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1.
bioRxiv ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38766081

RESUMO

Precision nuclear run-on (PRO) sequencing (PRO-seq) is a powerful technique for mapping polymerase active sites with nucleotide resolution and measuring newly synthesized transcripts at both promoters and enhancer elements. The current PRO-seq protocol is time-intensive, technically challenging, and requires a large amount of starting material. To overcome these limitations, we developed rapid PRO-seq (rPRO-seq) which utilizes pre-adenylated single-stranded DNAs (AppDNA), a dimer blocking oligonucleotide (DBO), on-bead 5' RNA end repair, and column-based purification. These modifications enabled efficient transcriptome mapping within a single day (∼12 hours) increasing ligation efficiency, abolished adapter dimers, and reduced sample loss and RNA degradation. We demonstrate the reproducibility of rPRO-seq in measuring polymerases at promoters, gene bodies, and enhancers as compared to original PRO-seq protocols. Additionally, rPRO-seq is scalable, allowing for transcriptome mapping with as little as 25,000 cells. We apply rPRO-seq to study the role of Integrator in mouse hematopoietic stem and progenitor cell (mHSPC) homeostasis, identifying Ints11 as an essential component of transcriptional regulation and RNA processing in mHSPC homeostasis. Overall, rPRO-seq represents a significant advance in the field of nascent transcript analyses and will be a valuable tool for generating patient-specific genome-wide transcription profiles with minimal sample requirements.

2.
Cardiovasc Res ; 120(3): 286-300, 2024 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-38271281

RESUMO

AIMS: Doxorubicin (DXR) is a chemotherapeutic agent that causes dose-dependent cardiotoxicity. Recently, it has been proposed that the NADase CD38 may play a role in doxorubicin-induced cardiotoxicity (DIC). CD38 is the main NAD+-catabolizing enzyme in mammalian tissues. Interestingly, in the heart, CD38 is mostly expressed as an ecto-enzyme that can be targeted by specific inhibitory antibodies. The goal of the present study is to characterize the role of CD38 ecto-enzymatic activity in cardiac metabolism and the development of DIC. METHODS AND RESULTS: Using both a transgenic animal model and a non-cytotoxic enzymatic anti-CD38 antibody, we investigated the role of CD38 and its ecto-NADase activity in DIC in pre-clinical models. First, we observed that DIC was prevented in the CD38 catalytically inactive (CD38-CI) transgenic mice. Both left ventricular systolic function and exercise capacity were decreased in wild-type but not in CD38-CI mice treated with DXR. Second, blocking CD38-NADase activity with the specific antibody 68 (Ab68) likewise protected mice against DIC and decreased DXR-related mortality by 50%. A reduction of DXR-induced mitochondrial dysfunction, energy deficiency, and inflammation gene expression were identified as the main mechanisms mediating the protective effects. CONCLUSION: NAD+-preserving strategies by inactivation of CD38 via a genetic or a pharmacological-based approach improve cardiac energetics and reduce cardiac inflammation and dysfunction otherwise seen in an acute DXR cardiotoxicity model.


Assuntos
NAD+ Nucleosidase , NAD , Camundongos , Animais , NAD+ Nucleosidase/metabolismo , ADP-Ribosil Ciclase 1/genética , ADP-Ribosil Ciclase 1/metabolismo , NAD/metabolismo , Cardiotoxicidade , Camundongos Transgênicos , Doxorrubicina/toxicidade , Inflamação , Mamíferos/metabolismo
3.
Cell Rep ; 42(9): 113037, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37624694

RESUMO

The superior colliculus (SC) is a sensorimotor structure in the midbrain that integrates input from multiple sensory modalities to initiate motor commands. It undergoes well-characterized steps of circuit assembly during development, rendering the mouse SC a popular model to study establishment of neural connectivity. Here we perform single-nucleus RNA-sequencing analysis of the mouse SC isolated at various developmental time points. Our study provides a transcriptomic landscape of the cell types that comprise the SC across murine development with particular emphasis on neuronal heterogeneity. We report a repertoire of genes differentially expressed across the different postnatal ages, many of which are known to regulate axon guidance and synapse formation. Using these data, we find that Pax7 expression is restricted to a subset of GABAergic neurons. Our data provide a valuable resource for interrogating the mechanisms of circuit development and identifying markers for manipulating specific SC neuronal populations and circuits.


