Epstein-Barr virus-associated epithelial and mesenchymal neoplasms

Differential B-lymphocyte regulation by CD40 and its viral mimic, latent membrane protein 1

CD40 plays a vital role in humoral immunity, via its potent and multifaceted function as an activating receptor of various immune cells, most notably B lymphocytes. The Epstein-Barr virus-encoded transforming protein latent membrane protein 1 (LMP1) serves as a functional mimic of CD40 signals to B cells but lacks key regulatory controls that restrain CD40 signaling. This allows LMP1 to activate B cells in an abnormal manner that can contribute to the pathogenesis of human B-cell lymphoma and autoimmune disease. This review focuses upon a comparative analysis of CD40 versus LMP1 functions and mechanisms of action in B lymphocytes, discussing how this comparison can provide valuable information on both how CD40 signaling is normally regulated and how LMP1 disrupts the normal CD40 pathways, which can provide information of value to therapeutic design.

Burkitt lymphoma: pathogenesis and immune evasion

B-cell lymphomas arise at distinct stages of cellular development and maturation, potentially influencing antigen (Ag) presentation and T-cell recognition. Burkitt lymphoma (BL) is a highly malignant B-cell tumor associated with Epstein-Barr Virus (EBV) infection. Although BL can be effectively treated in adults and children, leading to high survival rates, its ability to mask itself from the immune system makes BL an intriguing disease to study. In this paper, we will provide an overview of BL and its association with EBV and the c-myc oncogene. The contributions of EBV and c-myc to B-cell transformation, proliferation, or attenuation of cellular network and immune recognition or evasion will be summarized. We will also discuss the various pathways by which BL escapes immune detection by inhibiting both HLA class I- and II-mediated Ag presentation to T cells. Finally, we will provide an overview of recent developments suggesting the existence of BL-associated inhibitory molecules that may block HLA class II-mediated Ag presentation to CD4+ T cells, facilitating immune escape of BL.

Viral hit and run-oncogenesis: genetic and epigenetic scenarios

It is well documented that viral genomes either inserted into the cellular DNA or co-replicating with it in episomal form can be lost from neoplastic cells. Therefore, "hit and run"-mechanisms have been a topic of longstanding interest in tumor virology. The basic idea is that the transient acquisition of a complete or incomplete viral genome may be sufficient to induce malignant conversion of host cells in vivo, resulting in neoplastic development. After eliciting a heritable change in the gene expression pattern of the host cell (initiation), the genomes of tumor viruses may be completely lost, i.e. in a hit and run-scenario they are not necessary for the maintenance of the malignant state. The expression of viral oncoproteins and RNAs may interfere not only with regulators of cell proliferation, but also with DNA repair mechanisms. DNA recombinogenic activities induced by tumor viruses or activated by other mechanisms may contribute to the secondary loss of viral genomes from neoplastic cells. Viral oncoproteins can also cause epigenetic dysregulation, thereby reprogramming cellular gene expression in a heritable manner. Thus, we expect that epigenetic scenarios of viral hit and run-tumorigenesis may facilitate new, innovative experiments and clinical studies in spite of the fact that the regular presence of a suspected human tumor virus in an early phase of neoplastic development and its subsequent regular loss have not been demonstrated yet. We propose that virus-specific "epigenetic signatures", i.e. alterations of the host cell epigenome, especially altered DNA methylation patterns, may help to identify viral hit and run-oncogenic events, even after the complete loss of tumor viruses from neoplastic cells.

Vaccination against a hit-and-run viral cancer

Cancers with viral aetiologies can potentially be prevented by antiviral vaccines. Therefore, it is important to understand how viral infections and cancers might be linked. Some cancers frequently carry gammaherpesvirus genomes. However, they generally express the same viral genes as non-transformed cells, and differ mainly in also carrying oncogenic host mutations. Infection, therefore, seems to play a triggering or accessory role in disease. The hit-and-run hypothesis proposes that cumulative host mutations can allow viral genomes to be lost entirely, such that cancers remaining virus-positive represent only a fraction of those to which infection contributes. This would have considerable implications for disease control. However, the hit-and-run hypothesis has so far lacked experimental support. Here, we tested it by using Cre-lox recombination to trigger transforming mutations in virus-infected cells. Thus, 'floxed' oncogene mice were infected with Cre recombinase-positive murid herpesvirus-4 (MuHV-4). The emerging cancers showed the expected genetic changes but, by the time of presentation, almost all lacked viral genomes. Vaccination with a non-persistent MuHV-4 mutant nonetheless conferred complete protection. Equivalent human gammaherpesvirus vaccines could therefore potentially prevent not only viral genome-positive cancers, but possibly also some cancers less suspected of a viral origin because of viral genome loss.

