman who had been diagnosed with advanced gastric cancer and multiple liver metastases was referred to our hospital. The initial treatment with docetaxel and S-1 considerably reduced both the gastric cancer and liver tumors; consequently we performed surgical resection. Pathological examination revealed that no viable tumor cells remained in the stomach and chemotherapy resulted in complete remission of the gastric cancer. The liver tumors were immunohistochemically diagnosed as LMS. A tumor of the sigmoid colon was subsequently discovered and the liver tumors were found to have recurred. The surgically resected sigmoid colon and liver tumors were all immunohistochemically diagnosed as LMS. These findings indicated that the multiple liver metastases arose from the LMS in the sigmoid colon, and that they were accompanied by advanced gastric cancer. We performed another surgical resection and administered chemotherapy to treat the recurring liver metastases. The patient survived for 4 years and 10 months after initial presentation at our hospital.

Conclusion

Colonic LMS is rare and its joint occurrence with gastric cancer is extremely unusual. Although LMS is a high-grade neoplasm, a multimodal therapeutic approach can increase patient survival time even when multiple liver metastases are present.

Epstein-Barr virus and methotrexate-related CNS lymphoma in a patient with rheumatoid arthritis

Patients with rheumatoid arthritis (RA), especially those treated with methotrexate (MTX), might have an increased risk of lymphoproliferative disorders that are associated with Epstein-Barr virus (EBV). We describe a case of EBV-associated central nervous system (CNS) lymphoma (diffuse large B-cell lymphoma) in a patient with RA on a short course of MTX treatment. The neoplastic cells express the B-cell surface markers (CD20, Pax-5 and CD30), and EBV-encoded RNA was demonstrated by in situ hybridization. The patient's lymphoma did not recur for the 8-year follow-up period after the tumor resection and cessation of MTX. MTX may promote EBV-positive CNS lymphoma in RA patient due to its immunosuppressive properties as well as reactivating latent EBV infection.

Challenges and opportunities in research on early-life events/exposures and cancer development later in life

It is becoming increasingly evident that early-life events and exposures have important consequences for cancer development later in life. However, epidemiological studies of early-life factors and cancer development later in life have had significant methodological challenges such as the long latency period, the distinctiveness of each cancer, and large number of subjects that must be studied, all likely to increase costs. These traditional hurdles might be mitigated by leveraging several existing large-scale prospective studies in the United States (US) and globally, as well as birth databases and birth cohorts, in order to launch both association and mechanistic studies of early-life exposures and cancer development later in life. Dedicated research funding will be needed to advance this paradigm shift in cancer research, and it seems justified by its potential to produce transformative understanding of how cancer develops over the life-course. This in turn has the potential to transform cancer prevention strategies through interventions in early-life rather than later in life, as is the current practice, where it is perhaps less effective.

Epstein-Barr virus infection and sporadic breast cancer risk: a meta-analysis

Background

A large number of epidemiological studies have evaluated the association between Epstein-Barr virus infection and breast carcinoma risk but results have been inconsistent.

Methodology

Research using the polymerase chain reaction technique for detecting the Epstein-Barr virus was selected; 24 studies and 1535 cases were reviewed. Information on the study populations, sample types, publication calendar period and histological types of breast carcinoma were collected. An unconditional logistic regression model was used to analyze potential parameters related to the Epstein-Barr virus prevalence. A Kappa test was used to evaluate the consistency in detecting different Epstein-Barr virus DNA regions. Nine studies that included control groups and 1045 breast cancer cases were adopted in this meta-analysis.

Conclusions

We found that 29.32% of the patients with breast carcinoma were infected with the Epstein-Barr virus. The prevalence of Epstein-Barr was highest in Asia (35.25%) and lowest in the USA (18.27%). Statistical analysis revealed a trend that showed lobular breast carcinoma might have the strongest association with Epstein-Barr virus infection. This meta-analysis showed a significant increase in breast malignancy risk in patients testing positive for the Epstein-Barr virus (OR = 6.29, 95% CI = 2.13–18.59). This result suggests that an Epstein-Barr virus infection is statistically associated with increased breast carcinoma risk.

Possible role of EBV in breast cancer and other unusually EBV-associated cancers

Epstein-Barr virus (EBV) a ubiquitous gamma herpesvirus persists for life, generally without health consequences. However, it is associated with several well-recognized malignancies, such as Burkitt's lymphoma and nasopharyngeal carcinoma. A growing list of malignancies has been proposed to be EBV-associated: most of which are consistently EBV-positive whereas others show inconsistent results. The possible contribution of EBV to the development and/or progression of different "non-classical" tumors is discussed in terms of putative "non-traditional'' infection in EBV-related tumors.

Epstein-Barr virus-associated adrenal smooth muscle tumors and disseminated diffuse large B-cell lymphoma in a child with common variable immunodeficiency: a case report and review of the literature

This article reports the clinical and the histological features in a 7-year-old girl affected by common variable immunodeficiency (CVID) who developed multiple Epstein-Barr virus-associated tumors, represented by bilateral adrenal smooth muscle tumors (EBV-SMT) and multifocal diffuse large B-cell lymphoma. The EBV-SMTs showed features compatible with a benign or at least a low-malignant potential neoplasm. A peculiar feature observed in both EBV-SMTs was the occurrence of numerous lymphocytes intermingled with the spindle cells, which consisted of CD3+ CD5+ T-cells, with a predominant cytotoxic CD8+ component. Interestingly, EBV status differed in the neoplasms, since the EBV-SMTs were negative for LMP1 and positive for EBER, whereas the B-cell lymphoma expressed both EBV markers. Furthermore, EBV-LMP1 deletion was positive only in the EBV-SMTs, thus indicating that these tumors were the consequence of 2 distinct, EBV-dependent transformations. Similarly, lymphocyte clonality assay also showed different clonal bands in different sites (skin and nasal cavity), suggesting the development of intratumoral mutations. Finally, the authors review all 127 previously reported EBV-SMT, with discussion of their clinical and pathological features.

