However, it is now appreciated that they play a significant function in gene regulation. This study investigated the expression levels of candidate miRNAs in CaP, evaluating their relationship to the expression of AMACR, EZH2 and PSMA (which are known to be overexpressed in CaP). They used prediction programs to search for miRNAs that are putative regulators of CaP associated genes. They selected miR138, miR224, and miR186 for analysis by quantitative PCR using 50 malignant and matched non-malignant tissue samples from radical prostatectomies. For controls, 30 samples of BPH tissue were used. They used previous data from the same patients for expression of the respective CaP associated genes.
The expression of miR138, miR224 and miR186 in CaP tissue samples was significantly decreased compared to matched non-malignant tissue (median -3.45 to -5.61 fold) and to BPH tissue (median -2.70 to -5.49 fold). The upregulation of the CaP associated genes correlated significantly with the downregulation of the predicted miRNA. Spearman correlation coefficient between AMACR and miR224 was -0.385 (p <0.01), -0.215 between EZH2 and miR138 (p <0.05), and -0.418 between PSMA and miR186 (p <0.01), respectively. For miR186, a significant difference between organ confined and non-organ confined CaP was observed. No significant associations between the differential miRNA expression and Gleason score were found.
Presented by Kati Erdmann, et al. at the 26th Annual European Association of Urology (EAU) Congress - March 18 - 21, 2011 - Austria Centre Vienna, Vienna, Austria