DETECTION OF POLYOMAVIRAL DNA-SEQUENCES IN NORMAL AND ADENOMATOUS HUMAN PITUITARY TISSUES USING THE POLYMERASE CHAIN-REACTION

Background. Tumor viruses are known to have a role in the pathogenesis of many types of benign and malignant human tumors. The possible role s of these viruses in the development of human pituitary tumors have n ot been investigated. Methods. The polymerase chain reaction was used to screen human pituitary tumors for human papillomaviral (HPV) and Po lyomaviral DNA sequences. Sets of consensus primers, which are capable of amplifying HPV Types 16, 18, and 33 and polyomavirus BK, JC, and S V40, were used in these experiments. Results. Amplification products w ere not detected using HPV consensus primers in 30 tumors. Twenty-six of 30 tumors demonstrated an amplification product with polyomaviral p rimers that hybridized to SV40 and BK internal probes and was confirme d to be SV40 in one tumor by direct sequencing. Ten normal postmortem pituitary samples then were examined similarly with Polyomaviral conse nsus primers; 8 of 10 normal samples demonstrated a similar amplificat ion product that also hybridized with SV40 and BK internal probes by S outhern blotting. Polyomaviral DNA sequences in normal and tumor sampl es were not present at levels detectable by genomic Southern blotting. Expressed viral protein (large T antigen) was not demonstrated in pos itive samples by Western blot analysis. Conclusions. These findings, t hat polyomaviral DNA sequences are detectable at low levels in certain normal tissues, are in agreement with those of other groups and, to t he authors' knowledge, serve as the first report of polyomaviral laten cy in human pituitary tissue. A role for polyomaviruses in pituitary t umorigenesis could not be established in this analysis.