Assuntos
Neurônios GABAérgicos , Colículos Superiores , Camundongos , Animais , Colículos Superiores/fisiologia , Transcriptoma/genética , Perfilação da Expressão Gênica , Análise de Sequência de RNA
4.
J Clin Invest ; 133(13)2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-37200093

RESUMO

During emergency hematopoiesis, hematopoietic stem cells (HSCs) rapidly proliferate to produce myeloid and lymphoid effector cells, a response that is critical against infection or tissue injury. If unresolved, this process leads to sustained inflammation, which can cause life-threatening diseases and cancer. Here, we identify a role of double PHD fingers 2 (DPF2) in modulating inflammation. DPF2 is a defining subunit of the hematopoiesis-specific BAF (SWI/SNF) chromatin-remodeling complex, and it is mutated in multiple cancers and neurological disorders. We uncovered that hematopoiesis-specific Dpf2-KO mice developed leukopenia, severe anemia, and lethal systemic inflammation characterized by histiocytic and fibrotic tissue infiltration resembling a clinical hyperinflammatory state. Dpf2 loss impaired the polarization of macrophages responsible for tissue repair, induced the unrestrained activation of Th cells, and generated an emergency-like state of HSC hyperproliferation and myeloid cell-biased differentiation. Mechanistically, Dpf2 deficiency resulted in the loss of the BAF catalytic subunit BRG1 from nuclear factor erythroid 2-like 2-controlled (NRF2-controlled) enhancers, impairing the antioxidant and antiinflammatory transcriptional response needed to modulate inflammation. Finally, pharmacological reactivation of NRF2 suppressed the inflammation-mediated phenotypes and lethality of Dpf2Δ/Δ mice. Our work establishes an essential role of the DPF2-BAF complex in licensing NRF2-dependent gene expression in HSCs and immune effector cells to prevent chronic inflammation.


Assuntos
Cromatina , Neoplasias , Camundongos , Animais , Antioxidantes , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Montagem e Desmontagem da Cromatina , Inflamação/genética , Expressão Gênica , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
bioRxiv ; 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-36778361

RESUMO

The superior colliculus (SC) is a sensorimotor structure in the midbrain that integrates input from multiple sensory modalities to initiate motor commands. It undergoes well-characterized steps of circuit assembly during development, rendering the mouse SC a popular model to study establishment and refinement of neural connectivity. Here we performed single nucleus RNA-sequencing analysis of the mouse SC isolated at various developmental time points. Our study provides a transcriptomic landscape of the cell types that comprise the SC across murine development with particular emphasis on neuronal heterogeneity. We used these data to identify Pax7 as a marker for an anatomically homogeneous population of GABAergic neurons. Lastly, we report a repertoire of genes differentially expressed across the different postnatal ages, many of which are known to regulate axon guidance and synapse formation. Our data provide a valuable resource for interrogating the mechanisms of circuit development, and identifying markers for manipulating specific SC neuronal populations and circuits.

6.
Sci Adv ; 9(6): eadf0597, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36763664

RESUMO

MicroRNA (miRNA) homeostasis is crucial for the posttranscriptional regulation of their target genes during development and in disease states. miRNAs are derived from primary transcripts and are processed from a hairpin precursor intermediary to a mature 22-nucleotide duplex RNA. Loading of the duplex into the Argonaute (AGO) protein family is pivotal to miRNA abundance and its posttranscriptional function. The Integrator complex plays a key role in protein coding and noncoding RNA maturation, RNA polymerase II pause-release, and premature transcriptional termination. Here, we report that loss of Integrator results in global destabilization of mature miRNAs. Enhanced ultraviolet cross-linking and immunoprecipitation of Integrator uncovered an association with duplex miRNAs before their loading onto AGOs. Tracing miRNA fate from biogenesis to stabilization by incorporating 4-thiouridine in nascent transcripts pinpointed a critical role for Integrator in miRNA assembly into AGOs.


