AIm: Colorectal cancer (CRC) is a major cause of morbidity and
mortality worldwide. In 2008, CRC was ranked as the second most common
cancer among all newly diagnosed cancers in Jordan. It was recently
suggested that the JC virus (JCV) could be linked to the development of
CRC. However, this topic remains highly controversial. JCV is a common
human polyomavirus that first infects individuals during early
childhood. Infection with JCV can occur due to intake of contaminated
water and food. The vast majority of those infected have no symptoms;
however, severe immunosuppression can trigger reactivation of the virus.
The oncogenicity of JCV was suggested to be related to its large
T-antigen (T-Ag). This study aimed to investigate the incidence of JCV
in CRC tissue of patients from northern Jordan.
Materials & methods:
Paraffin-embedded tissues from cases previously diagnosed with CRC were
used. Immunohistochemistry and PCR techniques were used to detect the
presence of JCV.
Results: In total, 15.6% of CRC samples were
positive for JCV T-Ag protein, whereas none of the noncancer control
samples were positive. In total, 43.5% of CRC samples contained the JCV T-Ag gene compared with 16.7% within control samples. All CRC samples expressing the JCV T-Ag protein harbored the JCV T-Ag gene. However, not all samples that harbored the T-Ag gene expressed the T-Ag protein.
Conclusion:
Our results are consistent with recently published data and raise the
possibility of an association between JCV infection and CRC. These
findings deserve further investigation in larger-scale studies in order
to elucidate the possible molecular carcinogenesis pathways in
JCV-infected colorectal neoplasms.