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1.
Cell Death Dis ; 12(5): 452, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33958580

RESUMO

One of the critical events that regulates muscle cell differentiation is the replacement of the lamin B receptor (LBR)-tether with the lamin A/C (LMNA)-tether to remodel transcription and induce differentiation-specific genes. Here, we report that localization and activity of the LBR-tether are crucially dependent on the muscle-specific chaperone HSPB3 and that depletion of HSPB3 prevents muscle cell differentiation. We further show that HSPB3 binds to LBR in the nucleoplasm and maintains it in a dynamic state, thus promoting the transcription of myogenic genes, including the genes to remodel the extracellular matrix. Remarkably, HSPB3 overexpression alone is sufficient to induce the differentiation of two human muscle cell lines, LHCNM2 cells, and rhabdomyosarcoma cells. We also show that mutant R116P-HSPB3 from a myopathy patient with chromatin alterations and muscle fiber disorganization, forms nuclear aggregates that immobilize LBR. We find that R116P-HSPB3 is unable to induce myoblast differentiation and instead activates the unfolded protein response. We propose that HSPB3 is a specialized chaperone engaged in muscle cell differentiation and that dysfunctional HSPB3 causes neuromuscular disease by deregulating LBR.


Assuntos
Proteínas de Choque Térmico Pequenas/genética , Proteínas de Choque Térmico/metabolismo , Desenvolvimento Muscular/imunologia , Músculo Esquelético/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Linhagem Celular , Células HeLa , Humanos , Músculo Esquelético/citologia , Transfecção , Receptor de Lamina B
2.
J Womens Health (Larchmt) ; 30(5): 758-764, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33337929

RESUMO

Background: The last two decades have seen a growing number of pregnancies in women who needed the donation of oocytes. With oocyte donation pregnancies, studies on obstetric outcomes among these women revealed an increased incidence of pre-eclampsia and pregnancy-induced hypertension. Furthermore, several studies have found a higher incidence of low birth weight, preterm birth, and delivery by cesarean section in oocyte donation rather than in women subjected to assisted reproduction techniques (ART) with autologous oocytes. Numerous studies have also shown a deep connection between cardiovascular and thrombotic risk factors and adverse pregnancy outcomes. In this setting, to strictly assess the preconceptional risk for women who undergo egg donation to achieve pregnancy, the aim of our study is to draw a detailed assessment of the vascular risk profile of patients with gamete donation ART indications through the evaluation of comorbidities and cardiometabolic and thrombophilic markers Materials and Methods: Patients undergoing ART with oocyte or sperm donation or double donation of gametes underwent a careful clinical assessment through a detailed personal and family anamnesis and they were evaluated for cardiometabolic and thrombophilic profile. Clinical and demographic characteristics, comorbidities, and biohumoral parameters were collected. The study was approved by the Regional Ethical Committee(Em 2018-017 CINECA 10189). Results: We evaluated 525 women. Around 73.1% were >40 years and 35% of them were older than 45 years. There was a high prevalence of dyslipidemias (58.1%), smoking habit (24.6%), a body mass index >25 in 28.6% of patients, a high abdominal circumference in 58.1% of cases, a prevalence of acquired thrombophilia in about 7% and hereditary of 19.2%. Around 39.2% of patients had total cholesterol >200 mg/dL, 19.5% had high-density lipoprotein <48 mg/dL and 43.6% had low-density lipoprotein >115 mg/dL, and 6.9% had triglyceride values >150 mg/dL. Conclusions: A careful assessment of the preconceptional status of patients undergoing ART programs with oocyte donation can be highly recommended.


Assuntos
Doação de Oócitos , Nascimento Prematuro , Cesárea/efeitos adversos , Feminino , Fertilização in vitro , Humanos , Recém-Nascido , Doação de Oócitos/efeitos adversos , Gravidez , Resultado da Gravidez , Estudos Retrospectivos
3.
Transl Androl Urol ; 8(Suppl 1): S22-S30, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31143668

