Unveiling Another Missing Piece in EBV-Driven Lymphomagenesis: EBV-Encoded MicroRNAs Expression in EBER-Negative Burkitt Lymphoma Cases

Abstract

Epstein–Barr virus (EBV) is a gammaherpesvirus linked to a number of lymphoid and epithelial malignancies, including Burkitt lymphoma (BL) in which its frequency ranges from 30% in sporadic cases to 100% in the endemic ones. The possible contribution of EBV to BL pathogenesis is largely unknown. It has been suggested that EBV may be associated with all of the cases, including those diagnosed as EBV negative by a mechanism of hit-and-run. Early during oncogenesis, viral genes are essential for initiating disease. Progressively, viral genome is lost to escape the immune system and host mutations accumulate in proto-oncogenic cell. The main problem with the hit-and-run hypothesis is the lack of evidence in primary tumors. The routine methods applied to detect the virus [i.e., immunohistochemistry and EBV-encoded RNAs (EBER) in situ hybridization (ISH)] have a low specificity and accuracy. The aim of this study was to identify the most suitable method to detect EBV infection in pathology samples by applying conventional and non-conventional methods (i.e., EBV-microRNAs detection and EBV viral load measurement). We investigated a total of 10 cases and we found that all the samples (n = 6) diagnosed as EBV negative by immunohistochemistry and EBER-ISH demonstrated the presence of EBV-microRNAs and EBV genome. This points at the possibility that EBV might have contributed to lymphomagenesis in all our patients, and propose microRNAs detection as the most specific and sensitive tool to recognize EBV vestiges. It is worth noting that our data would have considerable implications for EBV-related diseases control. By using anti-EBV vaccines, one could potentially prevent also some cancers less suspected of a viral origin because of viral genome loss.

Seroepidemiological analysis and literature review of the prevalence of Epstein‐Barr virus and herpesvirus infections in pediatric cases with non‐Hodgkin lymphoma in Central Europe

“…Reexamination of EBV‐negative cases by standard detection methods (EBNA‐1 immunohistochemistry and EBER‐ISH) using a variety of assays has revealed partially defective and integrated EBV genomes . Advanced diagnostics have detected EBV in all 10 apparently EBV‐negative Italian BL cases; with microRNA detection being the most sensitive and specific detection method . The loss of viral genome may reduce immunogenicity and selective pressure and therefore could represent a survival advantage, in Malawian BL relapses EBER is less frequent than at initial diagnosis .…”

“…40 Advanced diagnostics have detected EBV in all 10 apparently EBV-negative Italian BL cases; with microRNA detection being the most sensitive and specific detection method. 41 The loss of viral genome may reduce immunogenicity and selective pressure and therefore could represent a survival advantage, 2,42 in Malawian BL relapses EBER is less frequent than at initial diagnosis. 43 The initiation and maintenance of the viral effects by epigenetic mechanisms may obviate the need for the continued presence of the virus in subsequent stages of tumorigenesis.…”

Simultaneous Occurrence of Rosai–Dorfman Disease and Nodal Marginal Zone Lymphoma in a Patient with Sjögren’s Syndrome

“…Evidence has shown that samples identified as EBV negative by immunohistochemistry and EBER-ISH demonstrated the presence of EBV-microRNAs and EBV genome [ 21 ]. In our case, we also failed to detect EBER-ISH in the lymph node affected by MZL and RDD, and only the PCR showed the presence of DNA EBV in this sample.…”

Interplay between the epigenetic enzyme lysine (K)-specific demethylase 2B and Epstein-Barr virus infection

“…UltraView Universal Detection Kit (Ventana) using HRP multimer and DAB (as chromogen) was employed. ISH for EBER was carried out in each sample on 4 µm-thick section, as previously reported (31). A control slide, prepared from a paraffin-embedded tissue block containing metastatic nasopharyngeal carcinoma in a lymph node was used as positive control.…”