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1.
Int J Mol Sci ; 25(15)2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39125761

RESUMO

MicroRNAs (miRNAs) are mighty post-transcriptional regulators in cell physiology and pathophysiology. In this review, we focus on the role of miR-223-3p (henceforth miR-223) in various cancer types. MiR-223 has established roles in hematopoiesis, inflammation, and most cancers, where it can act as either an oncogenic or oncosuppressive miRNA, depending on specific molecular landscapes. MiR-223 has also been linked to either the sensitivity or resistance of cancer cells to treatments in a context-dependent way. Through this detailed review, we highlight that for some cancers (i.e., breast, non-small cell lung carcinoma, and glioblastoma), the oncosuppressive role of miR-223 is consistently reported in the literature, while for others (i.e., colorectal, ovarian, and pancreatic cancers, and acute lymphocytic leukemia), an oncogenic role prevails. In prostate cancer and other hematological malignancies, although an oncosuppressive role is frequently described, there is less of a consensus. Intriguingly, NLRP3 and FBXW7 are consistently identified as miR-223 targets when the miRNA acts as an oncosuppressor or an oncogene, respectively, in different cancers. Our review also describes that miR-223 was increased in biological fluids or their extracellular vesicles in most of the cancers analyzed, as compared to healthy or lower-risk conditions, confirming the potential application of this miRNA as a diagnostic and prognostic biomarker in the clinic.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , MicroRNAs , Neoplasias , Humanos , MicroRNAs/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Animais
2.
Circ Res ; 127(6): 707-723, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32527198

RESUMO

RATIONALE: How endothelial cells (ECs) migrate and form an immature vascular plexus has been extensively studied. Yet, mechanisms underlying vascular remodeling remain poorly established. A better understanding of these processes may lead to the design of novel therapeutic strategies complementary to current angiogenesis inhibitors. OBJECTIVE: Starting from our previous observations that PP2A (protein phosphatase 2) regulates the HIF (hypoxia-inducible factor)/PHD-2 (prolyl hydroxylase 2)-constituted oxygen machinery, we hypothesized that this axis could play an important role during blood vessel formation, tissue perfusion, and oxygen restoration. METHODS AND RESULTS: We show that the PP2A regulatory subunit B55α is at the crossroad between vessel pruning and vessel maturation. Blood vessels with high B55α counter cell stress conditions and thrive for stabilization and maturation. When B55α is inhibited, ECs cannot cope with cell stress and undergo apoptosis, leading to massive pruning of nascent blood vessels. Mechanistically, we found that the B55α/PP2A complex restrains PHD-2 activity, promoting EC survival in a HIF-dependent manner, and furthermore dephosphorylates p38, altogether protecting ECs against cell stress occurring, for example, during the onset of blood flow. In tumors, EC-specific B55α deficiency induces pruning of immature-like tumor blood vessels resulting in delayed tumor growth and metastasis, without affecting nonpathological vessels. Consistently, systemic administration of a pan-PP2A inhibitor disrupts vascular network formation and tumor progression in vivo without additional effects on B55α-deficient vessels. CONCLUSIONS: Our data underline a unique role of the B55α/PP2A phosphatase complex in vessel remodeling and suggest the use of PP2A-inhibitors as potent antiangiogenic drugs targeting specifically nascent blood vessels with a mode-of-action complementary to VEGF-R (vascular endothelial growth factor receptor)-targeted therapies. Graphical Abstract: A graphical abstract is available for this article.


Assuntos
Apoptose , Neoplasias da Mama/enzimologia , Carcinoma Pulmonar de Lewis/enzimologia , Células Endoteliais/enzimologia , Neovascularização Patológica , Proteína Fosfatase 2/metabolismo , Remodelação Vascular , Inibidores da Angiogênese/farmacologia , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/patologia , Linhagem Celular Tumoral , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Inibidores Enzimáticos/farmacologia , Feminino , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/enzimologia , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2/genética , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
3.
Int J Mol Sci ; 23(13)2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35805964

