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Enhancers, critical regulatory elements within the human genome, are often transcribed into enhancer RNAs. The dysregulation of enhancers leads to diseases collectively termed enhanceropathies. While it is known that enhancers play a role in diseases by regulating gene expression, the specific mechanisms by which individual enhancers cause diseases are not well understood. Studies of individual enhancers are needed to fill this gap. This study delves into the role of APOE-activating noncoding RNA, AANCR, in the central nervous system, elucidating its function as a genetic modifier in Alzheimer's Disease. We employed RNA interference, RNaseH-mediated degradation, and single-molecule RNA fluorescence in situ hybridization to demonstrate that mere transcription of AANCR is insufficient; rather, its transcripts are crucial for promoting APOE expression. Our findings revealed that AANCR is induced by ATM-mediated ERK phosphorylation and subsequent AP-1 transcription factor activation. Once activated, AANCR enhances APOE expression, which in turn imparts an inflammatory phenotype to astrocytes. These findings demonstrate that AANCR is a key enhancer RNA in some cell types within the nervous system, pivotal for regulating APOE expression and influencing inflammatory responses, underscoring its potential as a therapeutic target in neurodegenerative diseases.
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BACKGROUND: Triple-negative breast cancer (TNBC) remains a clinically challenging subtype due to its aggressive nature and limited treatment options post-neoadjuvant failure. Historically, capecitabine has been the cornerstone of adjuvant therapy for TNBC patients not achieving a pathological complete response (pCR). However, the integration of new modalities such as immunotherapy and PARP inhibitors has prompted a re-evaluation of traditional post-neoadjuvant approaches. METHODS: This review synthesizes data from pivotal clinical trials and meta-analyses to evaluate the efficacy of emerging therapies in the post-neoadjuvant setting. We focus on the role of immune checkpoint inhibitors (ICIs), PARP inhibitors (PARPis), and antibody-drug conjugates (ADCs) alongside or in place of capecitabine in TNBC treatment paradigms. RESULTS: The addition of ICIs like pembrolizumab to neoadjuvant regimens has shown increased pCR rates and improved event-free survival, posing new questions about optimal post-neoadjuvant therapies. Similarly, PARPis have demonstrated efficacy in BRCA-mutated TNBC populations, with significant improvements in disease-free survival (DFS) and overall survival (OS). Emerging studies on ADCs further complicate the adjuvant landscape, offering potentially efficacious alternatives to capecitabine, especially in patients with residual disease after neoadjuvant therapy. DISCUSSION: The challenge remains to integrate these new treatments into clinical practice effectively, considering factors such as drug resistance, patient-specific characteristics, and socio-economic barriers. This review discusses the implications of these therapies and suggests a future direction focused on personalized medicine approaches in TNBC. CONCLUSIONS: As the treatment landscape for TNBC evolves, the role of capecitabine is being critically examined. While it remains a viable option for certain patient groups, the introduction of ICIs, PARPis, and ADCs offers promising alternatives that could redefine adjuvant therapy standards. Ongoing and future trials will be pivotal in determining the optimal therapeutic strategies for TNBC patients with residual disease post-neoadjuvant therapy.
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Capecitabina , Terapia Neoadjuvante , Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Capecitabina/uso terapêutico , Terapia Neoadjuvante/métodos , Inibidores de Checkpoint Imunológico/uso terapêutico , Feminino , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêuticoRESUMO
In the nucleus, biological processes are driven by proteins that diffuse through and bind to a meshwork of nucleic acid polymers. To better understand this interplay, we present an imaging platform to simultaneously visualize single protein dynamics together with the local chromatin environment in live cells. Together with super-resolution imaging, new fluorescent probes, and biophysical modeling, we demonstrate that nucleosomes display differential diffusion and packing arrangements as chromatin density increases whereas the viscoelastic properties and accessibility of the interchromatin space remain constant. Perturbing nuclear functions impacts nucleosome diffusive properties in a manner that is dependent both on local chromatin density and on relative location within the nucleus. Our results support a model wherein transcription locally stabilizes nucleosomes while simultaneously allowing for the free exchange of nuclear proteins. Additionally, they reveal that nuclear heterogeneity arises from both active and passive processes and highlight the need to account for different organizational principles when modeling different chromatin environments.
