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1.
Artigo em Inglês | MEDLINE | ID: mdl-35627773

RESUMO

Assuming the multidimensionality of health literacy, new complex and comprehensive approaches are more adequate to specific disease contexts, such as cancer. Assessing cancer literacy levels is a priority, since it entails potential serious implications for disease outcomes and patient's quality of life. This article reports on the translation and cultural adaptation of the Cancer Health Literacy Test to measure cancer literacy in Portuguese cancer patients. A multidisciplinary team of experts ensured the translation and cultural adaptation of the CHLT-30. A pre-test was conducted in two stages to evaluate the Portuguese version (CHLT-30 PT) in a sample of cancer patients (n = 71). Descriptive statistics were used to characterize the sample. Reliability (test-retest and internal consistency) and construct validity of CHLT-30 PT were assessed. The results obtained show a good internal consistency of the tool, respectively (Cronbach's alpha = 0.86 in the test and 0.80 in the retest). Patients' raw score mean in both test (23.96) and retest (25.97) and the distribution of scores categories are not statistically different. A suggestive association between higher education level and better total score was found compared to the results reported in CHLT-30-DKspa. The results obtained in the pre-test are favorable, and the instrument is now suitable for the next steps of the validation process. A Portuguese version of this tool will allow outlining patients' cancer literacy along the cancer care continuum, enabling the identification and implementation of adequate socio-educational strategies with highly positive impacts on health outcomes.


Assuntos
Letramento em Saúde , Neoplasias , Comparação Transcultural , Humanos , Neoplasias/terapia , Portugal , Qualidade de Vida , Reprodutibilidade dos Testes , Inquéritos e Questionários
2.
J Cancer Educ ; 34(3): 556-561, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-29508229

RESUMO

Cancer literacy is currently one of the most important dimensions of cancer continuum. Objective assessment of cancer knowledge in populations remains a challenging field to public health entities. Different evaluation tools are currently available; still, some groups remain disregarded due to the absence of validated instruments. Cancer literacy in adolescents and young adults has been clearly overlooked being a subject that requires new tools to be properly studied. To address this topic, we developed a new instrument and field tested it in a classroom environment for internal reliability, construct, and face validity. "Students Knowledge and Perceptions about Cancer questionnaire" was designed in Portuguese language and adapted to the Portuguese context by a multidisciplinary team. The final version of the questionnaire includes 35 items organized in three sections, encompassing knowledge and perceptions about cancer and socio-biographic data. Cancer experts ensured content validity, while tailoring of contents was refined with high school teachers. Test and retest of the instrument showed a good reliability of the scale and construct validity. Also, the clarity of the questionnaire and suitability to proper evaluate cancer knowledge was consistent between test and retest. The Students' Knowledge and Perceptions About Cancer Questionnaire (SKPaC) showed to be a valid tool to assess adolescents' knowledge and perceptions about cancer that can be used in the educational context.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Neoplasias/etiologia , Neoplasias/prevenção & controle , Estudantes , Inquéritos e Questionários , Adolescente , Feminino , Letramento em Saúde , Humanos , Masculino , Portugal , Reprodutibilidade dos Testes
3.
J Cancer Educ ; 34(5): 847-853, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29931456

RESUMO

Cancer prevention should start as early as possible. Young adults would benefit largely from the use of a smartphone app aiming at promoting cancer prevention behaviours. The aims of the study described in this paper are to (1) examine the user participation and engagement with a cancer prevention app in real-life settings and (2) assess changes in the users' cancer prevention behaviours. A cancer prevention smartphone app called Happy was developed and released to the general population. Data from registered app users' (N = 3326) demographics and baseline cancer prevention behaviours was analysed. App engagement was measured and all behaviour data logged through the app was analysed to assess the effectiveness of the app in the promotion of cancer prevention behaviours. User demographics and baseline behaviour assessment show that the app reached its intended target population: young adults that generally do not comply with cancer prevention guidelines. Logged behavioural data showed an increased frequency in several cancer prevention behaviours and a significant increase in the overall putative cancer prevention level (p < 0.001). However, user engagement with the app was limited and might condition the long-term impact of such changes. Happy reached its intended population and seems to be an effective tool to promote cancer prevention. Further research is needed to fully assess its long-term persuasive potential.


