JC virus DNA is present in the mucosa of the human colon and in colorectalcancers

JC virus (JCV) is a polyoma virus that commonly infects humans. We have fou nd T antigen DNA sequences of JCV in the mucosa of normal human colons, col orectal cancers, colorectal cancer xenografts raised in nude mice, and in t he human colon cancer cell line SW480. A larger number of viral copies is p resent in cancer cells than in non-neoplastic colon cells, and sequence mic roheterogeneity occurs within individual colonic mucosal specimens. The imp roved yield of detection after treatment with topoisomerase I suggests that the viral DNA is negatively supercoiled in the human tissues. These result s indicate that JCV DNA can be found in colonic tissues, which raises the p ossibility that this virus may play a role in the chromosomal instability o bserved in colorectal carcinogenesis.