Circulating miRNAs as potential biomarkers for the early diagnosis of prostate cancer

.Prostate cancer (PCa) is the most common type of cancer and the third cause of death by cancer in Argentinian men. miRNAs are small non-coding RNA molecules that regulate gene expression. miRNAs can be secreted by tumor cells and circulate in the bloodstream. Our aim was to identify circulating miRNAs as candidate biomarkers for the diagnosis of PCa. GeneChip® miRNA 4.0 Arrays (Affymetrix) were hybridized with circulating RNA obtained from serum of PCa patients or healthy donors. Diagnosed PCa patients, free of treatment, were divided into subcategories according to Gleason grade. After data normalization, we identified a list of miRNAs (miR-4668-5p, miR 2277-5p, miR-3613-3p, miR-101-3p, miR-320e-5p, miR-6750- 5p, miR-548x-3p, miR-320a, miR-4532, miR-21-5p) that were increased in PCa patients serum compared to healthy donors. To validate these results, NSG mice were inoculated s.c. with PC3 or 22Rv1 PCa cell lines. After tumor growth, mice with tumors and a non-tumor mice group (control) were sacrificed. Blood and tumor samples were collected for RNA isolation. miRNA expression levels were assessed by stem-loop RT-qPCR. miR-4668-5p, miR 2277-5p, miR-3613-3p and miR-21-5p were significantly increased in the circulation of mice inoculated with PC3 cells compared to control. Also, miR-101-3p and miR-3613-3p were significantly upregulated in the plasma of mice that were inoculated with 22Rv1 compared to control. miR-2277-5p was not detected in the plasma of 22Rv1 injected mice. Interestingly, miR-101-3p was increased in circulation of 22Rv1 compared to PC3 injected mice, while miR-4668-5p was increased in plasma of PC3 compared to 22Rv1 injected mice. Additionally, miR-101- 3p was upregulated in 22Rv1 compared to PC3 xenografts. In summary, our work defines novel candidate biomarkers for PCa diagnosis based on circulating miRNAs from human serum samples. These biomarkers were also detected in xenografts and plasma from mice.Fil: Duca, Rocío Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Farré, Paula Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Graña, Karen Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Massillo, Cintia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Garcia, Nicolas. Ministerio de Defensa. Ejército Argentino. Hospital Militar Central Cirujano Mayor "Dr. Cosme Argerich"; ArgentinaFil: Dimase, Federico. Ministerio de Defensa. Ejército Argentino. Hospital Militar Central Cirujano Mayor "Dr. Cosme Argerich"; ArgentinaFil: Gandini, Norberto Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Dalton, Guillermo Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: de Siervi, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaReunión Anual de Sociedades de BiocienciaMar del PlataArgentinaSociedad Argentina de Investigación ClínicaAsociación Argentina de Farmacología ExperimentalSociedad Argentina de BiologíaSociedad Argentina de ProtozoologíaAsociación Argentina de NanomedicinasAsociación Argentina de Ciencia y Tecnología de Animales de LaboratorioThe Histochemical Societ