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1.
J Nat Prod ; 87(2): 332-339, 2024 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-38294825

RESUMO

Neopetrotaurines A-C (1-3), unusual alkaloids possessing two isoquinoline-derived moieties that are linked via a unique taurine bridge, were isolated from a Neopetrosia sp. marine sponge. These new compounds have proton-deficient structural scaffolds that are difficult to unambiguously assign using only conventional 2- and 3-bond 1H-13C and 1H-15N heteronuclear correlation data. Thus, the application of LR-HSQMBC and HMBC NMR experiments optimized to detect 4- and 5-bond long-range 1H-13C heteronuclear correlations facilitated the structure elucidation of these unusual taurine-bridged marine metabolites. Neopetrotaurines A-C (1-3) showed significant inhibition of transcription driven by the oncogenic fusion protein PAX3-FOXO1, which is associated with alveolar rhabdomyosarcoma, and cytotoxic activity against PAX3-FOXO1-positive cell lines.


Assuntos
Alcaloides , Poríferos , Rabdomiossarcoma Alveolar , Animais , Rabdomiossarcoma Alveolar/metabolismo , Linhagem Celular , Alcaloides/farmacologia , Isoquinolinas/farmacologia
2.
Methods Mol Biol ; 2779: 273-286, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38526790

RESUMO

Oncogenic fusion genes are attractive therapeutic targets because of their tumor-specific expression and central "driver" roles in various human cancers. However, oncogenic fusions involving transcription factors such as PAX3-FOXO1 in alveolar fusion gene-positive rhabdomyosarcoma (FP-RMS) have been difficult to inhibit due to the apparent lack of tractable drug-like binding sites comparable to that recognized by Gleevec (imatinib mesylate) on the BCR-ABL1 tyrosine kinase fusion protein. Toward the identification of novel small molecules that selectively target PAX3-FOXO1, we used CRISPR-Cas9-mediated knock-in to append the pro-luminescent HiBiT tag onto the carboxy terminus of the endogenous PAX3-FOXO1 fusion protein in two human FP-RMS cell lines (RH4 and SCMC). HiBiT is an 11-amino acid peptide derived from the NanoLuc luciferase that produces a luminescence signal which is ~100-fold brighter than firefly or Renilla luciferases through high-affinity binding to a complementary NanoLuc peptide fragment called LgBiT. To facilitate single-cell clonal isolation of knock-ins, the homology-directed repair template encoding HiBiT was followed by a P2A self-cleaving peptide for coexpression of an mCherry fluorescent protein as a fluorescence-activated cell sorter (FACS)-selectable marker. HiBiT tagging thus allows highly sensitive luminescence detection of endogenous PAX3-FOXO1 levels permitting quantitative high-throughput screening of large compound libraries for the discovery of PAX3-FOXO1 inhibitors and degraders.


Assuntos
Fatores de Transcrição Box Pareados , Proteína Vermelha Fluorescente , Rabdomiossarcoma , Humanos , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Sistemas CRISPR-Cas , Rabdomiossarcoma/genética , Peptídeos/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica
3.
Nat Commun ; 15(1): 1703, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402212

RESUMO

Fusion-positive rhabdomyosarcoma (FP-RMS) is an aggressive pediatric sarcoma driven primarily by the PAX3-FOXO1 fusion oncogene, for which therapies targeting PAX3-FOXO1 are lacking. Here, we screen 62,643 compounds using an engineered cell line that monitors PAX3-FOXO1 transcriptional activity identifying a hitherto uncharacterized compound, P3FI-63. RNA-seq, ATAC-seq, and docking analyses implicate histone lysine demethylases (KDMs) as its targets. Enzymatic assays confirm the inhibition of multiple KDMs with the highest selectivity for KDM3B. Structural similarity search of P3FI-63 identifies P3FI-90 with improved solubility and potency. Biophysical binding of P3FI-90 to KDM3B is demonstrated using NMR and SPR. P3FI-90 suppresses the growth of FP-RMS in vitro and in vivo through downregulating PAX3-FOXO1 activity, and combined knockdown of KDM3B and KDM1A phenocopies P3FI-90 effects. Thus, we report KDM inhibitors P3FI-63 and P3FI-90 with the highest specificity for KDM3B. Their potent suppression of PAX3-FOXO1 activity indicates a possible therapeutic approach for FP-RMS and other transcriptionally addicted cancers.


