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Rochford R. Reframing Burkitt lymphoma: virology not epidemiology defines clinical variants. ANNALS OF LYMPHOMA 2021; 5:22. [PMID: 34888589 PMCID: PMC8654190 DOI: 10.21037/aol-21-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In 1964, Epstein-Barr virus (EBV) was identified in a biopsy from a patient with Burkitt lymphoma (BL) launching a new field of study into this ubiquitous human virus. Almost 60 years later, insights into the role of EBV in lymphomagenesis are still emerging. While all BL carry the hallmark c-myc translocation, the epidemiologic classification of BL (e.g., endemic, sporadic or immunodeficiency-associated) has traditionally been used to define BL clinical variants. However, recent studies using molecular methods to characterize the transcriptional and genetic landscape of BL have identified several unique features are observed that distinguish EBV+ BL including a high level of activation induced deaminase mutation load, evidence of antigen selection in the B cell receptor, and a decreased mutation frequency of TCF3/ID3, all found predominantly in EBV+ compared to EBV- BL. In this review, the focus will be on summarizing recent studies that have done in depth characterization of genetic and transcriptional profiles of BL, describing the differences and similarities of EBV+ and EBV- BL, and what they reveal about the etiology of BL. The new studies put forth a compelling argument that the association with EBV should be the defining etiologic feature of clinical variants of BL. This reframing of BL has important implications for therapeutic interventions for BL that distinguish the EBV+ from the EBV- lymphomas.
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Affiliation(s)
- Rosemary Rochford
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
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Epstein-Barr Virus Genomes Reveal Population Structure and Type 1 Association with Endemic Burkitt Lymphoma. J Virol 2020; 94:JVI.02007-19. [PMID: 32581102 DOI: 10.1128/jvi.02007-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 06/16/2020] [Indexed: 12/14/2022] Open
Abstract
Endemic Burkitt lymphoma (eBL), the most prevalent pediatric cancer in sub-Saharan Africa, is distinguished by its inclusion of Epstein-Barr virus (EBV). In order to better understand the impact of EBV variation in eBL tumorigenesis, we improved viral DNA enrichment methods and generated a total of 98 new EBV genomes from both eBL cases (n = 58) and healthy controls (n = 40) residing in the same geographic region in Kenya. Using our unbiased methods, we found that EBV type 1 was significantly more prevalent in eBL patients (74.5%) than in healthy children (47.5%) (odds ratio = 3.24, 95% confidence interval = 1.36 to 7.71, P = 0.007), as opposed to similar proportions in both groups. Controlling for EBV type, we also performed a genome-wide association study identifying six nonsynonymous variants in the genes EBNA1, EBNA2, BcLF1, and BARF1 that were enriched in eBL patients. In addition, viruses isolated from plasma of eBL patients were identical to their tumor counterparts consistent with circulating viral DNA originating from the tumor. We also detected three intertypic recombinants carrying type 1 EBNA2 and type 2 EBNA3 regions, as well as one novel genome with a 20-kb deletion, resulting in the loss of multiple lytic and virion genes. Comparing EBV types, viral genes displayed differential variation rates as type 1 appeared to be more divergent, while type 2 demonstrated novel substructures. Overall, our findings highlight the complexities of the EBV population structure and provide new insight into viral variation, potentially deepening our understanding of eBL oncogenesis.IMPORTANCE Improved viral enrichment methods conclusively demonstrate EBV type 1 to be more prevalent in eBL patients than in geographically matched healthy controls, which previously underrepresented the prevalence of EBV type 2. Genome-wide association analysis between cases and controls identifies six eBL-associated nonsynonymous variants in EBNA1, EBNA2, BcLF1, and BARF1 genes. Analysis of population structure reveals that EBV type 2 exists as two genomic subgroups and was more commonly found in female than in male eBL patients.
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Carrasco-Avino G, Riquelme I, Padilla O, Villaseca M, Aguayo FR, Corvalan AH. The conundrum of the Epstein-Barr virus-associated gastric carcinoma in the Americas. Oncotarget 2017; 8:75687-75698. [PMID: 29088902 PMCID: PMC5650457 DOI: 10.18632/oncotarget.18497] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 05/29/2017] [Indexed: 02/07/2023] Open
Abstract
Epstein-Barr virus-associated gastric carcinoma shows a higher prevalence in the Americas than Asia. We summarize all studies of Epstein Barr virus-associated gastric carcinoma in the Americas, focusing on host characteristics, environmental associations and phylogeographic diversity of Epstein-Barr virus strains. In the Americas, the prevalence of Epstein Barr virus-associated gastric carcinoma is 11.4%, more frequent in males and portray predominantly diffuse-type histology. EBERs, EBNAs, BARTs and LMP are the highest expressed genes; their variations in healthy individuals may explain the phylogeographic diversity of Epstein-Barr virus across the region. Gastric cancer cases harbor exclusively the western genotype (subtype D and kept Xho I site), suggesting a disrupted co-evolution between the pathogen and its host. Epstein-Barr virus-associated gastric carcinoma molecular subtype cases from The Cancer Genome Atlas display PIK3CA gene mutations, amplification of JAK2, PD-L1 and PD-L2 and CpG island methylator phenotype, leading to more extensive methylation of host and viral genomes than any other subtypes from the study. Environmental conditions include negative- and positive- associations with being firstborn child and smoking, respectively. A marginal association with H. pylori has also been reported. Lymphoepithelioma-like carcinoma is associated with Epstein Barr virus in 80%-86% of cases, most of which have been included as part of Epstein Barr virus-associated gastric carcinoma series (prevalence 1.1%-7.6%). Whether these cases represent a variant of Epstein-Barr virus-associated gastric carcinoma is discussed. We propose novel research strategies to solve the conundrum of the high prevalence of Epstein-Barr virus-associated gastric carcinoma in the Americas.
