Epstein-Barr Virus in Nasopharyngeal Carcinoma of Guatemalan and Brazilian Patients

Analysis of Epstein-Barr Virus (EBV) and PD-L1 Expression in Nasopharyngeal Carcinoma Patients in a Non-Endemic Region

BACKGROUND

The purpose of this study was to evaluate the status of Epstein-Barr virus (EBV) infection and the expression of programmed cell death ligand-1 (PD-L1) in tumor samples from patients with nasopharyngeal carcinoma (NPC).

METHODS

Evaluation of EBV infection was performed through the detection of EBV-encoded small ribonucleic acids (EBER) by in situ hybridization, and PD-L1 expression was performed through immunohistochemistry.

RESULTS

In total, 124 samples were evaluated for EBER and 120 for PD-L1 expression. A total of 86.3% of cases were positive for EBER and 55.8% were positive for PD-L1. There was a correlation between EBER positivity and the presence of undifferentiated carcinoma histology (p = 0.007) as well as the absence of tobacco history (p = 0.019). There was a correlation between PD-L1 expression and EBER positivity (p = 0.004). There was no statistically significant difference between overall survival (OS) and EBER (p = 0.290) or PD-L1 (p = 0.801) expression.

CONCLUSIONS

This study corresponds to one of the largest cohorts of NPC in a non-endemic region. Phase III studies with checkpoint inhibitors are ongoing and may provide more data about the role of PD-L1 expression in this disease.

High-Risk Human Papillomavirus and Epstein-Barr Virus Coinfection: A Potential Role in Head and Neck Carcinogenesis

Simple Summary

A subset of carcinomas that arise in the head and neck region show a viral etiology. In fact, a subgroup of oropharyngeal cancers are caused by some types of human papillomavirus (HPV), so-called high-risk (HR)-HPVs, whereas undifferentiated nasopharyngeal carcinomas are etiologically related to Epstein–Barr virus (EBV). However, studies have reported the presence of both HR-HPV and EBV in some types of head and neck cancers. In this review, we discuss the potential contribution and role of HR-HPV/EBV coinfection in head and neck carcinogenesis, as well as the mechanisms that are potentially involved. In addition, HR-HPV/EBV interaction models are proposed.

Abstract

High-risk human papillomaviruses (HR-HPVs) and Epstein–Barr virus (EBV) are recognized oncogenic viruses involved in the development of a subset of head and neck cancers (HNCs). HR-HPVs are etiologically associated with a subset of oropharyngeal carcinomas (OPCs), whereas EBV is a recognized etiological agent of undifferentiated nasopharyngeal carcinomas (NPCs). In this review, we address epidemiological and mechanistic evidence regarding a potential cooperation between HR-HPV and EBV for HNC development. Considering that: (1) both HR-HPV and EBV infections require cofactors for carcinogenesis; and (2) both oropharyngeal and oral epithelium can be directly exposed to carcinogens, such as alcohol or tobacco smoke, we hypothesize possible interaction mechanisms. The epidemiological and experimental evidence suggests that HR-HPV/EBV cooperation for developing a subset of HNCs is plausible and warrants further investigation.

Epstein–Barr Virus (EBV) Viral Load in Tumor Cells Did Not Predict Tumor Extensiveness in Nasopharyngeal Cancer