RESUMO

BACKGROUND: The purpose of this study is to assess the impact of paternal age on the oocyte-donation outcomes in intracytoplasmic sperm injection (ICSI) cycles. METHODS: Two hundred and seventy-eight infertile couples were retrospectively involved. Inclusion criteria were: infertility from almost 1 year, normal or sub-fertile seminal parameters, overall oocyte survival rate greater than 85%. Baseline characteristics included male age, recipient age, male body mass index (BMI), smoking, drinking status. Main outcome measures: fertilization rate (FR), cleavage rate (CR), pregnancy rate (PR). RESULTS: Patients were categorized in group 1 ≤45, group 2 >45 years. A total of 1,724 frozen oocytes were included. After warming, 1,642 oocytes survived. Median overall oocyte survival rate was 100% [interquartile range (IQR), 85-100%]. Median male age was 44±5.60 years (IQR, 31-70 years). Median recipients age was 42±3.62 years (IQR, 29-50 years). Group 1 included 166 men, group 2 112 men. Two hundred and seventy-eight fresh ICSI cycle were performed. "Two-pronuclear" (2PN) FR was 72.6%±0.20%, CR 93.0%±0.16%, PR 39.6%. Miscarriage rate was 25.5%. Live birth rate per cycles was 29.5%. Comparison between group 1, group 2 and ICSI outcomes confirmed an association with FR, resulting 80.0% (IQR, 67.0-83.0%) and 67.0% (IQR, 50.0-80.0%), respectively (P<0.01). There were no significant differences between the two groups with respect to seminal parameters. CONCLUSIONS: It would be recommended more emphasis on the advancing male age when counselling older couples who undergo egg donation program.

4.
Biochim Biophys Acta Gene Regul Mech ; 1861(5): 509-518, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29505822

RESUMO

The heterotrimeric NF-Y complex is a pioneer factor that binds to CCAAT-genes and regulates their transcription. NF-Y cooperates with multiple transcription factors and co-regulators in order to positively or negatively influence gene transcription. The recruitment of NF-Y to CCAAT box is significantly enriched in cancer-associated gene promoters loci and positively correlates with malignancy. NF-Y subunits, in particular the DNA-binding subunit NF-YA and the histone-fold subunit NF-YC, appear overexpressed in specific types of cancer. Here we demonstrate that NF-Y subunits expression is finely regulated through transcriptional and post-translational mechanisms thus allowing control over basal expression levels. NF-Y negatively regulates the transcription of the genes encoding for its subunits. DNA pull-down/affinity purification assay coupled with Mass Spectrometry identified putative co-regulators, such as Lamin A, involved in NF-YA gene transcription level. We also evidentiate how the stability of the complex is severely affected by the absence of one subunit. Our results identified for the first time one of the mechanisms responsible for NF-Y expression, which may be involved in the aberrant expression and activity observed in tumor cells and other pathological conditions.


Assuntos
Fator de Ligação a CCAAT/genética , Lamina Tipo A/genética , Neoplasias/genética , Transcrição Gênica , Regulação da Expressão Gênica , Células HCT116 , Humanos , Espectrometria de Massas , Neoplasias/patologia , Regiões Promotoras Genéticas , Ligação Proteica
5.
Oncotarget ; 7(29): 45901-45915, 2016 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-27323853

RESUMO

The expression of the high risk HPV18 E6 and E7 oncogenic proteins induces the transformation of epithelial cells, through the disruption of p53 and Rb function. The binding of cellular transcription factors to cis-regulatory elements in the viral Upstream Regulatory Region (URR) stimulates E6/E7 transcription. Here, we demonstrate that the CCAAT-transcription factor NF-Y binds to a non-canonical motif within the URR and activates viral gene expression. In addition, NF-Y indirectly up-regulates HPV18 transcription through the transactivation of multiple cellular transcription factors. NF-YA depletion inhibits the expression of E6 and E7 genes and re-establishes functional p53. The activation of p53 target genes in turn leads to apoptotic cell death. Finally, we show that NF-YA loss sensitizes HPV18-positive cells toward the DNA damaging agent Doxorubicin, via p53-mediated transcriptional response.


Assuntos
Fator de Ligação a CCAAT/metabolismo , Transformação Celular Viral/fisiologia , Proteínas de Ligação a DNA/biossíntese , Regulação Viral da Expressão Gênica/fisiologia , Proteínas Oncogênicas Virais/biossíntese , Proteína Supressora de Tumor p53/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Células HeLa , Papillomavirus Humano 18 , Humanos , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/metabolismo , Ativação Transcricional
6.
J Craniomaxillofac Surg ; 44(8): 1037-46, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27288326