Prognostic utility of anti-EBV antibody testing for defining NPC risk among individuals from high-risk NPC families

PURPOSE

Epstein-Barr virus (EBV) infection and a family history of nasopharyngeal carcinoma (NPC) are associated with NPC risk. We examined the risk associated with EBV markers and their clinical utility to identify NPC susceptibles within high-risk NPC families.

EXPERIMENTAL DESIGN

We evaluated antibody titers against viral capsid antigen (VCA) IgA, EBV nuclear antigen-1 (EBNA1) IgA, and DNase among unaffected relatives of NPC cases from 358 multiplex families in Taiwan. Incident NPC cases were identified via linkage to the National Cancer Registry. Clinical examinations of 924 individuals were also done to identify occult, asymptomatic NPC. Baseline EBV serology was used to estimate NPC risk using rate ratios with 95% CI. Associated sensitivity/specificity and receiver operating characteristic (ROC) curves were calculated.

RESULTS

A total of 2,444 unaffected individuals with 15,519 person-years (6.5 years median follow-up) yielded 14 incident NPC cases (nearly 11 times the general population rate). The absolute rate of NPC among anti-EBV EBNA1 IgA seropositives using a standard positivity cutoff versus an optimized cutoff point defined by ROC analyses was 265/100,000 person-years with a 4.7-fold increased risk of NPC (95% CI: 1.4-16) and 166/100,000 person-years with a 6.6-fold increase (95% CI: 1.5-61), respectively. Sensitivity and specificity using the optimized positivity cutoff points were 85.7% and 51.2%, respectively. It is estimated that active evaluation of 49% of individuals from high-risk NPC families seropositive for this marker could lead to earlier detection of up to 86% of NPC cases. Risks associated with the other three EBV markers were weaker.

CONCLUSIONS

Future efforts are needed to identify susceptibility markers among high-risk NPC families that maximize both sensitivity and specificity.

Herpesvirus-encoded GPCRs rewire cellular signaling

Viral G-protein-coupled receptors (vGPCRs) are chemokine receptor homologues encoded by the Herpes- and Capripoxviridae. They are thought to have been hijacked from the host genome during the course of evolution. These vGPCRs play different roles in the viral lifecycle and associated pathologies. Three members of the Herpesviridae, Kaposi sarcoma-associated herpesvirus (KSHV), Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) are capable of setting up persistent latent infections in humans. Two of the herpesviruses, KSHV and EBV, are associated with cancer, while HCMV may have an oncomodulary effect. The vGPCRs may contribute to the escape of immune surveillance and (constitutively) activate signaling pathways linked to proliferation and inflammation. Some vGPCRs induce activation of autocrine and paracrine signaling, resulting in secretion of growth factors and/or cytokines. As a result, vGPCRs effectively rewire cellular signaling networks. Delineating the cellular signaling networks modulated by these vGPCRs will be crucial for treatment of virus-associated pathologies.

Sequence analysis of the Epstein-Barr virus (EBV) BRLF1 gene in nasopharyngeal and gastric carcinomas

Background

Epstein-Barr virus (EBV) has a biphasic infection cycle consisting of a latent and a lytic replicative phase. The product of immediate-early gene BRLF1, Rta, is able to disrupt the latency phase in epithelial cells and certain B-cell lines. The protein Rta is a frequent target of the EBV-induced cytotoxic T cell response. In spite of our good understanding of this protein, little is known for the gene polymorphism of BRLF1.

Results

BRLF1 gene was successfully amplified in 34 EBV-associated gastric carcinomas (EBVaGCs), 57 nasopharyngeal carcinomas (NPCs) and 28 throat washings (TWs) samples from healthy donors followed by PCR-direct sequencing. Fourteen loci were found to be affected by amino acid changes, 17 loci by silent nucleotide changes. According to the phylogenetic tree, 5 distinct subtypes of BRLF1 were identified, and 2 subtypes BR1-A and BR1-C were detected in 42.9% (51/119), 42.0% (50/119) of samples, respectively. The distribution of these 2 subtypes among 3 types of specimens was significantly different. The subtype BR1-A preferentially existed in healthy donors, while BR1-C was seen more in biopsies of NPC. A silent mutation A/G was detected in all the isolates. Among 3 functional domains, the dimerization domain of Rta showed a stably conserved sequence, while DNA binding and transactivation domains were detected to have multiple mutations. Three of 16 CTL epitopes, NAA, QKE and ERP, were affected by amino acid changes. Epitope ERP was relatively conserved; epitopes NAA and QKE harbored more mutations.

Conclusions

This first detailed investigation of sequence variations in BRLF1 gene has identified 5 distinct subtypes. Two subtypes BR1-A and BR1-C are the dominant genotypes of BRLF1. The subtype BR1-C is more frequent in NPCs, while BR1-A preferentially presents in healthy donors. BR1-C may be associated with the tumorigenesis of NPC.