RESUMO

The development of midbrain dopaminergic (DA) neurons requires a fine temporal and spatial regulation of a very specific gene expression program. Here, we report that during mouse brain development, the microRNA (miR-) 204/211 is present at a high level in a subset of DA precursors expressing the transcription factor Lmx1a, an early determinant for DA-commitment, but not in more mature neurons expressing Th or Pitx3. By combining different in vitro model systems of DA differentiation, we show that the levels of Lmx1a influence the expression of miR-204/211. Using published transcriptomic data, we found a significant enrichment of miR-204/211 target genes in midbrain dopaminergic neurons where Lmx1a was selectively deleted at embryonic stages. We further demonstrated that miR-204/211 controls the timing of the DA differentiation by directly downregulating the expression of Nurr1, a late DA differentiation master gene. Thus, our data indicate the Lmx1a-miR-204/211-Nurr1 axis as a key component in the cascade of events that ultimately lead to mature midbrain dopaminergic neurons differentiation and point to miR-204/211 as the molecular switch regulating the timing of Nurr1 expression.


Assuntos
Neurônios Dopaminérgicos , Proteínas com Homeodomínio LIM , MicroRNAs , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares , Animais , Diferenciação Celular/fisiologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Proteínas com Homeodomínio LIM/genética , Proteínas com Homeodomínio LIM/metabolismo , Mesencéfalo/metabolismo , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
J Immunol ; 200(2): 847-856, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29212908

RESUMO

TLR agonists are effective at treating superficial cancerous lesions, but their use internally for other types of tumors remains challenging because of toxicity. In this article, we report that murine and human naive CD4+ T cells that sequester Pam3Cys4 (CD4+ TPam3) become primed for Th1 differentiation. CD4+ TPam3 cells encoding the OVA-specific TCR OT2, when transferred into mice bearing established TGF-ß-OVA-expressing thymomas, produce high amounts of IFN-γ and sensitize tumors to PD-1/programmed cell death ligand 1 blockade-induced rejection. In contrast, naive OT2 cells without Pam3Cys4 cargo are prone to TGF-ß-dependent inducible regulatory Foxp3+ CD4+ T cell conversion and accelerate tumor growth that is largely unaffected by PD-1/programmed cell death ligand 1 blockade. Ex vivo analysis reveals that CD4+ TPam3 cells are resistant to TGF-ß-mediated gene expression through Akt activation controlled by inputs from the TCR and a TLR2-MyD88-dependent PI3K signaling pathway. These data show that CD4+ TPam3 cells are capable of Th1 differentiation in the presence of TGF-ß, suggesting a novel approach to adoptive cell therapy.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Neoplasias/imunologia , Neoplasias/metabolismo , Receptor 2 Toll-Like/agonistas , Fator de Crescimento Transformador beta/metabolismo , Evasão Tumoral/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Expressão Gênica , Interferon gama/genética , Interferon gama/metabolismo , Ligantes , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Modelos Biológicos , Fator 88 de Diferenciação Mieloide/metabolismo , Neoplasias/genética , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Receptor 2 Toll-Like/genética , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
5.
BMC Cell Biol ; 16: 27, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26577150

RESUMO

BACKGROUND: The nucleolus is a multi-domain enriched with proteins involved in ribosome biogenesis, cell cycle and apoptosis control, viral replication and differentiation of stem cells. Several authors have suggested a role for the nucleolus also in malignant transformation. We have recently demonstrated that under specific circumstances the transcriptional factor EGR1 is shuttled to the nucleolus where it functions as a negative regulator of RNA polymerase I. Since this activity is hampered in ARF -/- cells, and ARF transcription is regulated by EGR1 while the turnover of ARF protein is under the control of B23, we speculated that some sort of cooperation between EGR1 and B23 might also exist. RESULTS: In this work we identified a canonical EGR1 binding site on the B23 promoter through experiments of transactivation and in vitro DNA binding assay. We then found that the levels of B23 expression are directly correlated with those of EGR1, and that this correlation applies to several cellular types and to different stress conditions. Furthermore, we showed that EGR1 stability and accumulation within the nucleolus is in turn regulated by B23 through proteasome involvement, similarly to ARF turnover. CONCLUSION: Our results highlight EGR1 as a regulator of B23 expression actively playing within the newly discovered nucleolar B23-ARF-EGR1 network.


