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1.
J Neurosci ; 39(9): 1720-1732, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30643025

RESUMO

Developmental dyslexia is characterized by the inability to acquire typical reading and writing skills. Dyslexia has been frequently linked to cerebral cortex alterations; however, recent evidence also points toward sensory thalamus dysfunctions: dyslexics showed reduced responses in the left auditory thalamus (medial geniculate body, MGB) during speech processing in contrast to neurotypical readers. In addition, in the visual modality, dyslexics have reduced structural connectivity between the left visual thalamus (lateral geniculate nucleus, LGN) and V5/MT, a cerebral cortex region involved in visual movement processing. Higher LGN-V5/MT connectivity in dyslexics was associated with the faster rapid naming of letters and numbers (RANln), a measure that is highly correlated with reading proficiency. Here, we tested two hypotheses that were directly derived from these previous findings. First, we tested the hypothesis that dyslexics have reduced structural connectivity between the left MGB and the auditory-motion-sensitive part of the left planum temporale (mPT). Second, we hypothesized that the amount of left mPT-MGB connectivity correlates with dyslexics RANln scores. Using diffusion tensor imaging-based probabilistic tracking, we show that male adults with developmental dyslexia have reduced structural connectivity between the left MGB and the left mPT, confirming the first hypothesis. Stronger left mPT-MGB connectivity was not associated with faster RANln scores in dyslexics, but was in neurotypical readers. Our findings provide the first evidence that reduced cortico-thalamic connectivity in the auditory modality is a feature of developmental dyslexia and it may also affect reading-related cognitive abilities in neurotypical readers.SIGNIFICANCE STATEMENT Developmental dyslexia is one of the most widespread learning disabilities. Although previous neuroimaging research mainly focused on pathomechanisms of dyslexia at the cerebral cortex level, several lines of evidence suggest an atypical functioning of subcortical sensory structures. By means of diffusion tensor imaging, we here show that dyslexic male adults have reduced white matter connectivity in a cortico-thalamic auditory pathway between the left auditory motion-sensitive planum temporale and the left medial geniculate body. Connectivity strength of this pathway was associated with measures of reading fluency in neurotypical readers. This is novel evidence on the neurocognitive correlates of reading proficiency, highlighting the importance of cortico-subcortical interactions between regions involved in the processing of spectrotemporally complex sound.


Assuntos
Conectoma , Dislexia/fisiopatologia , Corpos Geniculados/fisiopatologia , Adulto , Córtex Auditivo/diagnóstico por imagem , Córtex Auditivo/fisiopatologia , Dislexia/diagnóstico por imagem , Corpos Geniculados/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino
2.
Exp Mol Pathol ; 106: 17-26, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30439350

RESUMO

Invadopodia, cancer cell protrusions with proteolytic activity, are functionally associated with active remodeling of the extracellular matrix. Here, we show that the invadopodia-related protein TKS5 is expressed in human pancreatic adenocarcinoma lines, and demonstrate that pancreatic cancer cells depend on TKS5 for invadopodia formation and function. Immunofluorescence staining of human pancreatic cancer cells reveals that TKS5 is a marker of mature and immature invadopodia. We also analyze the co-staining patterns of TKS5 and the commonly used invadopodia marker Cortactin, and find only partial co-localization of these two proteins at invadopodia, with a large fraction of TKS5-positive invadopodia lacking detectable levels of Cortactin. Whereas compelling evidence exist on the role of invadopodia as mediators of invasive migration in cultured cells and in animal models of cancer, these structures have never been detected inside human tumors. Here, using antibodies against TKS5 and Cortactin, we describe for the first time structures strongly resembling invadopodia in various paraffin-embedded human tumor surgical specimens from pancreas and other organs. Our results strongly suggest that invadopodia are present inside human tumors, and warrants further investigation on their regulation and occurrence in surgical specimens, and on the value of TKS5 antibodies as pathological research and diagnostic tools.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/fisiologia , Adenocarcinoma/patologia , Proteínas de Neoplasias/fisiologia , Neoplasias Pancreáticas/patologia , Podossomos/fisiologia , Adenocarcinoma/química , Adenocarcinoma/cirurgia , Adenocarcinoma/ultraestrutura , Adulto , Idoso , Linhagem Celular Tumoral , Cortactina/análise , Feminino , Técnica Direta de Fluorescência para Anticorpo , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias/química , Neoplasias/patologia , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/ultraestrutura , Inclusão em Parafina , Podossomos/química , Podossomos/ultraestrutura , Interferência de RNA , RNA Interferente Pequeno/genética
3.
Neuroimage ; 178: 721-734, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29772380