Assuntos
MicroRNAs , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Regulação da Expressão Gênica , Núcleo Celular/metabolismo
7.
iScience ; 25(11): 105431, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36388973

RESUMO

In mammals, nicotinamide (NAM) is the primary NAD precursor available in circulation, a signaling molecule, and a precursor for methyl-nicotinamide (M-NAM) synthesis. However, our knowledge about how the body regulates tissue NAM levels is still limited. Here we demonstrate that dietary vitamin B3 partially regulates plasma NAM and NAM-derived metabolites, but not their tissue levels. We found that NAD de novo synthesis from tryptophan contributes to plasma and tissue NAM, likely by providing substrates for NAD-degrading enzymes. We also demonstrate that tissue NAM is mainly generated by endogenous metabolism and that the NADase CD38 is the main enzyme that produces tissue NAM. Tissue-specific CD38-floxed mice revealed that CD38 activity on endothelial and immune cells is the major contributor to tissue steady-state levels of NAM in tissues like spleen and heart. Our findings uncover the presence of different pools of NAM in the body and a central role for CD38 in regulating tissue NAM levels.

8.
Exp Neurol ; 355: 114147, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35738417

RESUMO

Following injury in the central nervous system, a population of astrocytes occupy the lesion site, form glial bridges and facilitate axon regeneration. These astrocytes originate primarily from resident astrocytes or NG2+ oligodendrocyte progenitor cells. However, the extent to which these cell types give rise to the lesion-filling astrocytes, and whether the astrocytes derived from different cell types contribute similarly to optic nerve regeneration remain unclear. Here we examine the distribution of astrocytes and NG2+ cells in an optic nerve crush model. We show that optic nerve astrocytes partially fill the injury site over time after a crush injury. Viral mediated expression of a growth-promoting factor, ciliary neurotrophic factor (CNTF), in retinal ganglion cells (RGCs) promotes axon regeneration without altering the lesion size or the degree of lesion-filling GFAP+ cells. Strikingly, using inducible NG2CreER driver mice, we found that CNTF overexpression in RGCs increases the occupancy of NG2+ cell-derived astrocytes in the optic nerve lesion. An EdU pulse-chase experiment shows that the increase in NG2 cell-derived astrocytes is not due to an increase in cell proliferation. Lastly, we performed RNA-sequencing on the injured optic nerve and reveal that CNTF overexpression in RGCs results in significant changes in the expression of distinct genes, including those that encode chemokines, growth factor receptors, and immune cell modulators. Even though CNTF-induced axon regeneration has long been recognized, this is the first evidence of this procedure affecting glial cell fate at the optic nerve crush site. We discuss possible implication of these results for axon regeneration.


Assuntos
Traumatismos do Nervo Óptico , Traumatismos do Sistema Nervoso , Animais , Astrócitos/metabolismo , Axônios/patologia , Fator Neurotrófico Ciliar , Citocinas/metabolismo , Camundongos , Regeneração Nervosa/fisiologia , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/metabolismo , Traumatismos do Sistema Nervoso/metabolismo
9.
Sci Adv ; 7(45): eabe3393, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34730992

RESUMO

Integrator regulates the 3'-end processing and termination of multiple classes of noncoding RNAs. Depletion of INTS11, the catalytic subunit of Integrator, or ectopic expression of its catalytic dead enzyme impairs the 3'-end processing and termination of a set of protein-coding transcripts termed Integrator-regulated termination (IRT) genes. This defect is manifested by increased RNA polymerase II (RNAPII) readthrough and occupancy of serine-2 phosphorylated RNAPII, de novo trimethylation of lysine-36 on histone H3, and a compensatory elevation of the cleavage and polyadenylation (CPA) complex beyond the canonical polyadenylation sites. 3' RNA sequencing reveals that proximal polyadenylation site usage relies on the endonuclease activity of INTS11. The DNA sequence encompassing the transcription end sites of IRT genes features downstream polyadenylation motifs and an enrichment of GC content that permits the formation of secondary structures within the 3'UTR. Together, this study identifies a subset of protein-coding transcripts whose 3' end processing requires the Integrator complex.

