Virus de Epstein-Barr: más que una mononucleosis infecciosa / Epstein-Barr virus: more than infectious mononucleosis

El virus de Epstein-Barr (VEB) fue el primer virus asociado a neoplasias en humanos. Infecta el 95 % de la población mundial, y aunque usualmente es asintomático, puede causar mononucleosis infecciosa y se relaciona con más de 200.000 casos de neoplasias al año. De igual forma, se asocia con esclerosis múltiple y otras enfermedades autoinmunes. A pesar de ser catalogado como un virus oncogénico, solo un pequeño porcentaje de los individuos infectados desarrollan neoplasias asociadas a VEB. Su persistencia involucra la capacidad de alternar entre una serie de programas de latencia, y de reactivarse cuando tiene la necesidad de colonizar nuevas células B de memoria, con el fin de sostener una infección de por vida y poder transmitirse a nuevos hospederos. En esta revisión se presentan las generalidades del VEB, además de su asociación con varios tipos de neoplasias, como son el carcinoma nasofaríngeo, el carcinoma gástrico, el linfoma de Hodgkin y el linfoma de Burkitt, y la esclerosis múltiple. Adicionalmente, se describen los mecanismos fisiopatológicos de las diferentes entidades, algunos de ellos no completamente dilucidados

Epstein-Barr virus (EBV) was the first virus associated with human cancer. It infects 95% of the world's population, and although it is usually asymptomatic, it causes infectious mononucleosis. It is related to more than 200,000 cases of cancer per year, and is also associated with multiple sclerosis and other autoimmune diseases. Despite being classified as an oncogenic virus, only a small percentage of infected individuals develop EBV-associated cancer. Its persistence involves the ability to alternate between a series of latency programs, and the ability to reactivate itself when it needs to colonize new memory B cells, in order to sustain a lifelong infection and be able to transmit to new hosts. In this review, the general characteristics of EBV are presented, in addition to its association with various types of cancers, such as nasopharyngeal carcinoma, gastric carcinoma, Hodgkin's lymphoma and Burkitt's lymphoma, and multiple sclerosis. Additionally, the pathophysiological mechanisms of the different entities are described, some of them not completely elucidated yet

Impacto del virus Epstein Barr en el cáncer gástrico en el Perú / Impact of the Epstein Barr virus on gastric cancer in Peru

El virus de Epstein Barr (VEB) es responsable del 10% del cáncer gástrico (CG) y se correlaciona con mejor tasa de sobrevida. En Perú, no existen estudios sobre prevalencia y características clínicas de CG VEB positivo. Objetivos: Determinar la prevalencia y las características clínico patológicas del CG VEB positivo. Materiales y métodos: 111 muestras de GC fueron examinadas centralmente por hibridización cromogénica in situ del RNA del VEB (EBER CISH). Resultados: El 8,4% de los casos fueron positivos para VEB. La mayoría de los casos VEB positivos tuvieron más de 60 años, varones y la localización, antro / píloro fue la más frecuente. La mayoría de los casos fueron de tipo intestinal y un patrón tubular con una tendencia a un mejor pronóstico en comparación con los casos de VEB negativo. Conclusión: CG VEB positivo es una entidad con una prevalencia de 8,4% en Perú con características clínicas y morfológicas distintivas.

Epstein Barr Virus (EBV) is responsible of 10% of Gastric Cancer (GC), correlating with better survival rates. In Peru, there were not studies about prevalence and clinical characteristics of CG EBV positive. Objective: Determine prevalence and clinicopathological characteristics of GC EBV positive. Materials and methods: 111 GC tumour samples were centrally screened by Chromogenic in situ hybridization (CISH) technique for EBV-encoded RNA (EBER) transcript. Results: 8.4% of cases were positive for EBV. Most cases EBV positive were more than 60 years old; male, antrum/pylorus had more frequent localizations. Most cases had an intestinal type and tubular patter and a tendency to better prognostic in comparison EBV negative cases. Conclusion: EBV positive GC is an entity with a prevalence of 8.4% in Peru with distinctive clinical and morphological characteristics.