Clinicopathologic analysis of cutaneous lymphoma in taiwan: a high frequency of extranodal natural killer/t-cell lymphoma, nasal type, with an extremely poor prognosis

CONTEXT

Primary cutaneous lymphoma is an uncommon, extranodal lymphoma, and it is usually more indolent with a better prognosis than its histologically similar systemic counterpart is.

OBJECTIVES

To illustrate the clinicopathologic features of cutaneous lymphomas in Taiwan and to compare the relative frequencies of subtypes of cutaneous lymphoma among different geographic areas.

DESIGN

A total of 56 patients with cutaneous lymphomas were retrospectively collected and were reclassified according to the 2005 World Health Organization and the European Organization for Research and Treatment of Cancer and the 2008 World Health Organization classifications. The data were compared with those from other studies for different geographic areas.

RESULTS

Thirty-one (55%) tumors were primary cutaneous lymphomas, and twenty-five (45%) tumors were secondary or concurrent cutaneous lymphomas. Among primary cutaneous lymphomas, 23 cases (74%) were T-cell or natural killer-cell lymphomas, and 8 cases (26%) were B-cell lymphomas. The most common types were extranodal natural killer/T-cell lymphoma, nasal type, and primary cutaneous peripheral T-cell lymphoma, unspecified (5 cases each; 16%). In contrast with other primary cutaneous B-cell and T-cell lymphomas, either primary or secondary extranodal cutaneous natural killer/T-cell lymphomas, nasal type, had extremely poor prognoses (1-year overall survival, 0%).

CONCLUSIONS

This study showed that the frequency of subtypes of primary cutaneous lymphoma varied in different geographic areas. Compared with the Western countries, there was a higher frequency of extranodal natural killer/T-cell lymphoma, nasal type, and a lower frequency of mycosis fungoides in Taiwan. Extranodal natural killer/T-cell lymphoma, nasal type, also had an extremely poor prognosis compared with other lymphomas.

Host inflammatory response predicts survival of patients with Epstein-Barr virus-associated gastric carcinoma

BACKGROUND & AIMS

Lymphoepithelioma-like carcinoma (LELC) is a rare subtype of gastric carcinoma (GC) with a better survival rate than other GCs; most cases of LELC are associated with Epstein-Barr virus (EBV) infection. We investigated whether the survival advantage of LELC is related to the EBV infection itself or to associated inflammatory immune responses.

METHODS

From 1994 to 2008, 123 EBV-associated GCs were identified and compared with 405 EBV-negative GCs. EBV-associated GCs were subclassified, based on the pattern of host inflammatory immune responses, into 3 histologic subtypes: typical LELC (n = 53, 43.1%), Crohn's disease-like lymphocytic reaction (CLR) (n = 52, 42.3%), and conventional adenocarcinoma (n = 18, 14.6%). Patients with curatively resected EBV-negative GC were controls. Univariate and multivariate analyses were used, with Bonferroni correction.

RESULTS

Patients with EBV-associated GC had tumors of proximal location, lower N stage (P < .0001), and lower T stage (P = .02) and were older than controls (P = .0003). Upon univariate analysis, patients with EBV-associated GC had longer survival times than controls (P < .004); this difference was not significant in a multivariate analysis with Cox proportional hazards. Stratification of EBV-associated GCs by host cellular immune responses showed that patients with LELC and LELC+CLR have significantly longer overall survival time (hazard ratio, 0.09 and 0.42, respectively) and disease-free survival (hazard ratio, 0.05 and 0.46, respectively; P < .02).

CONCLUSIONS

Prognosis of EBV-associated GCs depends on the patient's inflammatory response. The definition of LELC should be expanded to include EBV-associated GCs with CLR because these have a prognosis similar to LELC.