10.
Nature ; 599(7885): 485-490, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34759321

RESUMO

Fatty acid uptake and altered metabolism constitute hallmarks of metastasis1,2, yet evidence of the underlying biology, as well as whether all dietary fatty acids are prometastatic, is lacking. Here we show that dietary palmitic acid (PA), but not oleic acid or linoleic acid, promotes metastasis in oral carcinomas and melanoma in mice. Tumours from mice that were fed a short-term palm-oil-rich diet (PA), or tumour cells that were briefly exposed to PA in vitro, remained highly metastatic even after being serially transplanted (without further exposure to high levels of PA). This PA-induced prometastatic memory requires the fatty acid transporter CD36 and is associated with the stable deposition of histone H3 lysine 4 trimethylation by the methyltransferase Set1A (as part of the COMPASS complex (Set1A/COMPASS)). Bulk, single-cell and positional RNA-sequencing analyses indicate that genes with this prometastatic memory predominantly relate to a neural signature that stimulates intratumoural Schwann cells and innervation, two parameters that are strongly correlated with metastasis but are aetiologically poorly understood3,4. Mechanistically, tumour-associated Schwann cells secrete a specialized proregenerative extracellular matrix, the ablation of which inhibits metastasis initiation. Both the PA-induced memory of this proneural signature and its long-term boost in metastasis require the transcription factor EGR2 and the glial-cell-stimulating peptide galanin. In summary, we provide evidence that a dietary metabolite induces stable transcriptional and chromatin changes that lead to a long-term stimulation of metastasis, and that this is related to a proregenerative state of tumour-activated Schwann cells.


Assuntos
Gorduras na Dieta/farmacologia , Metástase Neoplásica , Ácido Palmítico/farmacologia , Células de Schwann/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Cromatina/genética , Cromatina/metabolismo , Gorduras na Dieta/administração & dosagem , Proteína 2 de Resposta de Crescimento Precoce/metabolismo , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Feminino , Galanina/metabolismo , Histonas/química , Histonas/metabolismo , Humanos , Masculino , Camundongos , Ácido Palmítico/administração & dosagem , Células de Schwann/metabolismo
11.
BMC Genomics ; 22(1): 741, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34649511

RESUMO

BACKGROUND: Emerging evidence indicates that long noncoding RNAs (lncRNAs) are important regulators of various biological processes, and their expression can be altered following certain pathological conditions, including central nervous system injury. Retinal ganglion cells (RGCs), whose axons form the optic nerve, are a heterogeneous population of neurons with more than 40 molecularly distinct subtypes in mouse. While most RGCs, including the ON-OFF direction-selective RGCs (ooDSGCs), are vulnerable to axonal injury, a small population of RGCs, including the intrinsically photosensitive RGCs (ipRGCs), are more resilient. RESULTS: By performing systematic analyses on RNA-sequencing data, here we identify lncRNAs that are expressed in ooDSGCs and ipRGCs with and without axonal injury. Our results reveal a repertoire of different classes of lncRNAs, including long intergenic noncoding RNAs and antisense ncRNAs that are differentially expressed between these RGC types. Strikingly, we also found dozens of lncRNAs whose expressions are altered markedly in response to axonal injury, some of which are expressed exclusively in either one of the types. Moreover, analyses into these lncRNAs unraveled their neighboring coding genes, many of which encode transcription factors and signaling molecules, suggesting that these lncRNAs may act in cis to regulate important biological processes in these neurons. Lastly, guilt-by-association analysis showed that lncRNAs are correlated with apoptosis associated genes, suggesting potential roles for these lncRNAs in RGC survival. CONCLUSIONS: Overall, the results of this study reveal RGC type-specific expression of lncRNAs and provide a foundation for future investigation of the function of lncRNAs in regulating neuronal type specification and survival.


Assuntos
Traumatismos do Nervo Óptico , RNA Longo não Codificante , Animais , Axônios , Camundongos , Regeneração Nervosa , Traumatismos do Nervo Óptico/genética , RNA Longo não Codificante/genética , Células Ganglionares da Retina
12.
Mol Cancer Res ; 19(8): 1296-1307, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33980612

RESUMO

Acute lymphoblastic leukemia (ALL) is a leading cause of cancer-related death in children and adolescents, and cure rates for relapsed/refractory ALL remain dismal, highlighting the need for novel targeted therapies. To identify genome-wide metabolic-stress regulated genes, we used RNA-sequencing in ALL cells treated with AICAR, an AMPK activator. RNA-sequencing identified the immediate early genes (IEGs) as a subset of genes downregulated by AICAR. We show that AICAR-induced IEGs downregulation was blocked by an adenosine uptake inhibitor indicating AICAR was responsible for IEGs reprogramming. Using pharmacologic and genetic models we established this mechanism was AMPK-independent. Further investigations using kinase assays, PKD/PKC inhibitors and rescue experiments, demonstrated that AICAR directly inhibited PKD kinase activity and identified PKD as responsible for IEGs downregulation. Mechanistically, PKD inhibition suppressed phosphorylation and nuclear export of class IIa HDACs, which lowered histone H3 acetylation and decreased NFκB(p65) recruitment to IEGs promoters. Finally, PKD inhibition induced apoptosis via DUSP1/DUSP6 downregulation eliciting a DNA damage response. More importantly, ALL patient cells exhibited the same PKD-HDACs-IEGs-mediated mechanism. As proof of principle of the therapeutic potential of targeting PKD, we established the in vivo relevance of our findings using an NSG ALL mouse model. In conclusion, we identified a previously unreported PKD-dependent survival mechanism in response to AICAR-induced cellular stress in ALL through regulation of DUSPs and IEGs' expression. IMPLICATIONS: PKD mediates early transcriptional responses in ALL cells as an adaptive survival mechanism to overcome cellular stress.


