TGFβ1-induced cell motility but not cell proliferation is mediated through Cten in colorectal cancer

Cten (C-terminal tensin-like) is a member of the tensin protein family found in complex with integrins at focal adhesions. It promotes epithelial‐mesenchymal transition (EMT) and cell motility. The precise mechanisms regulating Cten are unknown, although we and others have shown that Cten could be under the regulation of several cytokines and growth factors. Since Transforming growth factor beta 1 (TGF-β1) regulates integrin function and promotes EMT / cell motility, we were prompted to investigate whether TGF-β1 induces EMT and cell motility through Cten signalling in colorectal cancer. TGF-β1 signalling was modulated by either stimulation with TGF-β1 or knockdown of TGF-β1 in the CRC cell lines SW620 and HCT116. The effect of this modulation on expression of Cten, EMT markers and on cellular function was tested. The role of Cten as a direct mediator of TGF-β1 signalling was investigated in a CRC cell line in which the Cten gene had been deleted (SW620ΔCten). When TGF-β1 was stimulated or inhibited, this resulted in, respectively, upregulation and downregulation of Cten expression and EMT markers (Snail, Rock, N-Cadherin, Src). Cell migration and cell invasion were significantly increased following TGF-β1 stimulation and lost by TGF-β1 knockdown. TGF-β1 stimulation of the SW620ΔCten cell line resulted in selective loss of the effect of TGF-β1 signalling pathway on EMT and cell motility whilst the stimulatory effect on cell proliferation was retained. These data suggested Cten may play an essential role in mediating TGF-β1 induced EMT and cell motility and may therefore play a role in metastasis in CRC

Fatores de risco para a infeção associada a cateter venoso central – revisão sistemática

O uso de Cateter Venoso Central é apontado como um importante fator de risco para infeção, aumentando a mortalidade e morbilidade, bem como o período de internamento e os custos associados. Identificar os fatores de risco para a infeção associados à utilização de Cateter Venoso Central em doentes adultos hospitalizados. Foram selecionados 30 artigos através dos descritores, Cateteres Venosos Centrais, Infeções Relacionadas com Cateter e Fatores de Risco, através da consulta electrónica nas bases de dados PubMed, Lilacs e Scielo. Definimos como critérios de inclusão, estudos publicados entre 2007 e 2013, realizados em adultos hospitalizados com utilização de Cateter Venoso Central, estarem publicados em língua portuguesa e em revistas com indexação ISI. Obtivemos uma total de 8 publicações tendo rejeitado 22 por não cumprirem os critérios de inclusão. Do total dos 8 estudos analisados, 62,5% referem como fatores de risco para a infeção do Cateter Venoso Central, o local de inserção, sendo a veia femoral e a jugular referidas em 37% dos estudos como os locais mais prevalentes. O tempo de tempo de permanência do Cateter foi outro dos fatores de risco encontrado em 75% dos estudos, sendo que a grande maioria verificou correlação positiva do risco de infeção do Cateter com o número de dias de permanência. O maior número de lúmenes do Cateter foi referido também como fator de risco em 50% dos estudos e em igual proporção a falta de cuidados na manutenção do Cateter, devido a uma má manipulação do mesmo aumentando o risco de infeção. Igualmente a situação clínica do doente constituiu um fator de risco em 50% dos estudos, sendo que a gravidade da história clínica elevou o risco de infeção. O aumento do tempo de internamento foi outro fator de risco referido em 12,5% dos estudos. Discussão e Conclusão: Tendo em conta o elevado número de fatores de risco associados às infeções do Cateter Venoso Central, torna-se fundamental ter conhecimento dos mesmos com vista à sua redução, pois é necessária a implementação de medidas de controlo de infeção por parte dos profissionais de saúde, quer no momento da sua inserção quer no seu manuseamento de forma a prevenir esta infeção

Cten promotes Epithelial–Mesenchymal Transition (EMT) in colorectal cancer through stabilisation of Src

Cten is an oncogene promoting EMT in many signaling pathways, namely through Snail. We investigated whether Cten function could be mediated through Src. Cten levels were modulated by forced expression in HCT116 and gene knockdown in SW620 CRC (colorectal cancer) cell lines. In all cell lines, Cten was a positive regulator of Src expression. The functional importance of Src was tested by simultaneous Cten overexpression and Src knockdown. This resulted in abrogation of Cten motility-inducing activity and reduction of colony formation ability together with failure to induce Cten targets. In SW620ΔCten reduced Src expression increased following restoration of Cten, also leading to increased cell motility and colony formation, which were lost if Src was concomitantly knocked down. By qRT-PCR we showed modulation of Cten had no effect on Src mRNA. However, a CHX pulse chase assay demonstrated stabilization of Src protein by Cten. Finally, expression of Cten and Src was tested in a series of 84 primary CRCs and there was a significant correlation between them (P = 0.001). We conclude that Src is a novel and functionally important target of the Cten signaling pathway and that Cten protein causes post-transcriptional stabilization of Src in promoting EMT and possibly metastasis in CRC

Áreas marinhas protegidas da costa alentejana. Estudos científicos sobre os seus efeitos - o projeto PROTECT.