Immunotherapeutic options for Epstein-Barr virus-associated lymphoproliferative disease following transplantation

Epstein-Barr virus-associated lymphoproliferative diseases (EBV-LPD) after hematopoietic stem cell transplantation or solid-organ transplantation remain a serious and potentially life-threatening complication. In the last decade, outcomes for EBV-LPD have significantly improved. Key to this success was the development of early detection methods, such as serial measurements of EBV-DNA load in the peripheral blood of transplant recipients. Immunotherapeutic interventions for EBV-LPD include reduction of immunosuppression, CD20 monoclonal antibodies (rituximab) as monotherapy or in conjunction with chemotherapy, and adoptive immunotherapy with EBV-specific T cells. Pre-emptive immunotherapeutic interventions can prevent the development of EBV-LPD. As monotherapy, immunotherapy is effective in inducing remissions of EBV-LPD with low-risk features. For high-risk disease, combining immunotherapy with conventional therapies has led to superior outcomes. Current challenges consist of risk stratifying patients so that patients receive the most efficacious therapy without suffering from unwanted side effects.

A prospective study of Epstein-Barr virus antibodies and risk of non-Hodgkin lymphoma

Severe immunosuppression is an established risk factor for non-Hodgkin lymphoma (NHL), but an association with subclinical immune dysfunction is unclear. We conducted a case-control study nested in the Physicians' Health Study and the Nurses' Health Study cohorts to determine whether patterns of antibody response to Epstein-Barr virus (EBV) were associated with NHL risk. We measured antibody titers against viral capsid antigen, early antigen, and Epstein-Barr nuclear antigen (EBNA-1 and EBNA-2) in blood samples collected before diagnosis from 340 cases and 662 matched controls. Using conditional logistic regression, we estimated rate ratios (RRs) and 95% confidence intervals (CIs) for elevated versus normal titers and the ratio of anti-EBNA-1 to anti-EBNA-2 titers (≤ 1.0 vs > 1.0). We found no association between EBV serostatus, elevated titers, or an EBNA-1/EBNA-2 ratio ≤ 1.0 and NHL risk overall. For chronic lymphocytic leukemia/small lymphocytic lymphoma, suggestive associations were noted for elevated anti-EBNA-2 (RR, 1.74; 95% CI, 0.99-3.05), anti-viral capsid antigen (RR, 1.58; 95% CI, 0.79-3.14), and EBNA-1/EBNA-2 ratio ≤ 1.0 (RR, 1.52; 95% CI, 0.91-2.55). There was no evidence of heterogeneity by subtype. Overall, we found no evidence that EBV antibody profile predicts NHL risk in immunocompetent persons, with the possible exception of chronic lymphocytic leukemia/small lymphocytic lymphoma.

Epstein-Barr virus-associated pneumonia and bronchiolitis obliterans syndrome in a lung transplant recipient

We report the case of a 25-year-old lung and liver transplant recipient who developed respiratory failure. High levels of Epstein-Barr virus (EBV) genome copies were detectable in respiratory tract specimens, while the search for various other viral, bacterial or fungal pathogens remained empty. Post-transplant lymphoproliferative disease was excluded. Due to the rapid progression of respiratory insufficiency, a re-transplantation of the lung was performed. EBV-encoded small RNAs could be demonstrated by in situ hybridization within pneumocytes and lymphocytes of the explanted lung tissue. The clinical situation improved soon after re-transplantation, and the EBV load detected in the lower respiratory tract decreased significantly.

Possible DNA viral factors of human breast cancer

Viruses are considered to be one of the high-risk factors closely related to human breast cancer. However, different studies of viruses in breast cancer present conflicting results and some of these works remain in dispute. DNA viruses, such as specific types of human papillomaviruses (HPV), Epstein–Barr virus (EBV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), and human herpes virus type 8 (HHV-8), have emerged as causal factors of some human cancers. These respective exogenous viruses and the possibility of multiple viral factors are discussed in this review.

The extent of genetic diversity of Epstein-Barr virus and its geographic and disease patterns: a need for reappraisal

Epstein-Barr virus (EBV) is a ubiquitous, gamma-1 lymphotrophic virus etiologically linked to nasopharyngeal carcinoma (NPC), endemic to Southern China, and Burkitt lymphoma (BL), endemic to equatorial Africa, both of which are rare elsewhere in the world. Why EBV is associated with different malignancies in different geographic regions remains puzzling and may be related to EBV genotypic variability through specific disease and geographic associations. We review the literature on sequence variation in EBV genes, focusing on LMP-1, EBNA-1, and BZLF-1 and their distribution by geography and disease. Given the limitations of current studies, definitive conclusions regarding the link between EBV genotypes, disease and geography are not possible. We suggest that the true extent of EBV diversity is likely to be greater than is currently recognized. Additional studies conducted in carefully selected populations, that are sufficiently powered to provide robust estimates, and that utilize testing approaches that permit full characterization of viral diversity are needed to further our understanding of patterns of EBV genetic variation and their association with malignancies in different regions.

Adoptive Immunotherapy for EBV-associated Malignancies

Latent Epstein-Barr virus (EBV) infection is associated with a diverse group of malignancies including Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma (NPC), and lymphoproliferative disease (LPD). EBV proteins expressed in these malignancies provide targets for the adoptive immunotherapy with antigen-specific cytotoxic T cells (CTL) and EBV-specific CTL have been used successfully for the prophylaxis and treatment of EBV-LPD post hematopoietic stem cell transplantation (HSCT). The clinical experience with EBV-specific CTL for other EBV-associated malignancies such as Hodgkin's disease and NPC is limited and the results obtained so far indicate that EBV-specific CTL are less effective than for EBV-LPD post HSCT. Decreased CTL efficacy most likely reflect immune evasion strategies by tumor cells such as down regulation of immunodominant EBV proteins and secretion of inhibitory cytokines. To overcome these immune evasion strategies a number of approaches have been developed including targeting CTL to subdominant EBV antigens and genetically modifying CTL to increase their potency.

Down-regulation of gp130 in nasopharyngeal carcinoma

BACKGROUND

The purpose of this study was to explore the expression and biological functions of glycoprotein 130 (gp130) in Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). A prospective study was performed.