Assuntos
Comportamentos Relacionados com a Saúde , Promoção da Saúde/métodos , Aplicativos Móveis/estatística & dados numéricos , Neoplasias/prevenção & controle , Neoplasias/psicologia , Comportamento de Redução do Risco , Smartphone/estatística & dados numéricos , Adulto , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto Jovem
4.
Int J Med Inform ; 108: 125-133, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29132617

RESUMO

BACKGROUND: Estimates predict that more than half of all cancers are due to inadequate lifestyle choices. Smartphones can be successfully used to support the behaviour change needed to prevent cancer. OBJECTIVE: The purpose of this study was to field-test Happy, a smartphone app designed to promote cancer prevention behaviours, based on tailored-messages. METHODS: Thirty-two participants downloaded and used the app for 28 consecutive days (4 weeks). At the end of this period, they all answered an online questionnaire and ten of them were interviewed. Usability, feasibility, message receptivity, and perceived impact of the app were assessed. RESULTS: Compliance with cancer prevention guidelines was lower than expected. Happy was considered simple, intuitive and easy to use. Messages sent by the app were considered easy to understand, providing good advice and meaningful information that catch reader's attention. Participants also considered that Happy might be an effective way to promote cancer prevention. Collected data showed an increased frequency in several cancer prevention related behaviours and an increase in the overall putative cancer prevention level. CONCLUSIONS: This study showed the viability of designing and implementing smartphone-based interventions to promote cancer prevention behaviours. The results suggest that Happy is usable and might help users change their behaviour towards healthier choices and thus reduce their personal cancer risk.


Assuntos
Comportamentos Relacionados com a Saúde , Promoção da Saúde/métodos , Aplicativos Móveis/estatística & dados numéricos , Neoplasias/prevenção & controle , Smartphone/estatística & dados numéricos , Adulto , Feminino , Humanos , Estilo de Vida , Masculino , Projetos Piloto , Inquéritos e Questionários
5.
Oncol Lett ; 12(3): 1811-1817, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27602113

RESUMO

Despite the fact that the biological function of cluster of differentiation (CD)133 remains unclear, this glycoprotein is currently used in the identification and isolation of tumor-initiating cells from certain malignant tumors, including pancreatic cancer. In the present study, the involvement of mucin 1 (MUC1) in the signaling pathways of a highly tumorigenic CD133+ cellular subpopulation sorted from the pancreatic cancer cell line HPAF-II was evaluated. The expression of MUC1-cytoplasmic domain (MUC1-CD) and oncogenic signaling transducers (epidermal growth factor receptor, protein kinase C delta, glycogen synthase kinase 3 beta and growth factor receptor-bound protein 2), as well as the association between MUC1 and ß-catenin, were characterized in HPAF-II CD133+ and CD133low cell subpopulations and in tumor xenografts generated from these cells. Compared with HPAF CD133low cells, HPAF-II CD133+ cancer cells exhibited increased tumorigenic potential in immunocompromised mice, which was associated with overexpression of MUC1 and with the accordingly altered expression profile of MUC1-associated signaling partners. Additionally, MUC1-CD/ß-catenin interactions were increased both in the HPAF-II CD133+ cell subpopulation and derived tumor xenografts compared with HPAF CD133low cells. These results suggest that, in comparison with HPAF CD133low cells, CD133+ cells exhibit higher expression of MUC1, which contributes to their tumorigenic phenotype through increased interaction between MUC1-CD and ß-catenin, which in turn modulates oncogenic signaling cascades.

