Assessment and biological significance of JC polyomavirus in colorectal cancer in Tunisia.

PURPOSE Several reports have indicated the presence of JC polyomavirus (JCV) in many human tumors, including colorectal cancers (CRCs). The presence of JCV infection in CRC patients has not been investigated in African countries. METHODS We examined the prevalence and the biological significance of JCV in Tunisian CRC patients. The presence of JCV was assessed by polymerase chain reaction (PCR) in a series of 105 CRCs and 89 paired non-tumor colonic mucosa samples from Tunisian patients. Results were correlated with the clinicopathological features and immunohistochemical expression of β-catenin, p53, and the proliferation marker Ki-67. RESULTS JCV DNA was detected in 58.1% (61/105) of CRC and in only 14.6% (13/89) of paired non tumor colonic mucosa samples (p=0.03). The presence of JCV was significantly correlated with tumor differentiation (p=0.03). Moreover, JCV presence was significantly correlated with nuclear accumulation of β-catenin (p=0.008) and p53 accumulation (p=0.0001). Multivariate logistic regression analysis showed that tumor differentiation, β-catenin and p53 accumulation were independent parameters significantly associated with the presence of JCV in CRC (p=0.04; p=0.05; p=0.001, respectively). CONCLUSION We support a role of JCV in colorectal carcinogenesis in Tunisian patients, especially of well differentiated morphology.