Merkel cell polyomavirus is not detected in prostate cancers, surrounding stroma, or benign prostate controls

Background: Merkel cell polyomavirus (MCV or MCPyV) is a recently discovered human polyomavirus that is implicated in the pathogenesis of Merkel cell carcinoma (MCC). Although the transmission route for MCV is not yet known, other polyomaviruses, such as BKV, cause non-malignant pathology in the urinary tract. Like MCC, prostate cancer predominantly affects the elderly. Furthermore, prostate cancers and premalignant precursors exhibit chronic inflammation, which suggests a possible infectious involvement. We therefore examined whether MCV might participate in the pathogenesis of prostate cancer. Objective: To determine the presence of MCV RNA in prostate cancer and surrounding stroma or normal prostate tissue. Study design: RNA was extracted from 28 patient-matched cancerous and 28 benign prostate epithelial samples, and six additional cancer-adjacent stromal samples. All tissues were laser-capture micro-dissected. DNA and RNA from a sequence-verified MCV-containing MCC tumor served as a positive control. Quantitative reverse-transcription PCR was used to assess the presence or absence of MCV T antigen transcript. Results: No MCV T antigen was detected in prostate carcinomas, patient-matched benign samples, or tumor-adjacent stroma, with appropriate sensitivity of the assay demonstrated by an MCC tumor. Conclusions: MCV infection appears unlikely to be a significant factor in prostate carcinogenesis and there is no evidence of the prostate serving as a reservoir for MCV. (C) 2008 Elsevier B.V. All rights reserved.