Human polyomavirus JCV linked to colon cancer.

2003 FEB 4 - (NewsRx.com & NewsRx.net) -- Polyomavirus infections could promote colon cancer, researchers in the United States argue.

"Infection of the gastrointestinal tract by the human polyomavirus, JCV, which has been frequently detected in raw urban sewage, can occur via intake of contaminated water and food," according to S. Enam and coauthors, Temple University. "In light of earlier reports on the tumorigenecity of JCV, we investigated the presence of the JCV genome and the expression of viral proteins in a collection of 27 well-characterized epithelial malignant tumors of the large intestine."

Enam coworkers found the "viral early genome in 22 of 27 samples. Expression of the viral oncogenic early protein, T-antigen, and the late auxiliary protein, agnoprotein, was observed in more than 50% of the samples," they reported. "The absence of the viral capsid protein in the tumor cells excludes productive replication of the virus in neoplastic cells."

"Laser capture microdissection confirmed the presence of the JCV genome and expression of T-antigen in precancerous villous adenomas and regions of invasive adenocarcinoma," according to study data. "The ability of JCV T-antigen to interact with beta-catenin and the nuclear detection of beta-catenin in T-antigen-positive cells suggests dysregulation of the Wnt pathway in the tumor cells."

"The coproduction of T-antigen and beta-catenin in colon cancer cells enhanced transcription of the c-myc promoter, the downstream target of beta-catenin," the researchers added.

"These observations provide evidence for a possible association of JCV with colon cancer," Enam and colleagues concluded, "and suggest a novel regulatory role for T-antigen in the deregulation of the Wnt signaling pathway through beta-catenin in tumors of the gastrointestinal tract."

Enam coworkers published their study in Cancer Research (Association of human polyomavirus JCV with colon cancer: Evidence for interaction of viral T-antigen and beta-catenin. Cancer Res, 2002;62(23):7093-7101).

The contact person for this report is K. Khalili, Temple University, College of Science and Technology, Center for Neurovirology and Cancer Biology, 1900 N. 12th St., 015-96, Room 203, Philadelphia, PA 19122, USA.

To subscribe to the journal Cancer Research, contact the publisher: American Association for Cancer Research, P. O. Box 11806, Birmingham, AL 35202, USA.

The information in this article comes under the major subject areas of Gastroenterology, Infectious Disease, and Oncology.

This article was prepared by Cancer Weekly editors from staff and other reports.