Presence and physical state of HPV DNA in prostate and urinary-tract tissues

Neoplastic and non-neoplastic tissues from the urinary tract and the prostate were analyzed for the presence of human papillomavirus (HPV) DNA. The analysis was performed by PCR using primers specific for HPV 6/11 and 16. HPV DNA was present in bladder, ureter, kidney and prostate, with percentages ranging between 46% and 87%. Benign and oncogenic HPV types were detected with similar frequencies both in non-neoplastic and in neoplastic biopsies, and HPV 16 was not preferentially associated with malignant lesions. In all instances, small amounts of HPV DNA were present in the tissues, suggesting the absence of productive infection. Analysis of the physical state of HPV DNA performed by 2-dimensional gel electrophoresis and Southern blot hybridization revealed that HPV 16 DNA harbored in the urinary tract can be integrated also in non-neoplastic tissues. The results indicate that HPV 16 does not seem to be associated with urinary-tract and prostate oncogenesis, but that these tissues may represent an important reservoir for the transmission of HPV types normally infecting the genital tract.