METHODS

Ten patients with NPC and 10 patients with nasopharyngeal lymphoid hyperplasia (LH) were enrolled in this study. The transcripts of IL-27 receptors (gp130 and WSX-1) in the biopsy specimens derived from NPC were compared with that from LH by using reverse-transcription polymerase chain reaction. Cell lines including EBV(-), Burkitt-like lymphoma (BJAB) cells, human adult peripheral blood mononuclear cells, and lymphoblastoid cell lines were used to provide evidence of the biological function of gp130. In addition, killing assay for natural killer (NK) cells was performed in the presence of gp130.

RESULTS

There was significantly stronger expression of gp130 on the LH specimens than on the NPC specimens. The levels of gp130 mRNA were reduced in the EBV-transformed cells. The cytotoxicity ratio against gp130-deficient B cells was diminished compared with gp130-existent B cells.

CONCLUSION

The expression of gp130 is down-regulated in patients with NPC. We presume that EBV controls the functions of NK cells through regulation of gp130 cytokine receptor.

Immune therapy for cancer

Over the past decade, immune therapy has become a standard treatment for a variety of cancers. Monoclonal antibodies, immune adjuvants, and vaccines against oncogenic viruses are now well-established cancer therapies. Immune modulation is a principal element of supportive care for many high-dose chemotherapy regimens. In addition, immune activation is now appreciated as central to the therapeutic mechanism of bone marrow transplantation for hematologic malignancies. Advances in our understanding of the molecular interactions between tumors and the immune system have led to many novel investigational therapies and continue to inform efforts for devising more potent therapeutics. Novel approaches to immune-based cancer treatment strive to augment antitumor immune responses by expanding tumor-reactive T cells, providing exogenous immune-activating stimuli, and antagonizing regulatory pathways that induce immune tolerance. The future of immune therapy for cancer is likely to combine many of these approaches to generate more effective treatments.

Independent effect of EBV and cigarette smoking on nasopharyngeal carcinoma: a 20-year follow-up study on 9,622 males without family history in Taiwan

This study aimed to assess independent effects of EBV and cigarette smoking on nasopharyngeal carcinoma, which have never been assessed in long-term follow-up studies. A cohort of 9,622 men was enrolled from 1984 to 1986. Blood samples collected at study entry were tested for antibodies against EBV antigens (anti-EBV) viral capsid antigen immunoglobulin A and DNase. The cigarette smoking habit was inquired through questionnaire interview. Newly developed nasopharyngeal carcinoma cases were ascertained through computerized linkage with national cancer registry profile. Cox's proportional hazard regression analysis was used to estimate multivariate-adjusted hazard ratio with its 95% confidence interval (95% CI). During the follow-up of 173,706 person-years, 32 pathologically confirmed nasopharyngeal carcinoma cases were identified >1 year after recruitment. Increasing serum levels of anti-EBV viral capsid antigen immunoglobulin A and DNase were significantly associated with nasopharyngeal carcinoma risk in a dose-response relationship. The multivariate-adjusted hazard ratio (95% CI) of developing nasopharyngeal carcinoma for low and high antibody levels compared with seronegatives was 9.5 (2.2-40.1) and 21.4 (2.8-161.7), respectively, for anti-EBV viral capsid antigen immunoglobulin A (P < 0.001 for trend), and 1.6 (0.5-4.6) and 16.0 (5.4-47.1), respectively, for anti-EBV DNase (P < 0.001 for trend). The shorter the time interval between study entry and nasopharyngeal carcinoma diagnosis, the higher was the proportion of anti-EBV viral capsid antigen immunoglobulin A among nasopharyngeal carcinoma patients. The multivariate-adjusted hazard ratio (95% CI) was 3.0 (1.3-7.2) for > or =30 pack-years of cumulative cigarette smoking compared with <30 pack-years as the reference. The longer and heavier the cigarette smoking habit, the higher was the nasopharyngeal carcinoma risk. Anti-EBV viral capsid antigen immunoglobulin A, anti-EBV DNase, and long-term heavy cigarette smoking are independent nasopharyngeal carcinoma risk predictors.

Cigarette smoking and glutathione S-transferase M1 polymorphism associated with risk for uterine cervical cancer

AIM

To elucidate the role of tobacco smoking and polymorphisms of carcinogen metabolism genes in cervical carcinogenesis.

METHODS

We analyzed genotypes of nine genes, 11 polymorphisms encoding carcinogen metabolizing enzymes, information on smoking, and the presence of human papillomavirus in 124 Japanese cervical cancer patients and 125 healthy controls.

RESULTS

The incidence of human papillomavirus infection (95.5% vs 9.9%; P < 0.001; odds ratio (OR), 231.98; 95% confidence interval [CI], 57.17-941.22), and smoking (41.1% vs 18.4%; P < 0.001; OR, 3.40; 95% CI, 1.88-6.17) were both significantly higher in patients than in controls. The genotype distributions of CYP1A1, CYP2E1, CYP2A6, NQO1, NAT2, mEH, MPO and GSTT1 genes were not statistically different; however, the ratio of the GSTM1 null genotype was significantly higher in patients than in controls (62.1% vs 47.2%; P = 0.019; OR, 1.83; 95% CI, 1.11-3.04). The incidence of GSTM1 null was significantly higher in the non-smoking group (63.0% vs 47.1%; P = 0.038; OR, 1.92; 95% CI, 1.04-3.54), and not in the smoking group (60.8% vs 47.8%; P = 0.300; OR, 1.69; 95% CI, 0.63-4.56).