Assuntos
Rabdomiossarcoma Alveolar , Rabdomiossarcoma , Criança , Humanos , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Rabdomiossarcoma Alveolar/genética , Linhagem Celular Tumoral , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/genética , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição PAX3/genética , Fator de Transcrição PAX3/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Histona Desmetilases/metabolismo
4.
Am J Hematol ; 88(4): 265-72, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23475625

RESUMO

Multiple myeloma (MM) is characterized by the malignant expansion of differentiated plasma cells. Although many chemotherapeutic agents display cytotoxic activity toward MM cells, patients inevitably succumb to their disease because the tumor cells become resistant to the anticancer drugs. The cancer stem cell hypothesis postulates that a small subpopulation of chemotherapy-resistant cancer cells is responsible for propagation of the tumor. Herein we report that efflux of the pluripotent stem cell dye CDy1 identifies a subpopulation in MM cell lines characterized by increased expression of P-glycoprotein, a member of the ABC (ATP-binding cassette) superfamily of transporters encoded by ABCB1. We also demonstrate that ABCB1-overexpressing MM cells are resistant to the second-generation proteasome inhibitor carfilzomib that recently received accelerated approval for the treatment of therapy-refractive MM by the U.S. Food and Drug Administration. Moreover, increased resistance to carfilzomib in sensitive MM cells following drug selection was associated with upregulation of ABCB1 cell-surface expression which correlated with increased transporter activity as measured by CDy1 efflux. We further show that chemosensitization of MM cells to carfilzomib could be achieved in vitro by cotreatment with vismodegib, a hedgehog pathway antagonist which is currently in MM clinical trials. CDy1 efflux may therefore be a useful assay to determine whether high expression of ABCB1 is predictive of poor clinical responses in MM patients treated with carfilzomib. Our data also suggest that inclusion of vismodegib might be a potential strategy to reverse ABCB1-mediated drug resistance should it occur.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Antracenos , Antineoplásicos/farmacologia , Morfolinas , Mieloma Múltiplo/patologia , Células-Tronco Neoplásicas/patologia , Oligopeptídeos/farmacologia , Células-Tronco Pluripotentes/patologia , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Anilidas/farmacologia , Transporte Biológico , Diferenciação Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Combinação de Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Corantes Fluorescentes , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Plasmócitos/efeitos dos fármacos , Plasmócitos/metabolismo , Plasmócitos/patologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Células-Tronco Pluripotentes/metabolismo , Piridinas/farmacologia
5.
Methods ; 57(3): 318-30, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22293036

RESUMO

Fluorescent proteins are now a critical tool in all areas of biomedical research. In this article, we review the techniques required to use fluorescent proteins for flow cytometry, concentrating specifically on the excitation and emission requirements for each protein, and the specific equipment required for optimal use.


Assuntos
Proteínas de Bactérias/química , Citometria de Fluxo/métodos , Proteínas de Fluorescência Verde/química , Proteínas Luminescentes/química , Células Cultivadas , Escherichia coli/genética , Corantes Fluorescentes , Vetores Genéticos , Humanos , Proteínas Recombinantes de Fusão/química , Espectrometria de Fluorescência , Proteína Vermelha Fluorescente
6.
Neurooncol Adv ; 5(1): vdad102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37706203