Prevalence of Epstein-Barr virus associated with nasal lymphoma in patients attending the regional hospital of Valdivia, Chile, between 1987 and 2005

Epstein-Barr virus (EBV) is a ubiquitous herpes virus with a widespread infection in the world's adult population. EBV has been associated with human malignancies, mainly the nasal type NK/T cell lymphoma. The disease is more frequent in Asian than in Western countries. However, there are few studies from Latin American countries. The aim of this study was to determine the prevalence of EBV in patients with nasal lymphomas diagnosed in the Regional Hospital of Valdivia, southern Chile, during 1987-2005. Immunohistochemistry was done on paraffin sections using anti-CD3epsilon, anti-CD20, and anti-CD56. The presence of small ribonucleic acids (RNAs) of EBV was detected in paraffin sections by in situ hybridization using oligonucleotides targeting EBV-encoded small RNAs. The present study revealed a prevalence of 27.7% of Hodgkin's lymphomas and 72.3% of non-Hodgkin's lymphomas. From the latter group, there was a prevalence of 2.9% (10 cases) of nasal lymphoma. From these 10 cases, 6 (60%) were NK/T cell lymphomas, nasal type; 1 case (10%) was a T-cell phenotype; and 3 cases (30%) were B-cell phenotype. The prevalence was higher than reports from Western countries, but lower than the reports from Asian countries. These results agreed with previous reports suggesting that EBV is strongly associated with T lymphomas. This study contributes new epidemiological data on EBV in Chile.

Follicular Dendritic Cell Tumor in Liver: A Case Report and Collective Review

Follicular dendritic cells (FDC) are a subset of the immune system and present in the germinal centers of lymphoid follicles in the spleen and lymph nodes. They are functionally as antigen-presenting cells and thus improving the quality of the humoral immune response. Follicular dendritic cell tumor is rare but considered low-grade sarcoma. Including our case, there were totally 17 cases with FDC tumor involved the liver from Medline. In these cases, the mean age was 47 years old, ranged from 19 to 82. It was much more common in females than in males (13:4). The clinical manifestations of these patients included abdominal discomfort, palpable mass, weight loss and malaise. The average size of the tumor was 11 cm. Most of the FDC tumors were associated with Epstein-Barr virus expression, 13/17 (76.5%). Surgical resection remains the mainstay of the treatment.

Treatment for leiomyosarcoma and leiomyoma in children with HIV infection

BACKGROUND

Smooth muscle tumour (SMT) composed of leiomyoma and leiomyosarcoma recently has been described in many HIV-infected children. Leiomyosarcoma has become the second most frequent malignancy in children with HIV infection or other immunodeficiency diseases in the United States. Although leiomyosarcoma accounts for only 2% to 4% of childhood soft tissue sarcomas, the prognosis is poor in HIV-infected compared with non-infected patients. The development of Epstein-Barr virus (EBV)-associated SMT in children with acquired immunodeficiency virus (AIDS) decreases health, reduces quality of life, and often results in death. Some researchers, therefore, ascribe cause of death to SMT in the majority of these cases, not to AIDS. Currently, the optimal therapeutic strategy is controversial and there is a need to identify the efficacy and safety of different interventions for AIDS-associated SMT on overall survival and disease-free survival in children.

OBJECTIVES

To assess the effectiveness of current therapeutic interventions for previously untreated children with AIDS-associated leiomyoma and leiomyosarcoma

SEARCH STRATEGY

We searched the following electronic databases by subject headings and text words:Cochrane HIV/AIDS Group trials register (November 2009); Cochrane Central Register of Controlled Trials on Cochrane Library (Issue 4, 2009); MEDLINE (January 1966 to November 2009); EMBASE (January 1985 to November 2009); NLMGateway database and AEGIS; Chinese Biomedical Disc (CBMDisc 1978 to November 2009); VIP (1989 to present); and China National Knowledge Infrastructure (CNKI 1994 to 2009). We also searched physicians data query protocols, proceedings, and abstracts from AIDS and cancer conferences, and the reference lists from identified trials for unidentified trials to discover any unpublished or currently on-going relevant trials. All the trials were searched by comprehensive electronic databases or hand searching. The search was not limited by language.