Brochura de divulgação dos objetivos e principais resultados do projeto PROTECT - Estudos científicos para proteção marinha na costa alentejana

The APOE ε2 allele increases the risk of Earlier Age at onset in Machado-Joseph disease

Background. Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder of late onset, caused by a (CAG)n expansion at the ATXN3 gene (14q32.1). Variation in age-at-onset is partially explained by the size of the (CAG)n tract in expanded alleles. The remaining variation should be the product of other factors, namely modifier genes. The genotype at the APOE locus has been described as a possible modifier in different neurological disorders, namely Parkinson (PD) and Huntington disease (HD). In the CNS, apolipoprotein E constitutes an important mediator of cholesterol transport/metabolism, which is essential for synaptic integrity and neuronal function. Objective. To investigate a modulating effect of the APOE polymorphism on age-at-onset of MJD. Design and Subjects. The APOE polymorphism was typed in a series of 192 MJD patients. Results. Cases with the ε2/ε3 genotype presented an earlier onset, when compared with those with ε3/ε3 or ε3/ε4. In this series of patients, the presence of an APOE ε2 allele implies a decrease of nearly 5 years in the age-at-onset. When combining, in a general linear model, several other predictors, namely the presence/absence of the APOE ε2 allele, with the size of the (CAG)n in expanded alleles, the model was significantly improved and the explanation of onset variance was raised from 59.8% to 66.5%. Furthermore, the presence of the ε2 allele was associated with an onset below 39 years (OR=5.00; 95% CI: 1.18-21.14). Conclusions. These findings indicate that the polymorphism at the APOE gene plays a role as a genetic modifier of MJD phenotype.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/63121/2009, SFRH/BPD/38659/2007, M3.1.3/F/004/2009, “Secretaria Regional da Ciência, Tecnologia e Equipamentos”.Fundação para a Ciência e a Tecnologia (FCT) - “Transcriptional variation of the ATXN3 gene as modulator of the clinical heterogeneity in Machado-Joseph disease (MJD)” (PIC/IC/83074/2007)Institute of Biotechnology and Biomedicine (IBBA) - “High prevalence diseases in the Azores Islands” (M2.1.2/I/026/2008

Novel Machado-Joseph disease-modifying genes and pathways identified by whole-exome sequencing

Machado-Joseph disease (MJD/SCA3) is a neurodegenerative polyglutamine disorder exhibiting a wide spectrum of phenotypes. The abnormal size of the (CAG)n at ATXN3 explains ~55% of the age at onset variance, suggesting the involvement of other factors, namely genetic modifiers, whose identification remains limited. Our aim was to find novel genetic modifiers, analyse their epistatic effects and identify disease-modifying pathways contributing to MJD variable expressivity. We performed whole-exome sequencing in a discovery sample of four age at onset concordant and four discordant first-degree relative pairs of Azorean patients, to identify candidate variants which genotypes differed for each discordant pair but were shared in each concordant pair. Variants identified by this approach were then tested in an independent multi-origin cohort of 282 MJD patients. Whole-exome sequencing identified 233 candidate variants, from which 82 variants in 53 genes were prioritized for downstream analysis. Eighteen disease-modifying pathways were identified; two of the most enriched pathways were relevant for the nervous system, namely the neuregulin signaling and the agrin interactions at neuromuscular junction. Variants at PARD3, NFKB1, CHD5, ACTG1, CFAP57, DLGAP2, ITGB1, DIDO1 and CERS4 modulate age at onset in MJD, with those identified in CFAP57, ACTG1 and DIDO1 showing consistent effects across cohorts of different geographical origins. Network analyses of the nine novel MJD modifiers highlighted several important molecular interactions, including genes/proteins previously related with MJD pathogenesis, namely between ACTG1/APOE and VCP/ITGB1. We describe novel pathways, modifiers, and their interaction partners, providing a broad molecular portrait of age at onset modulation to be further exploited as new disease-modifying targets for MJD and related diseases

Novel Machado-Joseph disease-modifying genes and pathways identified by whole-exome sequencing

