Abstract 3110: Urinary miR-1825 and miR-484: An oncogene and a tumor- suppressor gene among prostate cancer patients

Abstract MicroRNAs (miRNAs) are short, single-stranded RNA molecules with the ability of acting as post-transcriptional regulators of gene expression. MiRNAs regulate a number of important pathways, such as: cellular differentiation, proliferation, and apoptosis. MiRNA expression profiling patterns were demonstrated to have more potential than the common mRNA expression profiling for the characterization of poorly differentiated tumours. Studying miRNA expression profiles “signatures” will help in understanding the role of these miRNAs in the process of cancer development. The aim of this study was to profile the urinary miRNA expression signatures among prostate cancer patients in comparison to healthy male individuals. To identify the miRNA signatures specific for PCa, total RNA was isolated from 2.5mL of urine from all prostate cancer patients and from healthy males. RNA isolated from each group were pooled together and the differential expression analysis of miRNAs between the pooled samples was performed using MiRNA Microarray technology. Differential expression of two individual miRNAs, miR-1825 and miR-484, was observed between healthy males and prostate cancer patients. The relative expression of these two miRNAs were assessed among among the prostate cancer group and the healthy male group using RT-qPCR. MiR-1825 was up-regulated in seven out of eight PCa samples (88%), whereas miR-484 was down-regulated in six out of the eight PCa samples (75%). It has been found that the putative target for miR-1825 is member-1 of the Discoidin Domain family of Receptors (DDR1). The over-expression of DDR1 was reported to be a prognostic marker for the poor survival in several cancer types and therefore is proposed that miR-1825 might function as a tumor-suppressor by normally or in response to cancer, inhibiting DDR1's translation. As for miR-484, E3 ubiquitin-protein ligase (UBR5), which is thought to be involved with DNA repair, has been found to be the putative target for miR-484. It has be reported that the over-expression of a mutated version of UBR5 was found in breast and ovarian cancers where its deregulation was cited as a possible cause of malignant progression. It is therefore being proposed that miR-484 might function as a tumor- suppressor whereby its expression controls progression via the regulation of genes, such as UBR5, that have already been potentially associated with cancer progression. Citation Format: Moemen Abdalla, Taha A. Haj-Ahmad, Yousef Haj-Ahmad. Urinary miR-1825 and miR-484: An oncogene and a tumor- suppressor gene among prostate cancer patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3110. doi:10.1158/1538-7445.AM2015-3110