Assuntos
Regulação para Baixo/genética , Histona Desacetilases/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteína Quinase C/genética , Aminoimidazol Carboxamida/análogos & derivados , Animais , Apoptose/genética , Linhagem Celular Tumoral , Dano ao DNA/genética , Ativação Enzimática/genética , Células HEK293 , Células HeLa , Humanos , Células Jurkat , Camundongos , Regiões Promotoras Genéticas/genética , Proteínas Serina-Treonina Quinases/genética , Ribonucleotídeos/genética , Transdução de Sinais/genética
13.
Cell Commun Signal ; 19(1): 5, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33430890

RESUMO

BACKGROUND: Androgen receptor (AR) and polycomb repressive complex 2 (PRC2) are known to co-occupy the loci of genes that are downregulated by androgen-stimulus. Long intergenic non-coding RNA (lincRNA) PVT1 is an overexpressed oncogene that is associated with AR in LNCaP prostate cancer cells, and with PRC2 in HeLa and many other types of cancer cells. The possible involvement of PVT1 in mediating androgen-induced gene expression downregulation in prostate cancer has not been explored. METHODS: LNCaP cell line was used. Native RNA-binding-protein immunoprecipitation with anti-AR or anti-EZH2 was followed by RT-qPCR with primers for PVT1. Knockdown of PVT1 with specific GapmeRs (or a control with scrambled GapmeR) was followed by differentially expressed genes (DEGs) determination with Agilent microarrays and with Significance Analysis of Microarrays statistical test. DEGs were tested as a tumor risk classifier with a machine learning Random Forest algorithm run with gene expression data from all TCGA-PRAD (prostate adenocarcinoma) tumors as input. ChIP-qPCR was performed for histone marks at the promoter of one DEG. RESULTS: We show that PVT1 knockdown in androgen-stimulated LNCaP cells caused statistically significant expression upregulation/downregulation of hundreds of genes. Interestingly, PVT1 knockdown caused upregulation of 160 genes that were repressed by androgen, including a significantly enriched set of tumor suppressor genes, and among them FAS, NOV/CCN3, BMF, HRK, IFIT2, AJUBA, DRAIC and TNFRSF21. A 121-gene-set (out of the 160) was able to correctly predict the classification of all 293 intermediate- and high-risk TCGA-PRAD tumors, with a mean ROC area under the curve AUC = 0.89 ± 0.04, pointing to the relevance of these genes in cancer aggressiveness. Native RIP-qPCR in LNCaP showed that PVT1 was associated with EZH2, a component of PRC2. PVT1 knockdown followed by ChIP-qPCR showed significant epigenetic remodeling at the enhancer and promoter regions of tumor suppressor gene NOV, one of the androgen-repressed genes that were upregulated upon PVT1 silencing. CONCLUSIONS: Overall, we provide first evidence that PVT1 was involved in signaling a genome-wide androgen-dependent transcriptional repressive program of tumor suppressor protein-coding genes in prostate cancer cells. Identification of transcriptional inhibition of tumor suppressor genes by PVT1 highlights the pathway to the investigation of mechanisms that lie behind the oncogenic role of PVT1 in cancer. Video Abstract.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , RNA Longo não Codificante/genética , Androgênios , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Humanos , Estimativa de Kaplan-Meier , Masculino , Neoplasias da Próstata/mortalidade , Receptores Androgênicos/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/genética
14.
Cell Commun Signal, v. 19, 5, jan. 2021
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-3446

