Mirella Marino1, Federica Ganci2, Teresa Bellissimo3, Etleva Korita2, Andrea Sacconi2, Federica Mori4, Enzo Gallo1, Annamaria Cambria5, Emanuele Russo6, Marco Anile6, Domenico Vitolo7, Edoardo Pescarmona1, Rosario Blandino8, Francesco Facciolo9, Federico Venuta6, Giovanni Blandino2, Francesco Fazi10
1Pathology, Regina Elena National Cancer Institute, Rome, Italy; 2Translational Oncogenomics Unit, Regina Elena National Cancer Institute, Rome, Italy; 3Section of Histology And Medical Embriology, Dahfmo, “Sapienza” University of Rome, Rome, Italy; 4Molecular Chemoprevention Unit, Regina Elena National Cancer Institute, Rome, Italy; 5Department of Oncology, Division Of Pathology, S. Vincenzo Hospital, Taormina, Italy; 6Department of Thoracic Surgery, Azienda Policlinico Umberto I, Sapienza University of Rome, Rome, Italy; 7Pathology, Azienda Policlinico Umberto I, “Sapienza” University of Rome, Rome, Italy; 8Department of Oncology, Division Of Oncological Surgery, S. Vincenzo Hospital, Taormina, Italy; 9Thoracic Surgery, Regina Elena National Cancer Institute, Rome, Italy; 10Department of Medico-Surgical Sciences And Biotechnologies, “Sapienza” University of Rome, Latina, Italy
Abstract: Thymic epithelial tumors (TET) are the most frequent human primary mediastinal tumors. For invasive and/or relapsing cases no effective treatment regimens have been definied, as relevant pathways are still not known. A biological characterization of the relevant molecules related to the pathogenesis and progression of neoplastic tissue in TET is strongly needed. MicroRNAs (miRNAs) constitute a large group of negative gene regulators playing an important role in carcinogenesis in several tumor systems. Mature miRNAs are single-stranded RNA molecules of 20- to 23-nucleotide (nt) length controlling gene expression in many cellular processes. We recently identified a group of mature miRNAs differentially expressed in tumor versus normal thymic tissues by microarray analysis of 54 formalin-fixed paraffin embedded (FFPE) thymic tumors and 12 normal counterparts. In particular, we found 56 miRNAs that were up-regulated and 31 down-regulated in thymic tumors. We found that a subgroup of these miRNAs was also differentially expressed among the different tumor histotypes. Finally, by bioinformatics analysis we identified molecular pathways whose members are putatively targeted by TET-associated miRNAs and that could impact on TET biology. We performed an Affimetrix-based study on a series of fresh frozen thymoma and normal thymic samples from our series. A deeper characterization of the identified pathways involved in TET carcinogenesis by the identification of the key molecular interactions is in progress. Our preliminary data support a key regulator role of mature miRNA in TET.
Keywords: MicroRNA (miRNA); thymoma; thymic carcinoma; thymic epithelial tumors (TET)
doi: 10.3978/j.issn.2072-1439.2015.AB057