CONCLUSIONS

In the current study, risk factors for developing cervical cancer were tobacco smoking and GSTM1 null; however, no association was observed between these two factors. We could not prove that smoking-GSTM1 null interaction was responsible for the increase in cervical cancer among young Japanese, and further studies with more detailed smoking status, not only active but passive smoking, will be required.

Epstein-Barr virus LMP2A accelerates MYC-induced lymphomagenesis

Despite the identification of Epstein-Barr virus (EBV) in tumors of Burkitt's lymphoma (BL) over 40 years ago, the exact contribution of EBV to BL is undefined. EBV encodes for multiple proteins in latent B cells that affect B cell survival and activation. One such protein, latent membrane protein 2A (LMP2A), protects B cells from numerous pro-apoptotic stimuli. Therefore, we tested whether LMP2A protects B cells from apoptosis induced by aberrant c-MYC expression that precedes and dominates BL. We crossed LMP2A-transgenic mice (LMP2A-Tg), in which all B cells express LMP2A, to a transgenic mouse that expresses a BL translocation of myc (lambda-MYC-Tg mice). LMP2A promotes proliferation and protects B cells from MYC-induced apoptosis in lambda-MYC-Tg mice. LMP2A also accelerates the development of lymphoma in LMP2A/lambda-MYC-Tg mice. Finally, LMP2A increases the expression of Bcl-X(L) in both pre-tumor B cells and tumor cells, suggesting a mechanism for LMP2A-mediated B cell survival in the presence of MYC. These results support a hypothesis that EBV LMP2A promotes tumor development by protecting pre-tumor B cells that would normally apoptose after the c-myc translocation.

Associations between infectious mononucleosis and cancer: record-linkage studies

Infection with Epstein-Barr virus (EBV) followed by infectious mononucleosis (IM) is now considered to be a risk factor for Hodgkin's disease (HD). It is less clear whether EBV infection and IM are associated with an increased risk of cancer generally. We used a longstanding record-linkage dataset in Oxford (years 1963-1998), and a more recent record-linkage dataset covering England (1999-2005), to compare rate ratios for cancer between people admitted to hospital for IM and a reference cohort. In the Oxford cohort, there was an increased risk of subsequent HD [rate ratio (RR) 6.0, 95% confidence interval (CI) 2.4-12.5] but not of other cancers combined (RR 0.85, 95% CI 0.57-1.23). In the England cohort, there were increased risks of HD (RR 3.2, 95% CI 1.2-7.0), non-Hodgkin's lymphoma (RR 5.6, 95% CI 2.9-9.8), and oropharyngeal cancer (RR 5.4, 95% CI 1.1-16.2), but no significant overall risk of cancer when lymphomas were excluded (RR 1.01, 95% CI 0.71-1.41). We confirm an association between IM and lymphoma; but the risk, if any, of cancer more generally is likely to be small.

Association of Epstein-Barr Virus with Nasopharyngeal Carcinoma and Current Status of Development of Cancer-derived Cell Lines

It is well known that the Epstein-Barr virus (EBV) contributes directly to tumourigenesis in nasopharyngeal carcinoma (NPC), primarily in the undifferentiated form of NPC (WHO type III; UNPC or UC), which is commonly found in South East Asia. Unfortunately, research in NPC has been severely hampered by the lack of authentic EBV-positive (EBV+) human NPC cell lines for study. Since 1975, there have been more than 20 reported NPC cell lines. However, many of these NPC-derived cell lines do not express EBV transcripts in long-term culture, and therefore that finding may dispute the fundamental theory of NPC carcinogenesis. In fact, currently only one EBV+ human NPC cell line (C-666) in long-term culture has been reported. Hence, most of the NPC cell lines may not be representative of the disease itself. In order to better understand and treat NPC, there is an urgent need to develop more EBV+ human NPC cell lines. In this review, we discuss the authenticity of existing NPC cell lines and the impact of our understanding of NPC biology on the treatment of the disease and the relationship of EBV to NPC in the context of cell lines. Key words: Carcinogenesis, Cell culture, Epstein-Barr virus, Hayflick’s limit

Racial/ethnic variation in EBV-positive classical Hodgkin lymphoma in California populations

Epstein-Barr virus (EBV) is detected in the tumor cells of some but not all Hodgkin lymphoma (HL) patients, and evidence indicates that EBV-positive and -negative HL are distinct entities. Racial/ethnic variation in EBV-positive HL in international comparisons suggests etiologic roles for environmental and genetic factors, but these studies used clinical series and evaluated EBV presence by differing protocols. Therefore, we evaluated EBV presence in the tumors of a large (n = 1,032), racially and sociodemographically diverse series of California incident classical HL cases with uniform pathology re-review and EBV detection methods. Tumor EBV-positivity was associated with Hispanic and Asian/Pacific Islander (API) but not black race/ethnicity, irrespective of demographic and clinical factors. Complex race-specific associations were observed between EBV-positive HL and age, sex, histology, stage, neighborhood socioeconomic status (SES), and birth place. In Hispanics, EBV-positive HL was associated not only with young and older age, male sex, and mixed cellularity histology, but also with foreign birth and lower SES in females, suggesting immune function responses to correlates of early childhood experience and later environmental exposures, respectively, as well as of pregnancy. For APIs, a lack of association with birth place may reflect the higher SES of API than Hispanic immigrants. In blacks, EBV-positive HL was associated with later-stage disease, consistent with racial/ethnic variation in certain cytokine polymorphisms. The racial/ethnic variation in our findings suggests that EBV-positive HL results from an intricate interplay of early- and later-life environmental, hormonal, and genetic factors leading to depressed immune function and poorly controlled EBV infection.

