Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters











Database
Language
Publication year range
1.
Oncol Rep ; 43(4): 1199-1207, 2020 04.
Article in English | MEDLINE | ID: mdl-32323788

ABSTRACT

Ewing sarcoma (ES) is a primary bone marrow tumor that very rarely develops in extra­osseous tissues, such as lung. The hallmark of ES tumors is a translocation between chromosomes 11 and 22, resulting in a fusion protein, commonly referred to as EWS­FLI1. The epigenetic profile (histone acetylation and methylation enrichment of the promoter region) that may regulate the expression of the aberrant transcription factor EWS­FLI1, remains poorly studied and understood. Knowledge of epigenetic patterns associated with covalent histone modification and expression of enzymes associated with this process, can contribute to the understanding of the molecular basis of the disease, as well as to the identification of possible molecular targets involved in expression of the EWS­FLI1 gene, so that therapeutic strategies may be improved in the future. In the present study, the transcriptional activation and repression of the EWS­FLI1 fusion gene in ES was accompanied by selective deposition of histone markers on its promoter. The EWS­FLI1 fusion gene was evaluated in two patients with ES using conventional cytogenetic, fluorescence in situ hybridization and nested PCR assays, which revealed that the aberrant expression of the EWS­FLI1 gene is accompanied by enrichment of H3K4Me3, H3K9ac and H3K27ac at the promoter region.


Subject(s)
Biomarkers, Tumor/genetics , Bone Neoplasms/pathology , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Oncogene Proteins, Fusion/genetics , Promoter Regions, Genetic , Proto-Oncogene Protein c-fli-1/genetics , RNA-Binding Protein EWS/genetics , Sarcoma, Ewing/pathology , Adult , Bone Neoplasms/genetics , Female , Histone Code , Humans , In Situ Hybridization, Fluorescence/methods , Male , Middle Aged , Sarcoma, Ewing/genetics , Translocation, Genetic , Young Adult
2.
Cancer Genet ; 230: 21-27, 2019 01.
Article in English | MEDLINE | ID: mdl-30470587

ABSTRACT

BACKGROUND: Overall survival of Ewing sarcoma (EWS) remains poor and less than 30% of patients with metastatic or recurrent disease survive despite current treatments. Thus, there is a constant search for new biomarkers for diagnosis, prognosis and prediction of therapy. Numerous studies have reported the abnormal expression of miR-708-5p in tumors of different origins. However, its role in EWS remains unclear. PROCEDURE: qRT-PCR was performed in nineteen consecutive EWS samples and twelve non-tumor bone samples from age-matched controls. Functional assays were performed in SK-ES-1 cells transfected with miR-708 lentiviral-based vectors and results analyzed in terms of clonogenicity, migration, invasion and western blot. RESULTS: We show that miR-708-5p is downregulated in EWS tissues though no associations with any prognostic features such as HUVOS grade, event or survival were found in our cohort. Nonetheless, expression levels of this micro-RNA were inversely associated with the presence of the EWS/FLI1 translocation. When miR-708-5p was transfected into the SK-ES-1 cell line, it did not affect migration or clonogenicity, but promoted a significant increase on the invasive potential of cells endorsed with high expression of MMP2. CONCLUSIONS: Taken together, our results suggest that despite downregulated in EWS samples, this miRNA might represent a secondary genetic alteration derived from the pleiotropic cellular effects of the abnormal EWS/FLI1 transcription factor that does not affect tumor growth but instead, is related with the promotion of tumor invasion, not being suitable for future therapeutic intervention.


Subject(s)
Bone Neoplasms/genetics , MicroRNAs/metabolism , Oncogene Proteins, Fusion/genetics , Proto-Oncogene Protein c-fli-1/genetics , RNA-Binding Protein EWS/genetics , Sarcoma, Ewing/genetics , Adolescent , Adult , Bone Neoplasms/mortality , Bone Neoplasms/pathology , Bone Neoplasms/surgery , Cell Line, Tumor , Child , Child, Preschool , Down-Regulation , Female , Follow-Up Studies , Gene Expression Regulation, Neoplastic , Humans , Male , Neoplasm Grading , Neoplasm Invasiveness/genetics , Prognosis , Sarcoma, Ewing/mortality , Sarcoma, Ewing/pathology , Sarcoma, Ewing/surgery , Survival Analysis , Young Adult
3.
Mol Neurobiol ; 55(9): 7242-7258, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29397557