Assuntos
Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Neoplasias/metabolismo , Proteínas Nucleares/genética , Animais , Sequência de Bases , Sítios de Ligação , Proteína 1 de Resposta de Crescimento Precoce/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Neoplasias/genética , Neoplasias/fisiopatologia , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Nucleofosmina , Regiões Promotoras Genéticas , Ligação Proteica , Estresse Fisiológico
6.
Cell Mol Life Sci ; 71(13): 2547-59, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24202686

RESUMO

In this work, we show for the first time that a second splicing variant of the core clock gene Period 2 (Per2), Per2S, is expressed at both the mRNA and protein levels in human keratinocytes and that it localizes in the nucleoli. Moreover, we show that a reversible perturbation of the nucleolar structure acts as a resetting stimulus for the cellular clock. Per2S expression and periodic oscillation upon dexamethasone treatment were assessed by qRT-PCR using specific primers. Western blot (WB) analysis using an antibody against the recombinant human PER2 (abRc) displayed an intense band at a molecular weight of ~55 kDa, close to the predicted size of Per2S, and a weaker band at the expected size of Per2 (~140 kDa). The antibody raised against PER2 pS662 (abS662), an epitope absent in PER2S, detected only the higher band. Immunolocalization studies with abRc revealed a peculiar nucleolar signal colocalizing with the nucleolar marker nucleophosmin, whereas with abS662 the signal was predominantly diffuse all over the nucleus and partially colocalized with abRc in the nucleolus. The analysis of cell fractions by WB confirmed the enrichment of PER2S and the presence of PER2 in the nucleolar compartment. Finally, a pulse (1 h) of actinomycin D (0.01 µg/ml) induced reversible nucleolar disruption, PER2S de-localization and circadian synchronization of clock and Per2S genes. Our work represents the first evidence that the Per2S splicing isoform is a clock component expressed in human cells localizing in the nucleolus. These results suggest a critical role for the nucleolus in the process of circadian synchronization in human keratinocytes.


Assuntos
Processamento Alternativo/genética , Ritmo Circadiano/genética , Proteínas Circadianas Period/genética , Isoformas de Proteínas/genética , Linhagem Celular , Nucléolo Celular/genética , Nucléolo Celular/ultraestrutura , Dexametasona/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Humanos , Proteínas Circadianas Period/metabolismo , Isoformas de Proteínas/metabolismo
7.
Nat Cancer ; 5(8): 1206-1226, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38844817

RESUMO

Many individuals with cancer are resistant to immunotherapies. Here, we identify the gene encoding the pyrimidine salvage pathway enzyme cytidine deaminase (CDA) among the top upregulated metabolic genes in several immunotherapy-resistant tumors. We show that CDA in cancer cells contributes to the uridine diphosphate (UDP) pool. Extracellular UDP hijacks immunosuppressive tumor-associated macrophages (TAMs) through its receptor P2Y6. Pharmacologic or genetic inhibition of CDA in cancer cells (or P2Y6 in TAMs) disrupts TAM-mediated immunosuppression, promoting cytotoxic T cell entry and susceptibility to anti-programmed cell death protein 1 (anti-PD-1) treatment in resistant pancreatic ductal adenocarcinoma (PDAC) and melanoma models. Conversely, CDA overexpression in CDA-depleted PDACs or anti-PD-1-responsive colorectal tumors or systemic UDP administration (re)establishes resistance. In individuals with PDAC, high CDA levels in cancer cells correlate with increased TAMs, lower cytotoxic T cells and possibly anti-PD-1 resistance. In a pan-cancer single-cell atlas, CDAhigh cancer cells match with T cell cytotoxicity dysfunction and P2RY6high TAMs. Overall, we suggest CDA and P2Y6 as potential targets for cancer immunotherapy.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Imunoterapia , Difosfato de Uridina , Humanos , Difosfato de Uridina/metabolismo , Imunoterapia/métodos , Resistencia a Medicamentos Antineoplásicos/imunologia , Animais , Camundongos , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/terapia , Carcinoma Ductal Pancreático/tratamento farmacológico , Citidina Desaminase/metabolismo , Citidina Desaminase/genética , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/metabolismo , Linhagem Celular Tumoral , Receptores Purinérgicos P2/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Microambiente Tumoral/imunologia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/tratamento farmacológico , Nucleotídeos/metabolismo , Tolerância Imunológica , Receptor de Morte Celular Programada 1
8.
J Cell Mol Med ; 17(4): 552-66, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23490231

