# JC Polyomavirus in Prostate Cancer—Friend or Foe?

## TL;DR

This study investigates the role of JC polyomavirus (JCV) in prostate cancer, finding it often co-occurs with EBV and may influence cancer progression.

## Contribution

The study reveals JCV's potential role as a co-factor in EBV-related prostate cancer progression.

## Key findings

- JCV DNA was detected in 49.6% of prostate cancer samples, primarily in co-infection with EBV.
- Single EBV infection was associated with more advanced cancer stages and higher EBV load.
- Patients with EBV/JCV co-infection were more often classified as low risk compared to those with single EBV infection.

## Abstract

Various viruses, including polyomaviruses (JCV, BKV) and EBV, are considered as potential factors in the development and/or progression of prostate cancer (PCa), one of the most common cancers in men. Therefore, the aim of the presented study was to assess the frequency of JCPyV DNA in PCa tissue. We detected viral DNA in 49.6% of clinical samples, including 71.9%—single EBV infection and 28.1%—EBV/JCV co-infection. We did not detect BKV or a single JCV infection. In the EBV single infection group, most patients were classified as intermediate/high risk; a higher level of anti-EBV antibodies and EBV load were found compared to EBV/JCV co-infection and a more advanced clinical stage. Does JCV only “reside” in prostate cells or is it a co-factor in EBV infection? In light of these studies, there is a need to clarify the role of JCV virus in the development and/or progression of prostate cancer.

Background/Objectives: Recently, many researchers have evaluated various viruses, including polyomaviruses (JCV, BKV) and EBV, as potential factors playing a role in the development and/or progression of prostate cancer (PCa), one of the most common cancers in men. Therefore, we aimed to assess the frequency of the JCPyV DNA in tissue collected from PCa patients. Methods: We detected the presence of viral DNA (PCR) in 49.6% of clinical samples, including 71.9% with single EBV infection and 28.1% with EBV/JCV co-infection. We did not detect BKV or a single JCV infection. Therefore, we compared patients with EBV mono-infection with EBV/JCV co-infected patients in the context of risk group, Gleason score, and TNM classification. Results: Our results showed differences in clinicopathological features between single EBV infection and EBV/JCV co-infection. In the group of patients with single EBV infection, most patients were classified as medium/high risk, while in the group with EBV/JCV co-infection, most patients were classified as low risk. Conclusions: Among patients with single EBV infection, a more advanced stage of cancer was observed than in EBV/JCV co-infection. Moreover, the level of anti-EBVCA and anti-EBNA antibodies as well as EBV load was higher in the case of single infection compared to EBV/JCV co-infection. Higher antibody levels were detected in more advanced tumor stages in single EBV infection. Does JCV only “reside” in prostate cells or is it a co-factor in EBV infection? In light of these studies, there is a need to clarify the role of JCV virus in the development and/or progression of prostate cancer.