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ABSTRACT: Loss-of-function mutations in have been found in patients with Congenital Short Bowel Syndrome (CSBS), suggesting that its encoded protein plays a major role in intestinal development. CLMP is a membrane protein that co-localizes with tight junction proteins, but its function is largely unknown. We expressed wild-type (WT)-CLMP and a mutant-CLMP (associated with CSBS) in human intestinal epithelial T84 cells that, as we show here, do not produce endogenous CLMP. We investigated the effects of WT-CLMP and mutant-CLMP proteins on key cellular processes that are important for intestinal epithelial development, including migration, proliferation, viability and transepithelial resistance. Our data showed that expression of WT-CLMP or mutant-CLMP does not affect any of these processes. Moreover, our aggregation assays in CHO cells show that CLMP does not act as a strong adhesion molecule. Thus, our data suggest that, in the model systems we used, the key processes involved in intestinal epithelial development appear to be unaffected by WT-CLMP or mutant-CLMP. Further research is needed to determine the role of CLMP in the development of the intestine.
PLoS ONE 01/2013; 8(2):e54649. · 4.09 Impact Factor
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ABSTRACT: P-cadherin is a cell-cell adhesion molecule codified by the CDH3 gene, which expression is highly associated with undifferentiated cells in normal adult epithelial tissues, as well as with poorly differentiated carcinomas. In breast cancer, P-cadherin is frequently overexpressed in high-grade tumours and is a well-established indicator of aggressive tumour behaviour and poor patient prognosis. However, till now, the mechanisms controlling CDH3 gene activation have been poorly explored. Since we recently described the existence of several CCAAT/Enhancer Binding Protein β (C/EBPβ) transcription factor binding sites at the CDH3 promoter, the aim of this study was to assess if the distinct C/EBPβ isoforms were directly involved in the transcriptional activation of the CDH3 gene in breast cancer cells. DNA-protein interactions, mutation analysis and luciferase reporter assay studies have been performed. We demonstrated that C/EBPβ is co-expressed with P-cadherin in breast cancer cells and all the three isoforms function as transcriptional regulators of the CDH3 gene, directly interacting with specific regions of its promoter. Interestingly, this transcriptional activation was only reflected at the P-cadherin protein level concerning the LIP isoform. Taken together, our data show that CDH3 is a newly defined transcriptional target gene of C/EBPβ isoforms in breast cancer, and we also identified the binding sites that are relevant for this activation.
PLoS ONE 01/2013; 8(2):e55749. · 4.09 Impact Factor
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Ana Sofia Ribeiro,
Bárbara Sousa,
Laura Carreto,
Nuno Mendes,
Ana Rita Nobre,
Sara Ricardo,
André Albergaria,
Jorge F Cameselle-Teijeiro,
Rene Gerhard,
Ola Söderberg,
Raquel Seruca,
Manuel A Santos,
Fernando Schmitt, Joana Paredes
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ABSTRACT: P-cadherin overexpression is associated with worse breast cancer survival, being a prognostic marker, as well as a putative therapeutic target for the aggressive triple-negative and basal-like carcinomas (TNBC). Previously, we have shown that P-cadherin promotes breast cancer invasion of cells where membrane E-cadherin was maintained; however, it suppresses invasion in models without endogenous cadherins, like melanomas. Here, we investigated if P-cadherin expression would interfere with the normal adhesion complex and which were the cellular/molecular consequences, constituting, in this way, a new mechanism by which E-cadherin invasive-suppressor function was disrupted. Using breast TNBC models, we demonstrated, for the first time, that P-cadherin co-localizes with E-cadherin, promoting cell invasion due to the disruption caused in the interaction between E-cadherin and cytoplasmic catenins. P-cadherin also induces cell migration and survival, modifying the expression profile of cells expressing wild-type E-cadherin and contributing to alter their cellular behavior. Additionally, E- and P-cadherin co-expressing cells significantly enhanced in vivo tumor growth, compared with cells expressing only E- or only P-cadherin. Finally, we still found that co-expression of both molecules was significantly correlated with high-grade breast carcinomas, biologically aggressive and with poor patient survival, being a strong prognostic factor in this disease. Our results show a role for E- and P-cadherin co-expression in breast cancer progression and highlight the potential benefit of targeting P-cadherin in the aggressive tumors expressing high levels of this protein. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The Journal of Pathology 11/2012; · 6.32 Impact Factor
