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1.
Health Promot Int ; 38(3)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37326410

RESUMO

Cancer is a primary societal challenge worldwide, with over 23 million new cases/year, and 10 million deaths/year. Estimates of preventable cancer deaths rise as high as 70%, but such estimates rely heavily on individual behaviors, which in turn are correlated with knowledge and attitudes towards health and cancer. This paper describes the iterative evidence-based development of the first entertainment-education series on cancer prevention to be televised, and reports its effectiveness evaluation. A nominal group defined the guiding principles that were translated into key characteristics for a series named '2' Life-changing minutes'. Pilot episodes were produced and evaluated in two complementary studies-a focus group study with medical doctors and a survey study with prospective viewers. Results from these studies guided the optimization and production of the full series, which was broadcast on national public TV, in prime time. An evaluation study was performed afterwards with naturally-occurring viewers and results show audience reach on par with purely entertainment series, that health messages can be clearly conveyed through fictional narratives, and that the series has high levels of appreciation and health promotion potential. '2' Life-changing minutes' constitutes a novel and effective proposal for health promotion, that challenges the primacy of information and statistics still common in health communication, with a new format based on stories, characters and social contexts to successfully promote health.


Assuntos
Promoção da Saúde , Neoplasias , Humanos , Educação em Saúde/métodos , Televisão , Portugal , Estudos Prospectivos , Neoplasias/prevenção & controle
2.
Biochim Biophys Acta ; 1852(9): 1928-39, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26144047

RESUMO

Helicobacter pylori exploits host glycoconjugates to colonize the gastric niche. Infection can persist for decades promoting chronic inflammation, and in a subset of individuals lesions can silently progress to cancer. This study shows that H. pylori chronic infection and gastric tissue inflammation result in a remodeling of the gastric glycophenotype with increased expression of sialyl-Lewis a/x antigens due to transcriptional up-regulation of the B3GNT5, B3GALT5, and FUT3 genes. We observed that H. pylori infected individuals present a marked gastric local pro-inflammatory signature with significantly higher TNF-α levels and demonstrated that TNF-induced activation of the NF-kappaB pathway results in B3GNT5 transcriptional up-regulation. Furthermore, we show that this gastric glycosylation shift, characterized by increased sialylation patterns, favors SabA-mediated H. pylori attachment to human inflamed gastric mucosa. This study provides novel clinically relevant insights into the regulatory mechanisms underlying H. pylori modulation of host glycosylation machinery, and phenotypic alterations crucial for life-long infection. Moreover, the biosynthetic pathways here identified as responsible for gastric mucosa increased sialylation, in response to H. pylori infection, can be exploited as drug targets for hindering bacteria adhesion and counteract the infection chronicity.

3.
J Clin Invest ; 118(6): 2325-36, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18483624

RESUMO

Chronic Helicobacter pylori infection is recognized as a cause of gastric cancer. H. pylori adhesion to gastric cells is mediated by bacterial adhesins such as sialic acid-binding adhesin (SabA), which binds the carbohydrate structure sialyl-Lewis x. Sialyl-Lewis x expression in the gastric epithelium is induced during persistent H. pylori infection, suggesting that H. pylori modulates host cell glycosylation patterns for enhanced adhesion. Here, we evaluate changes in the glycosylation-related gene expression profile of a human gastric carcinoma cell line following H. pylori infection. We observed that H. pylori significantly altered expression of 168 of the 1,031 human genes tested by microarray, and the extent of these alterations was associated with the pathogenicity of the H. pylori strain. A highly pathogenic strain altered expression of several genes involved in glycan biosynthesis, in particular that encoding beta3 GlcNAc T5 (beta3GnT5), a GlcNAc transferase essential for the biosynthesis of Lewis antigens. beta3GnT5 induction was specific to infection with highly pathogenic strains of H. pylori carrying a cluster of genes known as the cag pathogenicity island, and was dependent on CagA and CagE. Further, beta3GnT5 overexpression in human gastric carcinoma cell lines led to increased sialyl-Lewis x expression and H. pylori adhesion. This study identifies what we believe to be a novel mechanism by which H. pylori modulates the biosynthesis of the SabA ligand in gastric cells, thereby strengthening the epithelial attachment necessary to achieve successful colonization.


