Epstein-Barr virus (EBV)-infected cells were frequently but dispersely detected in T-cell lymphomas of various types by in situ hybridization with an RNA probe specific to EBV-specific nuclear antigen 1

Prognostic significance of latent membrane protein 1 expression in non-Hodgkin lymphoma: A meta-analysis

BACKGROUND

The prognostic value of latent membrane protein 1 (LMP1) in non-Hodgkin lymphoma (NHL) has been evaluated in several studies. However, the conclusions remain controversial.

METHODS

We searched relevant literatures from Embase, PubMed, and China National Knowledge Infrastructure Platform databases and performed a meta-analysis to evaluate the prognostic significance of LMP1 expression in NHL. Pooled hazard ratio (HR), 95% confidence interval (CI), and P value were calculated. Nine relevant studies were analyzed in this meta-analysis. We performed a pooled analysis to assess the association between LMP1 expression and overall survival of NHL patients.

RESULTS

Our results revealed that LMP1-positive NHL patients had significantly poorer outcomes than LMP1-negative patients (HR = 2.13, 95% CI = 1.31-3.46, Pheterogeneity = 0.005, I = 63.5%). Furthermore, in the subgroup analysis stratified by country, a statistically significant association was found among Chinese (HR = 2.80, 95% CI = 1.53-5.15, Pheterogeneity = 0.342, I = 6.9%); however, no statistically significant relations were found among Japanese (HR = 1.55, 95% CI = 0.74-3.24, Pheterogeneity = 0.020, I = 65.7%).

CONCLUSION

The expression of LMP1 can be considered a poor predictor of survival in patients with NHL. In addition, LMP1 expression assessment could provide more detailed information for patients with NHL and could be used to optimize therapeutic schemes.

Effect of latent membrane protein 1 expression on overall survival in Epstein-Barr virus-associated cancers: a literature-based meta-analysis

Latent membrane protein 1 (LMP1) is identified as the main transforming oncoprotein of Epstein-Barr virus (EBV). LMP1 is frequently expressed in a variety of EBV-associated cancers, including nasopharyngeal carcinoma (NPC), non-Hodgkin lymphoma (NHL), Hodgkin disease (HD), and gastric cancer (GC). However, due to conflicting results, the prognostic value of LMP1 expression on clinical outcomes in EBV-associated cancers remains unclear. We performed a meta-analysis on 32 studies with a total of 3752 patients to explore the association between LMP1 expression and overall survival (OS) in EBV-associated cancers. Overall, LMP1 expression was significantly associated with poorer OS (hazard ratio, HR = 1.51, 95% confidence interval, CI, 1.13–2.03), irrespective of cancer type. Further analyses showed that LMP1 expression correlated with poorer OS in NPC (HR = 2.48, 95% CI, 1.77–3.47) and NHL patients (HR = 1.83, 95% CI, 1.07–3.15), but not in HD patients (HR = 0.98, 95% CI, 0.60–1.62) or GC patients (HR = 0.70, 95% CI, 0.44–1.12). Subgroup analyses indicated that the age and geographical factors seemed to have an effect on the clinical outcomes of HD patients with positive LMP1 expression. In conclusion, LMP1 expression can be used as a prognostic biomarker in NPC, NHL, and certain HD patients. This data suggests that novel therapies targeting LMP1 may improve clinical outcomes for EBV-associated cancer patients.

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Detection of Epstein–Barr virus infection and gene expression in human tumors by microarray analysis

Epstein-Barr virus (EBV) genome-chips are employed to determine the EBV infection rate and to reveal the gene expression patterns of EBV in tumor biopsies. These chips are produced with 71 consecutive PCR-amplified EBV DNA fragments of 1-3 kbp covering the entire EBV genome. The specificity of the EBV-chips is determined by hybridizing the DNA on the chips with biotin-labeled cDNA probes reverse transcribed from the mRNA of P3HR1 cells, which were B-cell infected latently by EBV. Hybridization results revealed only the expression of EBNA1, EBNA2, EBER1 and EBER2 in these cells. On the other hand, EBV lytic genes are expressed after the cells are treated with 12-O-tetradecanoylphorbol-13-acetate and sodium butyrate to induce the EBV lytic cycle. Fourty-four tumor biopsies from different organs are assayed with these chips, which showed many defined and interesting EBV gene expression patterns. This study demonstrates that the EBV-chip is useful for screening infection with EBV in tumors, which may lead to insights into tumorigenesis associated with this virus.

Generalized myositis mimicking polymyositis associated with chronic active Epstein-Barr virus infection

BACKGROUND

Chronic generalized myositis has not so far been reported as a complication of chronic active Epstein-Barr virus infection (CAEBV). We encountered three patients with chronic generalized myositis mimicking polymyositis associated with CAEBV.

METHODS

To clarify the pathological character of this myositis, we investigated the distribution, clonality, and the immunophenotype of EBV-infected cells and lymphocytes infiltrating in muscles.