RESUMO

Background: Deletions or loss-of-function mutations in phosphatase and tensin homolog (PTEN) are common in glioblastoma (GBM) and have been associated with defective DNA damage repair. Here we investigated whether PTEN deficiency presents a vulnerability to a simultaneous induction of DNA damage and suppression of repair mechanisms by combining topoisomerase I (TOP1) and PARP inhibitors. Methods: Patient-derived GBM cells and isogenic PTEN-null and PTEN-WT glioma cells were treated with LMP400 (Indotecan), a novel non-camptothecin TOP1 inhibitor alone and in combination with a PARP inhibitor, Olaparib or Niraparib. RNAseq analysis was performed to identify treatment-induced dysregulated pathways. Results: We found that GBM cells lacking PTEN expression are highly sensitive to LMP400; however, rescue of the PTEN expression reduces sensitivity to the treatment. Combining LMP400 with Niraparib leads to synergistic cytotoxicity by inducing G2/M arrest, DNA damage, suppression of homologous recombination-related proteins, and activation of caspase 3/7 activity significantly more in PTEN-null cells compared to PTEN-WT cells. LMP400 and Niraparib are not affected by ABCB1 and ABCG2, the major ATP-Binding Cassette (ABC) drug efflux transporters expressed at the blood-brain barrier (BBB), thus suggesting BBB penetration which is a prerequisite for potential brain tumor treatment. Animal studies confirmed both an anti-glioma effect and sufficient BBB penetration to prolong survival of mice treated with the drug combination. Conclusions: Our findings provide a proof of concept for the combined treatment with LMP400 and Niraparib in a subset of GBM patients with PTEN deficiency.

7.
EMBO Rep ; 11(9): 691-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20651739

RESUMO

High expression of metastasis-associated protein 1 co-regulator (MTA1), a component of the nuclear remodelling and histone deacetylase complex, has been associated with human tumours. However, the precise role of MTA1 in tumorigenesis remains unknown. In this study, we show that induced levels of MTA1 are sufficient to transform Rat1 fibroblasts and that the transforming potential of MTA1 is dependent on its acetylation at Lys626. Underlying mechanisms of MTA1-mediated transformation include activation of the Ras-Raf pathway by MTA1 but not by acetylation-inactive MTA1; this was due to the repression of Galphai2 transcription, which negatively influences Ras activation. We observed that acetylated MTA1-histone deacetylase (HDAC) interaction was required for the recruitment of the MTA1-HDAC complex to the Galphai2 regulatory element and consequently for the repression of Galphai2 transcription and expression leading to activation of the Ras-Raf pathway. The findings presented in this study provide for the first time--to the best of our knowledge--evidence of acetylation-dependent oncogenic activity of a cancer-relevant gene product.


Assuntos
Transformação Celular Neoplásica , Histona Desacetilases/metabolismo , Oncogenes , Proteínas Repressoras/metabolismo , Acetilação , Animais , Linhagem Celular , Movimento Celular , Feminino , Fibroblastos/citologia , Fibroblastos/fisiologia , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/genética , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/metabolismo , Regulação Neoplásica da Expressão Gênica , Histona Desacetilases/genética , Humanos , Lisina/metabolismo , Camundongos , Camundongos Nus , Neoplasias Experimentais , Proteínas Repressoras/genética , Transativadores , Transcrição Gênica , Transplante Heterólogo , Proteínas ras/genética , Proteínas ras/metabolismo
8.
Blood ; 114(3): 526-34, 2009 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-19470695

RESUMO

Insertional mutagenesis by retroviral vectors is a major impediment to the clinical application of hematopoietic stem cell gene transfer for the treatment of hematologic disorders. We recently developed an insulated self-inactivating gammaretroviral vector, RMSinOFB, which uses a novel enhancer-blocking element that significantly decreases genotoxicity of retroviral integration. In this study, we used the RMSinOFB vector to evaluate the efficacy of a newly bioengineered factor VIII (fVIII) variant (efVIII)--containing a combination of A1 domain point mutations (L303E/F309S) and an extended partial B domain for improved secretion plus A2 domain mutations (R484A/R489A/P492A) for reduced immunogenicity--toward successful treatment of murine hemophilia A. In cell lines, efVIII was secreted at up to 6-fold higher levels than an L303E/F309S A1 domain-only fVIII variant (sfVIIIDeltaB). Most important, when compared with a conventional gammaretroviral vector expressing sfVIIIDeltaB, lower doses of RMSin-efVIII-OFB-transduced hematopoietic stem cells were needed to generate comparable curative fVIII levels in hemophilia A BALB/c mice after reduced-intensity total body irradiation or nonmyeloablative chemotherapy conditioning regimens. These data suggest that the safety-augmented RMSin-efVIII-OFB platform represents an encouraging step in the development of a clinically appropriate gene addition therapy for hemophilia A.