SELECTION CRITERIA

We searched for published or unpublished randomised controlled trials (RCTs) or controlled clinical trials (CCTs) of therapy for leiomyosarcoma and leiomyoma in children with AIDS.

DATA COLLECTION AND ANALYSIS

Two authors screened the results of the search independently to select relevant studies. The full text of all potentially relevant studies was retrieved and the qualities were assessed by the two authors using predetermined criteria. No eligible RCTs or CCTs were identified.

MAIN RESULTS

We were unable to find any RCTs or CCTs of interventions for treating AIDS-associated SMT in children.

IMPLICATIONS FOR CLINICAL PRACTICE

We could not find any RCTs or CCTs of intervention for treating AIDS-associated SMT in children with HIV infection, and currently, the clinical practice of treating SMT in HIV-infected children is based on descriptive studies and simply situational analyses. Thus there is insufficient evidence to establish the efficacy and acceptability of these interventions, and we recommend a case-by-case treatment of patients until evidence becomes available.

IMPLICATIONS FOR RESEARCH

In future, high-quality RCTs are urgently needed before any final conclusion can be drawn. Rigorously designed, multicenter, randomised, double-blind controlled trials are required to evaluate these interventions as a way of improving the survival and decreasing mortality in that population. Policy makers and researchers should prioritise funding for these trials to increase the quantity and quality of such studies and provide strong evidence for the effectiveness of therapies for AIDS-associated SMTs. Meanwhile, safety and adverse events should be critically assessed by standardized monitoring or an effective self-report system, and attention should be paid to long-term adverse effects in children with HIV infection.

Myopericytoma in patients with AIDS: a new class of Epstein-Barr virus-associated tumor

Myopericytoma is an uncommon, benign perivascular myoid cell tumor that occurs almost exclusively in somatic soft tissues. We report 2 cases occurring in patients with acquired immunodeficiency syndrome who show unusual clinical and biologic features. One patient presented with a bronchial mass and the other developed mass lesions of the tongue, vocal cord, and brain. Histologically, oval to plump spindly tumor cells with uniform nuclei and scanty cytoplasm formed sheets or cuffs around gaping or narrow vascular spaces. Focally, these areas merged into fascicles of more elongated cells with eosinophilic cytoplasm. The tumor cells were immunoreactive for actin but not desmin, and showed uniform labeling for Epstein-Barr virus (EBV) encoded RNAs on in-situ hybridization. Both patients were alive 5 years after incomplete excision of the lesions. In conjunction with another case reported in the literature, myopericytoma occurring in acquired immunodeficiency syndrome patients exhibits several features distinct from sporadic myopericytoma: presentation in anatomic sites other than somatic soft tissues, frequent presence of multifocal disease, and association with EBV. This tumor type therefore also broadens the spectrum of neoplasms associated with EBV.

Expression of EBV latent antigens, mammalian target of rapamycin, and tumor suppression genes in EBV-positive smooth muscle tumors: clinical and therapeutic implications

PURPOSE

EBV-positive smooth muscle tumor (EBV+SMT) is a rare disease with no established therapy. We describe the largest single institution analysis in renal transplant recipients. It aims to define its clinical features and determine the expression of EBV latent genes as well as key molecular pathways.

EXPERIMENTAL DESIGN

Patients with EBV+SMT were identified from the Singapore General Hospital Renal Transplant Registry database. These tumors were investigated for expression of EBV latent genes with Southern blots, EBV latent antigens, mammalian target of rapamycin (mTOR), Akt, p70 S6 kinase, and vascular endothelial growth factor using immunohistochemistry, as well as methylation status of cancer-related genes using methylation-specific PCR.

RESULTS

Eight were found to be EBV+SMT in 1,123 transplant patients. All displayed indolent clinical courses and were unresponsive to immunosuppression reduction. Complete tumor regression was seen in one patient following administration of sirolimus. These tumors display the full range of known EBV latent genes. Immunohistochemistry with total and phosphorylated mTOR and Akt were positive for all patients, and vascular endothelial growth factor was positive in 25% of patients, suggesting activation of the mTOR/Akt pathway. Methylation of RASSF1A was found in all tissue samples, whereas promoter hypermethylation of RARbeta, GSTP1, DAPK, and p14 was observed in some samples.

