Lack of evidence for a role of Epstein-Barr virus in the increase of lung cancer in idiopathic pulmonary fibrosis

Assessment of viral RNA in idiopathic pulmonary fibrosis using RNA-seq

Background

Numerous publications suggest an association between herpes virus infection and idiopathic pulmonary fibrosis (IPF). These reports have employed immunohistochemistry, in situ hybridization and/or PCR, which are susceptible to specificity artifacts.

Methods

We investigated the possible association between IPF and viral RNA expression using next-generation sequencing, which has the potential to provide a high degree of both sensitivity and specificity. We quantified viral RNA expression for 740 viruses in 28 IPF patient lung biopsy samples and 20 controls. Key RNA-seq results were confirmed using Real-time RT-PCR for select viruses (EBV, HCV, herpesvirus saimiri and HERV-K).

Results

We identified sporadic low-level evidence of viral infections in our lung tissue specimens, but did not find a statistical difference for expression of any virus, including EBV, herpesvirus saimiri and HERV-K, between IPF and control lungs.

Conclusions

To the best of our knowledge, this is the first publication that employs RNA-seq to assess whether viral infections are linked to the pathogenesis of IPF. Our results do not address the role of viral infection in acute exacerbations of IPF, however, this analysis patently did not support an association between herpes virus detection and IPF.

Viral colonization in exhaled breath condensate of lung cancer patients: Possible role of EBV and CMV

INTRODUCTION

Today, an increasing interest is being addressed to the viral etiology of lung tumors. As a consequence, research efforts are currently being directed to the identification of the new viruses involved in lung carcinogenesis toward which the screening programs could be directed.

OBJECTIVES

The aim of this study was to investigate the airways colonization by the Epstein-Barr virus (EBV) and Citomegalovirus (CMV) in patients affected by lung cancer using, as a respiratory non-invasive sample, the exhaled breath condensate (EBC).

METHODS

About 70 lung-cancer patients and 40 controls were enrolled. All subjects underwent bronchial brushing and EBC collection. EBV-DNA and CMV-DNA were evaluated in both samples by real-time PCR assay.

RESULTS

They were able to detect EBV and CMV in the EBC. An increase of the EBV positivity in non-small cell lung cancer (NSCLC) patients compared with controls and of the CMV in advanced stages of lung cancer were observed. The association of the positivity of the cytology and the CMV test (in EBC or brushing) slightly increased the sensitivity of malignant diagnosis.

CONCLUSION

EBV and CMV resulted detectable in the EBC. In consideration of the potential involvement of these viruses in lung cancer, which was confirmed in this study, future studies in this direction were supported.

New insights into the pathogenesis and treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common and lethal of the idiopathic interstitial pneumonias. There are currently no effective pharmacological therapies approved for the treatment of IPF. Despite the focus on targeting fibrogenic pathways, recent clinical trials have been largely disappointing. Progress is being made in elucidating key cellular processes and molecular pathways critical to IPF pathogenesis, and this should facilitate the development of more effective therapeutics for this recalcitrant disease. Emerging pathobiological concepts include the role of aging and cellular senescence, oxidative stress, endoplasmic reticulum stress, cellular plasticity, microRNAs and mechanotransduction. Therapeutic approaches that target molecular pathways to modulate aberrant cellular phenotypes and promote tissue homeostasis in the lung must be developed. Heterogeneity in biological and clinical phenotypes of IPF warrants a personalized medicine approach to diagnosis and treatment of this lung disorder.

Epstein-Barr virus microRNAs and lung cancer

Background:

We conducted the first analysis of viral microRNAs (miRNAs) in lung cancer, with a focus on Epstein–Barr virus (EBV).

Methods:

We evaluated viral miRs with a two-channel oligo-array targeting mature, anti-sense miRNAs in 290 cases. In 48 cases, we compared microarray and real-time quantitative PCR (qPCR) expression for three EBV miRNAs. We tested for EBV DNA, RNA, and protein in tumour tissue from six cases with and six cases without strong qPCR-based evidence of EBV miRNAs.

