Detection of JC virus DNA sequences in brain tumors in pediatric patients

Object. The JC virus is a human neurotropic polyomavirus that causes progressive multifocal leukoencephalopathy and is closely related to simian virus 40. Several recent reports have indicated a possible association between the JC virus and the development of various human brain tumors. The authors examined the presence of JC virus DNA sequences in primary brain tumors in pediatric patients to evaluate the hypothesis that particular brain tumors can arise in the pediatric population as a consequence of infection with the JC virus. Methods. Genomic DNA sequences were isolated from 62 brain tumors (32 medulloblastomas, 18 ependymomas, five choroid plexus papillomas, and seven pilocytic astrocytomas) and analyzed for the presence of JC virus DNA by Southern blot hybridization and direct sequencing. The JC virus DNA sequence was detected in five ependymomas and one choroid plexus papilloma. Immunohistochemical studies revealed nuclear expression of the large T-antigen in a choroid plexus papilloma. None of the medulloblastomas or pilocytic astrocytomas contained JC virus DNA. Conclusions. The results of this study provide molecular evidence of the association between JC virus and the development of certain ependymomas and choroid plexus papillomas.