RESUMO

Muscarinic receptors, expressed in several primary and metastatic tumours, appear to be implicated in their growth and propagation. In this work we have demonstrated that M2 muscarinic receptors are expressed in glioblastoma human specimens and in glioblastoma cell lines. Moreover, we have characterized the effects of the M2 agonist arecaidine on cell growth and survival both in two different glioblastoma cell lines (U251MG and U87MG) and in primary cultures obtained from different human biopsies. Cell growth analysis has demonstrated that the M2 agonist arecaidine strongly decreased cell proliferation in both glioma cell lines and primary cultures. This effect was dose and time dependent. FACS analysis has confirmed cell cycle arrest at G1/S and at G2/M phase in U87 cells and U251 respectively. Cell viability analysis has also shown that arecaidine induced severe apoptosis, especially in U251 cells. Chemosensitivity assays have, moreover, shown arecaidine and temozolomide similar effects on glioma cell lines, although IC50 value for arecaidine was significantly lower than temozolomide. In conclusion, we report for the first time that M2 receptor activation has a relevant role in the inhibition of glioma cell growth and survival, suggesting that M2 may be a new interesting therapeutic target to investigate for glioblastoma therapy.


Assuntos
Antineoplásicos/farmacologia , Arecolina/análogos & derivados , Pontos de Checagem do Ciclo Celular , Sobrevivência Celular/efeitos dos fármacos , Receptor Muscarínico M2/agonistas , Apoptose , Arecolina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma , Humanos , Concentração Inibidora 50 , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor Muscarínico M2/metabolismo , Transdução de Sinais
9.
Can J Physiol Pharmacol ; 91(12): 1135-42, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24289086

RESUMO

Early growth response-1 one gene (Egr-1), one of the immediate early response genes, plays an important role in the adaptive response of the myocardium to hypertrophic stimuli. We aimed to investigate the effects of Egr-1 deletion on cardiac function. Egr-1 knock-out (Egr-1(-/-)) homozygous mice were employed to evaluate the electrophysiological and molecular properties of left ventricular cardiomyocytes (VCM) by using patch-clamp technique, intracellular calcium measurements, real-time PCR, and Western blot. Action potential was prolonged and diastolic potential was positive-shifted in VCMs isolated from Egr-1(-/-) mice, in comparison with those from their wild-type (WT) littermates. The calcium content of the sarcoplasmic reticulum was reduced and the decay time for steady-state calcium transient slowed down. Serca2, Ryr, L-type Ca(2+)-channel, and PLB mRNA expression were reduced in Egr-1(-/-) mice compared with the controls. Moreover, Serca2 protein was reduced, while the amount of Ncx1 protein was increased in Egr-1(-/-) hearts compared with those of the WT littermates. Furthermore, genes involved in heart development (GATA-4, TGF-ß) and in Egr-1 regulation (Nab1, Nab2) were down regulated in Egr-1(-/-) mice. These results suggest that Egr-1 plays a pivotal role in regulating excitation-contraction coupling in cardiac myocytes.


Assuntos
Cálcio/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Miócitos Cardíacos/metabolismo , Potenciais de Ação/genética , Animais , Regulação para Baixo/genética , Feminino , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismo , Ventrículos do Coração/metabolismo , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Retículo Sarcoplasmático/genética , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Trocador de Sódio e Cálcio/genética , Trocador de Sódio e Cálcio/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
10.
BMC Mol Cell Biol ; 23(1): 13, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35255831

RESUMO

BACKGROUND: The nucleolus is a subnuclear, non-membrane bound domain that is the hub of ribosome biogenesis and a critical regulator of cell homeostasis. Rapid growth and division of cells in tumors are correlated with intensive nucleolar metabolism as a response to oncogenic factors overexpression. Several members of the Epidermal Growth Factor Receptor (EGFR) family, have been identified in the nucleus and nucleolus of many cancer cells, but their function in these compartments remains unexplored. RESULTS: We focused our research on the nucleolar function that a specific member of EGFR family, the ErbB3 receptor, plays in glioblastoma, a tumor without effective therapies. Here, Neuregulin 1 mediated proliferative stimuli, promotes ErbB3 relocalization from the nucleolus to the cytoplasm and increases pre-rRNA synthesis. Instead ErbB3 silencing or nucleolar stress reduce cell proliferation and affect cell cycle progression. CONCLUSIONS: These data point to the existence of an ErbB3-mediated non canonical pathway that glioblastoma cells use to control ribosomes synthesis and cell proliferation. These results highlight the potential role for the nucleolar ErbB3 receptor, as a new target in glioblastoma.