RESUMO

OBJECTIVE: Evaluation of frontal vault symmetry and progressive facial symmetrization in a cohort of patients with hemicoronal single suture synostosis treated with a standardized cranioplasty and rigid fixation. PATIENTS AND METHODS: Fifty-four patients with hemicoronal synostosis operated between 1999 and 2014 were reviewed retrospectively. Pre, immediately postoperative and yearly photographs from the top of the skull and frontal views of the face were taken with the same head position and projection. A photogrammetric method was applied to quantify the pre and postoperative contour changes. The anterior skull hemispheres were traced, divided into two equal parts and the areas were compared. Angular measurements obtained by the intersection of the interpupillary line and the glabella perpendicular vertical line were calculated. The average photographic follow-up was 6.8 years. Range 1-14 years. RESULTS: The average advancement on the affected side was 18 mm (range: 16-23 mm). The pre-surgical cranial area on the affected side was increased on average 14.6 + 2.4% (range: 10-18%). The angular measurements documented the frontal symmetry obtained and the progressive improvement of facial symmetry. CONCLUSION: Cranioplasty with rigid fixation achieved a stable correction of anterior plagiocephaly leading to subsequent symmetrical facial growth. Photogrammetry allowed fora quantitative long-term validation.


Assuntos
Craniossinostoses/cirurgia , Face/anatomia & histologia , Osso Frontal/cirurgia , Órbita/cirurgia , Fotogrametria , Suturas Cranianas/cirurgia , Estética , Face/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Lactente , Masculino , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos
7.
Biochim Biophys Acta ; 1859(4): 627-38, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26921500

RESUMO

The heterotrimeric CCAAT-binding factor NF-Y controls the expression of a multitude of genes involved in cell cycle progression. NF-YA is present in two alternatively spliced isoforms, NF-YAs and NF-YAl, differing in 28 aminoacids in the N-terminal Q-rich activation domain. NF-YAs has been identified as a regulator of stemness and proliferation in mouse embryonic cells (mESCs) and human hematopoietic stem cells (hHSCs), whereas the role of NF-YAl is not clear. In the muscle system, NF-YA expression is observed in proliferating cells, but barely detectable in terminally differentiated cells in vitro and adult skeletal muscle in vivo. Here, we show that NF-YA inactivation in mouse myoblasts impairs both proliferation and differentiation. The overexpression of the two NF-YA isoforms differentially affects myoblasts fate: NF-YAs enhance cell proliferation, while NF-YAl boosts differentiation. The molecular mechanisms were investigated by expression profilings, detailing the opposite programs of the two isoforms. Bioinformatic analysis of the regulated promoters failed to detect a significant presence of CCAAT boxes in the regulated genes. NF-YAl activates directly Mef2D, Six genes, and p57kip2 (Cdkn1c), and indirectly the myogenic regulatory factors (MRFs). Specifically, Cdkn1c activation is induced by NF-Y binding to its CCAAT promoter and by reducing the expression of the lncRNA Kcnq1ot1, a negative regulator of Cdkn1c transcription. Overall, our results indicate that NF-YA alternative splicing is an influential muscle cell determinant, through direct regulation of selected cell cycle blocking genes, and, directly and indirectly, of muscle-specific transcription factors.


Assuntos
Fator de Ligação a CCAAT/genética , Diferenciação Celular/genética , Desenvolvimento Muscular/genética , Músculo Esquelético/crescimento & desenvolvimento , Isoformas de Proteínas/genética , Animais , Fator de Ligação a CCAAT/biossíntese , Proliferação de Células/genética , Ciclina B/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Hematopoéticas/metabolismo , Humanos , Camundongos , Mioblastos/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
8.
J Plast Reconstr Aesthet Surg ; 68(1): 79-86, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25287581

RESUMO

BACKGROUND: Maxillary distraction osteogenesis (DO) in cleft lip and palate patients has been described by several authors, but most studies have a relatively short follow-up and do not clearly separate growing patients from non-growing patients. METHOD: The records of 22 consecutive patients affected by cleft lip and palate, who underwent Le Fort I osteotomy and maxillary distraction with a rigid external distractor (RED), were reviewed. The sample was subdivided into a growing and a non-growing group. All patients had pre-DO cephalometric records, immediately post DO, 12 months post DO and long-term records with a long-term follow-up of >5 years (range 5-13 years). As a control sample for the growing group, cleft children with a negative overjet not subjected to distraction or any protraction treatment during growth were followed up until the completion of growth. RESULTS: The average maxillary advancement in the growing group was 22.2 ± 5.5 mm (range: 15-32 mm); in the non-growing group, it was 17.7 ± 6.6 mm (range: 6-25 mm). Excellent post-surgical stability was recorded in the adult sample. On the other hand, growing children had an average 16% relapse in the first year post DO and an additional 26% relapse in the long-term follow-up. CONCLUSIONS: This study seems to point out that early Le Fort I DO allows for the correction of very severe deformities. It is followed by a relatively high amount of true skeletal relapse in children with cleft lip and palate. Prognosis should be discussed in depth with the family and true aesthetic and psychological needs assessed.