RESUMO

The cerebral cortex modulates early sensory processing via feed-back connections to sensory pathway nuclei. The functions of this top-down modulation for human behavior are poorly understood. Here, we show that top-down modulation of the visual sensory thalamus (the lateral geniculate body, LGN) is involved in visual-speech recognition. In two independent functional magnetic resonance imaging (fMRI) studies, LGN response increased when participants processed fast-varying features of articulatory movements required for visual-speech recognition, as compared to temporally more stable features required for face identification with the same stimulus material. The LGN response during the visual-speech task correlated positively with the visual-speech recognition scores across participants. In addition, the task-dependent modulation was present for speech movements and did not occur for control conditions involving non-speech biological movements. In face-to-face communication, visual speech recognition is used to enhance or even enable understanding what is said. Speech recognition is commonly explained in frameworks focusing on cerebral cortex areas. Our findings suggest that task-dependent modulation at subcortical sensory stages has an important role for communication: Together with similar findings in the auditory modality the findings imply that task-dependent modulation of the sensory thalami is a general mechanism to optimize speech recognition.


Assuntos
Mapeamento Encefálico/métodos , Corpos Geniculados/fisiologia , Reconhecimento Psicológico/fisiologia , Percepção da Fala/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Adulto Jovem
4.
Proc Natl Acad Sci U S A ; 109(34): 13841-6, 2012 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-22869724

RESUMO

Developmental dyslexia, a severe and persistent reading and spelling impairment, is characterized by difficulties in processing speech sounds (i.e., phonemes). Here, we test the hypothesis that these phonological difficulties are associated with a dysfunction of the auditory sensory thalamus, the medial geniculate body (MGB). By using functional MRI, we found that, in dyslexic adults, the MGB responded abnormally when the task required attending to phonemes compared with other speech features. No other structure in the auditory pathway showed distinct functional neural patterns between the two tasks for dyslexic and control participants. Furthermore, MGB activity correlated with dyslexia diagnostic scores, indicating that the task modulation of the MGB is critical for performance in dyslexics. These results suggest that deficits in dyslexia are associated with a failure of the neural mechanism that dynamically tunes MGB according to predictions from cortical areas to optimize speech processing. This view on task-related MGB dysfunction in dyslexics has the potential to reconcile influential theories of dyslexia within a predictive coding framework of brain function.


Assuntos
Córtex Auditivo/fisiopatologia , Mapeamento Encefálico/métodos , Dislexia/fisiopatologia , Tálamo/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Modelos Biológicos , Modelos Genéticos , Neurônios/metabolismo , Fonética , Leitura , Percepção da Fala
5.
Prostate ; 74(2): 134-48, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24174371