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Cromatina , Nucleossomos , Imagem Individual de Molécula , Nucleossomos/metabolismo , Cromatina/metabolismo , Cromatina/química , Humanos , Imagem Individual de Molécula/métodos , Núcleo Celular/metabolismo , Histonas/metabolismo , Células HeLa , DifusãoRESUMO
INTRODUCTION: High prevalence of commercial tobacco product (CTP) use among American Indian and Alaska Native (AI/AN) youth is a public health crisis. A multi-level Tribal-community-based participatory research project under Tribal public health authority implemented a retailer-focused intervention to reduce AI/AN youth CTP use. METHODS: We sought resolutions in support of a retailer-focused CTP intervention from Tribal Nations organized by a tribally-directed research program. We identified tobacco retail outlets operating on and within 5 miles of 9 Tribal reservations, and CTP products sold at these outlets. We conducted a four-wave Reward and Reminder intervention with apparent minor buyers. Clerks who complied with the law received a modest reward and commendation in social media posts to the local Tribal communities, while clerks who sold without age verification were reminded of the laws. RESULTS: Of 18 retail outlets selling CTP, 8 sold e-cigarettes, and all sold combustible cigarettes. The Reward and Reminder intervention showed an approximate 25% reduction in sales of CTP to apparent minors, with a 33% baseline CTP sales rate without age verification and an 8% intervention CTP sales rate without age verification. CONCLUSIONS: The intervention increased awareness of laws prohibiting CTP sales to minors and mandating age verification for young adults seeking to buy CTP. The intervention, which had support from all governing Tribal Nations, builds the evidence base of effective practices which Tribal public health authorities may utilize to reduce youth access to CTP on and around Tribal reservations. IMPLICATIONS: Sovereign Tribes have authority over commercial businesses operating on their lands. Tobacco 21 laws aiming to restrict commercial tobacco availability to youth are supported by Tribes. A retailer intervention in which apparent minors attempt commercial tobacco purchases can offer accountability feedback to retailers both on and near Tribal reservations. Obtaining Tribal support and publicizing the interventions helps mobilize Tribal communities to support commercial tobacco prevention and promote healthy youth.
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BACKGROUND: An international multidisciplinary panel of experts aimed to provide consensus guidelines describing the optimal intratumoral and intranodal injection of NBTXR3 hafnium oxide nanoparticles in head and neck squamous cell carcinoma (HNSCC) of the oral cavity, oropharynx, and cervical lymph nodes and to review data concerning safety, feasibility, and procedural aspects of administration. METHODS: The Delphi method was used to determine consensus. A 4-member steering committee and a 10-member monitoring committee wrote and revised the guidelines, divided into eight sections. An independent 3-member reading committee reviewed the recommendations. RESULTS: After two rounds of voting, strong consensus was obtained on all recommendations. Intratumoral and intranodal injection was deemed feasible. NBTXR3 volume calculation, choice of patients, preparation and injection procedure, potential side effects, post injection, and post treatment follow-up were described in detail. CONCLUSIONS: Best practices for the injection of NBTXR3 were defined, thus enabling international standardization of intratumoral nanoparticle injection.
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Neoplasias de Cabeça e Pescoço , Injeções Intralesionais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Humanos , Neoplasias de Cabeça e Pescoço/terapia , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia , Técnica Delphi , Háfnio/administração & dosagem , Óxidos/administração & dosagem , Nanopartículas/administração & dosagem , Masculino , Consenso , Feminino , Carcinoma de Células Escamosas/terapia , Carcinoma de Células Escamosas/patologia , Guias de Prática Clínica como AssuntoRESUMO
In the nucleus, biological processes are driven by proteins that diffuse through and bind to a meshwork of nucleic acid polymers. To better understand this interplay, we developed an imaging platform to simultaneously visualize single protein dynamics together with the local chromatin environment in live cells. Together with super-resolution imaging, new fluorescent probes, and biophysical modeling, we demonstrated that nucleosomes display differential diffusion and packing arrangements as chromatin density increases whereas the viscoelastic properties and accessibility of the interchromatin space remain constant. Perturbing nuclear functions impacted nucleosome diffusive properties in a manner that was dependent on local chromatin density and supportive of a model wherein transcription locally stabilizes nucleosomes while simultaneously allowing for the free exchange of nuclear proteins. Our results reveal that nuclear heterogeneity arises from both active and passive process and highlights the need to account for different organizational principals when modeling different chromatin environments.