Assuntos
Glioblastoma , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Proliferação de Células , Glioblastoma/metabolismo , Humanos , Receptor ErbB-3/genética , Receptor ErbB-3/metabolismo , Transcrição Gênica
11.
Cancer Cell Int ; 11: 5, 2011 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-21366897

RESUMO

BACKGROUND: Less than 30% of malignant gliomas respond to adjuvant chemotherapy. Here, we have asked whether variations in the constitutive expression of early-growth response factor 1 (EGR-1) predicted acute cytotoxicity and clonogenic cell death in vitro, induced by six different chemotherapics. MATERIALS AND METHODS: Cytotoxicity assays were performed on cells derived from fresh tumor explants of 18 human cases of malignant glioma. In addition to EGR-1, tumor cultures were investigated for genetic alterations and the expression of cancer regulating factors, related to the p53 pathway. RESULTS: We found that sensitivity to cisplatin correlates significantly with levels of EGR-1 expression in tumors with wild-type p53/INK4a/p16 status. CONCLUSION: Increased knowledge of the mechanisms regulating EGR-1 expression in wild-type p53/INK4a/p16 cases of glioma may help in the design of new chemotherapeutic strategies for these tumors.

12.
Cell Death Dis ; 12(12): 1139, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34880223

RESUMO

Transcriptional and cellular-stress surveillance deficits are hallmarks of Huntington's disease (HD), a fatal autosomal-dominant neurodegenerative disorder caused by a pathological expansion of CAG repeats in the Huntingtin (HTT) gene. The nucleolus, a dynamic nuclear biomolecular condensate and the site of ribosomal RNA (rRNA) transcription, is implicated in the cellular stress response and in protein quality control. While the exact pathomechanisms of HD are still unclear, the impact of nucleolar dysfunction on HD pathophysiology in vivo remains elusive. Here we identified aberrant maturation of rRNA and decreased translational rate in association with human mutant Huntingtin (mHTT) expression. The protein nucleophosmin 1 (NPM1), important for nucleolar integrity and rRNA maturation, loses its prominent nucleolar localization. Genetic disruption of nucleolar integrity in vulnerable striatal neurons of the R6/2 HD mouse model decreases the distribution of mHTT in a disperse state in the nucleus, exacerbating motor deficits. We confirmed NPM1 delocalization in the gradually progressing zQ175 knock-in HD mouse model: in the striatum at a presymptomatic stage and in the skeletal muscle at an early symptomatic stage. In Huntington's patient skeletal muscle biopsies, we found a selective redistribution of NPM1, similar to that in the zQ175 model. Taken together, our study demonstrates that nucleolar integrity regulates the formation of mHTT inclusions in vivo, and identifies NPM1 as a novel, readily detectable peripheral histopathological marker of HD progression.


Assuntos
Doença de Huntington , Animais , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Camundongos , Neurônios/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo
13.
Cell Mol Biol Lett ; 15(3): 365-76, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20386994

RESUMO

The mechanism by which the mitochondrial large rRNA is involved in the restoration of the pole cell-forming ability in Drosophila embryos is still unknown. We identified a 15-ribonucleotide sequence which is conserved from the protobacterium Wolbachia to the higher eukaryotes in domain V of the mitochondrial large rRNA. This short sequence is sufficient to restore pole cell determination in UV-irradiated Drosophila embryos. Here, we provide evidence that the conserved 15-base sequence is sufficient to restore luciferase activity in vitro. Moreover, we show that the internal GAGA sequence is involved in protein binding and that mutations in this tetranucleotide affect the sequence's ability to restore luciferase activity. The obtained results lead us to propose that mtlrRNA may be involved either in damaged protein reactivation or in protein biosynthesis during pole cell determination.


