RESUMO
The Sin3A-associated proteins SAP30 and SAP30L share 70% sequence identity and are part of the multiprotein Sin3A corepressor complex. They participate in gene repression events by linking members of the complex and stabilizing interactions among the protein members as well as between proteins and DNA. While most organisms have both SAP30 and SAP30L, the zebrafish is exceptional because it only has SAP30L. Here we demonstrate that SAP30L is expressed ubiquitously in embryonic and adult zebrafish tissues. Knockdown of SAP30L using morpholino-mediated technology resulted in a morphant phenotype manifesting as cardiac insufficiency and defective hemoglobinization of red blood cells. A microarray analysis of gene expression in SAP30L morphant embryos revealed changes in the expression of genes involved in regulation of transcription, TGF-beta signaling, Wnt-family transcription factors, and nuclear genes encoding mitochondrial proteins. The expression of the heart-specific nkx2.5 gene was markedly down-regulated in SAP30L morphants, and the cardiac phenotype could be partially rescued by nkx2.5 mRNA. In addition, changes were detected in the expression of genes known to be important in hemoglobin synthesis and erythropoiesis. Our results demonstrate that SAP30L regulates several transcriptional pathways in zebrafish embryos and is involved in the development of cardiac and hematopoietic systems.
Assuntos
Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Hematopoese , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero/citologia , Eritrócitos/metabolismo , Eritrócitos/patologia , Técnicas de Silenciamento de Genes , Coração/anatomia & histologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genéticaRESUMO
PURPOSE: Small nucleolar RNAs (snoRNAs) direct sequence-specific modifications to ribosomal RNA. We hypothesized that the expression of snoRNAs may be altered in leukemic cells. METHODS: The expression of snoRNAs was analyzed in various leukemic cell lines by massive parallel sequencing (SOLiD). Quantitative real-time PCR (RT-qPCR) was used to validate the expression profiles. RESULTS: Our results show characteristic differences in the expression patterns of snoRNAs between cell lines representing the main subgroups of leukemia, AML, pre-B-ALL and T-ALL, respectively. In RT-qPCR analyses, several snoRNAs were found to be differentially expressed in T-ALL as compared to pre-B-ALL cell lines. CONCLUSIONS: snoRNAs are differentially expressed in various leukemic cell lines and could, therefore, be potentially useful in the classification of leukemia subgroups.
Assuntos
Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , RNA Neoplásico/genética , RNA Nucleolar Pequeno/genética , Linhagem Celular Tumoral , Análise por Conglomerados , Biblioteca Gênica , Células HL-60 , Células HeLa , Humanos , Células Jurkat , Leucemia/classificação , Leucemia/genética , Leucemia/patologia , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
The zebrafish has proven to be a valuable vertebrate model in which to elucidate the molecular mechanisms of various diseases. A high degree of genetic and morphological similarity in hematopoiesis between the zebrafish and human indicates that zebrafish can provide valuable knowledge about the mechanisms behind pathogenesis of leukemia. To date, a small number of zebrafish leukemia models have been published and they have already provided some interesting information. However, the full potential of these models, especially the identification of contributing genetic factors and high-throughput drug screens, is yet to be fulfilled. Further transgenic or mutant animals are needed, especially for modeling high-risk leukemias, such as MLL rearranged infant leukemias.
Assuntos
Modelos Animais de Doenças , Leucemia/etiologia , Peixe-Zebra/fisiologia , Animais , Animais Geneticamente Modificados , Transplante de Células/métodos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Leucemia/genética , Leucemia/patologia , Pesquisa/tendências , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Peixe-Zebra/genéticaRESUMO
The function of the nucleolus is intimately connected to cell proliferation, division and growth. Many cancer cells have enlarged nucleoli, and several nucleolar proteins have been linked to tumorigenesis. In order to find proteins whose expression is altered in the nucleoli of leukemic cells, we carried out two-dimensional difference gel electrophoresis (2-D DIGE) analyses. Prohibitin (PHB) and TAR-DNA-binding protein-43 (TDP-43) were strongly expressed in the nucleoli of the pre-B-ALL cell line MHH-CALL3. Our results demonstrate that leukemic cells have differences in their nucleolar protein composition, and suggest that it may be possible to exploit these differences in identification of leukemia subtypes.