Induction of papillary ependymomas and insulinomas in the Syrian golden hamster by BK virus, a human papovavirus.

Newborn hamsters were inoculated intracerebrally with BK virus. Between 3 and 6 months after inoculation, they developed papillary ependymoma (8 hamsters, 42%) or functional malignant islet cell tumors of the pancreas (insulinoma, 8 hamsters), or both (1 hamster). Both tumors contained an antigen reactive to SV40 T-antibody, suggesting that at least a part of BK virus genomen has been integrated into the tumor cells. No infectious virus was detected in the extract of these tumors.