ABSTRACT
BACKGROUND: In the current study, we explore the feasibility of detecting exfoliated prostate cancer cells in urine using an RNA in situ hybridization (RISH) assay. We hypothesized that robust and specific labeling of prostate cancer cells could be achieved in post-digital rectal examination (DRE) urine samples using RISH. METHODS: We focused on method development, optimization, and analytical evaluation of RISH-based detection of prostate cancer in urine. We optimized a sample collection, processing, and target detection workflow for urine cytology specimens in conjunction with RNA target detection by RISH. We screened a panel of 11 prostate-specific RNA targets, and selected NKX3-1 and PRAC1 as markers for cells of prostate origin and PCA3 as a marker of prostate malignancy. Following analytical validation of a multiplexed NKX3-1/PRAC1/PCA3 assay, we evaluated whether prostate cancer cells can be detected in a pilot cohort of 19 post-DRE specimens obtained from men diagnosed with prostate cancer. RESULTS: Using cytology specimens prepared from spiked urine samples, we established the analytical validity of the RISH assay for detection and visualization of prostate cells in urine. Cells of prostate origin could be readily and specifically identified and separated into benign and malignant cell populations based on the multiplex test that consisted of markers specific for prostate cells (NKX3-1, PRAC1) and prostate cancer cells (PCA3). Upon evaluation of post-DRE urine from a pilot cohort of prostate cancer patients, we identified 11 samples in which prostate cells were present, 6 of which were also positive for prostate cancer cells. CONCLUSIONS: Multiplex RISH enables the direct visualization and molecular characterization of individual exfoliated prostate cells in urine. This proof-of-principle study provides evidence supporting the application of RISH as a potential noninvasive tool for prostate cancer detection.
Subject(s)
Antigens, Neoplasm/genetics , In Situ Hybridization/methods , Prostatic Neoplasms/urine , RNA, Neoplasm/analysis , Antigens, Neoplasm/urine , Biomarkers, Tumor/genetics , Biomarkers, Tumor/urine , Humans , Male , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , RNA, Neoplasm/urine , Tumor Cells, CulturedABSTRACT
In the current era of individualized medicine, a biorepository of human samples is essential to support clinical and translational research. There have been limited efforts in this arena within the field of urology, as cost, logistical and ethical issues represent significant deterrents to biobanking. The Johns Hopkins Brady Urological Institute Biorepository was founded in 1994 as a resource to facilitate discovery. Since its inception, the biorepository has enabled numerous research endeavours including pivotal trials leading to the regulatory approval of four diagnostic tests for prostate cancer. In the present review, we discuss the current state of biobanking within urology, outline the specific ethical and financial challenges to biobanking as well as solutions, and describe the operations of a successful urological biorepository.