Assuntos
Fator VIII/administração & dosagem , Terapia Genética/métodos , Transplante de Células-Tronco Hematopoéticas , Hemofilia A/terapia , Animais , Fator VIII/genética , Fator VIII/metabolismo , Vetores Genéticos , Células-Tronco Hematopoéticas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Engenharia de Proteínas , Retroviridae/genética , Transdução Genética , Condicionamento Pré-Transplante
9.
Genes Chromosomes Cancer ; 49(2): 119-31, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19862821

RESUMO

Translocations resulting in ectopic expression of the TLX1 homeobox gene (previously known as HOX11) are recurrent events in human T-cell acute lymphoblastic leukemia (T-ALL). Transduction of primary murine hematopoietic stem/progenitor cells with retroviral vectors expressing TLX1 readily yields immortalized hematopoietic progenitor cell lines. Understanding the processes involved in TLX1-mediated cellular immortalization should yield insights into the growth and differentiation pathways altered by TLX1 during the development of T-ALL. In recent clinical gene therapy trials, hematopoietic clonal dominance or T-ALL-like diseases have occurred as a direct consequence of insertional activation of the EVI1, PRDM16 or LMO2 proto-oncogenes by the retroviral vectors used to deliver the therapeutic genes. Additionally, the generation of murine hematopoietic progenitor cell lines due to retroviral integrations into Evi1 or Prdm16 has also been recently reported. Here, we determined by linker-mediated nested polymerase chain reaction the integration sites in eight TLX1-immortalized hematopoietic cell lines. Notably, no common integration site was observed among the cell lines. Moreover, no insertions into the Evi1 or Prdm16 genes were identified although insertion near Lmo2 was observed in one instance. However, neither Lmo2 nor any of the other genes examined surrounding the integration sites showed differential vector-influenced expression compared to the cell lines lacking such insertions. While we cannot exclude the possibility that insertional side effects transiently provided a selective growth/survival advantage to the hematopoietic progenitor populations, our results unequivocally rule out insertions into Evi1 and Prdm16 as being integral to the TLX1-initiated immortalization process.


Assuntos
Hematopoese/genética , Proteínas de Homeodomínio/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Proto-Oncogênicas/genética , Animais , Southern Blotting , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Diferenciação Celular , Divisão Celular , Linhagem Celular Tumoral , Primers do DNA , Feminino , Genes Homeobox , Estudo de Associação Genômica Ampla , Humanos , Cariotipagem , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante de Células-Tronco/métodos
10.
Mol Cancer ; 9: 181, 2010 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-20618946

RESUMO

BACKGROUND: The homeobox gene TLX1 (for T-cell leukemia homeobox 1, previously known as HOX11) is inappropriately expressed in a major subgroup of T cell acute lymphoblastic leukemia (T-ALL) where it is strongly associated with activating NOTCH1 mutations. Despite the recognition that these genetic lesions cooperate in leukemogenesis, there have been no mechanistic studies addressing how TLX1 and NOTCH1 functionally interact to promote the leukemic phenotype. RESULTS: Global gene expression profiling after downregulation of TLX1 and inhibition of the NOTCH pathway in ALL-SIL cells revealed that TLX1 synergistically regulated more than 60% of the NOTCH-responsive genes. Structure-function analysis demonstrated that TLX1 binding to Groucho-related TLE corepressors was necessary for maximal transcriptional regulation of the NOTCH-responsive genes tested, implicating TLX1 modulation of the NOTCH-TLE regulatory network. Comparison of the dataset to publicly available biological databases indicated that the TLX1/NOTCH-coregulated genes are frequently targeted by MYC. Gain- and loss-of-function experiments confirmed that MYC was an essential mediator of TLX1/NOTCH transcriptional output and growth promotion in ALL-SIL cells, with TLX1 contributing to the NOTCH-MYC regulatory axis by posttranscriptional enhancement of MYC protein levels. Functional classification of the TLX1/NOTCH-coregulated targets also showed enrichment for genes associated with other human cancers as well as those involved in developmental processes. In particular, we found that TLX1, NOTCH and MYC coregulate CD1B and RAG1, characteristic markers of early cortical thymocytes, and that concerted downregulation of the TLX1 and NOTCH pathways resulted in their irreversible repression. CONCLUSIONS: We found that TLX1 and NOTCH synergistically regulate transcription in T-ALL, at least in part via the sharing of a TLE corepressor and by augmenting expression of MYC. We conclude that the TLX1/NOTCH/MYC network is a central determinant promoting the growth and survival of TLX1+ T-ALL cells. In addition, the TLX1/NOTCH/MYC transcriptional network coregulates genes involved in T cell development, such as CD1 and RAG family members, and therefore may prescribe the early cortical stage of differentiation arrest characteristic of the TLX1 subgroup of T-ALL.