ABSTRACT

There is an urgent need for advances in the treatment of Ewing sarcoma (EWS), an aggressive childhood tumor with possible neuroectodermal origin. Inhibition of histone deacetylases (HDAC) can revert aberrant epigenetic states and reduce growth in different experimental cancer types. Here, we investigated whether the potent HDAC inhibitor, sodium butyrate (NaB), has the ability to reprogram EWS cells towards a more differentiated state and affect their growth and survival. Exposure of two EWS cell lines to NaB resulted in rapid and potent inhibition of HDAC activity (1 h, IC50 1.5 mM) and a significant arrest of cell cycle progression (72 h, IC50 0.68-0.76 mM), marked by G0/G1 accumulation. Delayed cell proliferation and reduced colony formation ability were observed in EWS cells after long-term culture. NaB-induced effects included suppression of cell proliferation accompanied by reduced transcriptional expression of the EWS-FLI1 fusion oncogene, decreased expression of key survival and pluripotency-associated genes, and re-expression of the differentiation neuronal marker ßIII-tubulin. Finally, NaB reduced c-MYC levels and impaired survival in putative EWS cancer stem cells. Our findings support the use of HDAC inhibition as a strategy to impair cell growth and survival and to reprogram EWS tumors towards differentiation. These results are consistent with our previous studies indicating that HDis can inhibit the growth and modulate differentiation of cells from other types of childhood pediatric tumors possibly originating from neural stem cells.


Subject(s)
Cell Cycle Checkpoints/drug effects , Cell Differentiation/drug effects , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , Neurons/pathology , Sarcoma, Ewing/pathology , Butyric Acid/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cell Survival/genetics , Gene Expression Regulation, Neoplastic/drug effects , Humans , Neurons/drug effects , Neurons/metabolism , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Proto-Oncogene Protein c-fli-1/genetics , Proto-Oncogene Protein c-fli-1/metabolism , RNA-Binding Protein EWS/genetics , RNA-Binding Protein EWS/metabolism , Sarcoma, Ewing/genetics , Spheroids, Cellular/drug effects , Spheroids, Cellular/metabolism , Spheroids, Cellular/pathology , Transcription, Genetic/drug effects
4.
Blood ; 129(26): 3486-3494, 2017 06 29.
Article in English | MEDLINE | ID: mdl-28432223

ABSTRACT

Friend leukemia virus integration 1 (FLI1), a critical transcription factor (TF) during megakaryocyte differentiation, is among genes hemizygously deleted in Jacobsen syndrome, resulting in a macrothrombocytopenia termed Paris-Trousseau syndrome (PTSx). Recently, heterozygote human FLI1 mutations have been ascribed to cause thrombocytopenia. We studied induced-pluripotent stem cell (iPSC)-derived megakaryocytes (iMegs) to better understand these clinical disorders, beginning with iPSCs generated from a patient with PTSx and iPSCs from a control line with a targeted heterozygous FLI1 knockout (FLI1+/-). PTSx and FLI1+/- iMegs replicate many of the described megakaryocyte/platelet features, including a decrease in iMeg yield and fewer platelets released per iMeg. Platelets released in vivo from infusion of these iMegs had poor half-lives and functionality. We noted that the closely linked E26 transformation-specific proto-oncogene 1 (ETS1) is overexpressed in these FLI1-deficient iMegs, suggesting FLI1 negatively regulates ETS1 in megakaryopoiesis. Finally, we examined whether FLI1 overexpression would affect megakaryopoiesis and thrombopoiesis. We found increased yield of noninjured, in vitro iMeg yield and increased in vivo yield, half-life, and functionality of released platelets. These studies confirm FLI1 heterozygosity results in pleiotropic defects similar to those noted with other critical megakaryocyte-specific TFs; however, unlike those TFs, FLI1 overexpression improved yield and functionality.


Subject(s)
Jacobsen Distal 11q Deletion Syndrome/pathology , Megakaryocytes/cytology , Proto-Oncogene Protein c-fli-1/blood , Thrombopoiesis , Animals , Blood Platelets/metabolism , Cell Differentiation , Cell Line , Humans , Induced Pluripotent Stem Cells , Mice , Mice, SCID , Proto-Oncogene Mas
5.
Infect Genet Evol ; 49: 212-220, 2017 04.
Article in English | MEDLINE | ID: mdl-28119029