Assuntos
Adesinas Bacterianas/metabolismo , Helicobacter pylori/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Oligossacarídeos/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia , Sequência de Carboidratos , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Glicosilação , Humanos , Ligantes , Modelos Biológicos , Dados de Sequência Molecular , Filogenia , Antígeno Sialil Lewis X , Transfecção
4.
J Histochem Cytochem ; 57(1): 79-86, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18854599

RESUMO

Aberrant mucin O-glycosylation is often observed in cancer and is characterized by the expression of immature simple mucin-type carbohydrate antigens. UDP-N-acetyl-d-galactosamine:polypeptide N-acetylgalactosaminyltransferase-6 (ppGalNAc-T6) is one of the enzymes responsible for the initial step in O-glycosylation. This study evaluated the expression of ppGalNAc-T6 in human gastric mucosa, intestinal metaplasia, and gastric carcinomas. Our results showed that ppGalNAc-T6 is expressed in normal gastric mucosa and in intestinal metaplasia. A heterogeneous expression and staining pattern for this enzyme was observed in gastric carcinomas. ppGalNAc-T6 was expressed in 79% of the cases, and its expression level was associated with the presence of venous invasion. Our results provide evidence that ppGalNAc-T6 is an IHC marker associated with venous invasion in gastric carcinoma and may contribute to the understanding of the molecular mechanisms that underlie aberrant glycosylation in gastric carcinogenesis and in gastric carcinoma.


Assuntos
Biomarcadores Tumorais/biossíntese , Mucosa Gástrica/metabolismo , Mucosa Intestinal/metabolismo , N-Acetilgalactosaminiltransferases/biossíntese , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Humanos , Imuno-Histoquímica , Intestinos/patologia , Metaplasia , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias Gástricas/patologia , Veias/patologia
5.
World J Gastroenterol ; 14(9): 1411-4, 2008 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-18322957

RESUMO

AIM: To evaluate the influence of MUC1 mucin variable number of tandem repeats (VNTR) variability on H pylori adhesion to gastric cells. METHODS: Enzyme linked immunosorbent assay (ELISA)-based adhesion assays were performed to measure the adhesion of different H pylori strains (HP26695 and HPTx30a) to gastric carcinoma cell lines (GP202 and MKN45) and GP202 clones expressing recombinant MUC1 with different VNTR lengths. RESULTS: Evaluation of adhesion results shows that H pylori pathogenic strain HP26695 has a significantly higher (P<0.05) adhesion to all the cell lines and clones tested, when compared to the non-pathogenic strain HPTx30a. Bacteria showed a significantly higher (P<0.05) adhesion to the GP202 cell line, when compared to the MKN45 cell line. Furthermore, both strains showed a significantly higher (P<0.05) adhesion to GP202 clones with larger MUC1 VNTR domains. CONCLUSION: This work shows that MUC1 mucin variability conditions H pylori binding to gastric cells. The extent of bacterial adhesion depends on the size of the MUC1 VNTR domain. The adhesion is further dependent on bacterial pathogenicity and the gastric cell line. MUC1 mucin variability may contribute to determine H pylori colonization of the gastric mucosa.


Assuntos
Aderência Bacteriana/genética , Células Epiteliais/microbiologia , Helicobacter pylori/patogenicidade , Repetições Minissatélites/genética , Mucina-1/genética , Polimorfismo Genético/genética , Neoplasias Gástricas/microbiologia , Linhagem Celular Tumoral , Células Epiteliais/patologia , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Humanos , Neoplasias Gástricas/patologia
6.
Cancer Lett ; 249(2): 157-70, 2007 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-16965854

RESUMO

The activation of an abnormal glycosylation pathway in cancer cells leads to the formation of the sialyl-Tn antigen, blocking regular carbohydrate chain elongation. Sialyl-Tn antigen is rarely expressed in normal tissues but is aberrantly expressed in a variety of carcinomas, where it constitutes a marker of poor prognosis. Although the clinical significance of sialyl-Tn is well characterized, a functional role for this glycan and its contribution to cancer progression remain to be elucidated. This study evaluates the capability of sialyl-Tn to modify processes like cell cycle, apoptosis, actin cytoskeleton dynamics, adhesion and motility on ECM components, cell-cell aggregation and invasion. De-novo expression of sialyl-Tn leads to major morphological and cell behavior alterations in gastric carcinoma cells which were reverted by specific antibody blockage. Sialyl-Tn antigen is able to modulate a malignant phenotype inducing a more aggressive cell behavior, such as decreased cell-cell aggregation and increased ECM adhesion, migration and invasion.