RESUMO

Background: Androgen receptor (AR) and polycomb repressive complex 2 (PRC2) are known to co-occupy the loci of genes that are downregulated by androgen-stimulus. Long intergenic non-coding RNA (lincRNA) PVT1 is an overexpressed oncogene that is associated with AR in LNCaP prostate cancer cells, and with PRC2 in HeLa and many other types of cancer cells. The possible involvement of PVT1 in mediating androgen-induced gene expression downregulation in prostate cancer has not been explored. Methods: LNCaP cell line was used. Native RNA-binding-protein immunoprecipitation with anti-AR or anti-EZH2 was followed by RT-qPCR with primers for PVT1. Knockdown of PVT1 with specifc GapmeRs (or a control with scrambled GapmeR) was followed by diferentially expressed genes (DEGs) determination with Agilent microarrays and with Signifcance Analysis of Microarrays statistical test. DEGs were tested as a tumor risk classifer with a machine learning Random Forest algorithm run with gene expression data from all TCGA-PRAD (prostate adenocarcinoma) tumors as input. ChIP-qPCR was performed for histone marks at the promoter of one DEG. Results: We show that PVT1 knockdown in androgen-stimulated LNCaP cells caused statistically signifcant expression upregulation/downregulation of hundreds of genes. Interestingly, PVT1 knockdown caused upregulation of 160 genes that were repressed by androgen, including a signifcantly enriched set of tumor suppressor genes, and among them FAS, NOV/CCN3, BMF, HRK, IFIT2, AJUBA, DRAIC and TNFRSF21. A 121-gene-set (out of the 160) was able to correctly predict the classifcation of all 293 intermediate- and high-risk TCGA-PRAD tumors, with a mean ROC area under the curve AUC=0.89±0.04, pointing to the relevance of these genes in cancer aggressiveness. Native RIP-qPCR in LNCaP showed that PVT1 was associated with EZH2, a component of PRC2. PVT1 knockdown followed by ChIP-qPCR showed signifcant epigenetic remodeling at the enhancer and promoter regions of tumor suppressor gene NOV, one of the androgen-repressed genes that were upregulated upon PVT1 silencing. Conclusions: Overall, we provide frst evidence that PVT1 was involved in signaling a genome-wide androgendependent transcriptional repressive program of tumor suppressor protein-coding genes in prostate cancer cells. Identifcation of transcriptional inhibition of tumor suppressor genes by PVT1 highlights the pathway to the investiga‑tion of mechanisms that lie behind the oncogenic role of PVT1 in cancer.

15.
Sci Adv ; 6(27): eaaz9072, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32923585

RESUMO

RNA 3' end processing provides a source of transcriptome diversification which affects various (patho)-physiological processes. A prime example is the transcript isoform switch that leads to the read-through expression of the long non-coding RNA NEAT1_2, at the expense of the shorter polyadenylated transcript NEAT1_1. NEAT1_2 is required for assembly of paraspeckles (PS), nuclear bodies that protect cancer cells from oncogene-induced replication stress and chemotherapy. Searching for proteins that modulate this event, we identified factors involved in the 3' end processing of polyadenylated RNA and components of the Integrator complex. Perturbation experiments established that, by promoting the cleavage of NEAT1_2, Integrator forces NEAT1_2 to NEAT1_1 isoform switching and, thereby, restrains PS assembly. Consistently, low levels of Integrator subunits correlated with poorer prognosis of cancer patients exposed to chemotherapeutics. Our study establishes that Integrator regulates PS biogenesis and a link between Integrator, cancer biology, and chemosensitivity, which may be exploited therapeutically.

16.
Cell Rep ; 32(3): 107917, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32697989

RESUMO

Transcription by RNA polymerase II (RNAPII) is pervasive in the human genome. However, the mechanisms controlling transcription at promoters and enhancers remain enigmatic. Here, we demonstrate that Integrator subunit 11 (INTS11), the catalytic subunit of the Integrator complex, regulates transcription at these loci through its endonuclease activity. Promoters of genes require INTS11 to cleave nascent transcripts associated with paused RNAPII and induce their premature termination in the proximity of the +1 nucleosome. The turnover of RNAPII permits the subsequent recruitment of an elongation-competent RNAPII complex, leading to productive elongation. In contrast, enhancers require INTS11 catalysis not to evict paused RNAPII but rather to terminate enhancer RNA transcription beyond the +1 nucleosome. These findings are supported by the differential occupancy of negative elongation factor (NELF), SPT5, and tyrosine-1-phosphorylated RNAPII. This study elucidates the role of Integrator in mediating transcriptional elongation at human promoters through the endonucleolytic cleavage of nascent transcripts and the dynamic turnover of RNAPII.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Endonucleases/metabolismo , Elongação da Transcrição Genética , Biocatálise , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica , Células HeLa , Humanos , Nucleossomos/metabolismo , Fosforilação , Regiões Promotoras Genéticas , RNA/metabolismo , RNA Polimerase II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Terminação da Transcrição Genética
17.
Phytopathology ; 110(11): 1751-1755, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32520631