Results:

The EBV miRNAs strongly differentiated between adenocarcinoma and squamous cell carcinoma using the microarray (P<0.01 for 9 out of 16 EBV miRNAs). However, microarray and qPCR measurements of BART1, BART2, and BHRF1–3 expression were not significantly correlated (P=0.53, 0.94, and 0.47, respectively). Although qPCR provided substantial evidence of EBV miRNAs in 7 out of 48 cases, only 1 of these 7 cases had detectable EBV DNA in tumour tissue. None had detectable EBV RNA or protein by histochemical stains.

Conclusion:

In a comprehensive evaluation of EBV miRNA, DNA, RNA, and protein in lung cancer, we found little evidence of EBV in lung tumour tissue. Discrepancies between microarray- and qPCR-based strategies highlight the difficulty of validating molecular markers of disease. Our results do not support a role of EBV in lung cancer.

Epstein-Barr virus WZhet DNA can induce lytic replication in epithelial cells in vitro, although WZhet is not detectable in many human tissues in vivo

OBJECTIVE

WZhet is a rearranged and partially deleted form of the Epstein-Barr virus (EBV) genome in which the BamH1W region becomes juxtaposed with and activates BZLF1, resulting in constitutive viral replication. We tested whether WZhet induces viral replication in epithelial cells, and we studied its prevalence in a wide range of lesional tissues arising in vivo.

METHODS

A quantitative real-time PCR assay targeting EBV WZhet DNA was developed to measure this recombinant form of the EBV genome.

RESULTS

WZhet DNA was undetectable in any of 324 plasma or paraffin-embedded tissue samples from patients with EBV-associated and EBV-negative disorders. These included specimens from patients with Hodgkin or non-Hodgkin lymphoma, post-transplant lymphoproliferation, nasopharyngeal or gastric adenocarcinoma, and infectious mononucleosis. However, WZhet DNA was detected in vitro in EBV-infected AGS gastric cancer cells. Additionally, transient transfection of infected AGS gastric cancer cells showed that viral replication could be induced by a WZhet plasmid.

CONCLUSION

This is the first evidence that WZhet induces the EBV lytic cycle in an epithelial cell line. Our negative findings in natural settings suggest that WZhet is a defective viral product that thrives in the absence of a host immune system but is rarely present in vivo.

Epstein-Barr-virus-induced interstitial lung disease

PURPOSE OF REVIEW

We describe a patient in whom Epstein-Barr virus infection appears to have caused an unusual interstitial lung disease with multisystem involvement resembling sarcoidosis and interstitial lung disease. We have reviewed the relevant literature about the relation of Epstein-Barr virus and interstitial lung disease.

RECENT FINDINGS

Epstein-Barr virus replication within type II alveolar cells was shown to occur in adult cryptogenic fibrosing alveolitis. Latent membrane protein 1 is one of the Epstein-Barr-virus-associated proteins and is expressed on the surface of Epstein-Barr-virus-infected cells in the latent and replicating phases. Latent membrane protein 1 was positive in the cuboidal epithelial cells of the lungs from some patients with idiopathic pulmonary fibrosis, and that its positivity correlated with poor prognosis. Epstein-Barr virus was also found in the lungs of children with lymphocytic interstitial pneumonia, AIDS and Langerhans cell histiocytosis. Epstein-Barr virus DNA was not detectable in patients with sarcoidosis. There was also lack of evidence for a role of Epstein-Barr virus in the increase of lung cancer in idiopathic pulmonary fibrosis.

SUMMARY

Using monoclonal antibodies against viral antigen Epstein-Barr virus was shown to replicate within type II alveolar cells of adult idiopathic pulmonary fibrosis patients. Latent membrane protein 1positivity indicates poor prognosis; Epstein-Barr virus positivity did not increase the incidence of lung cancer in these patients. Epstein-Barr virus was also associated with lymphocytic interstitial pneumonia, AIDS and Langerhans cell histiocytosis but not with sarcoidosis.