Assuntos
Regulação Neoplásica da Expressão Gênica/fisiologia , Proteínas de Homeodomínio/fisiologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Proteínas Proto-Oncogênicas/fisiologia , Receptores Notch/fisiologia , Transcrição Gênica/fisiologia , Divisão Celular/fisiologia , Perfilação da Expressão Gênica , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética
11.
Biochem Biophys Res Commun ; 380(2): 361-5, 2009 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-19250647

RESUMO

The role of Groucho/transducin-like Enhancer of split (Gro/TLE) family members as corepressors of transcription is well documented. TLX1 is a homeodomain transcription factor involved in splenogenesis and neuron formation, and its aberrant expression gives rise to T-cell acute lymphoblastic leukemia. We demonstrate by glutathione-S-transferase pull-down assays, in vivo biotinylation tagging and confocal laser microscopy that TLX1 interacts with TLE1 via an Eh1-like motif. Paradoxically, we found that this motif is essential for optimal transcriptional activation of two TLX1 target genes, Aldh1a1 and Fhl1. Using a well characterized target of the Hairy/Enhancer of split 1 (HES1).TLE1 repressor complex, the ASCL1 gene, we show that TLX1 counteraction of ASCL1 repression by HES1 in SK-N-BE(2) neuroblastoma cells is associated with dismissal of TLE1 from the ASCL1 promoter and requires the Eh1-like motif for maximal effect. Collectively, these results indicate that TLX1-mediated target gene activation can occur in part via derepression strategies involving Gro/TLE corepressors.


Assuntos
Proteínas de Homeodomínio/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/metabolismo , Ativação Transcricional , Aldeído Desidrogenase/genética , Família Aldeído Desidrogenase 1 , Motivos de Aminoácidos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Proteínas Correpressoras , Proteínas de Homeodomínio/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas com Domínio LIM , Camundongos , Proteínas Musculares/genética , Regiões Promotoras Genéticas , Mapeamento de Interação de Proteínas , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Retinal Desidrogenase
12.
Stem Cells ; 26(12): 3257-66, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18787211

RESUMO

Insertional mutagenesis by retroviral vectors has emerged as a serious impediment to the widespread application of hematopoietic stem cell gene transfer for the treatment of hematologic diseases. Here we report the development of a 77-base pair element, FII/BEAD-A (FB), which contains the minimal enhancer-blocking components of the chicken beta-globin 5'HS4 insulator and a homologous region from the human T-cell receptor alpha/delta BEAD-1 insulator. With a new flow cytometry-based assay, we show that the FB element is as effective in enhancer-blocking activity as the prototypical 1.2-kilobase 5'HS4 insulator fragment. When incorporated into the residual U3 region of the 3' long terminal repeat (LTR) of a self-inactivating (SIN) gammaretroviral vector, the FB element was stably transferred to the 5' LTR during reverse transcription, flanking the integrated transgene expression cassette. Notably, using a recently established in vitro insertional mutagenesis assay involving primary murine hematopoietic cells, we found that SIN gammaretroviral vectors, as well as SIN lentiviral vectors, containing the FB element exhibited greatly reduced transforming potential-to background levels under the experimental conditions used-compared with their unshielded counterparts. These results suggest that the FB element-mediated enhancer-blocking modification is a promising approach to dramatically improve the safety of retroviral vectors for therapeutic gene transfer.


Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Globinas beta/metabolismo , Animais , Galinhas , Elementos Facilitadores Genéticos , Fibroblastos/metabolismo , Técnicas de Transferência de Genes , Vetores Genéticos , Lentivirus/genética , Camundongos , Mutagênese , Células NIH 3T3 , Regiões Promotoras Genéticas , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Retroviridae/genética
13.
Mol Med Rep ; 19(4): 2861-2868, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30720078

RESUMO

Coronary artery disease (CAD), including acute myocardial infarction (AMI), is a common complex disease; however, the genetic causes remain largely unknown. Recent epidemiological investigations indicated that the incidence of CAD in patients with congenital heart diseases is markedly higher than that observed in healthy controls. It was therefore hypothesized that the dysregulated expression of cardiac developmental genes may be involved in CAD development. GATA binding protein 4 (GATA4) serves essential roles in heart development and coronary vessel formation. In the present study, the GATA4 gene promoter was analyzed in patients with AMI (n=395) and in ethnically­matched healthy controls (n=397). A total of 14 DNA variants were identified, including two single­nucleotide polymorphisms. Three novel heterozygous DNA variants (g.31806C>T, g.31900G>C and g.32241C>T) were reported in three patients with AMI. These DNA variants significantly increased the activity of the GATA4 gene promoter. The electrophoretic mobility shift assay revealed that the DNA variant g.32241C>T influenced the binding ability of transcription factors. Taken together, the DNA variants may alter GATA4 gene promoter activity and affect GATA4 levels, thus contributing to AMI development.


Assuntos
Fator de Transcrição GATA4/genética , Predisposição Genética para Doença , Variação Genética , Infarto do Miocárdio/genética , Regiões Promotoras Genéticas , Adulto , Idoso , Sítios de Ligação , Feminino , Fator de Transcrição GATA4/metabolismo , Expressão Gênica , Genes Reporter , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Análise de Sequência de DNA , Ativação Transcricional
14.
Methods Mol Biol ; 434: 183-203, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18470646

RESUMO

The recent development of leukemia in gene therapy patients with X-linked severe combined immunodeficiency disease because of retroviral vector insertional mutagenesis has prompted reassessment of the genotoxic potential of integrating vector systems. In this chapter, various strategies are described to reduce the associated risks of retroviral genomic integration. These include deletion of strong transcriptional enhancer-promoter elements in the retroviral long terminal repeats, flanking the retroviral transcriptional unit with enhancer blocking sequences and designing vectors with improved RNA 3' end processing. Protocols are provided to evaluate the relative biosafety of the modified vectors based on their ability to immortalize hematopoietic progenitor cells and propensity to trigger clonal hematopoiesis or leukemogenesis following hematopoietic stem cell transplantation.


Assuntos
Terapia Genética/métodos , Vetores Genéticos/genética , Retroviridae/genética , Regiões 3' não Traduzidas/genética , Animais , Células Cultivadas , Elementos Facilitadores Genéticos/genética , Feminino , Células-Tronco Hematopoéticas/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese Insercional , Testes de Mutagenicidade , Regiões Promotoras Genéticas , Sequências Repetidas Terminais/genética , Transdução Genética , Transfecção
15.
J Vasc Res ; 44(6): 483-94, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17657164

RESUMO

The inappropriate survival of cells in the neointima contributes to atherosclerotic plaque progression, while apoptosis in the fibrous cap of lesions contributes to myocardial infarction and stroke. Prior genomic-scale transcript profiling of human carotid artery plaque cells with known sensitivity or resistance to fas-induced apoptosis identified candidate genes involved in lesion cell apoptosis. Retroviral overexpression indicated that several candidate factors were not causative, but that Bcl-X(L) conferred complete resistance to apoptosis induced by fas ligation. Resistant cells failed to efficiently activate caspase 8, an effect which was also observed in Bcl-X(L)-transfected cells. Small-molecule Bcl-2/X(L) inhibitors and siRNA knockdown of Bcl-X(L) markedly sensitized resistant cells to apoptosis, and partially restored caspase 8 activation. Caspase 3, 6 and 9 inhibitors reduced caspase 8 activation and blocked apoptosis. Complete knockdown of caspase 9 did not reduce apoptosis, while knockdown of Bid suppressed apoptosis, suggesting that mitochondrial pathways independent of caspase 9, such as Smac/Diablo or AIF, provide a necessary mitochondrial input to efficient caspase activation. Bcl-X(L) appears to modulate lesion cell apoptosis by suppressing mitochondrial amplification of caspase activation loops. The results may have direct implications for controlling plaque instability/progression, and identify a new class of small molecules to inhibit restenosis.