Assuntos
Antígenos Glicosídicos Associados a Tumores/metabolismo , Carcinoma/metabolismo , Neoplasias Gástricas/metabolismo , Antígenos de Neoplasias/metabolismo , Apoptose , Carcinoma/patologia , Adesão Celular , Agregação Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Humanos , Mucina-1 , Mucinas/metabolismo , Invasividade Neoplásica , Fenótipo , Sialiltransferases/genética , Neoplasias Gástricas/patologia
7.
BMC Cancer ; 7: 124, 2007 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-17617904

RESUMO

BACKGROUND: Sialyl Lewis x (sLex) antigen is a carbohydrate antigen that is considered not only a marker for cancer but also implicated functionally in the malignant behaviour of cancer cells. Overexpression of sLex is associated with enhanced progression and metastases of many types of cancer including those of the mammary gland. Canine mammary tumours can invade and give rise to metastases via either lymphatic or blood vessels.E-Cadherin is specifically involved in epithelial cell-to-cell adhesion. In cancer, E-Cadherin underexpression is one of the alterations that characterizes the invasive phenotype and is considered an invasion/tumour suppressor gene. Partial or complete loss of E-Cadherin expression correlates with poor prognosis in canine malignant mammary cancer. The aim of this study was to analyse the sLex expression in canine malignant mammary tumours and to evaluate if the presence of sLex correlates with the expression of E-Cadherin and with clinicopathological features. METHODS: Fifty-three cases of canine mammary carcinomas were analysed immunohistochemically using monoclonal antibodies against sLex (IgM) and E-Cadherin (IgG). The clinicopathological data were then assessed to determine whether there was a correlation with sLex tumour expression. Double labelled immunofluorescence staining was performed to analyse the combined expression of sLex and E-Cadherin. RESULTS: sLex expression was consistently demonstrated in all cases of canine mammary carcinomas with different levels of expression. We found a significant relationship between the levels of sLex expression and the presence of lymph node metastases. We also demonstrated that when E-Cadherin expression was increased sLex was reduced and vice-versa. The combined analysis of both adhesion molecules revealed an inverse relationship. CONCLUSION: In the present study we demonstrate the importance of sLex in the malignant phenotype of canine malignant mammary tumours. Our results support the use of sLex as a prognostic tumour marker in canine mammary carcinomas. Furthermore, we showed that sLex and E-Cadherin expression were inversely correlated. Future studies are warranted to clarify the molecular mechanism underlying the relation between sLex and E-Cadherin in canine mammary carcinoma cells which represents an important comparative model to woman breast cancer.


Assuntos
Biomarcadores Tumorais/análise , Caderinas/metabolismo , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia , Invasividade Neoplásica/patologia , Oligossacarídeos/metabolismo , Animais , Biomarcadores Tumorais/genética , Biópsia por Agulha , Caderinas/genética , Transformação Celular Neoplásica/patologia , Cães , Feminino , Regulação Neoplásica da Expressão Gênica , Imuno-Histoquímica , Neoplasias Mamárias Animais/genética , Modelos Animais , Estadiamento de Neoplasias , Oligossacarídeos/genética , Probabilidade , Distribuição Aleatória , Valores de Referência , Sensibilidade e Especificidade , Antígeno Sialil Lewis X
8.
J Histochem Cytochem ; 54(5): 585-91, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16618943

RESUMO

Helicobacter pylori (Hp) infection is associated with the development of gastric lesions including gastritis, intestinal metaplasia (IM), and gastric carcinoma. In humans, Hp is found almost exclusively in the foveolar epithelium of the gastric mucosa and rarely colonizes the deeper portions where mucous cells of the glands produce mucins with terminal alpha1,4-GlcNAc O-glycans. This structure exerts antimicrobial activity against Hp. The development of IM in the stomach is characterized by Hp clearance from the metaplastic glands and by major alterations in the expression of mucins and mucin-carbohydrates. The present work evaluated whether terminal alpha1,4-GlcNAc and sialyl-Tn antigen are implicated in the process of Hp clearance from metaplastic glands by analyzing the expression of these antigens in different types of IM-complete (n=12) and incomplete (n=8)-and in gastric cell lines. Terminal alpha1,4-GlcNAc was not detected in IM except in a single foci of one case, indicating that this structure is not implicated in the clearance of Hp from IM, in contrast to what is observed in normal gastric mucosa. None of the gastric carcinoma cell lines studied showed terminal alpha1,4-GlcNAc, suggesting that they do not display a gastric gland mucous cell phenotype and therefore are useful models for in vitro Hp studies. Finally, sialyl-Tn antigen colocalizes with MUC2 mucin and is present in all cases of complete and incomplete IM, suggesting that either or both can be implicated in Hp clearance from IM.


