Download PCA3 and miR-16 Molecular Urine Tests: a Potential Use in the

PCA3 and miR-16 Molecular Urine Tests: A Potential Use in the Prostate Cancer
Diagnosis
Introduction and Objectives: The use of the serum prostate-specific antigen (PSA) test for
prostate cancer (PCa) screening is limited due to its inaccuracy. Prostate cancer gene 3
(PCA3) encodes a prostate-specific mRNA with a median 66-fold up-regulation in malignant
prostate lesions compared to adjacent benign tissue. After normalization with PSA whose
expression is similar in cancerous and benign cells, PCA3 expression has been shown to be
useful for PCa diagnosis. The aim of this study is to develop a urine quantitative PCA3-based
test and to assess diagnostic values of miRNAs (miR-16).
Materials and Methods: This is a prospective single center clinical study of 163 patients who
underwent transrectal ultrasound guided prostate biopsy (TRUSBP) at out institute.
Indications of TRUSBP were elevated PSA and/or suspicious digital rectal examination
(DRE). PCA3 scores were assessed from first-catch urine collected after DRE before biopsy.
Total RNA was isolated with Trizol, amplified, and quantified by a real-time PCR. PSA mRNA
was used to normalize PCA3 expression and confirm the yield of prostate-specific RNA.
PCA3 score was calculated by one thousand times of PCA3/PSA mRNA ratio. Receiver
Operating Characteristic (ROC) curve analysis was applied to evaluate performance of PCA3
assay and miRNA assay according to prostate biopsy results.
Results: PCA3 scores were obtained from 134 out of 163 collected urine samples. Using inhouse PCA3 (miR16) values of 400, 1500, 8000 and 25000 in detection of prostate cancer
has a sensitivity of 95%, 78%, 43% and 21% respectively; and specificity of 20%, 44%, 67%
and 95%, respectively. The area under the curve (AUC) for in- house PCA3 test was 0.678
(95% CI, 0.556-0.791; p value 0.02) while that of commercially available PCA3 test was 0.636
(95% CI, 0.511-0.760; p value 0.05).
Conclusion: The established PCA3 assay combines simple specimen processing with
precise assays and can add specificity to the current PCa diagnosis. Compared to the
commercial kit, it provides equivalently useful information and competitive accuracy in a costefficient and easy-available way. miR-16 could be used as a feasible biomarker for PCa
screening.