Polyomavirus May Have Role in Prostate Cancer

Evidence has emerged suggesting human polyomavirus BK (BKV) is involved in maintaining and enhancing an environment suitable for prostate cancer growth.

The role the virus infection plays in cancers of the genitourinary tract could lead to preventive and or therapeutic prostate cancer vaccines as different immune responses against the virus' large tumor antigen have been found.

Scientists at the University of Zurich (Switzerland) examined 60 consecutive patients diagnosed for prostate cancer (PCa) and 50 with benign prostate hyperplasia (BPH), urinary obstructive symptoms, and acute urinary retention. The virus was detected in tissue specimen tissues excised during surgical procedures were formalin fixed and paraffin embedded. DNA was extracted from three sections randomly picked within the tumor area (PCa) or within the atrophic-hyperplastic gland (BPH) using a QIAamp DNA minikit (Qiagen; Basel, Switzerland).

BKV-specific antibody detection was performed by enzyme immunoassay (EIA) with a glutathione S-transferase (GST)-BKV fusion protein. The optical density at 492 nm was measured using an automated plate reader (Tecan Group, Ltd.; Männedorf, Switzerland). The scientists found a degree of different immune responses against the virus' large tumor antigen between seropositive patients with prostate cancers, those seropositive patients with benign prostatic hyperplasia and those without prostate abnormalities.

Maurizio Provanzano, MD, PhD, the senior investigator, said “There are three major reasons why polyomavirus BK might play a causal role in genitourinary tract cancers: the virus resides asymptomatically in the genitourinary tract of nearly 80% of young individuals; it is expressed in inflammatory lesions at very early stages of prostate cancer onset; and it binds and sequesters the tumor suppressor protein p53 in its wild-type form in the cytoplasm of infected cells.” He added that the strong association between the detection of the virus in prostate cancer and disease recurrence suggests that boosting their immune systems might protect virus-positive individuals. The study was published in the August 2012 issue of the Journal of Virology.

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University of Zurich
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Tecan Group, Ltd.