BACKGROUND: High-throughput gene expression profiling has recently shown that the mRNA for alpha-methylacyl CoA racemase (AMACR or P504S) is overexpressed in prostate carcinomas (PCa). Several immunohistochemical studies have reported the usefulness of anti-AMACR/P504S for detecting prostate cancer over the full range of prostate specimens encountered in surgical pathology. We tested real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for specific and sensitive detection of AMACR transcripts as a supplementary measure for discriminating between malignant and benign lesions in prostatic tissues. METHODS: Total RNA was isolated from snap-frozen chips in 55 cases of benign prostatic hyperplasia (BPH) and from frozen sections in 57 prostatectomy cases. The latter were analyzed by an uropathologist (J.K.) and found to contain at least 50% malignant epithelia. Relative quantification of AMACR transcripts was performed by RT-PCR using hybridization probes for detection and PBGD for normalization. RESULTS: Normalized AMACR transcript levels showed an average 3.75-fold increase in 57 prostate carcinomas cases when compared to 55 cases of BPH (p