6.
APMIS ; 124(11): 913-924, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27538373

RESUMO

Mucin 1 (MUC1) has been described as the renaissance molecule due to the large set of functions it displays in both normal and neoplastic cells. This membrane-tethered glycoprotein is overexpressed and aberrantly glycosylated in most epithelial cancers, being involved in several processes related with malignant phenotype acquisition. With a highly polymorphic structure, both in the polypeptide and glycan counterparts, MUC1 variability has been associated with susceptibility to several diseases, including cancer. Biochemical features and biological functions have been characterized upon the full-length MUC1 protein, remaining to clarify the real impact on cell dynamics of the plethora of MUC1 isoforms. This review aims to encompass a detailed characterization of MUC1 role in carcinogenesis, highlighting recent findings in cell differentiation and uncovering new evidences of MUC1 isoforms involvement in malignant phenotype.


Assuntos
Carcinogênese , Fenômenos Fisiológicos Celulares , Glicoproteínas/metabolismo , Mucina-1/química , Mucina-1/metabolismo , Humanos , Isoformas de Proteínas/metabolismo
7.
Int J Med Inform ; 94: 134-42, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27573321

RESUMO

OBJECTIVES: This study sought to explore the views and experiences of healthy young adults concerning the fundamental features of a cancer prevention smartphone app that seeks behaviour change. METHODS: Three focus groups were conducted with 16 healthy young adults that explored prior experiences, points of view and opinions about currently available health-related smartphone apps. Then, an online questionnaire was designed and applied to a larger sample of healthy young adults. Focus group and online questionnaire data were analysed and confronted. RESULTS: Study results identified behaviour tracking, goal setting, tailored information and use of reminders as the most desired features in a cancer prevention app. Participants highlighted the importance of privacy and were reluctant to share personal health information with other users. The results also point out important dimensions to be considered for long-term use of health promotion apps related with usability and perceived usefulness. Participants didn't consider gamification features as important dimensions for long-term use of apps. CONCLUSIONS: This study allowed the definition of a guideline set for the development of a cancer prevention app.


Assuntos
Aplicativos Móveis , Neoplasias/prevenção & controle , Smartphone , Adulto , Feminino , Grupos Focais , Promoção da Saúde/métodos , Humanos , Masculino , Motivação , Privacidade , Comportamento de Redução do Risco , Inquéritos e Questionários , Adulto Jovem
8.
Expert Opin Drug Deliv ; 13(8): 1075-81, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27087021

RESUMO

OBJECTIVES: Gold nanoparticles have become promising vectors for cancer diagnosis and treatment. The present study investigates the effect of bortezomib (BTZ), a proteasome inhibitor, conjugated with pegylated gold nanoparticles (PEGAuNPs) in pancreatic and lung cancer cells. METHODS: Synthesized gold nanoparticles (PEGAuNPs) were conjugated with bortezomib antitumor drug. We investigated the cytotoxicity induced by BTZ conjugated with functionalized gold nanoparticles in vitro, in the human pancreatic (S2-013) and lung (A549) cancer cell lines. RESULTS: We found an efficient of conjugation of BTZ with PEGAuNPs. In vitro assays showed that after 72 h' incubation with PEGAuNPs-BTZ cancer cells revealed alterations in morphology; also for S2-013 and A549 cancer cells, the IC50 value of free BTZ is respectively 1.5 and 4.3 times higher than the IC50 value of PEGAuNPs-BTZ. Furthermore, for TERT-HPNE, the IC50 value is around 63 times lower for free BTZ than the conjugated nanovehicle. Cell growth inhibition results showed a remarkable enhancement in the effect of BTZ when conjugated with AuNPs. CONCLUSIONS: Our findings showed that conjugation with PEGAuNPs enhance the BTZ growth-inhibition effect on human cancer cells (S2-013 and A549) and decreases its toxicity against normal cells (TERT-HPNE).