Assuntos
Acetilglucosamina/biossíntese , Mucosa Gástrica/metabolismo , Helicobacter pylori , Neoplasias Gástricas/metabolismo , Antígenos Glicosídicos Associados a Tumores/biossíntese , Linhagem Celular Tumoral , Mucosa Gástrica/patologia , Humanos , Imuno-Histoquímica , Metaplasia , Mucina-2 , Mucinas/biossíntese , Estômago/microbiologia , Estômago/patologia , Neoplasias Gástricas/patologia
9.
Cancer Res ; 64(19): 7050-7, 2004 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-15466199

RESUMO

The Sialyl-Tn antigen (Neu5Acalpha2-6GalNAc-O-Ser/Thr) is highly expressed in several human carcinomas and is associated with carcinoma aggressiveness and poor prognosis. We characterized two human sialyltransferases, CMP-Neu5Ac:GalNAc-R alpha2,6-sialyltransferase (ST6GalNAc)-I and ST6GalNAc-II, that are candidate enzymes for Sialyl-Tn synthases. We expressed soluble recombinant hST6GalNAc-I and hST6GalNAc-II and characterized the substrate specificity of both enzymes toward a panel of glycopeptides, glycoproteins, and other synthetic glycoconjugates. The recombinant ST6GalNAc-I and ST6GalNAc-II showed similar substrate specificity toward glycoproteins and GalNAcalpha-O-Ser/Thr glycopeptides, such as glycopeptides derived from the MUC2 mucin and the HIVgp120. We also observed that the amino acid sequence of the acceptor glycopeptide contributes to the in vitro substrate specificity of both enzymes. We additionally established a gastric cell line, MKN45, stably transfected with the full length of either ST6GalNAc-I or ST6GalNAc-II and evaluated the carbohydrate antigens expression profile induced by each enzyme. MKN45 transfected with ST6GalNAc-I showed high expression of Sialyl-Tn, whereas MKN45 transfected with ST6GalNAc-II showed the biosynthesis of the Sialyl-6T structure [Galbeta1-3 (Neu5Acalpha2-6)GalNAc-O-Ser/Thr]. In conclusion, although both enzymes show similar in vitro activities when Tn antigen alone is available, whenever both Tn and T antigens are present, ST6GalNAc-I acts preferentially on Tn antigen, whereas the ST6GalNAc-II acts preferentially on T antigen. Our results show that ST6GalNAc-I is the major Sialyl-Tn synthase and strongly support the hypothesis that the expression of the Sialyl-Tn antigen in cancer cells is due to ST6GalNAc-I activity.


Assuntos
Antígenos Glicosídicos Associados a Tumores/biossíntese , Sialiltransferases/metabolismo , Neoplasias Gástricas/metabolismo , Sequência de Carboidratos , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Glicopeptídeos/metabolismo , Humanos , Dados de Sequência Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Sialiltransferases/biossíntese , Sialiltransferases/genética , Sialiltransferases/isolamento & purificação , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/genética , Especificidade por Substrato , Transfecção
10.
J Histochem Cytochem ; 51(6): 761-71, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12754287

RESUMO

Mucin O-glycosylation in cancer is characterized by aberrant expression of immature carbohydrate structures leading to exposure of simple mucin-type carbohydrate antigens and peptide epitopes. Glycosyltransferases controlling the initial steps of mucin O-glycosylation are responsible for the altered glycosylation observed in cancer. We studied the expression in gastric cell lines of six UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-T1, T2, T3, T4, T6, T11) that catalyze the initial key step in the regulation of mucin O-glycosylation, the transfer of GalNAc from UDP-GalNAc to serine and threonine residues. We also studied the expression of ST6GalNAc-I, the enzyme responsible for the synthesis of Sialyl-Tn antigen (NeuAcalpha2,6GalNAc) and the ST3Gal-I, the enzyme responsible for the synthesis of Sialyl-T antigen (NeuAcalpha2,3Galbeta1,3GalNAc). This study was done using specific monoclonal antibodies, enzymatic assays, and RT-PCR. Our results showed that GalNAc-T1, -T2, and -T3 have an ubiquitous expression in all gastric cell lines, whereas GalNAc-T4, -T6, and -T11 show a restricted expression pattern. The immunoreactivity with MAb VU-2-G7 suggests that, apart from GalNAc-T4, another GalNAc transferase is involved in the glycosylation of the Thr in the PDTR region of the MUC1 tandem repeat. The expression of ST3Gal-I correlates with the expression of the Sialyl-T antigen in gastric cell lines and in the control cell lines studied. The expression of ST6GalNAc-I is low in gastric cell lines, in accordance with the low/absent expression of the Sialyl-Tn antigen.