Up-regulation of Murid herpesvirus 4 ORF50 by hypoxia: possible implication for virus reactivation from latency

Murid herpesvirus 4 (MuHV-4) is a member of the Gammaherpesvirus subfamily capable to establish a long-lasting latency and induce occasional malignancies. Because MuHV-4 is associated with cancer in a subset of virus-infected mice and because tumor development is often linked with hypoxia, we studied the influence of hypoxia on the biology of this virus. Using immunofluorescence and FACS analysis we detected increased proportion of MuHV-4 positive cells in the latently infected NB-78 cell line exposed to low oxygen conditions compared to normoxic controls. Moreover, the expression of ORF50, a crucial gene responsible for switch from latency to lytic virus replication, was induced upon the exposure of NB-78 cells to hypoxia. Luciferase reporter assays with ORF50 promoter confirmed the hypoxia-dependent induction. Transient co-transfections with hypoxia inducible factors showed that HIF-2alpha is a more potent activator of ORF50 expression than HIF-1alpha. Our results confirm that the MuHV-4 life cycle is influenced by low oxygen concentration.

T cell therapies

T cell therapies are increasingly used for the treatment of malignancies and viral-associated diseases. Initial studies focused on the use of unmanipulated T cell populations after allogeneic stem cell transplantation. More recently, the use of antigen-specific T cells has been explored. This chapter reviews the clinical experience with polyclonal Epstein-Barr virus (EBV)-specific cytotoxic T cells (CTL) for the treatment of EBV-associated malignancies. Strategies on how to improve the antitumor activity of EBV-specific CTL are being discussed. If effective, these strategies will have broad implications for T cell therapies for a range of human tumors with defined antigens.

Haplotype of gene Nedd4 binding protein 2 associated with sporadic nasopharyngeal carcinoma in the Southern Chinese population

BACKGROUND

Bcl-3 as an oncoprotein is overexpressed in nasopharyngeal carcinoma (NPC). Nedd4 binding protein 2 (N4BP2), which is located in the NPC susceptibility locus, is a Bcl-3 binding protein. This study is aimed to explore the association between N4BP2 genetic polymorphism and the risk of NPC.

METHODS

We performed a hospital-based case-control study, including 531 sporadic NPC and 480 cancer-free control subjects from southern China. PCR-sequencing was carried out on Exons, promoter region and nearby introns of the N4BP2 gene. The expression pattern of N4BP2 and Bcl-3 was also analyzed.

RESULTS

We observed a statistically significant difference in haplotype blocks ATTA and GTTG between cases and controls. In addition, three novel SNPs were identified, two of which were in exons (loc123-e3l-snp2, position 39868005, A/G, Met171Val; RS17511668-SNP2, position 39926432, G/A, Glu118Lys), and one was in the intron6 (RS794001-SNP1, position 39944127, T/G). Moreover, N4BP2 was at higher levels in a majority of tumor tissues examined, relative to paired normal tissues.

CONCLUSION

These data suggest that haplotype blocks ATTA and GTTG of N4BP2 is correlation with the risk of sporadic nasopharyngeal carcinoma in the Southern Chinese population and N4BP2 has a potential role in the development of NPC.

A phase 1/2 trial of arginine butyrate and ganciclovir in patients with Epstein-Barr virus-associated lymphoid malignancies

Malignancies associated with latent Epstein-Barr virus (EBV) are resistant to nucleoside-type antiviral agents because the viral enzyme target of these antiviral drugs, thymidine kinase (TK), is not expressed. Short-chain fatty acids, such as butyrate, induce EBV-TK expression in latently infected B cells. As butyrate has been shown to sensitize EBV(+) lymphoma cells in vitro to apoptosis induced by ganciclovir, arginine butyrate in combination with ganciclovir was administered in 15 patients with refractory EBV(+) lymphoid malignancies to evaluate the drug combination for toxicity, pharmacokinetics, and clinical responses. Ganciclovir was administered twice daily at standard doses, and arginine butyrate was administered by continuous infusion in an intrapatient dose escalation, from 500 mg/(kg/day) escalating to 2000 mg/(kg/day), as tolerated, for a 21-day cycle. The MTD for arginine butyrate in combination with ganciclovir was established as 1000 mg/(kg/day). Ten of 15 patients showed significant antitumor responses, with 4 CRs and 6 PRs within one treatment cycle. Complications from rapid tumor lysis occurred in 3 patients. Reversible somnolence or stupor occurred in 3 patients at arginine butyrate doses of greater than 1000 mg/(kg/day). The combination of arginine butyrate and ganciclovir was reasonably well-tolerated and appears to have significant biologic activity in vivo in EBV(+) lymphoid malignancies which are refractory to other regimens.

Epstein-Barr Virus-associated Primary Lymphoepitheliomalike Carcinoma of the Esophagus

Primary lymphoepitheliomalike carcinomas (LELC) of the esophagus are uncommon, with only 29 previously reported cases in the literature. Primary LELC of the esophagus is associated with Epstein-Barr virus (EBV). We herein report a 52-year-old man who presented with dysphagia and weight loss and was found to have a polypoid mass in the middle esophagus. Pathologic examination showed LELC. EBV infection was demonstrated by immunohistochemical detection of EBNA-1 in neoplastic cells and polymerase chain reaction amplification for EBNA-3C, BamHI-F, and W1/I1 regions but not by in situ hybridization by EBER-1 transcripts. EBV genotyping analysis demonstrated infection by a novel type "i"/XhoI loss recombinant strain. Although it is accepted that polymorphisms at BamHI-W1/I1 region cosegregate with polymorphisms at XhoI restriction site, this novel recombinant EBV has been identified in healthy donors and in nasal NK/T-cell lymphoma. To our knowledge, this is the first report that describes this recombinant type "i"/XhoI loss EBV strain in a primary LELC of the esophagus.