Assuntos
Apoptose , Artérias Carótidas/patologia , Doenças das Artérias Carótidas/patologia , Caspases/metabolismo , Proteína bcl-X/metabolismo , Receptor fas/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/enzimologia , Artérias Carótidas/metabolismo , Doenças das Artérias Carótidas/enzimologia , Doenças das Artérias Carótidas/genética , Doenças das Artérias Carótidas/metabolismo , Caspase 1/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Inibidores de Caspase , Caspases/genética , Linhagem Celular , Inibidores de Cisteína Proteinase/farmacologia , Ativação Enzimática , Vetores Genéticos , Humanos , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Retroviridae/genética , Fator de Transcrição STAT6/metabolismo , Fatores de Tempo , Técnicas de Cultura de Tecidos , Transfecção , Proteína de Morte Celular Associada a bcl/metabolismo , Proteína bcl-X/genética
16.
Mol Cell Biol ; 24(16): 6993-7002, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15282300

RESUMO

The Ras pathway transduces divergent signals determining normal cell fate and is frequently activated in hematopoietic malignancies, but the manner in which activation contributes to human leukemia is poorly understood. We report that a high level of activated H-Ras signaling in transduced primary human hematopoietic progenitors reduced their proliferation and enhanced monocyte/macrophage differentiation. However, the exposure of these cells to a farnesyltransferase inhibitor and establishment of a moderate level of Ras activity showed increased proliferation, an elevated frequency of primitive blast-like cells, and progenitors with enhanced self-renewal capacity. These results suggest that the amplitude of Ras pathway signaling is a determinant of myeloid cell fate and that moderate Ras activation in primitive hematopoietic cells can be an early event in leukemogenesis.


Assuntos
Alquil e Aril Transferases/antagonistas & inibidores , Células-Tronco Hematopoéticas/fisiologia , Leucemia/metabolismo , Transdução de Sinais/fisiologia , Proteínas ras/metabolismo , Alquil e Aril Transferases/metabolismo , Animais , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Linhagem da Célula , Células Cultivadas , Ativação Enzimática , Inibidores Enzimáticos/metabolismo , Farnesiltranstransferase , Técnicas de Transferência de Genes , Genes ras , Humanos , Leucemia/fisiopatologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Compostos Orgânicos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Quinases p38 Ativadas por Mitógeno , Proteínas ras/genética
17.
Explor Res Hypothesis Med ; 2(3): 63-67, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28966993

RESUMO

Large-scale screening has revealed that human hematopoietic cancer cell lines are generally more sensitive to various classes of drugs than cell lines established from solid tumors. A detailed examination of data in the Cancer Therapeutics Response Portal (http://portals.broadinstitute.org/ctrp/) suggests that this enhanced sensitivity is due to lower basal levels of activation of TAZ-TEAD mechanotransduction pathways in hematopoietic versus non-hematopoietic cells. Translation inhibitors such as omacetaxine mepesuccinate (homoharringtonine) fall into this category of hematopoietic-selective compounds. Moreover, additional molecular determinants of sensitivity suggest that homoharringtonine might show therapeutic efficacy in certain patients with advanced hematologic malignancies despite activation of these pathways.