RESUMO

BACKGROUND: The Src tyrosine kinase substrate and adaptor protein Tks5 had previously been implicated in the invasive phenotype of normal and transformed cell types via regulation of cytoskeletal structures called podosomes/invadopodia. The role of Src-Tks5 signaling in invasive prostate cancer, however, had not been previously evaluated. METHODS: We measured the relative expression of Tks5 in normal (n = 20) and cancerous (n = 184, from 92 patients) prostate tissue specimens by immunohistochemistry using a commercially available tumor microarray. We also manipulated the expression and activity of wild-type and mutant Src and Tks5 constructs in the LNCaP and PC-3 prostate cancer cell lines in order to ascertain the role of Src-Tks5 signaling in invadopodia development, matrix-remodeling activity, motility, and invasion. RESULTS: Our studies demonstrated that Src was activated and Tks5 upregulated in high Gleason score prostate tumor specimens and in invasive prostate cancer cell lines. Remarkably, overexpression of Tks5 in LNCaP cells was sufficient to induce invadopodia formation and associated matrix degradation. This Tks5-dependent increase in invasive behavior further depended on Src tyrosine kinase activity and the phosphorylation of Tks5 at tyrosine residues 557 and 619. In PC-3 cells we demonstrated that Tks5 phosphorylation at these sites was necessary and sufficient for invadopodia-associated matrix degradation and invasion. CONCLUSIONS: Our results suggest a general role for Src-Tks5 signaling in prostate tumor progression and the utility of Tks5 as a marker protein for the staging of this disease.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/fisiologia , Adenocarcinoma/patologia , Movimento Celular/fisiologia , Citoesqueleto/fisiologia , Neoplasias da Próstata/patologia , Quinases da Família src/fisiologia , Adenocarcinoma/fisiopatologia , Biomarcadores Tumorais/fisiologia , Estudos de Casos e Controles , Linhagem Celular Tumoral , Progressão da Doença , Humanos , Imuno-Histoquímica , Masculino , Fosforilação/fisiologia , Neoplasias da Próstata/fisiopatologia , Transdução de Sinais/fisiologia
6.
Cancer Res Commun ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949950

RESUMO

Myristoylation is a type of protein acylation by which the fatty acid myristate is added to the N-terminus of target proteins, a process mediated by N-myristoyltransferases. Myristoylation is emerging as a promising cancer therapeutic target, however the molecular determinants of sensitivity to N-myristoyltransferase inhibition or the mechanism by which it induces cancer cell death are not completely understood. We report that N-myristoyltransferases are a novel therapeutic target in lung carcinoma cells with LKB1 and/or KEAP1 mutations in a KRAS mutant background. Inhibition of myristoylation decreases cell viability in vitro and tumor growth in vivo. Inhibition of myristoylation causes mitochondrial ferrous iron overload, oxidative stress, elevated protein poly (ADP)-ribosylation and death by parthanatos. Furthermore, NMT inhibitors sensitized lung carcinoma cells to platinum-based chemotherapy. Unexpectedly, the mitochondrial transporter Translocase of Inner Mitochondrial Membrane 17 homologue A (TIM17A) is a critical target of myristoylation inhibitors in these cells. TIM17A silencing recapitulated the effects of NMT inhibition at inducing mitochondrial ferrous iron overload and parthanatos. Furthermore, sensitivity of lung carcinoma cells to myristoylation inhibition correlated with their dependency on TIM17A. This study reveals the unexpected connection between protein myristoylation, the mitochondrial import machinery, and iron homeostasis. It also uncovers myristoylation inhibitors as novel inducers of parthanatos in cancer, and the novel axis N-myristoyltransferase-TIM17A as a potential therapeutic target in highly aggressive lung carcinomas.

7.
J Neurosci ; 32(47): 16597-601, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23175815

RESUMO

Two studies (Golestani et al., 2007; Wong et al., 2008) have reported a positive correlation between the ability to perceive foreign speech sounds and the volume of Heschl's gyrus (HG), the structure that houses the auditory cortex. More precisely, participants with larger left Heschl's gyri learned consonantal or tonal contrasts faster than those with smaller HG. These studies leave open the question of the impact of experience on HG volumes. In the current research, we investigated the effect of early language exposure on Heschl's gyrus by comparing Spanish-Catalan bilinguals who have been exposed to two languages since childhood, to a group of Spanish monolinguals matched in education, socio-economic status, and musical experience. Manual volumetric measurements of HG revealed that bilinguals have, on average, larger Heschl's gyri than monolinguals. This was corroborated, for the left Heschl's gyrus, by a voxel-based morphometry analysis showing larger gray matter volumes in bilinguals than in monolinguals. Since the bilinguals in this study were not a self-selected group, this observation provides a clear demonstration that learning a second language is a causal factor in the increased size of the auditory cortex.