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PELP1 (Proline-, Glutamic acid-, Leucine-rich protein 1) is a large scaffolding protein that functions in many cellular pathways including steroid receptor (SR) coactivation, heterochromatin maintenance, and ribosome biogenesis. PELP1 is a proto-oncogene whose expression is upregulated in many human cancers, but how the PELP1 scaffold coordinates its diverse cellular functions is poorly understood. Here we show that PELP1 serves as the central scaffold for the human Rix1 complex whose members include WDR18, TEX10, and SENP3. We reconstitute the mammalian Rix1 complex and identified a stable sub-complex comprised of the conserved PELP1 Rix1 domain and WDR18. We determine a 2.7 Å cryo-EM structure of the subcomplex revealing an interconnected tetrameric assembly and the architecture of PELP1's signaling motifs, including eleven LxxLL motifs previously implicated in SR signaling and coactivation of Estrogen Receptor alpha (ERα) mediated transcription. However, the structure shows that none of these motifs is in a conformation that would support SR binding. Together this work establishes that PELP1 scaffolds the Rix1 complex, and association with WDR18 may direct PELP1's activity away from SR coactivation.
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Neoplasias da Mama , Fatores de Transcrição , Animais , Humanos , Feminino , Proteínas Correpressoras/metabolismo , Fatores de Transcrição/metabolismo , Microscopia Crioeletrônica , Ligação Proteica , Transdução de Sinais , Mamíferos/metabolismo , Cisteína Endopeptidases/metabolismo , Proteínas Nucleares/metabolismoRESUMO
The hormone-stimulated glucocorticoid receptor (GR) modulates transcription by interacting with thousands of enhancers and GR binding sites (GBSs) throughout the genome. Here, we examined the effects of GR binding on enhancer dynamics and investigated the contributions of individual GBSs to the hormone response. Hormone treatment resulted in genome-wide reorganization of the enhancer landscape in breast cancer cells. Upstream of the DDIT4 oncogene, GR bound to four sites constituting a hormone-dependent super enhancer. Three GBSs were required as hormone-dependent enhancers that differentially promoted histone acetylation, transcription frequency, and burst size. Conversely, the fourth site suppressed transcription and hormone treatment alleviated this suppression. GR binding within the super enhancer promoted a loop-switching mechanism that allowed interaction of the DDIT4 TSS with the active GBSs. The unique functions of each GR binding site contribute to hormone-induced transcriptional heterogeneity and demonstrate the potential for targeted modulation of oncogene expression.
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Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Dexametasona/farmacologia , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Receptores de Glucocorticoides/agonistas , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Transdução de Sinais , Fatores de Transcrição/genéticaRESUMO
The activities of RNA polymerase and the spliceosome are responsible for the heterogeneity in the abundance and isoform composition of mRNA in human cells. However, the dynamics of these megadalton enzymatic complexes working in concert on endogenous genes have not been described. Here, we establish a quasi-genome-scale platform for observing synthesis and processing kinetics of single nascent RNA molecules in real time. We find that all observed genes show transcriptional bursting. We also observe large kinetic variation in intron removal for single introns in single cells, which is inconsistent with deterministic splice site selection. Transcriptome-wide footprinting of the U2AF complex, nascent RNA profiling, long-read sequencing, and lariat sequencing further reveal widespread stochastic recursive splicing within introns. We propose and validate a unified theoretical model to explain the general features of transcription and pervasive stochastic splice site selection.