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ABSTRACT: AIMS: CD44, CD24 and ALDH1 are the most consistently used biomarkers to identify and characterise the breast cancer stem cell (CSC) phenotype. However, most studies performed until now analysed samples of invasive ductal carcinomas of no special type (IDC-NST). Therefore, prevalence and clinical significance of these CSC markers in breast carcinomas of special histological types (SHT) is largely unknown. For that reason, this study aims to determine the distribution of the breast CD44, CD24 and ALDH1 CSC markers among a series of invasive breast carcinomas of SHT, in comparison with a series of IDC-NST. METHODS: 117 invasive SHT breast carcinomas were analysed for the expression of CD44, CD24 and ALDH1, by immuhohistochemistry. The distribution of these CSC markers was evaluated among the distinct histological special types, and the results were compared with a series of 466 IDC-NST. RESULTS: The expression prevalence of the breast CSC markers differed between special types and IDC-NST. Medullary, papillary and tubular carcinomas were enriched in the CSC phenotype CD44(+)/CD24(-/low) (80.0%, 100.0% and 100.0%, respectively, vs 45.3% in IDC-NST). Considering the ALDH1 cytoplasmic tumour expression, only medullary and metaplastic carcinomas displayed significant increase in CD44(+)/CD24(-/low)/ALDH1(+) CSC phenotype frequency (36.4% and 28.6%, respectively, vs 4.8% in IDC-NST). CONCLUSIONS: The expression distribution of breast CSC markers is largely dependent on histological type. Interestingly, within the distinct SHT, medullary and metaplastic carcinomas are the two types highly associated with high-grade carcinomas, basal-like and claudin-low molecular subtypes, and to the CSC phenotype CD44(+)/CD24(-/low)/ALDH1(+).
Journal of clinical pathology 10/2012; · 2.43 Impact Factor
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Patrícia Carneiro,
Maria Sofia Fernandes,
Joana Figueiredo,
Joana Caldeira,
Joana Carvalho,
Hugo Pinheiro,
Marina Leite,
Soraia Melo,
Patrícia Oliveira,
Joana Simões-Correia,
Maria José Oliveira,
Fátima Carneiro,
Céu Figueiredo, Joana Paredes,
Carla Oliveira,
Raquel Seruca
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ABSTRACT: 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.
FEBS letters 07/2012; 586(18):2981-9. · 3.54 Impact Factor
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ABSTRACT: Breast cancer is a heterogeneous disease associated with diverse biological behaviours and clinical outcome. Although some molecular subgroups of breast cancer have a targeted therapy, the most aggressive tumours still lack a molecular target. Despite vitamin D being classically associated with the physiological role of calcium regulation and phosphate transport in bone metabolism, several studies have demonstrated a wide range of functions for this hormone, which are particularly important in the field of cancer. The mechanisms underlying the protective actions of vitamin D in cancer development are only sparsely understood, but evidence shows that vitamin D participates in cell growth regulation, apoptosis and cell differentiation. In addition, it has been implicated in the suppression of cancer cell invasion, angiogenesis and metastasis. Most of vitamin D biological actions are mediated by the vitamin D receptor and the synthesis and catabolism of this hormone are regulated by the enzymes CYP27B1 and CYP24A1. In the present review we highlight research data concerning the function of this hormone in the mammary gland, with a special focus on breast carcinogenesis. Hence, and although the available data are controversial, we consider not only updated information on the epidemiology of vitamin D in breast cancer and its potential value as a therapeutic agent or prophylactic (with an emphasis on molecular mechanisms and effectors of vitamin D action), but include data on its role in other stages of breast cancer progression as well. Accordingly, we review data on the influence of vitamin D in the development of normal breast and the expression of vitamin D-related proteins (VDR, CYP27B1 and CYP24A21) in benign mammary lesions and ductal carcinomas in situ.
Breast cancer research: BCR 05/2012; 14(3):211. · 5.24 Impact Factor
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Joana Paredes,
Joana Figueiredo,
André Albergaria,
Patrícia Oliveira,
Joana Carvalho,
Ana Sofia Ribeiro,
Joana Caldeira,
Angela Margarida Costa,
Joana Simões-Correia,
Maria José Oliveira, [......],
Salomé S Pinho,
Rita Mateus,
Celso A Reis,
Marina Leite,
Maria Sofia Fernandes,
Fernando Schmitt,
Fátima Carneiro,
Céu Figueiredo,
Carla Oliveira,
Raquel Seruca
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ABSTRACT: 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.