Assuntos
Córtex Auditivo/fisiologia , Multilinguismo , Adulto , Córtex Auditivo/anatomia & histologia , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
8.
Arch Esp Urol ; 66(6): 593-6, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-23985460

RESUMO

OBJECTIVE: We present the case of a spontaneous subcapsular renal hematoma with increase of the levels of blood pressure in a patient previously normotensive. METHODS: Patient with abdominal pain, spontaneous without previous trauma. CT showed a right subcapsular kidney hematoma. High levels of blood pressure were noticed at the admission in urology. CONCLUSION: Page kidney is a cause of arterial hypertension due to external compression of renal parenchyma. It could be unnoticed as essential hypertension if high suspicion is not taken into account. Nowadays, the main cause of Page kidney is the renal biopsy in the context of kidney transplantation. The treatment is not recommended in the guidelines although the conservative management is proposed as first option.


Assuntos
Hematoma/complicações , Hematoma/patologia , Hipertensão Renal/complicações , Nefropatias/complicações , Nefropatias/patologia , Rim/patologia , Pressão Sanguínea/fisiologia , Hematoma/diagnóstico por imagem , Humanos , Isquemia , Nefropatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Ultrassonografia
9.
Methods Mol Biol ; 2557: 765-784, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36512250

RESUMO

The architecture of the Golgi apparatus in mammalian cells changes dynamically in response to internal and external cues and may be permanently altered in disease states. Here, we present a method to quantify changes in Golgi morphology using immunofluorescence and confocal microscopy followed by CellProfiler software analysis. This method will assist researchers in evaluating alterations in the Golgi complex morphology of cultured cells under a variety of different experimental conditions.


Assuntos
Autoantígenos , Proteínas de Membrana , Animais , Complexo de Golgi , Imunofluorescência , Software , Mamíferos
10.
J Cell Biol ; 178(4): 675-86, 2007 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-17698610

RESUMO

Src functions depend on its association with the plasma membrane and with specific membrane-associated assemblies. Many aspects of these interactions are unclear. We investigated the functions of kinase, SH2, and SH3 domains in Src membrane interactions. We used FRAP beam-size analysis in live cells expressing a series of c-Src-GFP proteins with targeted mutations in specific domains together with biochemical experiments to determine whether the mutants can generate and bind to phosphotyrosyl proteins. Wild-type Src displays lipid-like membrane association, whereas constitutively active Src-Y527F interacts transiently with slower-diffusing membrane-associated proteins. These interactions require Src kinase activity and SH2 binding, but not SH3 binding. Furthermore, overexpression of paxillin, an Src substrate with a high cytoplasmic population, competes with membrane phosphotyrosyl protein targets for binding to activated Src. Our observations indicate that the interactions of Src with lipid and protein targets are dynamic and that the kinase and SH2 domain cooperate in the membrane targeting of Src.


Assuntos
Membranas/metabolismo , Proteínas Tirosina Quinases/metabolismo , Animais , Células COS , Proteína Tirosina Quinase CSK , Chlorocebus aethiops , Recuperação de Fluorescência Após Fotodegradação , Proteínas de Fluorescência Verde/metabolismo , Membranas/química , Paxilina/metabolismo , Proteínas Tirosina Quinases/química , Domínios de Homologia de src , Quinases da Família src
11.
Arch Esp Urol ; 65(8): 770-3, 2012 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-23117687

RESUMO

OBJECTIVE: To present a new case of renal infarction. METHODS: We report the case of an 84-year-old woman presenting with right flank colic pain of 24 hours of evolution and past history of acute myocardial infarction four months before. CONCLUSION: Renal infarction is a rare condition; in most of the cases it does not show specific symptoms and usually overlap with other more common urologic procedures, which results in a delay in diagnosis and treatment. The most conclusive imaging tests are i.v contrast CT scan or Doppler ultrasound but definitive diagnosis is achieved by angiography or CT angiography. Treatment is conservative, with parenteral and oral anticoagulation; invasive management is rare.


