RESUMO
Nucleolar disruption has recently emerged as a relevant means to activate p53 through inhibition of HDM2 by ribosome-free RPL11. Most drugs that induce nucleolar disruption also possess important genotoxic activity, which can have lasting mutagenic effects. Therefore, it is of interest to identify compounds that selectively produce nucleolar disruption in the absence of DNA damage. Here, we have performed a high-throughput screening to search for nucleolar disruptors. We have identified an acridine derivative (PubChem CID-765471) previously known for its capacity to activate p53 independently of DNA damage, although the molecular mechanism underlying p53 activation had remained uncharacterized. We report that CID-765471 produces nucleolar disruption by inhibiting ribosomal DNA transcription in a process that includes the selective degradation of the RPA194 subunit of RNA polymerase I. Following nucleolar disruption, CID-765471 activates p53 through the RPL11/HDM2 pathway in the absence of detectable DNA damage. In a secondary screening of compounds approved for medical use, we identify two additional acridine derivatives, aminacrine and ethacridine, that operate in a similar manner as CID-765471. These findings provide the basis for non-genotoxic chemotherapeutic approaches that selectively target the nucleolus.
Assuntos
Acridinas/farmacologia , Neoplasias Ósseas/metabolismo , Neoplasias do Colo/metabolismo , Naftiridinas/farmacologia , Osteossarcoma/metabolismo , Preparações Farmacêuticas/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas Ribossômicas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acridinas/administração & dosagem , Acridinas/química , Northern Blotting , Western Blotting , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Dano ao DNA/efeitos dos fármacos , Citometria de Fluxo , Imunofluorescência , Ensaios de Triagem em Larga Escala , Humanos , Imunoprecipitação , Naftiridinas/administração & dosagem , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/patologia , Preparações Farmacêuticas/administração & dosagem , Proteínas Proto-Oncogênicas c-mdm2/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Ribossômicas/antagonistas & inibidores , Proteínas Ribossômicas/genética , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genéticaRESUMO
A-type lamins are intermediate filament proteins that provide a scaffold for protein complexes regulating nuclear structure and function. Mutations in the LMNA gene are linked to a variety of degenerative disorders termed laminopathies, whereas changes in the expression of lamins are associated with tumourigenesis. The molecular pathways affected by alterations of A-type lamins and how they contribute to disease are poorly understood. Here, we show that A-type lamins have a key role in the maintenance of telomere structure, length and function, and in the stabilization of 53BP1, a component of the DNA damage response (DDR) pathway. Loss of A-type lamins alters the nuclear distribution of telomeres and results in telomere shortening, defects in telomeric heterochromatin, and increased genomic instability. In addition, A-type lamins are necessary for the processing of dysfunctional telomeres by non-homologous end joining, putatively through stabilization of 53BP1. This study shows new functions for A-type lamins in the maintenance of genomic integrity, and suggests that alterations of telomere biology and defects in DDR contribute to the pathogenesis of lamin-related diseases.
Assuntos
Reparo do DNA , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Telômero/metabolismo , Animais , Linhagem Celular , Núcleo Celular/química , Núcleo Celular/metabolismo , Proteínas Cromossômicas não Histona , Proteínas de Ligação a DNA , Fibroblastos/citologia , Fibroblastos/metabolismo , Deleção de Genes , Instabilidade Genômica , Peptídeos e Proteínas de Sinalização Intracelular/análise , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Telômero/química , Proteína 1 de Ligação à Proteína Supressora de Tumor p53RESUMO
Judith Agudo studies the mechanisms that adult and cancer stem cells use to evade the immune response with the goals of engineering autoimmunity- and allograft-resistant stem cells and improving the response of cancer stem cells to immunotherapy.
Assuntos
Imunoterapia , Neoplasias , Células-Tronco Neoplásicas , Humanos , Autoimunidade , ImunidadeRESUMO
Gina DeNicola investigates the metabolism of cancer cells in vivo with a focus on NRF2 and the tumor microenvironment.
RESUMO
Yogesh Kulathu studies signaling mechanisms with a focus on ubiquitin and other post-translational modifications such as UFMylation.
Assuntos
Processamento de Proteína Pós-Traducional , Ubiquitina , Ubiquitinação , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismoRESUMO
Chii Jou Chan investigates how tissue hydraulics regulates mammalian development, with a special focus on folliculogenesis and oocyte quality control.