18.
Oncoscience ; 4(7-8): 79-94, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28966941

RESUMO

Tight junction protein 1 (TJP1) has recently been proposed as a biomarker to identify multiple myeloma (MM) patients most likely to respond to bortezomib- and carfilzomib-based proteasome inhibitor regimens. Herein we report increased expression of TJP1 during the adaptive response mediating carfilzomib resistance in the LP-1/Cfz MM cell line. Moreover, increased TJP1 expression delineated a subset of relapsed/refractory MM patients on bortezomib-based therapy sharing an LP-1/Cfz-like phenotype characterized by activation of interacting transcriptional effectors of the Hippo signaling cascade (TAZ and TEAD1) and an adult tissue stem cell signature. siRNA-mediated knockdown of TJP1 or TAZ/TEAD1 partially sensitized LP-1/Cfz cells to carfilzomib. Connectivity Map analysis identified translation inhibitors as candidate therapeutic agents targeting this molecular phenotype. We confirmed this prediction by showing that homoharringtonine (omacetaxine mepesuccinate) - the first translation inhibitor to be approved by the U.S. Food and Drug Administration - displayed potent cytotoxic activity on LP-1/Cfz cells. Homoharringtonine treatment reduced the levels of TAZ and TEAD1 as well as the MM-protective proteins Nrf2 and MCL1. Thus, our data suggest the importance of further studies evaluating translation inhibitors in relapsed/refractory MM. On the other hand, use of TJP1 as a MM biomarker for proteasome inhibitor sensitivity requires careful consideration.

19.
Curr Protoc Cytom ; 80: 9.12.1-9.12.20, 2017 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-28369764

RESUMO

Fluorescent proteins have become standard tools for cell and molecular biologists. The color palette of fluorescent proteins spans the ultraviolet, visible, and near-infrared spectrum. Utility of fluorescent proteins has been greatly facilitated by the availability of compact and affordable solid state lasers capable of providing various excitation wavelengths. In theory, the plethora of fluorescent proteins and lasers make it easy to detect multiple fluorescent proteins simultaneously. However, in practice, heavy spectral overlap due to broad excitation and emission spectra presents a challenge. In conventional flow cytometry, careful selection of excitation wavelengths and detection filters is necessary. Spectral flow cytometry, an emerging methodology that is not confined by the "one color, one detector" paradigm, shows promise in the facile detection of multiple fluorescent proteins. This chapter provides a synopsis of fluorescent protein development, a list of commonly used fluorescent proteins, some practical considerations and strategies for detection, and examples of applications. © 2017 by John Wiley & Sons, Inc.


Assuntos
Citometria de Fluxo/métodos , Proteínas Luminescentes/metabolismo , Técnicas Biossensoriais , Biotinilação , Vetores Genéticos/metabolismo , Lasers , Mapeamento de Interação de Proteínas
20.
Neurosci Lett ; 646: 30-35, 2017 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-28279708

RESUMO

Parkinson's disease (PD) is a common and progressive neurodegenerative disease in which the majority of cases arise sporadically. Sporadic PD is caused by the interactions of genetic and environmental factors. To date, genetic causes for sporadic PD remain largely unknown. Autophagy, a highly conserved cellular process, has been implicated in PD pathogenesis. We speculated that genetic variants in autophagy-related genes (ATG) that regulate gene expression may contribute to PD development. In our previous studies, we have identified several functional DNA sequence variants (DSVs) in the ATG5, ATG7 and LC3 genes in sporadic PD patients. In this study, we further genetically and functionally analyzed the promoter of the ATG16L1 gene, a critical gene for autophagosome formation, in groups of sporadic PD patients and ethnic-matched healthy controls. One novel heterozygous DSV, 233251432C>T, was found in one PD patient. Functionally, this DSV did not affect the transcriptional activity of the ATG16L1 gene promoter in human dopaminergic SH-SY5Y cells. Two heterozygous DSVs including one SNP, 233251286G>A (rs539735288) and 233251582C>T, were found only in controls. In addition, five other SNPs were found in both PD patients and controls. Taken together, the data suggested that genetic variants within the ATG16L1 gene promoter were not a risk factor for sporadic PD development.


Assuntos
Proteínas Relacionadas à Autofagia/genética , Predisposição Genética para Doença , Variação Genética/genética , Doença de Parkinson/genética , Regiões Promotoras Genéticas/genética , Idoso , Idoso de 80 Anos ou mais , Autofagia/genética , Estudos de Casos e Controles , Feminino , Expressão Gênica/genética , Testes Genéticos/métodos , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade
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