RESUMO

Xylella fastidiosa subsp. pauca, once confined to South America and infecting mainly citrus and coffee plants, has been found to be associated with other hosts and in other geographic regions. We present high-quality draft genome sequences of X. fastidiosa subsp. pauca strains J1a12, B111, U24D, and XRB isolated from citrus plants in Brazil, strain Fb7 isolated from a citrus plant in Argentina and strains 3124, Pr8x, and Hib4 isolated, respectively, from coffee, plum, and hibiscus plants in Brazil. Sequencing was performed using Roche 454-GS FLX, MiSeq-Illumina or Pacific Biosciences platforms. These high-quality genome assemblies will be useful for further studies about the genomic diversity, evolution, and biology of X. fastidiosa.


Assuntos
Citrus , Hibiscus , Prunus domestica , Xylella , Argentina , Brasil , Café , Doenças das Plantas , Xylella/genética
18.
Genes Dev ; 34(9-10): 637-649, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32241802

RESUMO

The emergence of drug resistance is a major obstacle for the success of targeted therapy in melanoma. Additionally, conventional chemotherapy has not been effective as drug-resistant cells escape lethal DNA damage effects by inducing growth arrest commonly referred to as cellular dormancy. We present a therapeutic strategy termed "targeted chemotherapy" by depleting protein phosphatase 2A (PP2A) or its inhibition using a small molecule inhibitor (1,10-phenanthroline-5,6-dione [phendione]) in drug-resistant melanoma. Targeted chemotherapy induces the DNA damage response without causing DNA breaks or allowing cellular dormancy. Phendione treatment reduces tumor growth of BRAFV600E-driven melanoma patient-derived xenografts (PDX) and diminishes growth of NRASQ61R-driven melanoma, a cancer with no effective therapy. Remarkably, phendione treatment inhibits the acquisition of resistance to BRAF inhibition in BRAFV600E PDX highlighting its effectiveness in combating the advent of drug resistance.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Melanoma/tratamento farmacológico , Pirazóis/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Humanos , Melanoma/enzimologia , Melanoma/fisiopatologia , Proteína Fosfatase 2/antagonistas & inibidores
19.
Phytopathology, v. 110, n. 11, p. 1751-1755, jun. 2020
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-3065

RESUMO

Xylella fastidiosa subsp. pauca , once confined to South America and infecting mainly citrus and coffee plants, has been found to be associated with other hosts and in other geographic regions. We present high-quality draft genome sequences of X. fastidiosa subsp. pauca strains J1a12, B111, U24D and XRB isolated from citrus plants in Brazil, strain Fb7 isolated from a citrus plant in Argentina and strains 3124, Pr8x and Hib4 isolated, respectively, from coffee, plum and hibiscus plants in Brazil. Sequencing was performed using Roche 454-GS FLX, MiSeq-Illumina or Pacific Biosciences platforms. These high-quality genome assemblies will be useful for further studies about the genomic diversity, evolution, and biology of X. fastidiosa.

20.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib17726

RESUMO

Xylella fastidiosa subsp. pauca , once confined to South America and infecting mainly citrus and coffee plants, has been found to be associated with other hosts and in other geographic regions. We present high-quality draft genome sequences of X. fastidiosa subsp. pauca strains J1a12, B111, U24D and XRB isolated from citrus plants in Brazil, strain Fb7 isolated from a citrus plant in Argentina and strains 3124, Pr8x and Hib4 isolated, respectively, from coffee, plum and hibiscus plants in Brazil. Sequencing was performed using Roche 454-GS FLX, MiSeq-Illumina or Pacific Biosciences platforms. These high-quality genome assemblies will be useful for further studies about the genomic diversity, evolution, and biology of X. fastidiosa.

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