Assuntos
Drosophila melanogaster/embriologia , Embrião não Mamífero/efeitos da radiação , RNA Ribossômico 16S/química , RNA/química , Raios Ultravioleta , Animais , Sequência de Bases , Diferenciação Celular , Células Cultivadas , Drosophila melanogaster/metabolismo , Feminino , Conformação de Ácido Nucleico , Ligação Proteica , RNA/metabolismo , RNA Mitocondrial , RNA Ribossômico 16S/metabolismo , Proteínas de Ligação a RNA/metabolismo
14.
BMC Cell Biol ; 9: 32, 2008 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-18559082

RESUMO

BACKGROUND: Inside the cell, the HIV Tat protein is mainly found in the nucleus and nucleolus. The nucleolus, the site of ribosome biogenesis, is a highly organized, non-membrane-bound sub-compartment where proteins with a high affinity for nucleolar components are found. While it is well known that Tat accumulates in the nucleolus via a specific nucleolar targeting sequence, its function in this compartment it still unknown. RESULTS: To clarify the significance of the Tat nucleolar localization, we induced the expression of the protein during oogenesis in Drosophila melanogaster strain transgenic for HIV-tat gene. Here we show that Tat localizes in the nucleoli of Drosophila oocyte nurse cells, where it specifically co-localizes with fibrillarin. Tat expression is accompanied by a significant decrease of cytoplasmic ribosomes, which is apparently related to an impairment of ribosomal rRNA precursor processing. Such an event is accounted for by the interaction of Tat with fibrillarin and U3 snoRNA, which are both required for pre-rRNA maturation. CONCLUSION: Our data contribute to understanding the function of Tat in the nucleolus, where ribosomal RNA synthesis and cell cycle control take place. The impairment of nucleolar pre-rRNA maturation through the interaction of Tat with fibrillarin-U3snoRNA complex suggests a process by which the virus modulates host response, thus contributing to apoptosis and protein shut-off in HIV-uninfected cells.


Assuntos
HIV-1/fisiologia , Precursores de RNA/metabolismo , Processamento Pós-Transcricional do RNA , RNA Ribossômico/biossíntese , Produtos do Gene tat do Vírus da Imunodeficiência Humana/fisiologia , Animais , Animais Geneticamente Modificados , Nucléolo Celular/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Drosophila melanogaster/genética , Feminino , Humanos , RNA Nucleolar Pequeno/metabolismo , Ribossomos/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo
15.
Oncotarget ; 7(46): 74947-74965, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27732953

RESUMO

Epidermal Growth Factor Receptor (EGFR), a member of the ErbB family of receptor tyrosine kinase (RTK) proteins, is aberrantly expressed or deregulated in tumors and plays pivotal roles in cancer onset and metastatic progression. ZNF216 gene has been identified as one of Immediate Early Genes (IEGs) induced by RTKs. Overexpression of ZNF216 protein sensitizes 293 cell line to TNF-α induced apoptosis. However, ZNF216 overexpression has been reported in medulloblastomas and metastatic nasopharyngeal carcinomas. Thus, the role of this protein is still not clearly understood. In this study, the inverse correlation between EGFR and ZNF216 expression was confirmed in various human cancer cell lines differently expressing EGFR. EGF treatment of NIH3T3 cells overexpressing both EGFR and ZNF216 (NIH3T3-EGFR/ZNF216), induced a long lasting activation of EGFR in the cytosolic fraction and an accumulation of phosphorylated EGFR (pEGFR) more in the nuclear than in the cytosolic fraction compared to NIH3T3-EGFR cells. Moreover, EGF was able to stimulate an increased expression of ZNF216 in the cytosolic compartment and its nuclear translocation in a time-dependent manner in NIH3T3-EGFR/ZNF216. A similar trend was observed in A431 cells endogenously expressing the EGFR and transfected with Znf216. The increased levels of pEGFR and ZNF216 in the nuclear fraction of NIH3T3-EGFR/ZNF216 cells were paralleled by increased levels of phospho-MAPK and phospho-Akt. Surprisingly, EGF treatment of NIH3T3-EGFR/ZNF216 cells induced a significant increase of apoptosis thus indicating that ZNF216 could sensitize cells to EGF-induced apoptosis and suggesting that it may be involved in the regulation and effects of EGFR signaling.