Gamma interferon blocks gammaherpesvirus reactivation from latency

Establishment of latent infection and reactivation from latency are critical aspects of herpesvirus infection and pathogenesis. Interfering with either of these steps in the herpesvirus life cycle may offer a novel strategy for controlling herpesvirus infection and associated disease pathogenesis. Prior studies show that mice deficient in gamma interferon (IFN-gamma) or the IFN-gamma receptor have elevated numbers of cells reactivating from murine gammaherpesvirus 68 (gammaHV68) latency, produce infectious virus after the establishment of latency, and develop large-vessel vasculitis. Here, we demonstrate that IFN-gamma is a powerful inhibitor of reactivation of gammaHV68 from latency in tissue culture. In vivo, IFN-gamma controls viral gene expression during latency. Importantly, depletion of IFN-gamma in latently infected mice results in an increased frequency of cells reactivating virus. This demonstrates that IFN-gamma is important for immune surveillance that limits reactivation of gammaHV68 from latency.

Epidemiology of Epstein-Barr virus, cytomegalovirus, and Kaposi's sarcoma-associated herpesvirus infections in peripheral blood leukocytes revealed by a multiplex PCR assay

A multiplex polymerase chain reaction (PCR) has been developed for the simultaneous detection of Epstein-Barr virus (EBV), cytomegalovirus (CMV), and Kaposi's sarcoma-associated herpesvirus (KSHV) in a clinical sample. Primers of multiplex PCR were designed to amplify specific regions of the EBV EBNA1, CMV IE2, and KSHV LANA genes. This multiplex PCR assay was found to have detection sensitivities of 1-10 copies of purified viral DNA cloned into the plasmid. To assess diagnostic and pre-clinical applications with this method, we utilized KSHV-positive primary effusion lymphoma (PEL) cells, EBV-positive Burkitt's lymphoma cells, CMV-infected fibroblast cells, and clinically prepared peripheral blood leukocytes (PBLs) that had been infected with viruses. We found that this multiplex PCR assay has high sensitivity and specificity for simultaneous detection of EBV, CMV, and KSHV genomes in a single amplification from a clinical material. Using this multiplex PCR assay, we investigated the prevalence of EBV, CMV, and KSHV in PBL samples from normal Japanese randomly selected. KSHV, EBV, and CMV genomes were detected in samples from 2 (0.2%), 377 (39.5%), and 27 (2.8%) of the 953 blood donors, respectively. Interestingly, both EBV and CMV genomes were detected in samples from all KSHV-positive donors.

Contact-activated monocytes: efficient antigen presenting cells for the stimulation of antigen-specific T cells

Mature dendritic cells (DCs) are potent antigen presenting cells (APCs) that have been used in vaccine studies and adoptive immunotherapy protocols. For many clinical studies DCs are derived from monocytes in the presence of cytokines, which are expensive and often unavailable for clinical use. Here we describe a cytokine independent method for the differentiation of monocytes into APCs for the reactivation of antigen-specific memory T cells from both healthy donors and cancer patients. Contact activation of monocytes resulted in secretion of proinflammatory cytokines, such as IL-8, and increased cell surface expression of costimulatory molecules. To determine if activated monocytes (actMo) like DC can reactivate antigen-specific CTL, they were transduced with adenoviral vectors encoding the subdominant Epstein Barr virus antigens, latent membrane proteins (LMP) 1 and 2, which are expressed in Epstein Barr virus-positive malignancies. Stimulation of peripheral blood mononuclear cells with LMP1- and LMP2-expressing actMo activated LMP1- and LMP2-specific T cells, which could be further expanded with LMP1 or LMP2 expressing lymphoblastoid cell lines. The use of actMo as APCs simplifies the production/manufacture of antigen-specific T cells for clinical trials.

HHV-6 and EBV DNA quantitation in lymph nodes of 86 patients with Hodgkin's lymphoma

Human herpesvirus (HHV-6) and Epstein-Barr virus (EBV), are two ubiquitous human herpesviruses which share many common features although they belong to different sub-families. In particular, both viruses are found in lymph nodes of patients suffering from Hodgkin's lymphoma. The aim of this study was to detect and to quantify independently HHV-6 and EBV by a real-time PCR in lymph nodes from 86 patients with Hodgkin's lymphoma. EBV quantitative method was compared with LMP-1 protein detection among the same samples. EBV genome was detected for 61.6% of the patients (53/86) and the highest prevalence of this virus was observed in Hodgkin's lymphoma with mixed-cellularity histopathological type (80%). In contrast to that, HHV-6 genome was detected for 79.1% of the patients (68/86) and was most observed in the nodular-sclerosis group (83.6%). Among the 68 HHV-6 positive samples, 63 belonged to the B subtype. A large number of biopsies (47.7%) were positive for both viruses whereas a little number (7%) was negative for both. EBV quantitation and LMP-1 immunohistochemistry were correlated statistically but this latter technique was less sensitive. Among the nodular-sclerosis patients, HHV-6-/EBV+ patients were significatively older than HHV-6+/EBV- patients. Patients infected dually had higher values of quantitation for each virus than those positive for one virus. Data of the clinical follow-up obtained by diagnosis and during the treatment of 83 patients, were correlated with the virological findings.

The emerging concept of antigen-driven lymphomas: epidemiology and treatment implications

PURPOSE OF REVIEW

Dramatic increases in the incidence of lymphomas worldwide have stimulated considerable efforts to identify factors that contribute to the etiology of this heterogeneous group of malignancies. The treatment and, ultimately, the prevention of lymphoma depend on our understanding of the complex interaction of exogenous agents with the molecular milieu which initiates and sustains a lymphoid malignancy. This review discusses the current evidence for the role of foreign or self antigens in the initiation of lymphomagenesis.