Assuntos
Infarto/terapia , Nefropatias/terapia , Idoso de 80 Anos ou mais , Angiografia , Anticoagulantes/uso terapêutico , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Infarto/diagnóstico por imagem , Infarto/patologia , Nefropatias/diagnóstico por imagem , Nefropatias/patologia , Tomografia Computadorizada por Raios X
12.
Front Psychol ; 13: 1008963, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312157

RESUMO

Previous studies suggest a relationship between second-language learning and voice recognition processes, but the nature of such relation remains poorly understood. The present study investigates whether phoneme learning relates to voice recognition. A group of bilinguals that varied in their discrimination of a second-language phoneme contrast participated in this study. We assessed participants' voice recognition skills in their native language at the behavioral and brain electrophysiological levels during a voice-avatar learning paradigm. Second-language phoneme discrimination positively correlated with behavioral and brain measures of voice recognition. At the electrophysiological level, correlations were present at two time windows and are interpreted within the dual-process model of recognition memory. The results are relevant to understanding the processes involved in language learning as they show a common variability for second-language phoneme and voice recognition processes.

13.
Circulation ; 121(17): 1934-40, 2010 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-20404254

RESUMO

BACKGROUND: We examined predictors of early and very long-term outcome after combined mitral and tricuspid valve repair for rheumatic disease. METHODS AND RESULTS: Between 1974 and 2002, 153 consecutive patients (mean age, 46.0+/-13.2 years) underwent combined mitral and tricuspid valve repair for rheumatic disease. Mitral disease was predominantly stenosis (82.3%); 100% of patients had organic tricuspid valve disease, predominantly with regurgitation (53.6%) or some degree of tricuspid stenosis (46.4%). Mitral repair included commissurotomy in 132 patients (86.3%) associated with a flexible annuloplasty in 108. Tricuspid valve repair included flexible annuloplasty in 68 patients (44.4%) and suture annuloplasty in 20 patients (13.1%) combined with tricuspid commissurotomy in 62 patients (42.5%). Thirty-day mortality was 5.9%. Late mortality was 60.1%. The median follow-up was 15.8 years (interquartile range, 6 to 19 years). Follow-up was 97.9% complete. Age>65 years was the only predictor of late mortality. Kaplan-Meier survival probability was 74.4% at 10 years and 57.0% at 15 years. Sixty-three patients required valve reoperation (mitral valve, 59; tricuspid valve, 38). Predictors of valve reoperations were either mitral or tricuspid commissurotomy without associated prosthetic ring annuloplasty. At 20 years, Kaplan-Meier freedom from reoperation was 48.5+/-5.1%. CONCLUSIONS: Combined mitral and tricuspid valve repair in rheumatic disease showed satisfactory early results. Long-term results were poor because of high mortality and a high number of valve-related reoperations. The use of prosthetic ring annuloplasty was significantly associated with a reduced incidence of both mitral and tricuspid valve reoperations.


Assuntos
Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral/mortalidade , Insuficiência da Valva Mitral/cirurgia , Cardiopatia Reumática/mortalidade , Cardiopatia Reumática/cirurgia , Insuficiência da Valva Tricúspide/mortalidade , Insuficiência da Valva Tricúspide/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/métodos , Implante de Prótese de Valva Cardíaca/mortalidade , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Complicações Pós-Operatórias/mortalidade , Valor Preditivo dos Testes , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Adulto Jovem
14.
Proc Natl Acad Sci U S A ; 105(42): 16083-8, 2008 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-18852470

