Negative correlation of single-cell PAX3:FOXO1 expression with tumorigenicity in rhabdomyosarcoma.

Rhabdomyosarcomas (RMS) are phenotypically and functionally heterogeneous. Both primary human RMS cultures and low-passage Myf6Cre,Pax3:Foxo1,p53 mouse RMS cell lines, which express the fusion oncoprotein Pax3:Foxo1 and lack the tumor suppressor Tp53 (Myf6Cre,Pax3:Foxo1,p53), exhibit marked heterogeneity in PAX3:FOXO1 (P3F) expression at the single cell level. In mouse RMS cells, P3F expression is directed by the Pax3 promoter and coupled to eYFP YFPlow/P3Flow mouse RMS cells included 87% G0/G1 cells and reorganized their actin cytoskeleton to produce a cellular phenotype characterized by more efficient adhesion and migration. This translated into higher tumor-propagating cell frequencies of YFPlow/P3Flow compared with YFPhigh/P3Fhigh cells. Both YFPlow/P3Flow and YFPhigh/P3Fhigh cells gave rise to mixed clones in vitro, consistent with fluctuations in P3F expression over time. Exposure to the anti-tropomyosin compound TR100 disrupted the cytoskeleton and reversed enhanced migration and adhesion of YFPlow/P3Flow RMS cells. Heterogeneous expression of PAX3:FOXO1 at the single cell level may provide a critical advantage during tumor progression.

Lack of Electron Acceptors Contributes to Redox Stress and Growth Arrest in Asparagine-Starved Sarcoma Cells.

Amino acids are integral components of cancer metabolism. The non-essential amino acid asparagine supports the growth and survival of various cancer cell types. Here, different mass spectrometry approaches were employed to identify lower aspartate levels, higher aspartate/glutamine ratios and lower tricarboxylic acid (TCA) cycle metabolite levels in asparagine-deprived sarcoma cells. Reduced nicotinamide adenine dinucleotide (NAD+)/nicotinamide adenine dinucleotide hydride (NADH) ratios were consistent with redirection of TCA cycle flux and relative electron acceptor deficiency. Elevated lactate/pyruvate ratios may be due to compensatory NAD+ regeneration through increased pyruvate to lactate conversion by lactate dehydrogenase. Supplementation with exogenous pyruvate, which serves as an electron acceptor, restored aspartate levels, NAD+/NADH ratios, lactate/pyruvate ratios and cell growth in asparagine-deprived cells. Chemicals disrupting NAD+ regeneration in the electron transport chain further enhanced the anti-proliferative and pro-apoptotic effects of asparagine depletion. We speculate that reductive stress may be a major contributor to the growth arrest observed in asparagine-starved cells.

Growth inhibition associated with disruption of the actin cytoskeleton by Latrunculin A in rhabdomyosarcoma cells.

Functional genomic screening of KRAS-driven mouse sarcomas was previously employed to identify proliferation-relevant genes. Genes identified included Ubiquitin-conjugating enzyme E2 (Ube2c), Centromere Protein E (Cenpe), Hyaluronan Synthase 2 (Has2), and CAMP Responsive Element Binding Protein 3 Like 2 (Creb3l2). This study examines the expression and chemical inhibition of these candidate genes, identifying variable levels of protein expression and significant contributions to rhabdomyosarcoma (RMS) cell proliferation. Chemical treatment of human and murine RMS cell lines with bortezomib, UA62784, latrunculin A and sorafenib inhibited growth with approximate EC50 concentrations of 15-30nM for bortezomib, 25-80nM for UA62784 and 80-220nM for latrunculin A. The multi-kinase inhibitor sorafenib increased in vitro proliferation of 4 of 6 sarcoma cell lines tested. Latrunculin A was further associated with disruption of the actin cytoskeleton and reduced ERK1/2 phosphorylation. Together, this work advances opportunities for developing therapies to block progression of soft-tissue sarcomas and demonstrates that disruption of the actin cytoskeleton in sarcoma cells by latrunculin A is associated with a reduction in RMS cell growth. (167 words).

Vascular ageing and endothelial cell senescence: Molecular mechanisms of physiology and diseases.

Ageing leads to a progressive deterioration of structure and function of all organs over the time. During this process endothelial cells undergo senescence and manifest significant changes in their properties, resulting in impairment of the vascular functionality and neo-angiogenic capability. This ageing-dependent impairment of endothelial functions is considered a key factor contributing to vascular dysfunctions, which is responsible of several age-related diseases of the vascular system and other organs. Several mechanisms have been described to control ageing-related endothelial cell senescence including microRNAs, mitochondrial dysfunction and micro environmental stressors, such as hypoxia. In this review, we attempt to summarize the recent literature in the field, discussing the major mechanisms involved in endothelial cell senescence. We also underline key molecular aspects of ageing-associated vascular dysfunction in the attempt to highlight potential innovative therapeutic targets to delay the onset of age-related diseases.

