Presence of JC Polyomavirus in Non-Neoplastic Inflamed Colon Mucosa, Primary and Metastatic Colorectal Cancer: An Experience from Iran

Introduction: Colorectal cancer is one of the frequent human malignant neoplasms and is a major cause of mortality in Iran and throughout the world. Hence, the aim of the present study is to evaluate the JCPyV LTAg oncogene quantitative level in cancerous and non-cancerous colorectal samples.Methods: In this case-control study, a total of 223 formalin-fixed paraffin-embedded (FFPE) samples were examined.The aforementioned samples were obtained from the pathology department of Ayatollah Rouhani hospital. Five μm thick tissue sections were deparaffinized and deproteinized according to a standard protocol and then DNA was isolated from each tissue sample. Evaluation of JCPyV LTAg oncogene copy number in the cancerous and non-cancerous samples was carried out by absolute quantitative Real-Time PCR as a viral copy number per cell.Results: In total, 38 out of 223 samples (17%) were positive for JCPyV LT-Ag DNA. Although, JCPyV infection was higher in case group (18.6%) compared with noncancerous controls (15.5%), however there was no significant association between JCPyV positivity and assigning in case and control groups. Regarding the tumor origin, 2 samples with metastatic colon cancer diagnosis (from lung and liver) were JCPyV positive. The genome of the JCPyV was not detected in primary colon cancer specimens of these two metastatic samples. The median copy number of JCPyV LTAg DNA per cell in cases (0.64) was more than controls (0.13). There was no significant difference between cases and controls regarding median JCPyV LTAg DNA per cell (P=0.059). The median copy number of JCPyV LTAg DNA per cell in metastatic colon cancer samples was considerably higher than the other groups.Conclusion: The results of the present study showed that JCPyV infection can be detected with almost identical percentages in the cancerous and non-cancerous colorectal samples. The quantitative level of JCPyV LT-Ag oncogene was higher in cancerous samples (especially metastatic colon cancer) than non-cancerous ones. The findings of the present study should be interpreted with caution due to the lack of viral detection in primary colon cancer specimens associated with two JCPyV positive metastatic samples.

کلیدواژه ها:

Colorectal cancer ، JC human polyomavirus virus ، LT-Ag ، Real-Time ، PCR