RESUMO

Human beings differ in their ability to master the sounds of their second language (L2). Phonetic training studies have proposed that differences in phonetic learning stem from differences in psychoacoustic abilities rather than speech-specific capabilities. We aimed at finding the origin of individual differences in L2 phonetic acquisition in natural learning contexts. We consider two alternative explanations: a general psychoacoustic origin vs. a speech-specific one. For this purpose, event-related potentials (ERPs) were recorded from two groups of early, proficient Spanish-Catalan bilinguals who differed in their mastery of the Catalan (L2) phonetic contrast /e-epsilon/. Brain activity in response to acoustic change detection was recorded in three different conditions involving tones of different length (duration condition), frequency (frequency condition), and presentation order (pattern condition). In addition, neural correlates of speech change detection were also assessed for both native (/o/-/e/) and nonnative (/o/-/ö/) phonetic contrasts (speech condition). Participants' discrimination accuracy, reflected electrically as a mismatch negativity (MMN), was similar between the two groups of participants in the three acoustic conditions. Conversely, the MMN was reduced in poor perceivers (PP) when they were presented with speech sounds. Therefore, our results support a speech-specific origin of individual variability in L2 phonetic mastery.


Assuntos
Encéfalo/fisiologia , Idioma , Fonética , Percepção da Fala/fisiologia , Humanos
15.
Front Cell Dev Biol ; 9: 806482, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34957124

RESUMO

The Golgi apparatus plays a central role in normal cell physiology by promoting cell survival, facilitating proliferation, and enabling cell-cell communication and migration. These roles are partially mediated by well-known Golgi functions, including post-translational modifications, lipid biosynthesis, intracellular trafficking, and protein secretion. In addition, accumulating evidence indicates that the Golgi plays a critical role in sensing and integrating external and internal cues to promote cellular homeostasis. Indeed, the unique structure of the mammalian Golgi can be fine-tuned to adapt different Golgi functions to specific cellular needs. This is particularly relevant in the context of cancer, where unrestrained proliferation and aberrant survival and migration increase the demands in Golgi functions, as well as the need for Golgi-dependent sensing and adaptation to intrinsic and extrinsic stressors. Here, we review and discuss current understanding of how the structure and function of the Golgi apparatus is influenced by oncogenic transformation, and how this adaptation may facilitate cancer cell invasion and metastasis.

16.
Biomedicines ; 8(10)2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33050151

RESUMO

Pancreatic adenocarcinoma (PDAC) originates in the glandular compartment of the exocrine pancreas. Histologically, PDAC tumors are characterized by a parenchyma that is embedded in a particularly prominent stromal component or desmoplastic stroma. The unique characteristics of the desmoplastic stroma shape the microenvironment of PDAC and modulate the reciprocal interactions between cancer and stromal cells in ways that have profound effects in the pathophysiology and treatment of this disease. Here, we review some of the most recent findings regarding the regulation of PDAC cell invasion by the unique microenvironment of this tumor, and how new knowledge is being translated into novel therapeutic approaches.

17.
Sci Rep ; 10(1): 11952, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686708

RESUMO

N-myristoyltransferase-1 (NMT1) catalyzes protein myristoylation, a lipid modification that is elevated in cancer cells. NMT1 sustains proliferation and/or survival of cancer cells through mechanisms that are not completely understood. We used genetic and pharmacological inhibition of NMT1 to further dissect the role of this enzyme in cancer, and found an unexpected essential role for NMT1 at promoting lysosomal metabolic functions. Lysosomes mediate enzymatic degradation of vesicle cargo, and also serve as functional platforms for mTORC1 activation. We show that NMT1 is required for both lysosomal functions in cancer cells. Inhibition of NMT1 impaired lysosomal degradation leading to autophagy flux blockade, and simultaneously caused the dissociation of mTOR from the surface of lysosomes leading to decreased mTORC1 activation. The regulation of lysosomal metabolic functions by NMT1 was largely mediated through the lysosomal adaptor LAMTOR1. Accordingly, genetic targeting of LAMTOR1 recapitulated most of the lysosomal defects of targeting NMT1, including defective lysosomal degradation. Pharmacological inhibition of NMT1 reduced tumor growth, and tumors from treated animals had increased apoptosis and displayed markers of lysosomal dysfunction. Our findings suggest that compounds targeting NMT1 may have therapeutic benefit in cancer by preventing mTORC1 activation and simultaneously blocking lysosomal degradation, leading to cancer cell death.


