title: MiR-187 Targets the Androgen-Regulated Gene ALDH1A3 in Prostate Cancer.
abstract: miRNAs are predicted to control the activity of approximately 60% of all protein-coding genes participating in the regulation of several cellular processes and diseases, including cancer. Recently, we have demonstrated that miR-187 is significantly downregulated in prostate cancer (PCa) and here we propose a proteomic approach to identify its potential targets. For this purpose, PC-3 cells were transiently transfected with miR-187 precursor and miRNA mimic negative control. Proteins were analyzed by a two-dimensional difference gel electrophoresis (2D-DIGE) and defined as differentially regulated if the observed fold change was ±1.06. Then, MALDI-TOF MS analysis was performed after protein digestion and low abundance proteins were identified by LC-MS/MS. Peptides were identified by searching against the Expasy SWISS PROT database, and target validation was performed both in vitro by western blot and qRT-PCR and in clinical samples by qRT-PCR, immunohistochemistry and ELISA. DIGE analysis showed 9 differentially expressed spots (p<0.05) and 7 showed a down-regulated expression upon miR-187 re-introduction. Among these targets we identified aldehyde dehydrogenase 1A3 (ALDH1A3). ALDH1A3 expression was significantly downregulated in PC3, LNCaP and DU-145 cells after miR-187 re-introduction. Supporting these data, the expression of ALDH1A3 was found significantly (p<0.0001) up-regulated in PCa samples and inversely correlated (p<0.0001) with miR-187 expression, its expression being directly associated with Gleason score (p = 0.05). The expression of ALDH1A3 was measured in urine samples to evaluate the predictive capability of this biomarker for the presence of PCa and, at a signification level of 10%, PSA and also ALDH1A3 were significantly associated with a positive biopsy of PCa. In conclusion, our data illustrate for the first time the role of ALDH1A3 as a miR-187 target in PCa and provide insights in the utility of using this protein as a new biomarker for PCa.
authors.affiliation: Laboratory of Molecular Biology, Fundación Instituto Valenciano de Oncología, Valencia, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Casanova-Salas
authors.affiliation: Polymer Therapeutics Laboratory, Centro de Investigación Príncipe Felipe, Valencia, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Masiá
authors.affiliation: Polymer Therapeutics Laboratory, Centro de Investigación Príncipe Felipe, Valencia, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Armiñán
authors.affiliation: Department of Pathology, Fundación Instituto Valenciano de Oncología, Valencia, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Calatrava
authors.affiliation: Laboratory of Experimental Oncology, Istituto Ortopedico Rizzoli, Bologna, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Mancarella
authors.affiliation: Department of Urology, Fundación Instituto Valenciano de Oncología, Valencia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Rubio-Briones
authors.affiliation: Laboratory of Experimental Oncology, Istituto Ortopedico Rizzoli, Bologna, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Scotlandi
authors.affiliation: Polymer Therapeutics Laboratory, Centro de Investigación Príncipe Felipe, Valencia, Spain.
authors.forename: Maria Jesús
authors.initials: MJ
authors.lastname: Vicent
authors.affiliation: Laboratory of Molecular Biology, Fundación Instituto Valenciano de Oncología, Valencia, Spain.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: López-Guerrero
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000652:urine; D045744:Cell Line, Tumor; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000502:physiology*; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics*; D034622:RNA Interference
chemical_list: D014408:Biomarkers, Tumor; C571843:MIRN187 microRNA, human; D035683:MicroRNAs; D000445:Aldehyde Oxidoreductases; C018699:aldehyde dehydrogenase (NAD(P)+)