Análise comparativa do polimorfismo genético da glutationa transferase, do Helicobacter pylori e do vírus Epstein-Barr entre a área do tumor e as margens de ressecção proximal e distal do câncer gástrico / Comparative analysis of glutathione transferase genetic polymorphism, Helicobacter pylori and Epstein-Barr virus between the tumor area and the proximal and distal resection margins of gastric cancer

RESUMO Objetivo: comparar o polimorfismo dos genes Glutationa S-transferase teta 1 (GSTT1) e Glutationa S-transferase mu 1 (GSTM1) da área do tumor com as margens proximal e distal de espécimes de estômago ressecados de pacientes com câncer gástrico, e investigar a presença do DNA do vírus Epstein-Barr (EBV) e Helicobacter pylori. Métodos: coletamos prospectivamente amostras teciduais da área do tumor e das margens de ressecção proximal e distal dos estômagos de dez pacientes com adenocarcinoma gástrico submetidos à gastrectomia com linfadenectomia D2 e submetemos esses espécimes à extração de DNA. Comparamos a área do tumor com as margens proximal e distal dos estômagos ressecados para o polimorfismo dos genes GSTT1 e GSTM1 e investigamos a presença de DNA do EBV e H. pylori. Utilizamos o exon 5 do gene p53 como controle interno da reação de PCR multiplex. Resultados: em um paciente, detectamos genótipos GSTT1 e GSTM1 nulos na área do tumor, em contraste com a presença de ambos os genes nas margens proximal e distal. Encontramos DNA do EBV e H. pylori na área do tumor e também nas margens proximal e distal. Em outro paciente, a margem proximal foi negativa para GSTT1 e o DNA do EBV foi negativo na margem distal. Em três pacientes, o EBV-DNA foi negativo apenas na margem distal. Conclusão: este é o primeiro relato em que diferentes genótipos, infecção por EBV-DNA e H. pylori foram observados no mesmo paciente, indicando provável deleção desses genes em resposta à progressão tumoral e heterogeneidade intratumoral.

ABSTRACT Objective: to compare the polymorphism of the Glutathione S-transferase theta 1 (GSTT1) and Glutathione S-transferase mu 1 (GSTM1) genes from the tumor area with the proximal and distal margins of stomach specimens resected from patients with gastric cancer, and to investigate the presence of Epstein-Barr virus (EBV) DNA and Helicobacter pylori. Methods: we prospectively collected tissue specimens from the tumor area and from the proximal and distal resection margins of the stomachs of ten patients with gastric adenocarcinoma who underwent gastrectomy with D2 lymphadenectomy, and submitted these specimens to DNA extraction. We compared the tumor area with the proximal and distal margins of the resected stomachs for polymorphism of GSTT1 and GSTM1 genes and investigated the presence of EBV-DNA and H. pylori. We used the p53 exon 5 gene as an internal control of the multiplex PCR reaction. Results: in one patient, we detected null GSTT1 and GSTM1 genotypes in the tumor area, in contrast to the presence of both genes in the proximal and distal margins. We found EBV-DNA and H. pylori in the tumor area and also in the proximal and distal margins. In another patient, the proximal margin was negative for GSTT1, and EBV-DNA was negative in the distal margin. In three patients, EBV-DNA was negative only in the distal margin. Conclusion: this is the first report where different genotypes, EBV-DNA and H. pylori infection were observed in the same patient, indicating a probable deletion of these genes in response to tumor progression and intratumoral heterogeneity.

Epstein-Barr virus-positive gastric cancer: a distinct molecular subtype of the disease?

Abstract: Approximately 90% of the world population is infected by Epstein-Barr virus (EBV). Usually, it infects B lymphocytes, predisposing them to malignant transformation. Infection of epithelial cells occurs rarely, and it is estimated that about to 10% of gastric cancer patients harbor EBV in their malignant cells. Given that gastric cancer is the third leading cause of cancer-related mortality worldwide, with a global annual incidence of over 950,000 cases, EBV-positive gastric cancer is the largest group of EBV-associated malignancies. Based on gene expression profile studies, gastric cancer was recently categorized into four subtypes; EBV-positive, microsatellite unstable, genomically stable and chromosomal instability. Together with previous studies, this report provided a more detailed molecular characterization of gastric cancer, demonstrating that EBV-positive gastric cancer is a distinct molecular subtype of the disease, with unique genetic and epigenetic abnormalities, reflected in a specific phenotype. The recognition of characteristic molecular alterations in gastric cancer allows the identification of molecular pathways involved in cell proliferation and survival, with the potential to identify therapeutic targets. These findings highlight the enormous heterogeneity of gastric cancer, and the complex interplay between genetic and epigenetic alterations in the disease, and provide a roadmap to implementation of genome-guided personalized therapy in gastric cancer. The present review discusses the initial studies describing EBV-positive gastric cancer as a distinct clinical entity, presents recently described genetic and epigenetic alterations, and considers potential therapeutic insights derived from the recognition of this new molecular subtype of gastric adenocarcinoma.