Assuntos
Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Maxila/crescimento & desenvolvimento , Osteogênese por Distração/métodos , Osteotomia de Le Fort/métodos , Adolescente , Adulto , Fatores Etários , Análise de Variância , Cefalometria/métodos , Fenda Labial/diagnóstico , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Variações Dependentes do Observador , Estudos Retrospectivos , Medição de Risco , Fatores Sexuais , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
9.
PLoS One ; 8(1): e53664, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23326480

RESUMO

BACKGROUND: The activation of autophagy has been extensively described as a pro-survival strategy, which helps to keep cells alive following deprivation of nutrients/growth factors and other stressful cellular conditions. In addition to cytoprotective effects, autophagy can accompany cell death. Autophagic vacuoles can be observed before or during cell death, but the role of autophagy in the death process is still controversial. A complex interplay between autophagy and apoptosis has come to light, taking into account that numerous genes, such as p53 and Bcl-2 family members, are shared between these two pathways. METHODOLOGY/PRINCIPAL FINDINGS: In this study we showed a potent and irreversible cytotoxic activity of the stable Curcumin derivative bis-DeHydroxyCurcumin (bDHC) on human colon cancer cells, but not on human normal cells. Autophagy is elicited by bDHC before cell death as demonstrated by increased autophagosome formation -measured by electron microscopy, fluorescent LC3 puncta and LC3 lipidation- and autophagic flux -measured by interfering LC3-II turnover. The accumulation of poly-ubiquitinated proteins and ER-stress occurred upstream of autophagy induction and resulted in cell death. Cell cycle and Western blot analyses highlighted the activation of a mitochondrial-dependent apoptosis, which involves caspase 7, 8, 9 and Cytochrome C release. Using pharmacological inhibitions and RNAi experiments, we showed that ER-stress induced autophagy has a major role in triggering bDHC-cell death. CONCLUSION/SIGNIFICANCE: Our findings describe the mechanism through which bDHC promotes tumor selective inhibition of proliferation, providing unequivocal evidence of the role of autophagy in contrasting the proliferation of colon cancer cells.


Assuntos
Autofagia/efeitos dos fármacos , Neoplasias do Colo/patologia , Curcumina/análogos & derivados , Curcumina/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Mitocôndrias/metabolismo , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/enzimologia , Neoplasias do Colo/ultraestrutura , Curcumina/química , Diarileptanoides , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Ativação Enzimática/efeitos dos fármacos , Células HCT116 , Humanos , Mitocôndrias/ultraestrutura , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína Supressora de Tumor p53/metabolismo
10.
Oncotarget ; 3(2): 132-43, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22361592

RESUMO

p53 and p63 are transcription factors -TFs- playing master roles in the DNA-damage response and in the development and maintenance of pluristratified epithelia, respectively. p53 mutations are common in epithelial tumors and HaCaT keratinocytes harbor two p53 alleles -H179Y and R282Q- with gain-of-function (GOF) activity. Indeed, functional inactivation of mutp53 affects the growth rate of HaCaT. We investigated the strategy of mutp53, by performing ChIP-Seq experiments of mutp53 and p63 and analyzed the transcriptome after mutp53 inactivation. Mutp53 bind to 7135 locations in vivo, with a robust overlap with p63. De novo motifs discovery recovered a p53/p63RE with high information content in sites bound by p63 and mutp53/p63, but not by mutp53 alone: these sites are rather enriched in elements of other TFs. The HaCaT p63 locations are only partially overlapping with those of normal keratinocytes; importantly, and enriched in mutp53 sites which delineate a functionally different group of target genes. Our data favour a model whereby mutp53 GOF mutants act both by tethering growth-controlling TFs and highjacking p63 to new locations.