Assuntos
Carcinoma/metabolismo , Receptores ErbB/metabolismo , Proteínas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinoma/genética , Linhagem Celular Tumoral , Expressão Ectópica do Gene , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/genética , Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Células NIH 3T3 , Fosforilação/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Ligação Proteica , Transporte Proteico , Proteínas/genética , Proteólise , Transdução de Sinais
16.
Appl Immunohistochem Mol Morphol ; 23(2): e4-7, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25675084

RESUMO

Mutations at the K-RAS locus in colon cancer cells are frequently associated with lack of responsiveness to therapy with EGFR inhibitors, as a consequence of the activation of Ras-dependent intracellular signals. Here we report a colon cancer case carrying a novel combination of K-RAS mutations involving codon 13 (Gly to Asp) and codon 19 (Leu to Phe), on separate alleles. The double mutation was restricted to tumor cells bearing a mucinous-like phenotype.


Assuntos
Adenocarcinoma Mucinoso/diagnóstico , Biomarcadores Tumorais/genética , Neoplasias do Colo/diagnóstico , Genes ras , Mutação/genética , Adenocarcinoma Mucinoso/tratamento farmacológico , Adenocarcinoma Mucinoso/patologia , Idoso , Alelos , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Biomarcadores Farmacológicos/metabolismo , Cetuximab , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Análise Mutacional de DNA , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Genes ras/genética , Humanos , Panitumumabe , Inibidores de Proteínas Quinases/uso terapêutico
17.
Biomed Res Int ; 2015: 162439, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26495284

RESUMO

Human adipose tissue-derived mesenchymal stem cells (ADMSCs) are considered eligible candidates for cardiovascular stem cell therapy applications due to their cardiac transdifferentiation potential and immunotolerance. Over the years, the in vitro culture of ADMSCs by platelet lysate (PL), a hemoderivate containing numerous growth factors and cytokines derived from platelet pools, has allowed achieving a safe and reproducible methodology to obtain high cell yield prior to clinical administration. Nevertheless, the biological properties of PL are still to be fully elucidated. In this brief report we show the potential ability of PL to induce a permissive state of cardiac-like transdifferentiation and to cause epigenetic modifications. RTPCR results indicate an upregulation of Cx43, SMA, c-kit, and Thy-1 confirmed by immunofluorescence staining, compared to standard cultures with foetal bovine serum. Moreover, PL-cultured ADMSCs exhibit a remarkable increase of both acetylated histones 3 and 4, with a patient-dependent time trend, and methylation at lysine 9 on histone 3 preceding the acetylation. Expression levels of p300 and SIRT-1, two major regulators of histone 3, are also upregulated after treatment with PL. In conclusion, PL could unravel novel biological properties beyond its routine employment in noncardiac applications, providing new insights into the plasticity of human ADMSCs.


Assuntos
Adipócitos/citologia , Plaquetas/química , Transdiferenciação Celular/fisiologia , Guias como Assunto , Células-Tronco Mesenquimais/citologia , Miócitos Cardíacos/citologia , Adipócitos/metabolismo , Plaquetas/citologia , Células Cultivadas , Humanos , Mediastino/anatomia & histologia , Mediastino/fisiologia , Células-Tronco Mesenquimais/metabolismo , Miócitos Cardíacos/metabolismo
18.
PLoS One ; 9(5): e96037, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24787739

RESUMO

EGR1 is an immediate early gene with a wide range of activities as transcription factor, spanning from regulation of cell growth to differentiation. Numerous studies show that EGR1 either promotes the proliferation of stimulated cells or suppresses the tumorigenic growth of transformed cells. Upon interaction with ARF, EGR1 is sumoylated and acquires the ability to bind to specific targets such as PTEN and in turn to regulate cell growth. ARF is mainly localized to the periphery of nucleolus where is able to negatively regulate ribosome biogenesis. Since EGR1 colocalizes with ARF under IGF-1 stimulation we asked the question of whether EGR1 also relocate to the nucleolus to interact with ARF. Here we show that EGR1 colocalizes with nucleolar markers such as fibrillarin and B23 in the presence of ARF. Western analysis of nucleolar extracts from HeLa cells was used to confirm the presence of EGR1 in the nucleolus mainly as the 100 kDa sumoylated form. We also show that the level of the ribosomal RNA precursor 47S is inversely correlated to the level of EGR1 transcripts. The EGR1 iseffective to regulate the synthesis of the 47S rRNA precursor. Then we demonstrated that EGR1 binds to the Upstream Binding Factor (UBF) leading us to hypothesize that the regulating activity of EGR1 is mediated by its interaction within the transcriptional complex of RNA polymerase I. These results confirm the presence of EGR1 in the nucleolus and point to a role for EGR1 in the control of nucleolar metabolism.


