PGC and PSMA in prostate cancer diagnosis: tissue analysis from biopsy samples.

PURPOSE The discovery of new diagnostic tools for the diagnosis of prostate cancer (PCa) has become an important field of research. In this study, we analyzed the diagnostic value of the expression of the pepsinogen C (PGC) and prostate-specific membrane antigen (PSMA) genes in tissue samples obtained from prostate biopsies. MATERIALS AND METHODS This study was comprised of 51 consecutive patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsies between January 2010 and March 2010. The biopsies were performed with 12 cores, and an additional core was randomly retrieved from the peripheral zone from each patient for study purposes. The expression of the PGC and PSMA genes was analyzed from the cDNA from the samples via the qRT-PCR technology. The expression patterns of patients with PCa were compared with those of patients without a PCa diagnosis. RESULTS PSMA was overexpressed in only 43.4% of PCa cases, and PGC was overexpressed in 72.7% of cases. The median expression of PSMA was 1.5 times (0.1 to 43.9) and the median PGC expression was 8.7 times (0.1 to 50.0) the expression observed in prostatic tissue from TRUS-guided biopsies of normal patients. Analysis of patients with high-risk PCa indicated that PGC was overexpressed in 71.4% of cases (with a median expression of 10.6 times), and PSMA was overexpressed in only 35.7% of cases (with a median expression of 4.5 times). Among patients with low-risk PCa, PGC was also overexpressed in 71.4% of cases (with a median expression of 5.9 times), and PSMA was overexpressed in only 42.8% of cases (with a median expression of 2.5 times). CONCLUSIONS PGC gene expression is significantly higher in prostatic tissue in men affected by PCa when compared to normal prostates. Further analyses are necessary to confirm our results.