ABSTRACT

FLI1 (Friend leukemia virus integration 1) and IL6 (interleukin 6; IL-6) are associated with Leishmania braziliensis susceptibility. Cutaneous lesions show exaggerated matrix metalloproteinase 1 (MMP1). In other skin diseases, FLI1 promoter methylation reduces FLI1 expression, and low FLI1 down-regulates MMP1. IL-6 increases FLI1 expression. We hypothesized that epigenetic regulation of FLI1 in cutaneous leishmaniasis, together with IL-6, might determine MMP1 expression. While generally low (<10%), percent FLI1 promoter methylation was lower (P=0.001) in lesion biopsies than normal skin. Contrary to expectation, a strong positive correlation occurred between FLI1 methylation and gene expression in lesions (r=0.98, P=0.0005) and in IL-6-treated L. braziliensis-infected macrophages (r=0.99, P=0.0004). In silico analysis of the FLI1 promoter revealed co-occurring active H3K27ac and repressive DNA methylation marks to enhance gene expression. FLI1 expression was enhanced between 3 and 24hour post infection in untreated (P=0.0002) and IL-6-treated (P=0.028) macrophages. MMP1 was enhanced in lesion biopsies (P=0.0002), induced (P=0.007) in infected macrophages, but strongly inhibited by IL-6. No correlations occurred between FLI1 and MMP1 expression in lesions or infected macrophages (with/without IL-6). We conclude that MMP1 is regulated by factors other than FLI1, and that the influence of IL-6 on MMP1 was independent of its effect on FLI1.


Subject(s)
Epigenesis, Genetic , Host-Pathogen Interactions , Interleukin-6/genetics , Leishmaniasis, Cutaneous/genetics , Matrix Metalloproteinase 1/genetics , Proto-Oncogene Protein c-fli-1/genetics , Adolescent , Adult , Child , DNA Methylation , Female , Gene Expression Regulation , Histones/genetics , Histones/immunology , Humans , Interleukin-6/immunology , Leishmania braziliensis/pathogenicity , Leishmania braziliensis/physiology , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/pathology , Macrophages/immunology , Macrophages/pathology , Male , Matrix Metalloproteinase 1/immunology , Promoter Regions, Genetic , Proto-Oncogene Protein c-fli-1/immunology , Skin/immunology , Skin/pathology
6.
Genes Immun ; 12(7): 589-94, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21633373

ABSTRACT

Mapping murine genes controlling cutaneous leishmaniasis (CL) identified Fli1 as a candidate influencing resistance to L. major and enhanced wound healing. We examine FLI1 as a gene controlling CL and mucosal leishmaniasis (ML) caused by L. braziliensis in humans. Intron 1 single nucleotide polymorphisms tagging promoter and enhancer elements were analysed in 168 nuclear families (250 CL; 87 ML cases) and replicated in 157 families (402 CL; 39 ML cases). Robust case-pseudocontrol logistic regression analysis showed association between allele C (odds ratio (OR) 1.65; 95% confidence interval 1.18-2.29; P=0.003) of FLI1_rs7930515 and CL in the primary sample that was confirmed (OR 1.60; 95% confidence interval 1.10-2.33; P=0.014) in the replication set (combined P=1.8 × 10(-4)). FLI1_rs7930515 is in linkage disequilibrium with the functional GAn microsatellite in the proximal promoter. Haplotype associations extended across the enhancer, which was not polymorphic. ML associated with inverse haplotypes compared with CL. Wound healing is therefore important in CL, providing potential for therapies modulating FLI1.


Subject(s)
Genetic Predisposition to Disease , Leishmaniasis, Cutaneous/genetics , Polymorphism, Single Nucleotide , Proto-Oncogene Protein c-fli-1/genetics , Alleles , Brazil , Gene Frequency , Haplotypes , Humans , Introns , Racial Groups/genetics
7.
Pediatr Pathol Mol Med ; 22(5): 391-8, 2003.
Article in English | MEDLINE | ID: mdl-14692190

ABSTRACT

We report the clinical, histologic, immunohistochemical, and molecular findings of a Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) localized to the rectum in a 17-year-old boy. Notably the 4.5 x 4 x 4-cm sessile mass was spontaneously eliminated through the anus, producing an episode of hemorrhagic shock. Histologically the tumor presented as a proliferation of membrane CD99-positive, small round cells. EWS/FLI1 chimeric mRNA was demonstrated by nested reverse-transcription polymerase chain reaction (RT-PCR) analysis in the tumor tissue. The patient is alive and well 2 years after initial symptoms. We also review reported cases of ES/PNET of the digestive system.


Subject(s)
Neuroectodermal Tumors, Primitive, Peripheral/pathology , Rectal Neoplasms/pathology , Sarcoma, Ewing/pathology , 12E7 Antigen , Adolescent , Antigens, CD/metabolism , Biomarkers, Tumor , Cell Adhesion Molecules/metabolism , DNA-Binding Proteins/metabolism , Humans , Male , Neuroectodermal Tumors, Primitive, Peripheral/diagnosis , Neuroectodermal Tumors, Primitive, Peripheral/genetics , Neuroectodermal Tumors, Primitive, Peripheral/metabolism , Proto-Oncogene Protein c-fli-1 , Rectal Neoplasms/diagnosis , Rectal Neoplasms/genetics , Rectal Neoplasms/metabolism , Sarcoma, Ewing/diagnosis , Sarcoma, Ewing/genetics , Sarcoma, Ewing/metabolism , Trans-Activators/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL