INEB Institute for Biomedical Engineering

Porto, Portugal

INEB Institute for Biomedical Engineering

Porto, Portugal
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Carneiro P.,University of Porto | Fernandes M.S.,University of Porto | Figueiredo J.,University of Porto | Caldeira J.,University of Porto | And 14 more authors.
FEBS Letters | Year: 2012

E-cadherin plays a major role in cell-cell adhesion and inactivating germline mutations in its encoding gene predispose to hereditary diffuse gastric cancer. Evidence indicates that aside from its recognized role in early tumourigenesis, E-cadherin is also pivotal for tumour progression, including invasion and metastization. Herein, we discuss E-cadherin alterations found in a cancer context, associated cellular effects and signalling pathways, and we raise new key questions that will impact in the management of GC patients and families. © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Velho S.,University of Porto | Oliveira C.,University of Porto | Paredes J.,University of Porto | Sousa S.,University of Porto | And 25 more authors.
Human Molecular Genetics | Year: 2010

Mixed lineage kinase 3 (MLK3) is a serine/threonine kinase, regulating MAPkinase signalling, in which cancer-associated mutations have never been reported. In this study, 174 primary gastrointestinal cancers (48 hereditary and 126 sporadic forms) and 7 colorectal cancer cell lines were screened for MLK3 mutations. MLK3 mutations were significantly associated with MSI phenotype in primary tumours (P = 0.0005), occurring in 21% of the MSI carcinomas. Most MLK3 somatic mutations identified were of the missense type (62.5%) and more than 80% of them affected evolutionarily conserved residues. A predictive 3D model points to the functional relevance of MLK3 missense mutations, which cluster in the kinase domain. Further, the model shows that most of the altered residues in the kinase domain probably affect MLK3 scaffold properties, instead of its kinase activity. MLK3 missense mutations showed transforming capacity in vitro and cells expressing the mutant gene were able to develop locally invasive tumours, when subcutaneously injected in nude mice. Interestingly, in primary tumours, MLK3 mutations occurred in KRAS and/or BRAF wild-type carcinomas, although not being mutually exclusive genetic events. In conclusion, we have demonstrated for the first time the presence of MLK3 mutations in cancer and its association tomismatch repair deficiency. Further,we demonstrated that MLK3 missense mutations found in MSI gastrointestinal carcinomas are functionally relevant. © The Author 2009. Published by Oxford University Press.

PubMed | University of Porto, Abel Salazar Biomedical Sciences Institute, INEB Institute for Biomedical Engineering, Hospital Pedro Hispano and Portuguese Oncology Institute of Porto IPO Porto
Type: Journal Article | Journal: Oncotarget | Year: 2016

Invasive bladder tumours express the cell-surface Sialyl-Tn (STn) antigen, which stems from a premature stop in protein O-glycosylation. The STn antigen favours invasion, immune escape, and possibly chemotherapy resistance, making it attractive for target therapeutics. However, the events leading to such deregulation in protein glycosylation are mostly unknown. Since hypoxia is a salient feature of advanced stage tumours, we searched into how it influences bladder cancer cells glycophenotype, with emphasis on STn expression. Therefore, three bladder cancer cell lines with distinct genetic and molecular backgrounds (T24, 5637 and HT1376) were submitted to hypoxia. To disclose HIF-1-mediated events, experiments were also conducted in the presence of Deferoxamine Mesilate (Dfx), an inhibitor of HIF-1 proteasomal degradation. In both conditions all cell lines overexpressed HIF-1 and its transcriptionally-regulated protein CA-IX. This was accompanied by increased lactate biosynthesis, denoting a shift toward anaerobic metabolism. Concomitantly, T24 and 5637 cells acquired a more motile phenotype, consistent with their more mesenchymal characteristics. Moreover, hypoxia promoted STn antigen overexpression in all cell lines and enhanced the migration and invasion of those presenting more mesenchymal characteristics, in an HIF-1-dependent manner. These effects were reversed by reoxygenation, demonstrating that oxygen affects O-glycan extension. Glycoproteomics studies highlighted that STn was mainly present in integrins and cadherins, suggesting a possible role for this glycan in adhesion, cell motility and invasion. The association between HIF-1 and STn overexpressions and tumour invasion was further confirmed in bladder cancer patient samples. In conclusion, STn overexpression may, in part, result from a HIF-1 mediated cell-survival strategy to adapt to the hypoxic challenge, favouring cell invasion. In addition, targeting STn-expressing glycoproteins may offer potential to treat tumour hypoxic niches harbouring more malignant cells.

