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A7102 - Pulmonary Ewing Sarcoma: A Cytogenetic and Molecular Approach
Author Block: A. Canas1, C. Montoya2, L. Rey2, I. Madariaga2, A. Herreño2, A. Ramirez2, D. Troncoso2, O. Moreno3, A. P. Rojas4, Semillero Epigenetica y Cancer de Pulmon-Pontificia Universidad Javeriana; 1DEPARTAMENTO MEDICINA INTERNA, PONTIFICIA UNIVERSIDAD JAVERIANA, Bogota, Colombia, 2PONTIFICIA UNIVERSIDAD JAVERIANA, BOGOTA, Colombia, 3Instituto Genetica Humana, PONTIFICIA UNIVERSIDAD JAVERIANA, BOGOTA, Colombia, 4Facukty of Medicine Instituto Genetica Humana, Pontificia Universidad Javeriana, Bogotá, Colombia.
Ewing sarcoma is a rare and highly malignant aggressive type of tumor that mainly attacks adolescents and young adults. It develops primarily in bone and less frequently in soft tissues, but can easily metastasize to other tissues such as lung and bone marrow. Its pathological condition is consequence of a translocation that results in the formation of a fusion gene. 90 % of Ewing sarcoma cases are characterized by the translocation between EWSR1 gene on chromosome 22 and FLI1 gene located on chromosome 11, resulting in the establishment of the fusion gene commonly known as EWS-FLI1. However, 9% of the cases have been found to be related with the EWS-ERG fusions. The aim of this study is to identify and analyze expression profiles of the EWS, FLI1, EWS-FLI1, FLI1-EWS, ROR1 genes in two patients presenting pulmonary Ewing sarcoma, given the low frequency of this extraosseous tumoral condition. For its realization, tumoral cells from both patients were cultured and then genetic analysis were carried out by standard PCR and cytogenetic studies by fluorescent in situ hybridization (FISH). Cytogenetic studies showed the presence of structural clonal alterations such as deletions in chromosomes 16, 20 and 22 (16q22 [4/100], 20q13.2 [5/100] and 22q13 [14/100]) in one of the patients studied. All these results were compared with samples from human Ewing Sarcoma A673 cell lines (ATCC).