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Precursores de RNA/genética , Sítios de Splice de RNA/fisiologia , Transcrição Gênica , Éxons/genética , Humanos , Íntrons/genética , Precursores de RNA/metabolismo , Sítios de Splice de RNA/genética , Splicing de RNA/genética , Splicing de RNA/fisiologia , RNA Mensageiro/metabolismo , Spliceossomos/metabolismo , TranscriptomaRESUMO
Transcription in several organisms from certain bacteria to humans has been observed to be stochastic in nature: toggling between active and inactive states. Periods of active nascent RNA synthesis known as bursts represent individual gene activation events in which multiple polymerases are initiated. Therefore, bursting is the single locus illustration of both gene activation and repression. Although transcriptional bursting was originally observed decades ago, only recently have technological advances enabled the field to begin elucidating gene regulation at the single-locus level. In this review, we focus on how biochemical, genomic, and single-cell data describe the regulatory steps of transcriptional bursts.
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Cromatina/química , DNA/genética , Regulação da Expressão Gênica , Genoma , RNA Polimerase II/genética , RNA Mensageiro/genética , Transcrição Gênica , Animais , Cromatina/metabolismo , DNA/metabolismo , Células Eucarióticas/metabolismo , Loci Gênicos , Histonas/genética , Histonas/metabolismo , Humanos , Técnicas de Sonda Molecular , Sondas Moleculares/química , RNA Polimerase II/metabolismo , RNA Mensageiro/metabolismo , Análise de Célula Única/métodos , Processos EstocásticosRESUMO
BACKGROUND: The long-term survival of germline retinoblastoma patients is decreased due to the risk of second primary tumors (SPTs) that occur years after the diagnosis of retinoblastoma. This risk is related to genetic predisposition and other factors, such as the treatment of retinoblastoma by external beam radiotherapy (EBRT). PROCEDURE: We studied the incidence, risk factors, and prognosis of specific craniofacial SPTs developed within the margins of radiation field in a cohort of 209 patients with germline retinoblastoma treated with EBRT at our institution between 1977 and 2010. Clinical characteristics, survival, incidence, and histology of craniofacial SPTs were recorded. RESULTS: Fifty-three of the 209 patients developed 60 distinct craniofacial SPTs in irradiated field with a median time from EBRT of 16.9 years (4-35) and a median follow-up of 24.8 years (5.3-40). Osteosarcoma (33.3%) and undifferentiated sarcoma (23.3%) were the more prevalent histological entities. Benign tumors (16.7%) also occurred. The cumulative incidence of craniofacial SPTs reached 32.6% at 35 years after EBRT, and the median survival after diagnosis was five years. In our series, irradiation under 12 months of age, bilateral EBRT, or previous treatment of retinoblastoma with chemotherapy did not significantly increase the risk of craniofacial SPTs. CONCLUSIONS: This work presents a strong argument to avoid EBRT in the management of retinoblastoma and emphasizes the high risk and poor prognosis of specific craniofacial SPTs. This study also points to the question of the need and benefits of special programs for early detection of craniofacial SPTs in survivors of irradiated germline retinoblastoma.
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Predisposição Genética para Doença , Células Germinativas/patologia , Neoplasias Induzidas por Radiação/etiologia , Segunda Neoplasia Primária/etiologia , Radioterapia/efeitos adversos , Neoplasias da Retina/radioterapia , Retinoblastoma/radioterapia , Adolescente , Adulto , Sobreviventes de Câncer/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Neoplasias Induzidas por Radiação/patologia , Segunda Neoplasia Primária/patologia , Prognóstico , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Retinoblastoma/genética , Retinoblastoma/patologia , Estudos Retrospectivos , Taxa de Sobrevida , Adulto JovemRESUMO
We report on a case of a 14-year-old phenotypic female with a microdeletion at 13q31.1-q31.3, dysmorphic facial and limb features, and neurologic symptoms. She presented to her pediatrician with concerns for delayed puberty, and laboratory analysis revealed hypergonadotropic hypogonadism. She was found to have an XY karyotype and streak gonads. Further genetic studies did not reveal another cause for her gonadal dysgenesis and, to our knowledge, an association with her known 13q-microdeletion has not yet been reported. Given the risk of malignancy with XY gonadal dysgenesis, the patient had surgery to remove the gonads and had no postoperative complications after a 6-month follow-up visit. We also discuss the role of the pediatrician in cases of delayed puberty, from initial diagnosis to definitive management. [Pediatr Ann. 2019;48(12):e495-e500.].