Assessment of Epstein-Barr virus nucleic acids in gastric but not in breast cancer by next-generation sequencing of pooled Mexican samples

Gastric (GC) and breast (BrC) cancer are two of the most common and deadly tumours. Different lines of evidence suggest a possible causative role of viral infections for both GC and BrC. Wide genome sequencing (WGS) technologies allow searching for viral agents in tissues of patients with cancer. These technologies have already contributed to establish virus-cancer associations as well as to discovery new tumour viruses. The objective of this study was to document possible associations of viral infection with GC and BrC in Mexican patients. In order to gain idea about cost effective conditions of experimental sequencing, we first carried out an in silico simulation of WGS. The next-generation-platform IlluminaGallx was then used to sequence GC and BrC tumour samples. While we did not find viral sequences in tissues from BrC patients, multiple reads matching Epstein-Barr virus (EBV) sequences were found in GC tissues. An end-point polymerase chain reaction confirmed an enrichment of EBV sequences in one of the GC samples sequenced, validating the next-generation sequencing-bioinformatics pipeline.

Epstein-Barr virus associated lymphoepithelioma-like carcinoma at the lesser curvature of the upper gastric body: a Case Report / El virus de Epstein-Barr asociado al carcinoma de tipo linfoepitelioma en la curvatura menor de la parte superior del cuerpo gástrico: Reporte de Caso

Lymphoepithelioma-like gastric carcinoma (LELGC) is a rare neoplasm of the stomach with dense lymphocytic infiltration. More than 80% of LELGCs are positive for the Epstein-Barr virus (EBV). Here, we report a 64-year old Chinese man with swallowing discomfort while eating food. Endoscopy and computed tomography both showed a submucosal lesion at the lesser curvature of the upper gastric body. The first diagnostic impression was a gastrointestinal stromal tumour. Subsequently, the patient received a wedge resection of the stomach. On histopathological examination, the tumour was found to consist of small nests of neoplastic cells within dense lymphocytic infiltration. Additionally, most of the neoplastic cells were positive for cytokeratin and Epstein-Barr virus-encoded RNA (EBER). Subsequently, the diagnosis of LELGC was made. We believe that physicians should be aware of the diagnosis of submucosal gastric lesions, particularly in older male patients.

El carcinoma gástrico de tipo linfoepitelioma (CGLE) es una neoplasia rara del estómago con una infiltración linfocítica densa. Más del 80% de los CGLEs son positivos al virus de Epstein-Barr (EBV). Aquí reportamos el caso de un paciente chino de 64 años, que sentía malestar al efectuar la deglución de alimentos. Tanto la endoscopia como la tomografía computarizada mostraron una lesión submucosa en la curvatura menor de la parte superior del cuerpo gástrico. La primera impresión diagnóstica fue de un tumor del estroma gastrointestinal Posteriormente, al paciente se le hizo una resección en cuña del estómago. En el examen histopatológico, se halló que el tumor consistía de pequeños nidos de células neoplásicas dentro de una infiltración linfocítica densa. Además, la mayoría de las células neoplásicas eran positivas a la citoqueratina y al ARN codificado por el virus de Epstein-Barr (EBER). Posteriormente, se realizó el diagnóstico de CGLE. Creemos que los médicos deben tomar conciencia del diagnóstico de las lesiones submucosas gástricas, especialmente en los pacientes mayores hombres.

Linfoma de Celulas Grandes B Difuso Gastrointestinal del Anciano Asociado al Virus Epstein Barr: Reporte de Cinco Casos y Revision de la Literatura / Gastrointestinal Epstein Barr Virus positive diffuse large B cell lymphoma in elderly: report of five cases and review of literatura

El Linfoma de Células Grandes B difuso del anciano asociado al Epstein Barr es una nueva entidad incluida provisionalmente en la más reciente clasificación de neoplasias linfoides de la WHO. Usualmente afecta ancianos y tiene pobre sobrevida. El objetivo de este reporte fue evaluar las característica clínicas, endoscópicas y sobrevida de cinco pacientes portadores de esta entidad y compromiso gastrointestinal. Tres casos tuvieron infiltración gástrica y dos casos tuvieron compromiso del ileón y el ciego.