RECENT FINDINGS

Recent data have demonstrated an increased risk of lymphoma among individuals with chronic inflammatory conditions, persistent infections or immunodeficient states. Common to these clinical conditions is antigenic stimulation leading to an inflammatory cascade of cellular and cytokine reactions that may tax the host immune response, provoke tissue injury and eventually result in lymphoid neoplasia.

SUMMARY

Efforts to detect and suppress chronic, antigen-driven inflammation have suggested that neoplastic progression may often be interrupted and controlled. Elucidation of the etiologic mechanisms critical to the survival of these malignancies would provide promising alternatives for the prevention and treatment of some lymphomas.

Identification of major histocompatibility complex class II-restricted antigens and epitopes of the Epstein-Barr virus by a novel bacterial expression cloning approach

Epstein-Barr virus (EBV)-specific T cells have been successfully used to treat or prevent EBV-positive lymphoproliferative disease in hematopoietic stem cell transplant recipients, but the antigens recognized by the infused CD4+ T cells have remained unknown. Here, we describe a simple procedure that permits the identification of viral T-helper (TH)-cell antigens and epitopes. This direct antigen identification method is based on the random expression of viral polypeptides fused to chloramphenicol acetyltransferase (CAT) in bacteria, which are subsequently fed to major histocompatibility complex class II+ antigen-presenting cells and probed with antigen-specific T cells. The fusion of antigenic fragments to CAT offers several advantages. First, chloramphenicol treatment allows the selection of bacteria expressing antigen-CAT fusion proteins in frame, which greatly reduces the number of colonies to be screened. Second, antigenic fragments fused to CAT are expressed at high levels, even when derived from proteins that are toxic to bacteria. Third, the uniformly high expression level of antigen-CAT fusion proteins permits the establishment of large and representative pool sizes. Finally, antigen identification does not require knowledge of the restriction element and often leads directly to the identification of the T-cell epitope. Using this approach, the BALF4 and BNRF1 proteins were identified as targets of the EBV-specific T-helper-cell response, demonstrating that lytic cycle antigens are a relevant component of the EBV-specific TH-cell response.

Apoptotic effect of ganciclovir on primary effusion lymphoma cells infected with Kaposi's sarcoma-associated herpesvirus

We evaluated the cytotoxic and apoptotic effects of two purine nucleoside analogues, acyclovir (ACV) and ganciclovir (GCV), on lymphoma cells stably harboring Kaposi's sarcoma-associated herpesvirus (KSHV). Colorimetric caspase assay, flow cytometry, and immunoblotting with antibodies against apoptosis-related molecules revealed that GCV has cytotoxic activity toward KSHV-infected primary effusion lymphoma cells, while ACV has weak or little activity. In addition to the GCV-induced cytotoxicity, apoptosis via caspase-7/8, cleavage of poly(ADP-ribose) polymerase, and accumulation of p53 and p21 were induced by GCV treatment. In contrast, neither ACV nor GCV have cytotoxicity- or apoptosis-inducing activities toward uninfected cells.

Epstein?Barr virus in CD30+anaplastic large cell lymphoma involving the skin and lymphomatoid papulosis in South Korea

BACKGROUND

Epstein-Barr virus (EBV)-associated cutaneous lymphoproliferative disorders are prevalent in Asia, and less frequent in Western countries.

AIM

To elucidate the possible association of EBV with CD30+ anaplastic large cell lymphoma (ALCL) involving the skin and lymphomatoid papulosis (LyP) in South Korea.

METHODS

In situ hybridization for EBV-encoded small RNA (EBER) and immunohistochemistry including viral latent membrane protein-1 (LMP-1) were performed on formalin-fixed, paraffin-embedded skin specimens of 26 cases of LyP and 16 cases of CD30+ ALCL involving the skin which were selected from six university hospital medical centers in South Korea.

RESULTS

In situ hybridization studies showed positivity of the neoplastic cells for EBER in two of 16 cases of CD30+ ALCL and in none of the cases of LyP. One EBER-positive case was cutaneous CD30+ ALCL with concurrent lymph node involvement. The other was CD30+ ALCL involving the skin and other organs, including lymph nodes, bone, lung, and spleen. Immunostaining for LMP-1 was also positive only for the two cases of EBER-positive CD30+ ALCL.

CONCLUSION

LyP and primary cutaneous CD30+ ALCL are very rarely associated with EBV in South Korea.

Absence of Epstein-Barr virus infection in squamous cell carcinoma of upper urinary tract and urinary bladder

OBJECTIVES

To address whether Epstein-Barr virus (EBV) infection may be involved in the carcinogenesis of squamous cell carcinoma of the upper urinary tract and urinary bladder (SCC-UB). EBV has been implicated in the genesis of a variety of human cancers, including urothelial carcinoma of the urinary bladder.

METHODS

Whether EBV infection is related to SCC-UB carcinogenesis was investigated by in situ hybridization for EBV-encoded RNA and immunohistochemistry for latent membrane protein-1 in 26 cases of SCC-UB.

RESULTS

EBV-encoded RNA and latent membrane protein-1 were identified in the control case of nasopharyngeal carcinoma. None of the SCC-UB cases had a nuclear signal of EBV-encoded RNA, and the cancer cells, normal urothelial cells, and inflammatory cells were all negative for latent membrane protein-1, irrespective of the site of SCC-UB.

CONCLUSIONS

This study is the first to explore the role of EBV infection in SCC-UB. Our results suggest that EBV infection is not involved in the carcinogenesis of SCC of the renal pelvis, ureter, and urinary bladder.