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Amenorreia/fisiopatologia , Disgenesia Gonadal 46 XY/diagnóstico , Disgenesia Gonadal 46 XY/cirurgia , Ductos Paramesonéfricos/cirurgia , Puberdade Tardia/etiologia , Adolescente , Amenorreia/etiologia , Feminino , Seguimentos , Testes Genéticos , Humanos , Hipogonadismo/cirurgia , Fenótipo , Puberdade Tardia/fisiopatologia , Doenças Raras , Medição de Risco , Resultado do TratamentoRESUMO
OBJECTIVE: To evaluate the prognostic significance of lymph node count (LNC) at post-chemotherapy retroperitoneal lymphadenectomy (PC-RPLND) in metastatic non-seminomatous germ cell tumour (NSGCT) using the Surveillance, Epidemiology, and End Results (SEER) database and National Cancer Database (NCDB). PATIENTS AND METHODS: SEER (2000-2013, n = 572) and NCDB (2004-2013, n = 731) identified patients undergoing PC-RPLND for Stage II and III NSGCT. Correlation between linear or categorial variables and LNC was conducted using Spearman's rank correlation or Kruskal-Wallis test by ranks. Patients were stratified by ≤20, 21-40, and >40 LNs for Kaplan-Meier analysis. Cox proportional hazards models evaluated the association of LNC at PC-RPLND with overall mortality (OM) in the NCDB and cancer-specific mortality (CSM) in the SEER database. The relationship between LNC and OM or CSM was also modelled as a non-linear function to determine a threshold for survival benefit. RESULTS: Amongst all patients, the median (interquartile range) LNC was 17 (3-26) LNs in the NCDB, and 18 (6-31) LNs in the SEER database. More recent diagnosis year, higher hospital volume, higher median income, private insurance status, and positive LNC were associated with greater total LNC in one or both databases (P < 0.05). On Kaplan-Meier analysis, >40 LNs was associated with 5-year cancer-specific survival (CSS) of 99% and overall survival (OS) of 96%, whereas ≤20 LNs had a 5-year CSS of 91% and OS of 78% (CSS, P = 0.04; OS, P < 0.01). Risk-adjusted Cox model showed increasing LNC (per node) was inversely associated with OM (hazard ratio [HR] 0.96, 95% confidence interval [CI], 0.94-0.98; P < 0.01) and CSM (HR 0.96, 95% CI, 0.94-0.99; P = 0.01). Non-linear modelling showed the greatest benefit in OM at between 10 and 20 LNs, but continued survival benefit for OM and CSM beyond 20 LNs. CONCLUSIONS: Greater LNC during PC-RPLND appears to be associated with improved CSS and OS in NSGCT. Our data support the role of thorough RPLND for post-chemotherapy metastatic NSGCT.
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Linfonodos , Neoplasias Testiculares , Adulto , Antineoplásicos/uso terapêutico , Humanos , Estimativa de Kaplan-Meier , Excisão de Linfonodo , Linfonodos/patologia , Linfonodos/cirurgia , Masculino , Prognóstico , Espaço Retroperitoneal/cirurgia , Estudos Retrospectivos , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/mortalidade , Neoplasias Testiculares/patologia , Neoplasias Testiculares/terapia , Adulto JovemRESUMO
Transcriptional regulation in metazoans occurs through long-range genomic contacts between enhancers and promoters, and most genes are transcribed in episodic "bursts" of RNA synthesis. To understand the relationship between these two phenomena and the dynamic regulation of genes in response to upstream signals, we describe the use of live-cell RNA imaging coupled with Hi-C measurements and dissect the endogenous regulation of the estrogen-responsive TFF1 gene. Although TFF1 is highly induced, we observe short active periods and variable inactive periods ranging from minutes to days. The heterogeneity in inactive times gives rise to the widely observed "noise" in human gene expression and explains the distribution of protein levels in human tissue. We derive a mathematical model of regulation that relates transcription, chromosome structure, and the cell's ability to sense changes in estrogen and predicts that hypervariability is largely dynamic and does not reflect a stable biological state.