EBV-positive diffuse large B-cell lymphoma (DLBCL) in elderly is a new entity included provisionally in the most recent WHO Classification of lymphoid neoplasms. It usually affects elderly patients and has a poor survival. The goal of this report was to evaluate clinical, endoscopic characteristics and survival of five patients with this entity and gastrointestinal afectation. From five cases, three cases had gastric infiltration, one ileon and one in cecum.

Identificación de asociaciones clínico-patológicas e hipermetilación de genes supresores de tumores en cáncer gástrico difuso a través de análisis de Hierarchical clustering / Hierarchical clustering analysis to detect associations between clinical and pathological features of gastric tumors and hypermethylation of suppressor genes

Background:Methylation is an inactivation mechanism for tumor suppressor genes, that can have important clinical implications. Aim: To analyze the methylation status of 11 tumor suppressor genes in pathological samples of diffuse gastric cancer. Material and methods: Eighty three patients with diffuse gastric cancer with information about survival and infection with Epstein Barr virus, were studied. DNA was extracted from pathological slides and the methylation status of genes p14, p15, p16, APC, p73, FHIT, E-caderin, SEMA3B, BRCA-1, MINT-2 y MGMT, was studied using sodium bisulphite modification and polymerase chain reaction. Results were grouped according to the methylation index or Hierarchical clustering (TIGR MultiExperiment Viewer). Results: Three genes had a high frequency of methylation (FHIT, BRCA1, APC), four had an intermediate frequency (p15, MGMT, p14, MINT2) and four had a low frequency (p16, p73, E-cadherin, SEMA3B). The methylation index had no association with clinical or pathological features of tumors or patients survival. Hierarchical clustering generated two clusters. One grouped clinical and pathological features with FHIT, BRCA1, and APC and the other grouped the other eight genes and Epstein Barr virus infection. Two significant associations were found, between APC and survival and p16/p14 and Epstein Barr virus infection. Conclusions: Hierarchical clustering is a tool that identifies associations between clinical and pathological features of tumors and methylation of tumor suppressor genes.

Características clínico-moleculares del cáncer gástrico cardial asociado al virus Epstein Barr / Clinical and molecular features of cardial gastric cancer associated to Epstein Barr virus

Background: Mortality caused by cardial gastric cancer in Chile, is increasing. Previously we demonstrated an association between Epstein Barr virus and this specific location of gastric cancer. Aim: To perform a clinical and molecular characterization of cardial gastric cancer associated to Epstein Barr virus. Material and methods: Epstein Barr virus was identified in 93 cardial gastric tumors, by in situ hybridization. Clinical and pathological features, survival and expression of p53 and c-erbB2 were compared between tumors with or without the presence of the virus. Results: Twenty two (23.6%) tumors expressed Epstein Barr virus. No difference in sex or age of patients with tumors positive or negative for the virus was observed. Epstein Barr positive tumors had a tendency to have a higher frequency of Bormann III endoscopic appearance and a lower frequency of p53 accumulation (p=0.06). Five years survival was 67% and 42% of tumors positive and negative for the presence of the virus, respectively (p=0.57). Conclusions: Our results, although not significant, show a tendency towards unique characteristics of cardial gastric tumors associated to Epstein Barr virus.