Assuntos
N-Acetilgalactosaminiltransferases/metabolismo , Sialiltransferases/metabolismo , Anticorpos Monoclonais , Antígenos Glicosídicos Associados a Tumores/imunologia , Antígenos Glicosídicos Associados a Tumores/metabolismo , Imunofluorescência , Humanos , Mucina-1/imunologia , Mucina-1/metabolismo , N-Acetilgalactosaminiltransferases/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sialiltransferases/imunologia , Neoplasias Gástricas , Células Tumorais Cultivadas , beta-Galactosídeo alfa-2,3-Sialiltransferase
11.
Front Biosci (Elite Ed) ; 3(4): 1443-55, 2011 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-21622148

RESUMO

Sialyl-Tn is a simple mucin-type carbohydrate antigen aberrantly expressed in gastrointestinal adenocarcinomas and in the precursor lesion intestinal metaplasia. Sialyl-Tn tumour expression is an independent indicator of poor prognosis. We have previously shown in vitro that ST6GalNAc-I and ST6GalNAc-II sialyltransferases can synthesize sialyl-Tn. The aim of the present study was to establish whether ST6GalNAc-I is the major enzyme responsible for the expression of sialyl-Tn. We used a model of CHO-ldlD cells producing only MUC1-Tn glycoform and showed that ST6GalNAc-I is the key-enzyme leading to sialyl-Tn biosynthesis. We developed novel monoclonal antibodies specific for ST6GalNAc-I and evaluated its expression in gastrointestinal tissues. ST6GalNAc-I was detected in normal colon mucosa co-localized with O-acetylated sialyl-Tn. Expression was largely unaltered in colorectal adenocarcinomas. In contrast, we found that ST6GalNAc-I is weakly expressed in normal gastric mucosa, but over-expressed in intestinal metaplasia, co-localized with sialyl-Tn. In gastric carcinomas ST6GalNAc-I was also associated with sialyl-Tn, but with heterogeneous staining and partial co-localization. Our results showed ST6GalNAc-I as the major enzyme controlling the expression of cancer-associated sialyl-Tn antigen in gastrointestinal tissues.


Assuntos
Trato Gastrointestinal/imunologia , Sialiltransferases/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Antígenos Glicosídicos Associados a Tumores , Sequência de Bases , Células CHO , Cricetinae , Cricetulus , Primers do DNA , Camundongos , Camundongos Endogâmicos BALB C , Sialiltransferases/imunologia
12.
FEMS Immunol Med Microbiol ; 56(3): 223-32, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19519784

RESUMO

Helicobacter pylori is recognized as the main cause of gastritis and is associated with gastric carcinogenesis. Syndecan-4 represents the major source of heparan sulfate (HS) in the gastric cells. HS proteoglycans expressed on the cell surface constitute targets for H. pylori at the early stage of infection. The aim of this study was to determine whether H. pylori induction of syndecan-4 expression is affected by the virulence characteristics of the infecting strain, namely the cytotoxic-associated gene (cag) pathogenicity island (PAI). We observed that individuals infected with highly pathogenic H. pylori strains express syndecan-4 in the foveolar epithelium of the gastric mucosa. The association between the cagPAI status of the infecting strain and syndecan-4 expression was further demonstrated by infection of gastric epithelial cell lines with a panel of cagPAI(+) and cagPAI(-)H. pylori strains, showing that expression of syndecan-4 was significantly increased in response to infection with the highly pathogenic strains. Moreover, infection of gastric cells with cagA and cagE mutant strains further confirmed that syndecan-4 induction is dependent on an intact cagPAI. The present study shows that highly pathogenic H. pylori strains induce syndecan-4 expression, both in human gastric mucosa and in gastric cell lines, in a cagPAI-dependent manner.


Assuntos
Aderência Bacteriana , Células Epiteliais/microbiologia , Ilhas Genômicas , Helicobacter pylori/patogenicidade , Sindecana-4/biossíntese , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Mucosa Gástrica/patologia , Perfilação da Expressão Gênica , Helicobacter pylori/genética , Humanos
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