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Regulação da Expressão Gênica/fisiologia , Expressão Gênica/fisiologia , Transcrição Gênica/fisiologia , Receptor alfa de Estrogênio/metabolismo , Estrogênios , Expressão Gênica/genética , Humanos , Modelos Teóricos , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/metabolismo , Análise de Célula Única/métodos , Transcrição Gênica/genética , Ativação Transcricional/fisiologia , Fator Trefoil-1/genéticaRESUMO
BACKGROUND: Transurethral resection of the prostate is the most commonly performed procedure for the management of benign prostatic obstruction. However, little is known about the effect surgical duration has on complications. We assess the relationship between operative time and TURP complications using a modern national surgical registry. METHODS: We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) from 2006 to 2016 for patients undergoing TURP. Patients were separated into five groups based on operative time: 0-30 min, 30.1-60 min, 60.1-90 min, 90.1-120 min, and greater than 120 min. Standard statistical analysis, including multivariate regression, was performed to determine factors associated with complications. RESULTS: 31,813 patients who underwent TURP were included. The overall complication rate was 9.0% and increased significantly with longer surgical duration (p < 0.001). Longer operative time was associated with a greater risk of postoperative sepsis or shock, transfusion, reoperation, and deep vein thrombus or pulmonary embolism. Longer surgical duration was associated with increased odds of any complication and, specifically, blood transfusion after controlling for age, race, comorbidities, American Society of Anesthesia (ASA) class, type of anesthesia administered, and trainee involvement. The adjusted risk of each of the above complications remained significantly increased for surgeries lasting longer than 120 min. CONCLUSIONS: As surgical duration increases, there is a significant increase in the rate of complications after TURP. These data demonstrate that this procedure is safest when performed in under 90 min.
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Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Doenças Prostáticas/complicações , Doenças Prostáticas/epidemiologia , Ressecção Transuretral da Próstata/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Prostáticas/cirurgia , Melhoria de Qualidade , Qualidade da Assistência à Saúde , Sistema de Registros , Fatores de Risco , Ressecção Transuretral da Próstata/métodos , Ressecção Transuretral da Próstata/estatística & dados numéricos , Estados Unidos/epidemiologiaRESUMO
We present near infrared high-precision photometry for eight transiting hot Jupiters observed during their predicted secondary eclipses. Our observations were carried out using the staring mode of the WIRCam instrument on the Canada-France-Hawaii Telescope (CFHT). We present the observing strategies and data reduction methods which delivered time series photometry with statistical photometric precision as low as 0.11%. We performed a Bayesian analysis to model the eclipse parameters and systematics simultaneously. The measured planet-to-star flux ratios allowed us to constrain the thermal emission from the day side of these hot Jupiters, as we derived the planet brightness temperatures. Our results combined with previously observed eclipses reveal an excess in the brightness temperatures relative to the blackbody prediction for the equilibrium temperatures of the planets for a wide range of heat redistribution factors. We find a trend that this excess appears to be larger for planets with lower equilibrium temperatures. This may imply some additional sources of radiation, such as reflected light from the host star and/or thermal emission from residual internal heat from the formation of the planet.
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The enhancer regions of the myogenic master regulator MyoD give rise to at least two enhancer RNAs. Core enhancer eRNA (CEeRNA) regulates transcription of the adjacent MyoD gene, whereas DRReRNA affects expression of Myogenin in trans. We found that DRReRNA is recruited at the Myogenin locus, where it colocalizes with Myogenin nascent transcripts. DRReRNA associates with the cohesin complex, and this association correlates with its transactivating properties. Despite being expressed in undifferentiated cells, cohesin is not loaded on Myogenin until the cells start expressing DRReRNA, which is then required for cohesin chromatin recruitment and maintenance. Functionally, depletion of either cohesin or DRReRNA reduces chromatin accessibility, prevents Myogenin activation, and hinders muscle cell differentiation. Thus, DRReRNA ensures spatially appropriate cohesin loading in trans to regulate gene expression.