Assuntos
Aciltransferases/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Neoplasias/metabolismo , Animais , Autofagia , Linhagem Celular Tumoral , Endossomos/metabolismo , Ativação Enzimática , Imunofluorescência , Humanos , Camundongos , Proteólise
18.
J Cell Biol ; 166(3): 317-23, 2004 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-15289494

RESUMO

Transformation of fibroblasts by oncogenic Src causes disruption of actin stress fibers and formation of invasive adhesions called podosomes. Because the small GTPase Rho stimulates stress fiber formation, Rho inactivation by Src has been thought to be necessary for stress fiber disruption. However, we show here that Rho[GTP] levels do not decrease after transformation by activated Src. Inactivation of Rho in Src-transformed fibroblasts by dominant negative RhoA or the Rho-specific inhibitor C3 exoenzyme disrupted podosome structure as judged by localization of podosome components F-actin, cortactin, and Fish. Inhibition of Rho strongly inhibited Src-induced proteolytic degradation of the extracellular matrix. Furthermore, development of an in situ Rho[GTP] affinity assay allowed us to detect endogenous Rho[GTP] at podosomes, where it colocalized with F-actin, cortactin, and Fish. Therefore, Rho is not globally inactivated in Src-transformed fibroblasts, but is necessary for the assembly and function of structures implicated in tumor cell invasion.


Assuntos
Proteínas rho de Ligação ao GTP/metabolismo , Quinases da Família src/metabolismo , Actinas/metabolismo , Animais , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Microscopia de Fluorescência
19.
Data Brief ; 22: 132-136, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30581916

RESUMO

In this article, using human pancreatic cancer cell lines and tumor specimens, we analyze the expression and localization of the invadopodia-related proteins TKS5 and Cortactin. Specifically, we present data on: a) TKS5 expression and localization by immunofluorescence in human pancreatic tumors, b) Cortactin expression by western blotting in various human pancreatic adenocarcinoma cell lines, c) TKS5 and Cortactin localization at invadopodia in BxPC-3 pancreatic adenocarcinoma cells, and d) TKS5 and Cortactin localization by co-immunofluorescence in human pancreatic cancer specimens. Data presented here is related to and supportive of the research article by Chen et al., "TKS5-positive invadopodia-like structures in human tumor surgical specimens" (Chen et al., 2019), where interpretation of the research data presented here is available.

20.
MethodsX ; 6: 718-726, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31011543

RESUMO

Invadopodia, cancer cell protrusive structures with associated proteolytic activity, provide cancer cells with the ability to remodel the extracellular matrix. Invadopodia facilitate invasive migration and their formation correlates with cancer cell invasiveness and metastatic potential. The unambiguous identification of invadopodia is an important step to undergo studies on invadopodia regulatory inputs, functional outputs, as well as the prevalence and significance of invadopodia for cancer cells and human tumors. The adaptor protein TKS5 is a known invadopodia regulatory protein, which is necessary for invadopodia formation and activity. TKS5 is highly enriched at invadopodia and, unlike other commonly used invadopodia markers, it does not accumulate significantly in other types of cellular protrusions. However, the use of TKS5 as a marker of invadopodia has not been generalized, in part due to the availability of suitable antibodies against the human protein. We have evaluated two commercial antibodies raised against human TKS5. Here, we detail protocols for the detection of invadopodia-associated TKS5 in human cells in culture and in paraffin-embedded archived tumor surgical specimens using commercial antibodies. These methods should facilitate the identification and study of human invadopodia. •TKS5 staining identifies invadopodia in human cancer cell lines and archived surgical tumor specimens.

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