Funding Information: This work was funded by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020 , and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia / Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/DTP-PIC/2638/2017 ( POCI-01-0145-FEDER-016592 ); GenomePT ( POCI-01-0145-FEDER-022184 ); ICVS Scientific Microscopy Platform , member of the national infrastructure PPBI - Portuguese Platform of Bioimaging ( PPBI-POCI-01-0145-FEDER-022122 ; by National funds , through the Foundation for Science and Technology (FCT) - project UIDB/50026/2020 and UIDP/50026/2020 ; and by the project NORTE-01-0145-FEDER-000013 , supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) . MR is supported by FCT ( CEECIND/03018/2018 ). ARVM ( SFRH/BD/129547/2017 ) and AFF ( SFRH/BD/121101/2016 ) are supported by a PhD grant financed by FCT . CB is supported by the Multiple System Atrophy Trust and Alzheimer's Research UK . MDC received funding from National Ataxia Foundation (NAF) and from FCT ( SFRH/BPD/101925/2014 ); DV-C received a grant from FCT ( SFRH/BD/147826/2019 ). Publisher Copyright: © 2021Machado-Joseph disease (MJD/SCA3) is a neurodegenerative polyglutamine disorder exhibiting a wide spectrum of phenotypes. The abnormal size of the (CAG)n at ATXN3 explains ~55% of the age at onset variance, suggesting the involvement of other factors, namely genetic modifiers, whose identification remains limited. Our aim was to find novel genetic modifiers, analyse their epistatic effects and identify disease-modifying pathways contributing to MJD variable expressivity. We performed whole-exome sequencing in a discovery sample of four age at onset concordant and four discordant first-degree relative pairs of Azorean patients, to identify candidate variants which genotypes differed for each discordant pair but were shared in each concordant pair. Variants identified by this approach were then tested in an independent multi-origin cohort of 282 MJD patients. Whole-exome sequencing identified 233 candidate variants, from which 82 variants in 53 genes were prioritized for downstream analysis. Eighteen disease-modifying pathways were identified; two of the most enriched pathways were relevant for the nervous system, namely the neuregulin signaling and the agrin interactions at neuromuscular junction. Variants at PARD3, NFKB1, CHD5, ACTG1, CFAP57, DLGAP2, ITGB1, DIDO1 and CERS4 modulate age at onset in MJD, with those identified in CFAP57, ACTG1 and DIDO1 showing consistent effects across cohorts of different geographical origins. Network analyses of the nine novel MJD modifiers highlighted several important molecular interactions, including genes/proteins previously related with MJD pathogenesis, namely between ACTG1/APOE and VCP/ITGB1. We describe novel pathways, modifiers, and their interaction partners, providing a broad molecular portrait of age at onset modulation to be further exploited as new disease-modifying targets for MJD and related diseases.publishersversionpublishe

Ran GTPase is an independent prognostic marker in malignant melanoma which promotes tumour cell migration and invasion

Aims Ran GTPase is involved in nucleocytoplasmic shuttling of proteins and is overexpressed in several cancers. The expression of Ran in malignant melanoma (MM) and its functional activity have not been described and were investigated in this study.Methods The prognostic value of Ran expression was tested in a series of 185 primary cutaneous MM cases using immunohistochemistry. The functional activity of Ran was investigated in the two melanoma cell lines. Ran expression was knocked down using two siRNAs and the effect on the expression of the c-Met oncogene, a potential downstream target of Ran, was tested. Functional effects of Ran knockdown on cell motility and cell proliferation were also assessed.Results Positive Ran expression was seen in 12.4% of MM and was associated with advanced clinical stage and greater Breslow thickness. Positive expression was an independent marker of shorter overall survival (p=0.023). Knockdown of Ran results in decreased expression of c-Met and the downstream c-met signalling targets ERK1/2. There was a significant reduction in cell migration (p [less than] 0.001) and cell invasion (p [less than] 0.001). c-Met knockdown decreased the expression of Ran through MAPK and PI3K-AKT in A375 cell line, inhibited the cell viability and migration of both A375 and G361 melanoma cell lines while invasion was enhanced.Conclusion Ran is a poor prognostic marker in cutaneous MM. It upregulates expression of the oncogene c-Met and, possibly through this, it promotes cell motility which may in turn promote metastasis

Abstracts

Tradução para a língua inglesa dos resumos dos artigos publicados nesta edição

Sequence analysis of 5' regulatory regions of the Machado-Joseph Disease gene (ATXN3)

Machado–Joseph disease (MJD) is a late-onset autosomal dominant neurodegenerative disorder, which is caused by a coding (CAG)n expansion in the ATXN3 gene (14q32.1). The number of CAG repeats in the expanded alleles accounts only for 50 to 75 % of onset variance, the remaining variation being dependent on other factors. Differential allelic expression of ATXN3 could contribute to the explanation of different ages at onset in patients displaying similar CAG repeat sizes. Variation in 5′ regulatory regions of the ATXN3 gene may have the potential to influence expression levels and, ultimately, modulate the MJD phenotype. The main goal of this work was to analyze the extent of sequence variation upstream of the ATXN3 start codon. A fragment containing the core promoter and the 5′ untranslated region (UTR) was sequenced and analyzed in 186 patients and 59 controls (490 chromosomes). In the core promoter, no polymorphisms were observed. In the 5′ UTR, only one SNP (rs3814834) was found, but no improvements on the explanation of onset variance were observed, when adding its allelic state in a linear model. Accordingly, in silico analysis predicted that this SNP lays in a nonconserved position for CMYB binding. Therefore, no functional effect could be predicted for this variant.Institute of Biotechnology and Biomedicine of the Azores - “High Prevalence Diseases in the Azores Islands” M2.1.2/I/026/2008,Fundação para a Ciência e a Tecnologia (FCT) - “Transcriptional variation of the ATXN3 gene as modulator of the clinical heterogeneity in Machado–Joseph disease (MJD)Secretaria Regional da Ciência, Tecnologia e Equipamentos - M3.1.3/F/004/2009CNP