Background: Nasopharyngeal cancer is commonly associated with Epstein–Barr virus (EBV) infection, especially undifferentiated non-keratinized histology. EBV DNA quantification through nasopharyngeal brushing was previously reported to be not related to disease stage. This study aimed to reinvestigate the relationship of EBV viral load in tumor tissue with tumor extensiveness by more accurate EBV DNA quantification through microscopically confirmed tumor cells from nasopharyngeal biopsy. Method: The specimens for EBV DNA quantification were derived from histopathology slides which were pre-treated following the QIAsymphony® SP protocol for tissue DNA extraction. Then, the extracted DNA underwent real-time polymerase chain reaction (RT-PCR) using the artus® EBV RG PCR Kit for EBV DNA quantification. The tumor volume was determined by delineating the gross tumor based on 3D imaging of the patient’s nasopharynx. Result: Twenty-four subjects were included in this study. All subjects were stage III and above, with more males (75%) than females. EBV viral load in tumor cells was found to have no correlation to tumor volume both in local and nodal regions. The median local tumor volume was 81.3 cm3 ± 80 cm3. The median EBV viral load in tumor cells was 95,644.8 ± 224,758.4 copies/100 ng of DNA. The median nodal or regional tumor volume was 35.7 ± 73.63 cm3. Conclusion: EBV viral load from tumor cells from nasopharyngeal biopsy has no relationship with tumor extensiveness in nasopharyngeal cancer. The presence and amount of EBV in tumor cells did not translate into larger or smaller tumors. The EBV viral proteins and RNAs were perhaps more likely to confer some prognostic information due to the fact that those molecules were related to carcinogenesis.

miR-331-3p Inhibits Proliferation and Promotes Apoptosis of Nasopharyngeal Carcinoma Cells by Targeting elf4B-PI3K-AKT Pathway

BACKGROUND

The incidence of nasopharyngeal carcinoma is increasing gradually, but the pathogenesis is not completely clear. MicroRNA, a highly conserved endogenous noncoding small molecule RNA, plays an essential role in the regulation of gene expression and is a hotspot in cancer research worldwide.

OBJECTIVES

Although previous studies have confirmed that the abnormal expression of microRNAs is closely related to the progression of nasopharyngeal carcinoma, the role of miRNA-331-3p in nasopharyngeal carcinoma has not been studied. The purpose of this study was to explore the role and mechanism of miRNA-331-3p in the progression of nasopharyngeal carcinoma.

MATERIALS AND METHODS

Real-time quantitative reverse transcription polymerase chain reaction was performed to detect the expression of miRNA-331-3p in nasopharyngeal carcinoma clinical samples and cell lines (CNE-1 and 5-8F cells). After overexpression of miRNA-331-3p in CNE-1 cells, cell proliferation was measured by Cell Counting Kit-8 assay, cell invasion was detected by Transwell assay, and apoptosis was tested by flow cytometry. In addition, the dual-luciferase reporter assay was used to identify the target gene of miRNA-331-3p and Western blotting was performed to measure the relative protein expression.

RESULTS

The expression of miRNA-331-3p in nasopharyngeal carcinoma clinical samples and cells was decreased significantly. Overexpression of miRNA-331-3p markedly inhibited the proliferation and invasion of CNE-1 cells and promoted cell apoptosis. Moreover, overexpression of miRNA-331-3p reduced the expression of target gene elF4B, leading to inhibition of the phosphorylation of Phosphoinositide 3-kinase (PI3K) and Serine/ threonine kinase (AKT).

CONCLUSION

miRNA-331-3p inhibited cell proliferation and induced cell apoptosis in nasopharyngeal carcinoma by targeting elF4B gene and then blocked the PI3K-AKT signaling pathway.

SIGNIFICANCE

The role of miRNA-331-3p in the development of NPC and its mechanism provide new ideas for the treatment of nasopharyngeal carcinoma.

Laryngeal Epstein-Barr Virus-Associated Smooth Muscle Tumor in an Undernourished Child

Smooth muscle tumors associated with Epstein-Barr virus infections (EBV-SMT) of laryngeal origin are exceedingly rare and have been reported in few adult patients, but not in children. This reported case describes a lesion found in the larynx of an 8-year-old Guatemalan undernourished girl. Microscopically, the lesion showed a highly cellular mesenchymal spindle cell tumor, containing frequent lymphocytes. The immunohistochemical analysis revealed positivity for α-smooth muscle actin and h-caldesmon. In addition, most of the tumor cells were positive for EBV by in situ hybridization. To the best of the author's knowledge, this is the first literature-reported case of laryngeal EBV-SMT occurring in an undernourished child.