Biochimica et Biophysica Acta 05/2012; 1826(12):297-311. · 4.66 Impact Factor
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ABSTRACT: The identification and characterization of cancer stem cells might lead to more effective control of neoplastic disease, by directing therapies to the most aggressive cells. For that reason, the identification of cancer stem cells (CSCs) in breast tumours is one of the priorities in breast cancer research, which has resulted in many studies attempting to identify their presence based on the expression of specific molecular markers. In this review, we describe the main molecular markers that have been identified as being able to recognise CSCs in breast carcinomas, the major molecular pathways that regulate CSCs and their association with the different molecular subtypes.
Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 05/2012; 460(6):545-53. · 2.49 Impact Factor
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ABSTRACT: The claudin-low molecular subtype of breast cancer includes triple negative invasive carcinomas, with a high frequency of metaplastic and medullary features. The aim of this study was to evaluate the immunohistochemistry expression of claudins in a series of metaplastic breast carcinomas. We also assessed other claudin-low features, such as the cancer stem cell-like and epithelial-to-mesenchymal transition phenotypes.
The majority of the cases showed weak or negative staining for membrane claudins expression. We found 76.9% (10/13) low expressing cases for claudin-1, 84.6% (11/13) for claudin-3 and claudin-4, and 92.3% (12/13) for claudin-7. Regarding the cancer stem cell marker ALDH1, 30.8% (4/13) showed positive staining. We also showed that the majority of the cases presented a CD44(+)CD24(-/low) phenotype, positivity for vimentin and lack of E-cadherin expression. Interestingly, these claudin-low molecular features were specific of the mesenchymal component of metaplastic breast carcinomas, since its frequency was very low in other breast cancer molecular subtypes, as luminal, HER2-overexpressing and non-metaplastic triple negative tumors.
The negative/low expression of claudins and E-cadherin, high levels of vimentin, and the breast cancer stem cell phenotype suggests that metaplastic breast carcinomas have similar features to the ones included in the claudin-low molecular subtype, specially their mesenchymal components.
Breast (Edinburgh, Scotland) 03/2012; 21(3):354-60. · 2.09 Impact Factor
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André Filipe Vieira,
Sara Ricardo,
Matthew Paul Ablett,
Maria Rita Dionísio,
Nuno Mendes,
André Albergaria,
Gillian Farnie,
Renê Gerhard,
Jorge F Cameselle-Teijeiro,
Raquel Seruca,
Fernando Schmitt,
Robert B Clarke, Joana Paredes
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ABSTRACT: Although the luminal progenitor cell of the normal mammary gland hierarchy has been proposed as the cell-of-origin for basal-like breast cancers, finding the cancer stem cell (CSC) phenotype for this malignancy has proven a difficult task, mostly due to the lack of specific markers. Recently, basal-like sporadic and familial cases of breast cancer have been linked to BRCA1 gene inactivation, which enables the upregulation of the target-repressed CDH3/P-cadherin gene, an important biomarker of basal-like breast carcinomas. Previously, we demonstrated that P-cadherin overexpression can mediate aggressive behavior in these tumors. Thus, our aim was to test whether P-cadherin mediates stem cell properties in basal-like breast carcinomas. Using a series of breast cancer cell lines and primary tumors, we showed that P-cadherin was directly associated with the expression of the breast stem markers CD44, CD49f, and aldehyde dehydrogenase 1 in the basal subtype. Moreover, cell population enriched for P-cadherin expression comprised increased in vitro mammosphere-forming efficiency and capacity to grow colonies in three-dimensional cultures as well as greater tumorigenicity. Importantly, an association was found with stem-/progenitor-like phenotypes of the breast, including the luminal progenitor population, CD49f(+) CD24(+). Additionally, P-cadherin expression conferred resistance to x-ray-induced cell death, sustaining a role for this molecule in another stem cell property. In summary, we demonstrated, for the first time, that P-cadherin mediates stem cell properties, which could be explored in order to better define the CSC phenotype of basal-like breast tumors and the cell-of-origin of this malignancy.
Stem Cells 03/2012; 30(5):854-64. · 7.78 Impact Factor
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ABSTRACT: The triple-negative subgroup of breast cancer includes a cluster of tumors exhibiting low E-cadherin expression (metaplastic carcinomas). In several cancer models, 1 alpha,25-dihydroxyvitamin D(3) (1α,25(OH)(2)D(3)) induces differentiation by increasing E-cadherin expression. The Vitamin D receptor (VDR) was evaluated as a possible therapeutic target for metaplastic carcinomas and 1α,25(OH)(2)D(3) effects as a differentiating agent in triple-negative breast cancer cells were assessed.
Metaplastic carcinomas were assessed for VDR expression by immunohistochemistry; differences in E-cadherin expression in triple-negative breast cancer cells were evaluated by real-time PCR, western blotting and Cadherin 1 (CDH1) methylation status.
Most of the metaplastic carcinomas were positive for VDR expression. Furthermore, 1α,25(OH)(2)D(3) promoted differentiation of MDA-MB-231 cells by inducing de novo E-cadherin expression, an effect that was time- and dose-dependent. Also, E-cadherin expression was due to promoter demethylation.
Metaplastic carcinomas may respond to 1α,25(OH)(2)D(3), since they express VDR and 1α,25(OH)(2)D(3) induces de novo E-cadherin expression in breast cancer cells by promoter demethylation.
Anticancer research 01/2012; 32(1):249-57. · 1.73 Impact Factor
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Christine S Van Der Werf,
Tara D Wabbersen,
Nai-Hua Hsiao, Joana Paredes,
Heather C Etchevers,
Peter M Kroisel,
Dick Tibboel,
Candice Babarit,
Richard A Schreiber,
Edward J Hoffenberg, [......],
Sirkka L Zeder,
Isabella Ceccherini,
Stanislas Lyonnet,
Ana S Ribeiro,
Raquel Seruca,
Gerard J Te Meerman,
Sven C D van Ijzendoorn,
Iain T Shepherd,
Joke B G M Verheij,
Robert M W Hofstra
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ABSTRACT: Short-bowel syndrome usually results from surgical resection of the small intestine for diseases such as intestinal atresias, volvulus, and necrotizing enterocolitis. Patients with congenital short-bowel syndrome (CSBS) are born with a substantial shortening of the small intestine, to a mean length of 50 cm, compared with a normal length at birth of 190-280 cm. They also are born with intestinal malrotation. Because CSBS occurs in many consanguineous families, it is considered to be an autosomal-recessive disorder. We aimed to identify and characterize the genetic factor causing CSBS.
We performed homozygosity mapping using 610,000 K single-nucleotide polymorphism arrays to analyze the genomes of 5 patients with CSBS. After identifying a gene causing the disease, we determined its expression pattern in human embryos. We also overexpressed forms of the gene product that were and were not associated with CSBS in Chinese Hamster Ovary and T84 cells and generated a zebrafish model of the disease.
We identified loss-of-function mutations in Coxsackie- and adenovirus receptor-like membrane protein (CLMP) in CSBS patients. CLMP is a tight-junction-associated protein that is expressed in the intestine of human embryos throughout development. Mutations in CLMP prevented its normal localization to the cell membrane. Knock-down experiments in zebrafish resulted in general developmental defects, including shortening of the intestine and the absence of goblet cells. Because goblet cells are characteristic for the midintestine in zebrafish, which resembles the small intestine in human beings, the zebrafish model mimics CSBS.
Loss-of-function mutations in CLMP cause CSBS in human beings, likely by interfering with tight-junction formation, which disrupts intestinal development. Furthermore, we developed a zebrafish model of CSBS.
Gastroenterology 12/2011; 142(3):453-462.e3. · 11.68 Impact Factor
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Joana Caldeira,
Joana Simões-Correia, Joana Paredes,
Marta T Pinto,
Sónia Sousa,
Giovanni Corso,
Daniele Marrelli,
Franco Roviello,
Paulo S Pereira,
Dominique Weil,
Carla Oliveira,
Fernando Casares,
Raquel Seruca
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ABSTRACT: Gastric cancer (GC) is a highly prevalent disease, being the fourth most common cancer and the second leading cause of cancer-associated deaths worldwide. Although many genes have been implicated in its development, many cases remain genetically unexplained. Hence, there is an urgent need to find new disease-related genes.