Pereira-Castro I.,University of Porto | Costa A.M.S.,University of Porto | Oliveira M.J.,University of Porto | Oliveira M.J.,INEB Institute for Biomedical Engineering | And 5 more authors.
Journal of Cellular Biochemistry | Year: 2013

NET family members have recently emerged as important players in the development of multiple structures, from the trachea of fly larvae to the vertebrate eye and human breast cancers. However, their mechanisms of action are still poorly understood, and we lack a detailed characterization of their functional domains, as well as gene expression patterns-particularly in adult mammals. Here, we present a characterization of human NLZ1/ZNF703 (NocA-like zinc finger 1/Zinc finger 703), one of the two human NET family member genes. We show that the gene is ubiquitously expressed in adult human and mouse tissues, that three mRNA species with the same coding sequence are generated by alternative polyadenylation, and that the encoded protein contains six evolutionarily conserved domains, three of which are specific to NET proteins. Finally, we present functional evidence that these domains are necessary for proper subcellular distribution of and transcription repression by the NLZ1 protein, but not for its interaction with Groucho family co-repressors. © 2012 Wiley Periodicals, Inc.

Paredes J.,University of Porto | Figueiredo J.,University of Porto | Albergaria A.,University of Porto | Oliveira P.,University of Porto | And 20 more authors.
Biochimica et Biophysica Acta - Reviews on Cancer | Year: 2012

E-cadherin and P-cadherin are major contributors to cell-cell adhesion in epithelial tissues, playing pivotal roles in important morphogenetic and differentiation processes during development, and in maintaining integrity and homeostasis in adult tissues. It is now generally accepted that alterations in these two molecules are observed during tumour progression of most carcinomas. Genetic or epigenetic alterations in E- and P-cadherin-encoding genes (CDH1 and CDH3, respectively), or alterations in their proteins expression, often result in tissue disorder, cellular de-differentiation, increased invasiveness of tumour cells and ultimately in metastasis. In this review, we will discuss the major properties of E- and P-cadherin molecules, its regulation in normal tissue, and their alterations and role in cancer, with a specific focus on gastric and breast cancer models. © 2012 Elsevier B.V.

Velho S.,University of Porto | Pinto A.,University of Porto | Pinto A.,INEB Institute for Biomedical Engineering | Licastro D.,CBM S.c.r.l. AREA SCIENCE PARK | And 4 more authors.
BMC Cancer | Year: 2014

Background: MLK3 gene mutations were described to occur in about 20% of microsatellite unstable gastrointestinal cancers and to harbor oncogenic activity. In particular, mutation P252H, located in the kinase domain, was found to have a strong transforming potential, and to promote the growth of highly invasive tumors when subcutaneously injected in nude mice. Nevertheless, the molecular mechanism underlying the oncogenic activity of P252H mutant remained elusive.Methods: In this work, we performed Illumina Whole Genome arrays on three biological replicas of human HEK293 cells stably transfected with the wild-type MLK3, the P252H mutation and with the empty vector (Mock) in order to identify the putative signaling pathways associated with P252H mutation.Results: Our microarray results showed that mutant MLK3 deregulates several important colorectal cancer- associated signaling pathways such as WNT, MAPK, NOTCH, TGF-beta and p53, helping to narrow down the number of potential MLK3 targets responsible for its oncogenic effects. A more detailed analysis of the alterations affecting the WNT signaling pathway revealed a down-regulation of molecules involved in the canonical pathway, such as DVL2, LEF1, CCND1 and c-Myc, and an up-regulation of DKK, a well-known negative regulator of canonical WNT signaling, in MLK3 mutant cells. Additionally, FZD6 and FZD10 genes, known to act as negative regulators of the canonical WNT signaling cascade and as positive regulators of the planar cell polarity (PCP) pathway, a non-canonic WNT pathway, were found to be up-regulated in P252H cells.Conclusion: The results provide an overall view of the expression profile associated with mutant MLK3, and they support the functional role of mutant MLK3 by showing a deregulation of several signaling pathways known to play important roles in the development and progression of colorectal cancer. The results also suggest that mutant MLK3 may be a novel modulator of WNT signaling, and pinpoint the activation of PCP pathway as a possible mechanism underlying the invasive potential of MLK3 mutant cells. © 2014 Velho et al.; licensee BioMed Central Ltd.

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