Epstein-Barr virus infection and gastric carcinoma in São Paulo State, Brazil

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus, and most people have serological evidence of previous viral infection at adult age. EBV is associated with infectious mononucleosis and human cancers, including some lymphomas and gastric carcinomas. Although EBV was first reported in lymphoepithelioma-like gastric carcinoma, the virus was also found in conventional adenocarcinomas. In the present study, 53 gastric carcinomas diagnosed in São Paulo State, Brazil, were evaluated for EBV infection by non-isotopic in situ hybridization with a biotinylated probe (Biotin-AGACACCGTCCTCACCACCC GGGACTTGTA) directed to the viral transcript EBER-I, which is actively expressed in EBV latently infected cells. EBV infection was found in 6 of 53 (11.32 percent) gastric carcinomas, mostly from male patients (66.7 percent), with a mean age of 59 years old. Most EBV-positive tumors were in gastric antrum. Two EBV-positive tumors (33.3 percent) were conventional adenocarcinomas, whereas four (66.7 percent) were classified as lymphoepithelioma-like carcinomas. EBV infection in gastric carcinomas was reported elsewhere in frequencies that range from 5.6 percent (Korea) up to 18 percent (Germany). In Brazil, a previous work found EBV infection in 4 of 80 (5 percent) gastric carcinomas, whereas another study found 4.7 and 11.2 percent of EBV-positive gastric carcinomas of Brazilians of Japanese origin or not, respectively. In the present study, the frequency of EBV-positive gastric carcinomas is similar to that reported in other series, and the clinicopathologic characteristics of these EBV-positive tumors are in agreement with the data in the literature.

Carcinoma gástrico de tipo linfoepitelioma: variante inusual en muñón post-gastrectomía / Lymphoepithelioma-like gastric carcinoma: unusual variant in postgastrectomy stump

El carcinoma de tipo linfoepitelioma, indiferenciado con estroma linfoide o medular, constituye un 3,8% de los carcinomas gástricos. Microscópicamente es similar a linfoepiteliomas de otras localizaciones, tiene crecimiento expansivo y mejor pronóstico que otros tipos histológicos. Se postula probable relación con el virus de Epstein Barr. Una mujer de 56 años gastrectomizada por cáncer hacía 31 años (Billroth) mostró en la endoscopía lesión ulcerada próxima a neboca. Se biopsió con resultado positivo y se realizó gastrectomía. Se recibió pieza que incluía muñón gástrico, yeyuno anastomosis, epiplón y glanglios. Presentaba lesión sobreelevada, ulcerada, de 4,5 cm ubicada en cara anterior a 1,5 cm de neoboca. Se efectuó fijación en formol buffer, procesamiento según métodos habituales y coloración con Hematoxilina-Eosina. Se realizaron técnicas de Inmunohistoquímica para CKAE1-AE3, EMA, CEA, CD45, CD20, CD3 y CD45Ro, y de PCR para virus de Epstein Barr. Microscópicamente estaba constituida por una proliferación expansiva de células poligonades con citoplasma ligeiramente eosinófilo y núcleos vesiculares, dispuestas en pequeños nidos o asiladas, positivas para CKES1-AE3, EMA y CEA, con denso infiltrado linfoide maduro, de disposición folicular y difuso, positivo para CD45, CD45Ro, CD3 y CD20. La técnica de PCR fue positiva. Éste es el primer caso de este tipo registrado en nuestro servicio desde 1989. Además de las características peculiares de esta variedad, cuyo diagnóstico diferencial debe haceres con los linfomas. es relevante su origen en muñón gástrico, donde esta complicación aparece con cifras variables, estando el riesgo vinculado al tipo de cirgía y tiempo transcurrido.

Carcinoma indiferenciado de estomago tipo linfoepitelioma con virus epstein-barr / Undifferentiated gastric carcinoma of lymphoepithelioma type with Epstein-Barr virus

Se presenta el caso de un hombre de 62 años con un tumor gástrico que resultó corresponder a un carcinoma indiferenciado tipo linfoepitelioma. La naturaieza epitelial del tumor se confirmo por inmunohistoquímica (mezcla de queratinas AEl/AE3). La presencia del virus Epstein-Barr, realizada por hibridización in situ, se restringió a las células epiteliales, confirmando datos de la literatura y a favor de la propuesta relación etiopatogénica del virus y este tipo de tumor. Hasta esta presentación no se han relatado ejemplos de carcinoma indiferenciado tipo linfoepitelioma en nuestro medio.

Infección por Helicobacter pylori y el riesgo de carcinoma gástrico: presentación de un caso / Helicobacter pylori infection and the risk of gastric carcinoma: report of a case

The authors present the clinical history of a patient with gastritis of the antrum who subsequently had early gastric cancer of the antrum. The authors review the literature on the infection by Helicobacter pylori as a risk factor for gastric carcinoma. The infection produces chronic gastritis, gastric ulcer, duodenal ulcer and is a probable risk factor for gastric carcinoma