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Proteínas de Ciclo Celular/biossíntese , Proteínas Cromossômicas não Histona/biossíntese , Elementos Facilitadores Genéticos , Músculo Esquelético/metabolismo , Miogenina/biossíntese , RNA não Traduzido/metabolismo , Transcrição Gênica , Animais , Proteínas de Ciclo Celular/genética , Diferenciação Celular , Cromatina/genética , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Células HEK293 , Humanos , Camundongos , Músculo Esquelético/citologia , Proteína MyoD/biossíntese , Proteína MyoD/genética , Miogenina/genética , RNA não Traduzido/genética , CoesinasRESUMO
Spacecraft assembly facilities are oligotrophic and low-humidity environments, which are routinely cleaned using alcohol wipes for benchtops and spacecraft materials, and alkaline detergents for floors. Despite these cleaning protocols, spacecraft assembly facilities possess a persistent, diverse, dynamic, and low abundant core microbiome, where the Acinetobacter are among the dominant members of the community. In this report, we show that several spacecraft-associated Acinetobacter metabolize or biodegrade the spacecraft cleaning reagents of ethanol (ethyl alcohol), 2-propanol (isopropyl alcohol), and Kleenol 30 (floor detergent) under ultraminimal conditions. Using cultivation and stable isotope labeling studies, we show that ethanol is a sole carbon source when cultivating in 0.2 × M9 minimal medium containing 26 µM Fe(NH4)2(SO4)2. Although cultures expectedly did not grow solely on 2-propanol, cultivations on mixtures of ethanol and 2-propanol exhibited enhanced plate counts at mole ratios of ≤0.50. In support, enzymology experiments on cellular extracts were consistent with oxidation of ethanol and 2-propanol by a membrane-bound alcohol dehydrogenase. In the presence of Kleenol 30, untargeted metabolite profiling on ultraminimal cultures of Acinetobacter radioresistens 50v1 indicated (1) biodegradation of Kleenol 30 into products including ethylene glycols, (2) the potential metabolism of decanoate (formed during incubation of Kleenol 30 in 0.2 × M9), and (3) decreases in the abundances of several hydroxy- and ketoacids in the extracellular metabolome. In ultraminimal medium (when using ethanol as a sole carbon source), A. radioresistens 50v1 also exhibits a remarkable survival against hydrogen peroxide (â¼1.5-log loss, â¼108 colony forming units (cfu)/mL, 10 mM H2O2), indicating a considerable tolerance toward oxidative stress under nutrient-restricted conditions. Together, these results suggest that the spacecraft cleaning reagents may (1) serve as nutrient sources under oligotrophic conditions and (2) sustain extremotolerances against the oxidative stresses associated with low-humidity environments. In perspective, this study provides a plausible biochemical rationale to the observed microbial ecology dynamics of spacecraft-associated environments.
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Acinetobacter/enzimologia , Álcool Desidrogenase/metabolismo , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Astronave , 2-Propanol/metabolismo , Acinetobacter/efeitos dos fármacos , Detergentes/metabolismo , Contaminação de Equipamentos/prevenção & controle , Etanol/metabolismo , Peróxido de Hidrogênio/farmacologia , Viabilidade Microbiana/efeitos dos fármacosRESUMO
The diagnosis and management of prostate cancer have substantially changed over the last 3 decades. Serum prostate-specific antigen (PSA) was adopted for screening in the 1990s after it was found to be a sensitive indicator of disease. Because of a lack of specificity for significant disease, indiscriminate PSA testing led to overdiagnosis and overtreatment. Several biomarkers have been developed that are superior to PSA in stratifying a man's risk for harboring potentially lethal prostate cancer.