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/administração & dosagem , Bortezomib/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Adenocarcinoma de Pulmão , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Células Epiteliais/efeitos dos fármacos , Ouro/química , Humanos , Nanopartículas , Inibidores de Proteassoma/administração & dosagem
9.
Expert Opin Drug Deliv ; 13(1): 133-41, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26371512

RESUMO

OBJECTIVES: A drug delivery system based on colloidal pegylated gold nanoparticles (PEGAuNPs) conjugated with the tyrosine kinase inhibitor afatinib was designed and tested for enhancing the drug activity against pancreatic and NSCLC cells. METHODS: PEGAuNPs were synthesized and characterized physicochemically. Confocal imaging was performed to evaluate the nanoparticle (NP) internalization in cancer cells. For cell-cycle distribution analysis, conjugated NPs and afatinib alone were incubated with cells and alterations on the cell-cycle profile subsequently analyzed by total DNA staining. Cancer cell survival and growth inhibition following incubation with afatinib and PEGAuNPs-afatinib (concentrations between 0.007 and 0.500 µM afatinib) were evaluated. RESULTS: A higher cellular uptake of PEGAuNPs was observed by cancer cells. Our data suggest an efficient conjugation of PEGAuNPs with the drug, enhancing the afatinib activity in comparison with afatinib alone. In fact, IC50 and GI50 results obtained show that the PEGAuNPs-afatinib conjugate is ca. 5 and 20 times more potent than afatinib alone in S2-013 and A549 cell lines, respectively. CONCLUSIONS: Conjugating PEGAuNPs with afatinib is a promising antitumor delivery system for cancer therapy as it improves drug efficacy, allowing a reduction in drug dose used and minimizing possible toxicity-related side effects.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Ouro , Nanopartículas/química , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Tirosina Quinases/antagonistas & inibidores , Quinazolinas/administração & dosagem , Afatinib , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Concentração Inibidora 50 , Neoplasias Pancreáticas/patologia , Polietilenoglicóis/química
10.
J Biomed Mater Res A ; 103(4): 1476-84, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25046528

RESUMO

The aim of this study was to develop a drug delivery system based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles for an efficient and targeted action of the proteasome inhibitor bortezomib against pancreatic cancer cells. The PLGA nanoparticles were formulated with a poloxamer, and further surface-modified with transferrin for tumor targeting. The nanoparticles were characterized as polymer carriers of bortezomib, and the cellular uptake and growth inhibitory effects were evaluated in pancreatic cells. Cellular internalization of nanoparticles was observed in normal and cancer cells, but with higher uptake by cancer cells. The sustained release of the loaded bortezomib from PLGA nanoparticles showed cytotoxic effects against pancreatic normal and cancer cells. Noteworthy differential cytotoxicity was attained by transferrin surface-modified PLGA nanoparticles since significant cell growth inhibition by delivered bortezomib was only observed in cancer cells. These findings demonstrate that the ligand transferrin enhanced the targeted delivery of bortezomib-loaded PLGA nanoparticles to pancreatic cancer cells. These in vitro results highlight the transferrin surface-modified PLGA nanoparticles as a promising system for targeted delivery of anticancer drugs.


Assuntos
Ácido Láctico/química , Nanopartículas/química , Neoplasias Pancreáticas/patologia , Ácido Poliglicólico/química , Inibidores de Proteassoma/farmacologia , Transferrina/metabolismo , Ácidos Borônicos , Bortezomib , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Endocitose/efeitos dos fármacos , Humanos , Nanopartículas/ultraestrutura , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Pirazinas , Espectroscopia de Infravermelho com Transformada de Fourier , Telomerase/metabolismo
11.
PLoS One ; 9(5): e96672, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24817168