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Affiliation(s)
- Gonzalo Carrasco-Avino
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Catolica de Chile, Santiago, Chile
- Department of Pathology, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Ismael Riquelme
- Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de la Frontera, Temuco, Chile
- Department of Pathology, Universidad de la Frontera, Temuco, Chile
| | - Oslando Padilla
- Department of Public Health, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Miguel Villaseca
- Department of Pathology, Universidad de la Frontera, Temuco, Chile
| | - Francisco R. Aguayo
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Catolica de Chile, Santiago, Chile
- Department of Basic and Clinical Oncology, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Alejandro H. Corvalan
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Catolica de Chile, Santiago, Chile
- UC-Center for Investigational Oncology (CITO), Pontificia Universidad Catolica de Chile, Santiago, Chile
- Department of Hematology and Oncology, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
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Neves M, Marinho-Dias J, Ribeiro J, Esteves M, Maltez E, Baldaque I, Breda E, Monteiro E, Medeiros R, Sousa H. Characterization of Epstein-Barr virus strains and LMP1-deletion variants in Portugal. J Med Virol 2015; 87:1382-8. [PMID: 25879824 DOI: 10.1002/jmv.24190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2015] [Indexed: 11/08/2022]
Abstract
Variations in the genome sequence of Epstein-Barr Virus (EBV) are thought to lead to differential interaction with host cells, immune evasion, and transformation. The discussion regarding EBV strains as having a geographic or disease-association has been increasing and the majority of studies are performed in Asiatic populations. We developed a case-control study with 139 individuals, including 96 subjects with different malignancies and 43 healthy individuals, from the North region of Portugal. We have used PCR protocols for the characterization of EBV strains (type A or B) based on EBNA3C genome variation and for the LMP1 30bp-deletion variants (wt-LMP1 or del-LMP1). Our study showed that type A is the most prevalent in our population (100% of healthy controls, 96.9% of aHSCT patients, 90.8% of HNSCC patients, and 94.9% of NPC patients) and that type B was significantly associated with NPC (P = 0.019; RR = 8.90). Regarding the LMP1 30bp-deletion, we found a similar distribution of both wt- and del-LMP1 variants in controls and dispare results in cases: del-LMP1 was more frequent in aHSCT and HNSCC patients (64.7% and 63.2%, respectively) and wt-LMP1 in NPC patients (100%). In fact, the study reveals that wt-LPM1 was significantly associated with NPC (P < 0.001; RR = 18.4). Hence, our study showed that EBV type B and wt-LMP1 variant seem to be associated with NPC in our population, with a clear disease-association for wt-LMP1. These results contribute for the knowledge of EBV genetic diversity among Caucasian populations.
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Affiliation(s)
- Marco Neves
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Department of Biology, University of Aveiro, Campus de Santiago, Aveiro, Portugal
| | - Joana Marinho-Dias
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Virology Service, Portuguese Institute of Oncology of Porto, Porto, Portugal
| | - Joana Ribeiro
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Virology Service, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Faculty of Medicine of University of Porto, Porto, Portugal
| | - Marlene Esteves
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal
| | - Elsa Maltez
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal
| | - Inês Baldaque
- Virology Service, Portuguese Institute of Oncology of Porto, Porto, Portugal
| | - Eduardo Breda
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Otorhinolaryngology Department, Portuguese Institute of Oncology of Porto, Porto, Portugal
| | - Eurico Monteiro
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Otorhinolaryngology Department, Portuguese Institute of Oncology of Porto, Porto, Portugal
| | - Rui Medeiros
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Virology Service, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, Porto, Portugal.,Research Department, Portuguese League Against Cancer (Liga Portuguesa Contra o Cancro - Núcleo Regional do Norte), Porto, Portugal
| | - Hugo Sousa
- Molecular Oncology and Viral Pathology Group, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Virology Service, Portuguese Institute of Oncology of Porto, Porto, Portugal.,Faculty of Medicine of University of Porto, Porto, Portugal
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