RESULTS

Clinically, two patients showed symmetrical proximal weakness and muscle atrophy as the initial and main symptom. Although the condition resembled polymyositis, they had also lingual and/or orbital myositis. The other patient showed generalized myositis at the late phase of CAEBV. In all of them, immunotherapy was ineffective and prognosis was poor. Intramuscular infiltrating lymphocytes in our patients were mainly CD45RO+, CD3+, CD4-, CD8-, TCR betaF1-, TCR deltaTCS1-, CD56-, CD79a-, CD21-, HLA-DR+, ZEBRA -, LMP1-, and EBER+ T cells. Oligoclonal expansion of EBV-infected T cells was shown in the muscles. However, there were no malignant lymphocytes.

CONCLUSIONS

This new form of myositis must be distinguished from polymyositis and the other conventional forms of myositis. Careful investigation of hidden CAEBV is recommended when patients present with steroid non-responsive chronic progressive generalized myositis, in particular, with lingual or orbital involvement.

A case of Epstein-Barr Virus (EBV)-associated thymic carcinoid and investigation of existence of EBV-infected cells in thymus and thymic tumors

We describe the first case of Epstein-Barr virus (EBV)-associated thymic carcinoid tumor found by in situ hybridization (ISH) on paraffin-embedded sections. ISH revealed that both tumor cells and infiltrated lymphocytes were EBV positive, while a few EBV-infected lymphocytes were detected in 2 of 11 thymuses and 1 of 11 thymomas.

Vitamin E inhibits cyclosporin A and H2O2 promoted Epstein-Barr virus (EBV) transformation of human B cells as assayed by EBV oncogene LMP1 expression

BACKGROUND

We have previously shown that oxidative stress induced by H2O2 or cyclosporin A (CsA) can promote Epstein-Barr virus (EBV) transformation of human B cells as analyzed by colony formation, cell number, and by 3H-thymidine incorporation. In this report, we used EBV oncogene LMP1 as a marker to analyze H2O2 or CsA promotion of EBV transformation of human B cells and to test whether antioxidant vitamin E could inhibit H2O2 or CsA promoted LMP1 expression in the EBV-infected cells.

MATERIALS AND METHODS

Human splenocytes were prepared by centrifugation and plating technique to provide a greater than 80% pure preparation of B cells and were used for EBV infection. The EBV infected cells were treated with H2O2 (0.1 mM, 10 min), or with CsA (500 ng/ml) with or with out vitamin E (40 microM). The cells were cultured for up to 4 weeks. Samples were taken every week and were stained with phycoerythrin-conjugated mouse anti-LMP1 monoclonal antibody to assay LMP1 positive population by flow cytometry.

RESULTS

In EBV-infected cells, the LMP1-positive cell population reached 14% after 4 weeks of culture. CsA or H2O2 treatment promoted LMP1 positive population to 43% and 41% after 4 weeks of culture. Vitamin E (40 microM) completely inhibited LMP1 expression in EBV-infected cells and in CsA- or H2O2-treated cells.

CONCLUSION

In agreement with our previous observation, CsA or H2O2 can promote EBV transformation of human B cells. This oxidative stress induced promotion of EBV transformation can be blocked by antioxidant Vitamin E. This finding may have future therapeutic implications for post-transplant lymphoproliferative disorder.

Leukocytoclastic-vasculitic neuropathy associated with chronic Epstein-Barr virus infection

We report a patient with leukocytoclastic-vasculitic neuropathy associated with chronic Epstein-Barr virus (EBV) infection. A 55-year-old man had been suffering from chronic progressive axonal polyneuropathy and skin erythema for 3 years. A skin biopsy showed capillary vasculitis with clustered leukocyte fragments. Findings of serum assays, a polymerase chain reaction for EBV-DNA, and in situ hybridization indicated chronic EBV infection. Immunosuppressive treatment resulted in the gradual lessening of his general and neurologic symptoms.

Assessment of Epstein-Barr virus association with pediatric non-hodgkin lymphoma in immunocompetent and in immunocompromised patients in Argentina

CONTEXT

Epstein-Barr virus (EBV) has been classically associated with 3 malignancies, Burkitt lymphoma, B-cell lymphoproliferative syndromes, and nasopharyngeal carcinoma, and more recently with Hodgkin disease, T-cell lymphomas, and gastric and breast carcinomas, as well as with leiomyosarcoma and leiomyoma associated with immunosuppression.

OBJECTIVE

To compare EBV expression in Argentine tumor samples with those reported elsewhere, we analyzed EBV expression in an Argentine pediatric population with non-Hodgkin lymphoma and correlated these results with clinical course and outcome.

METHODS

We studied EBV presence by latent membrane protein-1 protein labeling by immunohistochemistry, by in situ hybridization, and by polymerase chain reaction for Epstein-Barr-encoded RNAs (EBERs) in formalin-fixed and paraffin-embedded non-Hodgkin lymphoma tissue samples (collected retrospectively) from 32 pediatric patients at Ricardo Gutiérrez Children's Hospital from 1993 to 2000.