Assuntos
Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Regulação da Expressão Gênica , Precursores de RNA/genética , RNA Ribossômico/genética , Transcrição Gênica , Animais , Biomarcadores/metabolismo , Linhagem Celular , Nucléolo Celular/ultraestrutura , Proteína 1 de Resposta de Crescimento Precoce/química , Células HeLa , Humanos , Camundongos , Proteínas Pol1 do Complexo de Iniciação de Transcrição/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , RNA Polimerase I/metabolismo
19.
Cancer Biol Ther ; 15(11): 1489-98, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25482946

RESUMO

The role of muscarinic receptors in several diseases including cancer has recently emerged. To evaluate the hypothesis that muscarinic acetylcholine receptors may play a role in bladder cancer as well as in other tumor types, we investigated their expression in bladder tumor specimens. All examined samples expressed the M1, M2 and M3 receptor subtypes. We also found that the level of M2 transcripts, but not those of M1 or M3, significantly increased with the tumor histologic grade. In view of these results, we proceeded to investigate whether the M2 agonist Arecaidine had any effect on in vitro cell growth and migration of T24 cells, a bladder tumor cell line expressing the muscarinic receptors, including the M2 subtype. We observed that Arecaidine significantly reduced T24 and 5637 cell proliferation and migration in a concentration dependent manner. The silencing of M2 receptor by siRNA in T24 and 5637 cell lines showed the inability of Arecaidine (100 µM) to inhibit cell proliferation after 48 hours, whereas the use of M1 and M3 antagonists in T24 appeared not to counteract the Arecaidine effect, suggesting that the inhibition of cell proliferation was directly dependent on M2 receptor activation. These data suggest that M2 muscarinic receptors may play a relevant role in bladder cancer and represent a new attractive therapeutic target.


Assuntos
Antagonistas Muscarínicos/farmacologia , Receptor Muscarínico M2/antagonistas & inibidores , Neoplasias da Bexiga Urinária/metabolismo , Arecolina/análogos & derivados , Arecolina/farmacologia , Biópsia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Expressão Gênica , Humanos , Gradação de Tumores , Receptor Muscarínico M2/agonistas , Receptor Muscarínico M2/genética , Receptor Muscarínico M2/metabolismo , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
20.
PLoS One ; 7(10): e47825, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23110108

RESUMO

In the present study we evaluated the expression of the intermediate conductance calcium-activated potassium (KCa3.1) channel in human glioblastoma stem-like cells (CSCs) and investigated its role in cell motility. While the KCa3.1 channel is not expressed in neuronal- and glial-derived tissues of healthy individuals, both the KCa3.1 mRNA and protein are present in the glioblastoma tumor population, and are significantly enhanced in CSCs derived from both established cell line U87MG and a primary cell line, FCN9. Consistent with these data, voltage-independent and TRAM-34 sensitive potassium currents imputable to the KCa3.1 channel were recorded in the murine GL261 cell line and several primary human glioblastoma cells lines. Moreover, a significantly higher KCa3.1 current was recorded in U87MG-CD133 positive cells as compared to the U87MG-CD133 negative subpopulation. Further, we found that the tumor cell motility is strongly associated with KCa3.1 channel expression. Blockade of the KCa3.1 channel with the specific inhibitor TRAM-34 has in fact a greater impact on the motility of CSCs (reduction of 75%), which express a high level of KCa3.1 channel, than on the FCN9 parental population (reduction of 32%), where the KCa3.1 channel is expressed at lower level. Similar results were also observed with the CSCs derived from U87MG. Because invasion of surrounding tissues is one of the main causes of treatment failure in glioblastoma, these findings can be relevant for future development of novel cancer therapeutic drugs.


Assuntos
Movimento Celular/fisiologia , Glioblastoma/fisiopatologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Células-Tronco Neoplásicas/fisiologia , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Imunofluorescência , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/antagonistas & inibidores , Camundongos , Técnicas de Patch-Clamp , Pirazóis/farmacologia , Reação em Cadeia da Polimerase em Tempo Real
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