A transgenic Drosophila model was used to screen for novel genes putatively involved in GC. The authors evaluated the expression of the most interesting candidates in GC cell lines and primary tumours by semi-quantitative reverse transcription PCR, dissected the molecular mechanisms responsible for the deregulation of the most relevant one, and analysed its functional role in vitro and in a chicken embryo model.
Six candidate genes were identified, of which cytoplasmic polyadenylation element binding protein 1 (CPEB1) was downregulated in all GC cell lines and in 11 of 12 primary GC tumours. The pivotal CPEB1 promoter CpG site was determined, and it was found that methylation at this 79th CpG site was associated with CPEB1 silencing in GC cell lines and primary tumours. It was also discovered that methylation of this site was significantly more prevalent in diffuse type GC (p=0.007) and in cases with lymph node metastases (p=0.042). In vitro, CPEB1 impaired invasion. Its antiangiogenic role was also discovered, which was associated with downregulation of MMP14 and VEGFA.
The first evidence of CPEB1 involvement in GC is presented, along with the molecular mechanism underlying the regulation of its expression and its potential role in invasion and angiogenesis.
Gut 11/2011; 61(8):1115-23. · 10.11 Impact Factor
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ABSTRACT: The study of CD44/CD24 and ALDH1 expression is the most accurate method to identify cancer stem cells (CSC) from breast cancer populations. However, the overlap between CD44(+)CD24(-/low) and ALDH1(high) CSC phenotypes in breast cancer seems to be very small, as well as their distribution among intrinsic breast cancer subtypes. Due to this discrepancy, it is imperative to improve the understanding of breast CSC marker distribution.
466 invasive breast carcinomas and eight breast cancer cell lines were analysed for the expression of CD44, CD24 and ALDH1, to evaluate their distribution among the distinct molecular subtypes.
Basal-like tumours (76.5%) contained the higher percentage of cells with the CSC phenotype CD44(+)CD24(-/low) (p<0.0001). From ALDH1-positive cases, 39.4% were also basal-like tumours (p<0.0001). The analysis of breast cancer cell lines indicated that luminal cell lines are mainly enriched in a CD44(-/low)CD24(+) cell population, basal/mesenchymal breast cancer cell lines are enriched in the CD44(+)CD24(-/low) phenotype, whereas the remaining basal/epithelial cell lines are mainly positive for both markers. ALDH1 activity was mainly found in HER-OE and basal/epithelial breast cancer cell.
CD44(+)CD24(-/low) and ALDH1(+) phenotypes seem to identify CSC with distinct levels of differentiation. It seems that the paramount method and biomarkers that identify breast CSC within the distinct molecular subtypes need to be better explored, because it is pivotal to translate the CSC concept to clinical practice. In the future, the recognition of reliable markers to distinguish the CSC pool in each molecular subtype will be decisive for the development of specific target therapies.
Journal of clinical pathology 06/2011; 64(11):937-46. · 2.43 Impact Factor
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ABSTRACT: The current system of pathologic classification of human breast cancers does not take into account the biologic determinants of prognosis, nor is there a consensus regarding the progression from in situ to invasive carcinoma. The present study compared the molecular phenotypes of in situ and invasive components of breast cancer in the same sample. We built a series of 189 in situ and invasive carcinomas using tissue microarrays and classified them according to their immunoprofiles regarding estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, epidermal growth factor receptor, cytokeratin 5, P-cadherin, and the antigen Ki-67 into luminal A and B, human epidermal growth factor receptor 2 overexpressing, and basal-like carcinomas. We also correlated the subgroups of carcinomas with some of the classical prognostic factors such as histologic grade, tumor size, and lymph node metastasis, as well as with the age of the patient at diagnosis. The overall concordance on the molecular phenotypes between in situ and invasive components was 94%. For the in situ component, 63% of the cases were luminal A; 15%, luminal B; 12%, human epidermal growth factor receptor 2 overexpressing; and 7%, basal-like. Regarding the invasive component, 61% of the cases were luminal A; 16%, luminal B; 12%, human epidermal growth factor receptor 2 overexpressing; and 8%, basal-like. The present study allowed the identification of different immunoprofiles of in situ and invasive breast carcinomas using a specific panel of biomarkers and showed that in most cases, there is a concordance between in situ and invasive component profiles, supporting the theory of parallel disease in breast tumorigenesis.
