Sarcoma histiocítico: análise molecular pela técnica de hibridação genômica comparativa, microRNA e imunoistoquímica

• Ano de defesa: 2015
• Autor(a) principal: Herbst, Thiago Eugenio Gouveia [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Sarcoma histiocítico; Linfoma; Imunohistoquímica; Expressão gênica; Morfologia; Lymphomas
• Link de acesso: http://hdl.handle.net/11449/132609; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/18-12-2015/000855647.pdf

Histiocytic sarcoma (HS) is a malignant neoplasm characterized by the proliferation of large cells that have morphological and immunophenotypic features similar to mature tissue histiocytes. It is a rare neoplasm, accounting for less than 1% of non-Hodgkin lymphomas. This rarity is partly explained by the difficulties in its diagnostic and morphological characterization, since it is confused with other pleomorphic malignant neoplasms. The objectives of this study were to evaluate changes in genomic gains and losses using the comparative genomic hybridization technique (CGH-array), microRNA profile (miRNA) evaluation, determine the principal morphological criteria and immunohistochemical markers (IMH) that could define this entity, and identify entities that can mistakenly lead to underdiagnosis. To achieve this, 7,600 pathology reports were reviewed and, of these, 47 possible cases of HS with nodal presentation were selected. Four cases with an established diagnosis of HS were also included in the analysis. Twelve morphological criteria and 5 IMH markers were evaluated. Among the 47 cases, 7 cases of HS were identified that had initially been diagnosed as undifferentiated metastatic neoplasm (undifferentiated carcinoma) or metastatic melanoma. The IMH markers that were most efficient for complementary diagnosis were CD163 and CD68. Evaluation of the profiles of 377 miRNAs showed clustering of 51 miRNA compared with the control; 44 were hypoexpressed and 7 were hyperexpressed and the most relevant were: miR-486-5p, miR-92a, miR-15b-5p (hyporegulated); and miR-10b-5p, miR-455-5p and miR-19 (hyperexpressed). These miRNA are involved in apoptosis, cell growth and proliferation pathways. The main genes involved in pathogenesis and candidates for validation in future studies are: ERBB2, TGFB1, TNF (activated); and TP53 and PD98059 (inhibited). These genes may represent future therapeutic targets. The CGH-array proved to be unfeasible in ...