RESULTS

Eight out of the 32 (25%) non-Hodgkin lymphoma cases showed latent membrane protein-1 and EBERs by in situ hybridization positive staining in tumor cells. Among EBERs and latent membrane protein-1-positive cases, there were 5 immunocompromised patients, with either human immunodeficiency virus infection or primary immunodeficiency. The EBERs in situ hybridization results were confirmed by EBERs polymerase chain reaction in good-quality DNA from 11 samples, with 3 proving positive and 8 negative.

CONCLUSIONS

The association of EBV with non-Hodgkin lymphoma in the Argentine pediatric population was low (25%), and this figure rose to 100% when only the immunocompromised patients subgroup was considered, confirming that the virus is probably a cofactor in the lymphomagenesis of some but not all pediatric non-Hodgkin lymphoma. So far, no differences in clinical outcome are discernible between EBV-positive and EBV-negative non-Hodgkin lymphoma patients.

Chronic immune activation and inflammation in the pathogenesis of AIDS and cancer

Infection with the human immunodeficiency virus (HIV) invariably leads to the development of acquired immunodeficiency syndrome (AIDS) in most infected humans, yet does so rarely, if at all, in HIV-infected chimpanzees. The differences between the two species are not due to differences in cellular receptors or an inability of the chimpanzee to be infected, but rather to the lack of pan-immune activation in the infected primate. This results in reduced apoptotic death in CD4+ T-helper lymphocytes and a lower viral load. In humans the degree of chronic immune activation correlates with virus load and clinical outcome with high immune activation leading to high viral loads and the more rapid progression to AIDS and death. The type of immune perturbation seen in HIV-associated AIDS is similar to that of chronic graft-versus-host disease (GVHD) where reduced cell-mediated immune (CMI) responses occur early in the course of the disease and where humoral responses (HI) predominate. A reduced CMI response occurs in a number of chronic infectious diseases, including tuberculosis and leishmaniasis. More recently, it has become increasingly apparent that the CMI response is suppressed in virtually all malignant diseases, including melanoma and colorectal and prostate cancer. This raises the possibility that, as the malignant process develops, the cancer cells evolve to subvert the CMI response. Moreover, the reduced CMI response seen in colorectal cancer (CRC) patients is completely reversed following curative surgery strongly supporting the hypothesis that CRC can suppress the systemic immune response. Wound healing, ovulation, embryo implantation, and fetal growth are all associated with suppressed CMI and neovascularization (the formation of new blood vessels) or angiogenesis (the formation of new blood vessels from an existing vasculature). If unresolved, wound healing results in chronic inflammation, which can give rise to the phenomenon of "scar cancers." Indeed all the chronic inflammatory conditions known to be associated with the subsequent development of malignant disease, including chronic obstructive airway disease (COPD), ulcerative colitis (UC), and asbestosis, give rise to similar proangiogenic, suppressed CMI, and HI-predominant environments. In keeping with this CMI-associated cytokines such as interleukin (IL)-2 and interferon (IFN)-gamma tend to be antiangiogenic, whereas HI cytokines such as IL-6 tend to be proangiogenic. Furthermore, chronic immune activation leads to the synthesis and release of factors such as macrophage inflammatory protein (MIP)-1 that inhibit apoptosis through suppression of p53 activity. The "Golden Triangle" of suppressed CMI, angiogenesis, and reduced apoptosis would provide the ideal environment for the serial mutations to occur that are required for the development of malignant disease. If the observed association is relevant to carcinogenesis, then treatments aimed at reducing the components of these inflammatory conditions may be useful both in the setting of chemoprevention and the therapeutic management of established disease.

Chronic immune activation and inflammation as the cause of malignancy

Several chronic infections known to be associated with malignancy have established oncogenic properties. However the existence of chronic inflammatory conditions that do not have an established infective cause and are associated with the development of tumours strongly suggests that the inflammatory process itself provides the prerequisite environment for the development of malignancy. This environment includes upregulation of mediators of the inflammatory response such as cyclo-oxygenase (COX)-2 leading to the production of inflammatory cytokines and prostaglandins which themselves may suppress cell mediated immune responses and promote angiogenesis. These factors may also impact on cell growth and survival signalling pathways resulting in induction of cell proliferation and inhibition of apoptosis. Furthermore, chronic inflammation may lead to the production of reactive oxygen species and metabolites such as malondialdehyde within the affected cells that may in turn induce DNA damage and mutations and, as a result, be carcinogenic. Here it is proposed that the conditions provided by a chronic inflammatory environment are so essential for the progression of the neoplastic process that therapeutic intervention aimed at inhibiting inflammation, reducing angiogenesis and stimulating cell mediated immune responses may have a major role in reducing the incidence of common cancers.