Human pathology 03/2011; 42(10):1438-46. · 3.03 Impact Factor
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ABSTRACT: P-cadherin is a cell-cell adhesion molecule, whose expression is highly associated with undifferentiated cells in normal adult epithelial tissues, as well as with poorly differentiated carcinomas. Its expression has been already reported in human embryonic stem cells and it is presumed to be a marker of stem or progenitor cells of some epithelial tissues. In normal breast, P-cadherin has an essential role during ductal mammary branching, being expressed by the monolayer of epithelial cap cells at the end buds. In mature mammary tissue, its expression is restricted to the myoepithelium; it has been postulated that it may also be present in early luminal progenitor cells. In breast cancer, P-cadherin is frequently overexpressed in high-grade tumours, being a well-established indicator of poor patient prognosis. It has been reported as an important inducer of cancer cell migration and invasion, with underlying molecular mechanisms involving the signalling mediated by its juxtamembrane domain, the secretion of matrix metalloproteases to the extracellular media, and the cleavage of a P-cadherin soluble form with pro-invasive activity. Intracellularly, this protein interferes with the endogenous cadherin/catenin complex, inducing p120-catenin delocalization to the cytoplasm, and the consequent activation of Rac1/Cdc42 and associated alterations in the actin cytoskeleton. Considering P-cadherin's role in cancer cell invasion and metastasis formation, a humanized monoclonal antibody was recently produced to antagonize P-cadherin-associated signalling pathways, which is currently under Phase I clinical trials. In this review, the most important findings about the role of P-cadherin in normal breast development and cancer will be illustrated and discussed, with emphasis on the most recent data.
The International journal of developmental biology 01/2011; 55(7-9):811-22. · 2.16 Impact Factor
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Giovanni Corso,
Sérgia Velho, Joana Paredes,
Corrado Pedrazzani,
Diana Martins,
Fernanda Milanezi,
Valeria Pascale,
Carla Vindigni,
Hugo Pinheiro,
Marina Leite,
Daniele Marrelli,
Sónia Sousa,
Fátima Carneiro,
Carla Oliveira,
Franco Roviello,
Raquel Seruca
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ABSTRACT: Mitogen-activated protein kinase (MAPK) cascade and phosphatidylinositol 3-kinase (PI3K) survival pathways are frequently activated in the progression of gastrointestinal malignancies. In this study, we aimed to determine the frequency of gene mutations in members of these pathways--Epithelial Growth Factor Receptor (EGFR), KRAS, BRAF, PIK3CA and MLK3 in a series of 63 gastric carcinomas with high levels of microsatellite instability (MSI).
Gene mutation analysis was performed by PCR amplification followed by direct sequencing. In selected tumour cases, EGFR expression was evaluated by immunohistochemistry. Association studies between molecular data and clinicopathologic characteristics were performed.
Mutations in EGFR (3'-untranslated region [UTR] polyA repeat), KRAS, PIK3CA and MLK3 genes occurred in 30 (47.6%), 11 (17.5%), 9 (14.3%) and 2 (3.2%) of the MSI gastric cancer (GC) cases, respectively. No BRAF or EGFR hotspot mutations were identified. Overall, mutations in at least one of these genes were found in 55.6% (35/63) of gastric carcinomas. From those mutant cases 40.0% (14/35) of them had concomitant gene mutations, always involving EGFR polyA deletions. Interestingly, we observed significant associations between oncogenic mutations and female gender (p = 0.046) old age of diagnosis (p = 0.001) and intestinal subtype (p = 0.043).
Our results show that MSI gastric carcinoma frequently shows activation of EGFR-MAPK and PI3K pathways. Within all alterations found, deletions of the A13 repeats of EGFR were common, suggesting this molecular event as an important biomarker for stratification of GC patients for treatment with EGFR inhibitors.
European journal of cancer (Oxford, England: 1990) 10/2010; 47(3):443-51. · 4.12 Impact Factor
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Bárbara Sousa, Joana Paredes,
Fernanda Milanezi,
Nair Lopes,
Diana Martins,
Rozany Dufloth,
Daniella Vieira,
André Albergaria,
Luiz Veronese,
Vitor Carneiro,
Sílvia Carvalho,
José Luis Costa,
Luiz Zeferino,
Fernando Schmitt
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ABSTRACT: The most suitable immunohistochemical criterion to identify basal-like breast carcinomas (BLBC), a molecular subgroup of breast cancer associated with poor prognosis, is the triple negative phenotype along with CK5 and/or EGFR immunoreactivity. However, several putative basal markers have been suggested as alternatives to identify BLBC with more accuracy.