Assuntos
Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Apoptose/genética , Imunoprecipitação da Cromatina/métodos , DNA/metabolismo , Dano ao DNA , Reparo do DNA , Proteínas de Ligação a DNA , Perfilação da Expressão Gênica , Humanos , Queratinócitos/metabolismo , Regiões Promotoras Genéticas , Transcriptoma
11.
J Med Chem ; 54(23): 8066-77, 2011 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-22029378

RESUMO

New curcumin analogues (ester and acid series) were synthesized with the aim to improve the chemical stability in physiological conditions and potential anticancer activity. Cytotoxicity against different tumorigenic cell lines (human ovarian carcinoma cells -2008, A2780, C13*, and A2780/CP, and human colon carcinoma cells HCT116 and LoVo) was tested to evaluate cellular specificity and activity. Physico-chemical properties such as acidity, lipophilicity, kinetic stability, and free radical scavenging activity were investigated to shed light on the structure-activity relationship and provide new attractive candidates for drug development. Most of ester derivatives show IC(50) values lower than curcumin and exhibit selectivity against colon carcinoma cells. Especially they are extremely active after 24 h exposure showing enhanced inhibitory effect on cell viability. The best performances of ester curcuminoids could be ascribed to their high lipophilicity that favors a greater and faster cellular uptake overcoming their apparently higher instability in physiological condition.


Assuntos
Antineoplásicos/síntese química , Curcumina/análogos & derivados , Curcumina/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Curcumina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Estabilidade de Medicamentos , Ésteres , Sequestradores de Radicais Livres/síntese química , Sequestradores de Radicais Livres/farmacologia , Humanos , Solubilidade , Estereoisomerismo , Relação Estrutura-Atividade , Fatores de Tempo
12.
Biochem Pharmacol ; 78(10): 1305-15, 2009 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-19580791

RESUMO

Curcumin, a phenolic compound from the plant Curcuma longa L., has shown a wide-spectrum of chemopreventive, antioxidant and antitumor properties. Although its promising chemotherapeutic activity, preclinical and clinical studies highlight Curcumin limited therapeutic application due to its instability in physiological conditions. To improve its stability and activity, many derivatives have been synthesized and studied, among which bis-DemethoxyCurcumin (bDMC) and diAcetylCurcumin (DAC). In this report, we show that both bDMC and DAC are more stable than Curcumin in physiological medium. To explore the mechanism of their chemotherapeutic effect, we studied their role in proliferation in the HCT116 human colon cancer cells. We correlated kinetic stability and cellular uptake data to their biological effects. Both bDMC and DAC impair correct spindles formation and induce a p53- and p21(CIP1/WAF1)-independent mitotic arrest, which is more stable and long-lasting for bDMC. A subsequent p53/p21(CIP1/WAF1)-dependent inhibition of G1 to S transition is triggered by Curcumin and DAC as a consequence of the mitotic slippage, preventing post-mitotic cells from re-entering the cell cycle. Conversely, the G1/S arrest induced by bDMC is a direct effect of the drug and concomitant to the mitotic block. Finally, we demonstrate that bDMC induces rapid DNA double-strand breaks, moving for its possible development in anti-cancer clinical applications.


Assuntos
Anticarcinógenos/farmacologia , Ciclo Celular/efeitos dos fármacos , Curcumina/análogos & derivados , Anticarcinógenos/química , Anticarcinógenos/farmacocinética , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Curcumina/química , Curcumina/farmacocinética , Curcumina/farmacologia , Diarileptanoides , Estabilidade de Medicamentos , Citometria de Fluxo , Humanos , Immunoblotting , Microscopia de Fluorescência , Mitose/efeitos dos fármacos , Estrutura Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Relação Estrutura-Atividade
13.
Nucleic Acids Res ; 36(5): 1415-28, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18187512

RESUMO

The transcription factor NF-Y is a trimer with histone-like subunits that binds and activates CCAAT-containing promoters. NF-Y controls the expression of several key regulators of the cell cycle. In this study, we examined the functional and molecular effects of NF-YB knockdown. Cell cycle progression is affected with a G2/M-specific depletion. This is due to the inability of activation of G2/M-specific genes, as evidenced by expression profiling, RT-PCR and ChIP data. Surprisingly, apoptosis is also observed, with Caspase 3/7/8 cleavage. A role of p53 and Bcl-2 family members is important. NF-YB inactivation is sufficient to functionally activate p53, in the absence of DNA damage. Failure to maintain a physiologic level of CCAAT-dependent transcription of anti-apoptotic genes contributes to impairment of Bax/Bcl-2 and Bax/Bcl-X(L) ratios. Our data highlight the importance of fine balancing the NF-Y-p53 duo for cell survival by (i) maintaining transcription of anti-apoptotic genes and (ii) preventing p53 activation that triggers the apoptotic cascade.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Apoptose/genética , Fator de Ligação a CCAAT/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Fator de Ligação a CCAAT/antagonistas & inibidores , Fator de Ligação a CCAAT/genética , Caspases/metabolismo , Ciclo Celular/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Humanos , Interferência de RNA , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Transcrição Gênica
14.
J Biol Chem ; 281(4): 2347-57, 2006 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-16293626