Setdb1, a novel interactor of ΔNp63, is involved in breast tumorigenesis.

ΔNp63 has been recently involved in self-renewal potential of breast cancer stem cells. Although the p63 transcriptional profile has been extensively characterized, our knowledge of the p63-binding partners potentially involved in the regulation of breast tumour progression is limited. Here, we performed the yeast two hybrid approach to identify p63α interactors involved in breast tumorigenesis and we found that SETDB1, a histone lysine methyl transferases, interacts with ΔNp63α and that this interaction contributes to p63 protein stability. SETDB1 is often amplified in primary breast tumours, and its depletion confers to breast cancer cells growth disadvantage. We identified a list of thirty genes repressed by ΔNp63 in a SETDB1-dependent manner, whose expression is positively correlated to survival of breast cancer patients. These results suggest that p63 and SETDB1 expression, together with the repressed genes, may have diagnostic and prognostic potential.

Tarefas para avaliação psicolinguística no português do Brasil: resultados preliminares / Tasks for psycholinguistic assessment in brazilian portuguese: preliminary results

Objetivo: Este estudo visou ao desenvolvimento e avaliação de consistência interna de tarefas para avaliação de distúrbios da linguagem na abordagem psicolinguística seguindo os critérios da bateria Psycholinguistc Assessment of Language. Métodos: Cinco tarefas de compreensão e quatro de produção de linguagem foram desenvolvidas em português do Brasil e administradas a um grupo clínico com diagnóstico de afasia (n=26) e um grupo controle (n=55). As amostras não foram pareadas, pois o foco recaiu sobre as tarefas. Resultados: Como esperado, o grupo clínico obteve escores significativamente mais baixos, porém consistentes. Conclusões: Ao permitirem discriminar entre os grupos, as tarefas foram adequadas à aplicação em populações com distúrbio de linguagem adquirido. Permitiram ainda, conhecer as habilidades preservadas no grupo clínico, já que os subsistemas linguísticos avaliados por cada tarefa revelaram-se diferentemente comprometidos.

Objective: This study aimed at developing and testing for internal consistency of tasks for the assessment of language disorders based on the psycholinguistic approach following the criteria of the Psycholinguistc Assessment of Language. Methods: Five language comprehension and four language production tasks in Brazilian Portuguese were designed and tested in a clinical group diagnosed as aphasics (n=26) and a control group (n=55). Groups were not paired since the tasks were at stake. Results: As expected, the clinical group scored significantly lower, but with consistent results. Conclusions: Since it discriminated between groups, the tasks were appropriate for use among the population with acquired language impairment. The psycholinguistic subsystems were distinctively impaired within the clinical group, by means of which it is possible to identify the spared language abilities.

Tarefas para avaliação psicolinguística no português do Brasil: resultados preliminares

Objetivo: Este estudo visou ao desenvolvimento e avaliação de consistência interna de tarefas para avaliação de distúrbios da linguagem na abordagem psicolinguística seguindo os critérios da bateria Psycholinguistc Assessment of Language. Métodos: Cinco tarefas de compreensão e quatro de produção de linguagem foram desenvolvidas em português do Brasil e administradas a um grupo clínico com diagnóstico de afasia (n=26) e um grupo controle (n=55). As amostras não foram pareadas, pois o foco recaiu sobre as tarefas. Resultados: Como esperado, o grupo clínico obteve escores significativamente mais baixos, porém consistentes. Conclusões: Ao permitirem discriminar entre os grupos, as tarefas foram adequadas à aplicação em populações com distúrbio de linguagem adquirido. Permitiram ainda, conhecer as habilidades preservadas no grupo clínico, já que os subsistemas linguísticos avaliados por cada tarefa revelaram-se diferentemente comprometidos.(AU)

Objective: This study aimed at developing and testing for internal consistency of tasks for the assessment of language disorders based on the psycholinguistic approach following the criteria of the Psycholinguistc Assessment of Language. Methods: Five language comprehension and four language production tasks in Brazilian Portuguese were designed and tested in a clinical group diagnosed as aphasics (n=26) and a control group (n=55). Groups were not paired since the tasks were at stake. Results: As expected, the clinical group scored significantly lower, but with consistent results. Conclusions: Since it discriminated between groups, the tasks were appropriate for use among the population with acquired language impairment. The psycholinguistic subsystems were distinctively impaired within the clinical group, by means of which it is possible to identify the spared language abilities.(AU)