The expression of CK5, EGFR, P-cadherin, CK14, Vimentin and p63 were evaluated in 462 invasive breast carcinomas to determine their sensitivity and specificity for BLBC identification.
P-cadherin and CK5 showed higher sensitivity values, while EGFR, Vimentin and CK14 were the most specific markers. The combination of CK5 with P-cadherin, Vimentin or CK14 proved to be a reliable option for distinguishing the basal phenotype, compared to the "gold standard" pair CK5/EGFR. Furthermore, P-cadherin was still able to recognize a large number of putative BLBC among the "unclassified" group (ER-/PR-/HER2-/CK5-/EGFR-).
P-cadherin, Vimentin and CK14 can recognize BLBC already identified in triple negative/ CK5 and/or EGFR+ tumors, and due to P-cadherin sensitivity for BLBC identification this marker can reliably recruit a large number of breast carcinomas with basal phenotype among immunohistochemistry triple negative/ CK5 and/or EGFR - pool of tumors. Although they need GEP validation, our results can introduce the idea of these markers as additional options in the daily workup of breast pathology laboratories to identify BLBC.
Histology and histopathology 08/2010; 25(8):963-74. · 2.48 Impact Factor
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ABSTRACT: Monocarboxylate transporters (MCTs) have been considered promising targets for cancer therapy, since they facilitate lactate efflux in glycolytic tumours. However, their role in solid tumours is still poorly understood. Thus, the present work aimed to contribute to understanding the involvement of MCT1 and MCT4 in breast cancer progression as well as MCT regulation by CD147.
The expression of the membrane transporters MCT1 and MCT4 was analysed in a series of breast carcinomas (249 cases) and their clinicopathological significance investigated. Additionally, we analysed the significance of CD147 co-expression, as an important regulator of MCT expression and activity. MCT1 was significantly increased in breast carcinomas when compared with normal breast tissue and, importantly, both MCT1 and CD147 were associated with poor prognostic variables such as basal-like subtype and high grade tumours.
These results provide evidence for a prognostic value of MCT1 in breast carcinoma and support the exploitation of the complex MCT1/CD147 as a promising target for cancer therapy, especially in basal-like breast carcinoma.
Histopathology 06/2010; 56(7):860-7. · 3.08 Impact Factor
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André Albergaria,
Ana Sofia Ribeiro,
Sandra Pinho,
Fernanda Milanezi,
Vítor Carneiro,
Bárbara Sousa,
Sónia Sousa,
Carla Oliveira,
José Carlos Machado,
Raquel Seruca, Joana Paredes,
Fernando Schmitt
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ABSTRACT: CDH3/P-cadherin is a classical cadherin. Overexpression of which has been associated with proliferative lesions of high histological grade, decreased cell polarity and poor survival of patients with breast cancer. In vitro studies showed that it can be up-regulated by ICI 182,780, suggesting that the lack of ERalpha signalling is responsible for the aberrant P-cadherin overexpression and for its role in inducing breast cancer cell invasion and migration. However, the mechanism by which ER-signalling inhibition leads to P-cadherin expression is still unknown. The aim of this study was to explore the molecular mechanism linking the ERalpha-signalling and P-cadherin-regulated expression in breast cancer cell lines. This study showed that ICI 182,780 is able to increase CDH3 promoter activity, inducing high levels of the active chromatin mark H3 lysine 4 dimethylation. We also observed, for the first time, that the transcription factor C/EBPbeta is able to up-regulate CDH3 promoter activity in breast cancer cells. Moreover, we showed that the expression of P-cadherin and C/EBPbeta are highly associated in human breast carcinomas and linked with a worse prognosis of breast cancer patients. This study demonstrates the existence of an epigenetic regulation by which ICI 182,780 up-regulates P-cadherin expression in MCF-7/AZ breast cancer cells through chromatin remodelling at CDH3 promoter, bringing forward the growing evidence that ERalpha signalling-abrogation by anti-oestrogens is able to induce the expression of ERalpha-repressed genes which, in the appropriate cell biology context, may contribute to a breast cancer cell invasion phenotype.CDH3 GenBank accession no. NT_010498.
Human Molecular Genetics 04/2010; 19(13):2554-66. · 7.64 Impact Factor