CONCLUSIONS

Our results suggest that these tumors display a EBV type III latency pattern. The mTOR pathway is also activated. EBV may play a role in silencing RASSF1A. EBV-specific immunotherapy, mTOR inhibitors, and demethylating agents are possible therapeutic options in this disease.

Epstein-Barr virus in lymphoproliferative processes: an update for the diagnostic pathologist

The Epstein-Barr virus is an orally transmitted herpesvirus that is widespread in human populations and exhibits marked B-cell tropism. It is associated with more human neoplasms than any other known virus, and its role in the pathogenesis of such neoplasms has been the subject of intense investigation. This review presents an overview and update of the biology of Epstein-Barr virus and the diagnostic features of lymphoproliferative disorders associated with this intriguing human pathogen.

The curious case of the tumour virus: 50 years of Burkitt's lymphoma

Burkitt's lymphoma (BL) was first described 50 years ago, and the first human tumour virus Epstein-Barr virus (EBV) was discovered in BL tumours soon after. Since then, the role of EBV in the development of BL has become more and more enigmatic. Only recently have we finally begun to understand, at the cellular and molecular levels, the complex and interesting interaction of EBV with B cells that creates a predisposition for the development of BL. Here, we discuss the intertwined histories of EBV and BL and their relationship to the cofactors in BL pathogenesis: malaria and the MYC translocation.

EBV-Associated Smooth Muscle Neoplasms: Solid Tumors Arising in the Presence of Immunosuppression and Autoimmune Diseases

Background. Epstein-Barr virus (EBV)-related smooth muscle neoplasms (SMNs) have been associated with immune dysregulation, most notably in patients who have undergone solid organ transplantation or in patients with HIV/AIDS. Objective. to report our experience with EBV-related neoplasms as well as describing the first EBV-related SMN in the setting of administration of glucocorticoids and the tumor necrosis factor inhibitor etanercept. Design. We have case reports, of minimum 3-year follow-up, 2002–2005. Setting. It was held in an academic and tertiary referral cancer center. Patients. Patients are with dysregulated immunity after solid organ transplantation, HIV/AIDS, or with psoriasis after treatment with etanercept. Interventions. There were discontinuation of etanercept, right hepatic trisegmentectomy, and chemotherapy. Measurements. We use survival as a measurement here. Results. Patients who were able to withstand reduction in immunosuppression survived. Surgical resection or chemotherapy was successful in delaying progression of disease. Limitations. There was a relatively short follow-up for these slow-growing neoplasms. Conclusion. EBV-related SMNs have variable aggressiveness. While chemotherapy may slow disease progression, resection and improving the host immune status provide the best opportunity for primary tumor control.

Inflammation, ageing and cancer

Cancer is generally recognized as an age-related disease. In fact, incidence and mortality rates of most human cancers increase consistently with age up to 90 years, but they plateau and decline thereafter. A low-grade systemic inflammation characterizes ageing and this pro-inflammatory status underlies biological mechanisms responsible for age-related inflammatory diseases. On the other hand, clinical and epidemiological studies show a strong association between chronic infection, inflammation and cancer and indicate that even in tumours not directly linked to pathogens, the microenvironment is characterized by the presence of a smouldering inflammation, fuelled primarily by stromal leukocytes. In this review, we have briefly mentioned inflammatory mediators involved in cancer although we decided to choose the ones which show a strict association with ageing and longevity. Inflammation is necessary to manage with damaging agents and is crucial for survival. But, in our opinion, the pro-inflammatory status of ageing might be one of the mechanisms which relate cancer to ageing. The most appropriate inflammatory genes have been selected to survive and to reproduce. Paradoxically, inflammatory age-related diseases (including cancer) are the marks of the same evolutionistic trait. Centenarians are characterized by a higher frequency of genetic markers associated with better control of inflammation. The reduced capacity of centenarians to mount inflammatory responses appears to exert a protective effect towards the development of those age-related pathologies having a strong inflammatory pathogenetic component, including cancer. All in all, centenarians seem to carry a genetic background with a peculiar resistance to cancer which is also an anti-inflammatory profile.