RESUMO

Repression of G(2)/M promoters after DNA damage is an active mechanism that requires the p53 tumor suppressor. We have recently found that histone deacetylase 4 (HDAC4) is recruited on NF-Y-dependent repressed promoters. In this report, we describe the relationship between p53 and HDAC4 recruitment following DNA damage using immunofluorescence, chromatin immunoprecipitation, and transfection experiments. HDAC4 shuttles from the cytoplasm into the nucleus, following DNA damage, independently of the activation of p53 and becomes associated with promoters through a p53-dependent mechanism. The C-terminal lysines of p53, which are acetylated and methylated, are required for HDAC4 recruitment and transcriptional repression. Trichostatin treatment, but not HDAC4 functional inactivation, relieves the adriamycin-mediated repression of G(2)/M promoters. Our results indicate that HDAC4 is a component of the DNA damage response and that post-translational modifications of p53 are important for repression of G(2)/M genes.


Assuntos
Núcleo Celular/enzimologia , Dano ao DNA , Histona Desacetilases/biossíntese , Lisina/química , Proteína Supressora de Tumor p53/química , Animais , Western Blotting , Ciclo Celular , Divisão Celular , Núcleo Celular/metabolismo , Imunoprecipitação da Cromatina , Ciclina B/metabolismo , Citoplasma/metabolismo , Metilação de DNA , Doxorrubicina/farmacologia , Fase G2 , Genes p53 , Imunoprecipitação , Luciferases/metabolismo , Camundongos , Microscopia de Fluorescência , Células NIH 3T3 , Plasmídeos/metabolismo , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Proteína Supressora de Tumor p53/metabolismo
15.
Mol Cell Biol ; 25(9): 3737-51, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15831478

RESUMO

In response to DNA damage, p53 activates G(1)/S blocking and apoptotic genes through sequence-specific binding. p53 also represses genes with no target site, such as those for Cdc2 and cyclin B, key regulators of the G(2)/M transition. Like most G(2)/M promoters, they rely on multiple CCAAT boxes activated by NF-Y, whose binding to DNA is temporally regulated during the cell cycle. NF-Y associates with p53 in vitro and in vivo through the alphaC helix of NF-YC (a subunit of NF-Y) and a region close to the tetramerization domain of p53. Chromatin immunoprecipitation experiments indicated that p53 is associated with cyclin B2, CDC25C, and Cdc2 promoters in vivo before and after DNA damage, requiring DNA-bound NF-Y. Following DNA damage, p53 is rapidly acetylated at K320 and K373 to K382, histones are deacetylated, and the release of PCAF and p300 correlates with the recruitment of histone deacetylases (HDACs)-HDAC1 before HDAC4 and HDAC5-and promoter repression. HDAC recruitment requires intact NF-Y binding sites. In transfection assays, PCAF represses cyclin B2, and a nonacetylated p53 mutant shows a complete loss of repression potential, despite its abilities to bind NF-Y and to be recruited on G(2)/M promoters. These data (i) detail a strategy of direct p53 repression through associations with multiple NF-Y trimers that is independent of sequence-specific binding of p53 and that requires C-terminal acetylation, (ii) suggest that p53 is a DNA damage sentinel of the G(2)/M transition, and (iii) delineate a new role for PCAF in cell cycle control.


Assuntos
Fator de Ligação a CCAAT/metabolismo , Dano ao DNA/fisiologia , Regiões Promotoras Genéticas/fisiologia , Proteínas Repressoras/fisiologia , Proteína Supressora de Tumor p53/fisiologia , Acetilação , Acetiltransferases/metabolismo , Animais , Ciclo Celular/genética , Ciclo Celular/fisiologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Divisão Celular , Imunoprecipitação da Cromatina , Dano ao DNA/genética , Regulação para Baixo , Fase G2 , Histona Acetiltransferases , Histona Desacetilases/metabolismo , Histona Desacetilases/fisiologia , Humanos , Camundongos , Mutação/genética , Regiões Promotoras Genéticas/genética , Mapeamento de Interação de Proteínas , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Fatores de Transcrição de p300-CBP
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