The overexpression of microRNA 21 correlates with biochemical recurrence after radical prostatectomy. Homo sapiens

The objective of this study was to utilize a microarray platform to determine the microRNA (miRNA) expression profile in prostate cancer tissue from patients who underwent radical prostatectomy and were followed for an average of 47 months. The GeneChip® miRNA Array (Affymetrix) contains more than 46,000 probes, and more than 1,100 mature human miRNAs and transcripts. An expression level higher or lower than 1.1 with a p0.2 ng/mL) revealed that 14 miRNAs were down-regulated and 17 were up-regulated. Considering the three prognostic factors and biochemical recurrence, miR-335 was overexpressed in pT3 tumors in patients with PSA>10 ng/mL, miR-1202 was overexpressed in recurrent tumors in which PSA >10 ng/mL, and miR-885 and miR-1226 were overexpressed in recurrent pT3 tumors. Six miRNAs (miR- 361, 378, 548, 574, 652 and 892) had decreased expression in pT3 tumors in patients with PSA >10 ng/mL. miR-16 was down-regulated in recurrent pT3 tumors. miR-92 and miR-450 exhibited decreased expression in recurrent tumors in patients with PSA > 10 ng/mL. miR-28 was down-regulated in pT3 adenocarcinomas with a GS ≥ 7. The differentially expressed miRNAs in recurrent tumors were validated using qRT-PCR in 74 additional specimens. miR-21 was overexpressed in recurrent tumors, and in the Cox model, expression levels higher than 0.64 were indicative of biochemical recurrence with a risk of 2.4. These results, which were based on clinical specimens from patients treated in a standardized way and followed for an average of 47 months, provide an initial understanding of the role of miRNAs in prostatecancer progression; the foremost representative is miR-21, which has been implicated in the progression of various human cancers. Overall design: Fifty-three patients underwent a radical prostatectomy performed by the same surgeon (MS) to treat localized PC between August 2000 and June 2002. The mean age was 65 years (SD: 7.5, range: 49 - 77). The mean Gleason score was 7 (SD: 1.1, range: 5 - 10); 15 tumors had a score of 5 or 6, and 38 had a score between 7 and 10. Twenty-four (45.3%) of the patients had pT2 tumors, and 29 (54.7%) had pT3 tumors. The control group consisted of three patients with lower urinary tract symptoms, a mean age of 55.3 years and a diagnosis of benign prostatic hyperplasia (BPH) who consented to open surgery.