The role of prostate specific membrane antigen and pepsinogen C tissue expression as an adjunctive method to prostate cancer diagnosis.
OBJECTIVE
The diagnosis of prostate cancer in men with persistently increased prostate specific antigen after a negative prostate biopsy has become a great challenge for urologists and pathologists. We analyzed the diagnostic value of 6 genes in the tissue of patients with prostate cancer.


METHODS
The study was comprised of 50 patients with localized disease who underwent radical prostatectomy. Gene selection was based on a previous microarray analysis. Among 4,147 genes with different expressions between 2 pools of patients 6 genes (PSMA, TMEFF2, GREB1, TH1L, IgH3 and PGC) were selected. These genes were tested for diagnostic value using the quantitative reverse transcription polymerase chain reaction method. Initially malignant tissue samples from 33 patients were analyzed and in the second part of the study we analyzed benign tissue samples from the other 17 patients with prostate cancer. The control group was comprised of tissue samples of patients with benign prostatic hyperplasia.


RESULTS
Analysis of malignant prostatic tissue demonstrated that prostate specific membrane antigen was over expressed (mean 9 times) and pepsinogen C was under expressed (mean 1.3 x 10(-4) times) in all cases compared to benign prostatic hyperplasia. The other 4 tested genes showed a variable expression pattern not allowing for differentiation between benign and malignant cases. When we tested these results in the benign prostate tissues from patients with cancer, pepsinogen C maintained the expression pattern. In terms of prostate specific membrane antigen, despite over expression in most cases (mean 12 times), 2 cases (12%) presented with under expression.


CONCLUSIONS
Pepsinogen C tissue expression may constitute a powerful adjunctive method to prostate biopsy in the diagnosis of prostate cancer cases.
Antunes
Alberto A
AA
Division of Urology, Laboratory of Medicine Investigation, University of Sao Paulo Medical School, São Paulo, Brazil. antunesuro@uol.com.br
Leite
Kátia R
KR
Sousa-Canavez
Juliana M
JM
Camara-Lopes
Luiz H
LH
Srougi
Miguel
M
D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D001707:Biopsy, Needle; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D020115:Pepsinogen C / Q000235:genetics / Q000378:metabolism*; D011336:Probability; D017430:Prostate-Specific Antigen / Q000235:genetics / Q000378:metabolism*; D011468:Prostatectomy / Q000379:methods; D011470:Prostatic Hyperplasia / Q000175:diagnosis / Q000235:genetics / Q000601:surgery; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000601:surgery; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D036761:Ultrasound, High-Intensity Focused, Transrectal
D014408:Biomarkers, Tumor; D012334:RNA, Neoplasm; D020115:Pepsinogen C; D017430:Prostate-Specific Antigen