Assuntos
Mamíferos , Oócitos , Folículo Ovariano , Animais , Oócitos/fisiologia , Folículo Ovariano/fisiologiaRESUMO
The TINCR (Terminal differentiation-Induced Non-Coding RNA) gene is selectively expressed in epithelium tissues and is involved in the control of human epidermal differentiation and wound healing. Despite its initial report as a long non-coding RNA, the TINCR locus codes for a highly conserved ubiquitin-like microprotein associated with keratinocyte differentiation. Here we report the identification of TINCR as a tumor suppressor in squamous cell carcinoma (SCC). TINCR is upregulated by UV-induced DNA damage in a TP53-dependent manner in human keratinocytes. Decreased TINCR protein expression is prevalently found in skin and head and neck squamous cell tumors and TINCR expression suppresses the growth of SCC cells in vitro and in vivo. Consistently, Tincr knockout mice show accelerated tumor development following UVB skin carcinogenesis and increased penetrance of invasive SCCs. Finally, genetic analyses identify loss-of-function mutations and deletions encompassing the TINCR gene in SCC clinical samples supporting a tumor suppressor role in human cancer. Altogether, these results demonstrate a role for TINCR as protein coding tumor suppressor gene recurrently lost in squamous cell carcinomas.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , RNA Longo não Codificante , Animais , Camundongos , Humanos , Ubiquitina/metabolismo , Carcinoma de Células Escamosas/genética , Genes Supressores de Tumor , Queratinócitos/metabolismo , Neoplasias de Cabeça e Pescoço/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , MicropeptídeosRESUMO
Sara Wickström combines biophysics, next-generation sequencing, and basic cell biology to investigate how cellular forces regulate the fate and position of stem cells within epithelial tissues.
Assuntos
Diferenciação Celular , Epitélio , Células-Tronco , Biofísica , Sequenciamento de Nucleotídeos em Larga Escala , Células-Tronco/citologiaRESUMO
Lena Ho studies small ORF-encoded peptides (SEPs; also known as micropeptides), with a particular focus on mitochondrial SEPs, and their role in vascular biology and immunometabolism.
Assuntos
Mitocôndrias , Peptídeos , Fases de Leitura Aberta , Peptídeos/genéticaRESUMO
Sara Cuylen-Haering studies the molecular mechanisms driving phase separation of chromosomes and other cellular organelles, with a special focus on biological surfactants.
Assuntos
Cromossomos , Organelas , Cromossomos/química , Organelas/químicaRESUMO
Bo Zhong studies the regulation of the antiviral innate immunity, inflammation, and tumorigenesis by the protein ubiquitination system.
Assuntos
Alergia e Imunologia/história , Imunidade Inata , Ubiquitinação , Virologia/história , Animais , China , História do Século XXI , Interações Hospedeiro-Patógeno , HumanosRESUMO
Ori Avinoam studies membrane remodeling with a focus on cell-to-cell fusion through the lens of correlative light and electron microscopy.
Assuntos
Fusão Celular , Membrana CelularRESUMO
Elvan Böke investigates the mechanisms that preserve the viability of dormant oocytes.
Assuntos
Sobrevivência Celular , Oócitos , Oócitos/citologiaRESUMO
Sachihiro Matsunaga studies the nuclear structure and chromatin dynamics of plants.
Assuntos
Núcleo Celular , Cromatina , Células Vegetais , Plantas , Plantas/genéticaRESUMO
Rushika M. Perera studies how pancreatic cancer cells use autophagy and the lysosome to adapt to stress.
Assuntos
Lisossomos/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Animais , História do Século XX , História do Século XXI , HumanosRESUMO
Dorothy Schafer investigates the role of microglia in neural circuit development and plasticity with a special focus on neurological disorders.
Assuntos
Microglia , Doenças do Sistema Nervoso , Plasticidade Neuronal , Pesquisa Biomédica , NeurogêneseRESUMO
Elda Grabocka investigates the role of stress granules in obesity and cancer.
Assuntos
Grânulos Citoplasmáticos/metabolismo , Estresse Fisiológico , História do Século XX , História do Século XXI , Humanos , Neoplasias/metabolismoRESUMO
Nan Yan studies the physiological function of innate immune signaling in the absence of pathogen infection.
Assuntos
Imunidade Inata/imunologia , Transdução de Sinais/imunologia , Animais , Interações Hospedeiro-Patógeno/imunologia , HumanosRESUMO
Vaishnavi Ananthanarayanan investigates the regulation of motor proteins and cytoskeleton-organelle interactions using single-molecule microscopy.
Assuntos
Biologia Celular/história , Ciência , Mulheres , História do Século XX , História do Século XXI , HumanosRESUMO
Gaia Pigino studies the molecular mechanisms and principles of self-organization in cilia using 3D cryo-EM.