RESUMO

Cancer is one of the leading causes of death worldwide, and thus represents a priority for national public health programs. Prevention has been assumed as the best strategy to reduce cancer burden, however most cancer prevention programs are implemented by healthcare professionals, which constrain range and educational impacts. We developed an innovative approach for cancer prevention education focused on high-school biology teachers, considered privileged mediators in the socialization processes. A training program, "Cancer, Educate to Prevent" was applied, so that the teachers were able to independently develop and implement prevention campaigns focused on students and school-related communities. The program encompassed different educational modules, ranging from cancer biology to prevention campaigns design. Fifty-four teachers were empowered to develop and implement their own cancer prevention campaigns in a population up to five thousands students. The success of the training program was assessed through quantitative evaluation--questionnaires focused on teachers' cancer knowledge and perceptions, before the intervention (pre-test) and immediately after (post-test). The projects developed and implemented by teachers were also evaluated regarding the intervention design, educational contents and impact on the students' knowledge about cancer. This study presents and discusses the results concerning the training program "Cancer, Educate to Prevent" and clearly shows a significant increase in teacher's cancer literacy (knowledge and perceptions) and teachers' acquired proficiency to develop and deliver cancer prevention campaigns with direct impact on students' knowledge about cancer. This pilot study reinforces the potential of high-school teachers and schools as cancer prevention promoters and opens a new perspective for the development and validation of cancer prevention education strategies, based upon focused interventions in restricted targets (students) through non-health professionals (teachers).


Assuntos
Docentes , Educação em Saúde/métodos , Neoplasias/prevenção & controle , Medicina Preventiva/educação , Adulto , Biologia/educação , Feminino , Educação em Saúde/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Projetos Piloto , Avaliação de Programas e Projetos de Saúde/métodos , Avaliação de Programas e Projetos de Saúde/estatística & dados numéricos , Instituições Acadêmicas , Estudantes , Inquéritos e Questionários , Ensino/métodos , Recursos Humanos
12.
Int J Cancer ; 134(6): 1270-8, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24105655

RESUMO

Tumour drug resistance is a major issue in the management of lung cancer patients as almost all lung tumours are either intrinsically resistant or quickly develop acquired resistance to chemotherapeutic drugs. Cancer drug resistance has recently been linked, at least in part, to the existence of cancer stem-like cells (CSLCs), a small sub-population of cells within the tumour that possess stem-like properties. CSLCs are often isolated by fluorescence activated cell sorting (FACS) according to the expression of certain stem-like cell membrane markers. Conflicting results regarding the specificity of particular stem cell surface markers for isolating CSLCs have, however, been recently reported. Therefore, alternative strategies enabling the identification and study of CSLCs should be considered, particularly in tumour types where appropriate stem cell markers are not well established and validated, like in lung cancer. In this article, we review data indicating therapy-selection as a valid approach for putative lung CSLCs enrichment. We believe that this strategy would be determinant for correctly assessing and characterising the sub-populations of CSLCs that are able to survive chemo or radiotherapy regimens and, at the same time, also have the ability to recapitulate and sustain tumour growth. Using therapy-induced enrichment of CSLCs may, therefore, prove to be an extremely useful method for studying CSLCs and provide new clues regarding potential therapeutic targets for their efficient elimination, which will undoubtedly play a decisive role in improving lung cancer patients' survival.


Assuntos
Terapia Combinada/efeitos adversos , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/terapia , Células-Tronco Neoplásicas/patologia , Animais , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos da radiação
13.
PLoS One ; 6(11): e26970, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22073229

RESUMO

BACKGROUND: Gastric carcinoma is the second leading cause of cancer-associated death worldwide. The high mortality associated with this disease is in part due to limited knowledge about gastric carcinogenesis and a lack of available therapeutic and prevention strategies. MUC1 is a high molecular weight transmembrane mucin protein expressed at the apical surface of most glandular epithelial cells and a major component of the mucus layer above gastric mucosa. Overexpression of MUC1 is found in approximately 95% of human adenocarcinomas, where it is associated with oncogenic activity. The role of MUC1 in gastric cancer progression remains to be clarified. METHODOLOGY: We downregulated MUC1 expression in a gastric carcinoma cell line by RNA interference and studied the effects on cellular proliferation (MTT assay), apoptosis (TUNEL assay), migration (migration assay), invasion (invasion assay) and aggregation (aggregation assay). Global gene expression was evaluated by microarray analysis to identify alterations that are regulated by MUC1 expression. In vivo assays were also performed in mice, in order to study the tumorigenicity of cells with and without MUC1 downregulation in MKN45 gastric carcinoma cell line. RESULTS: Downregulation of MUC1 expression increased proliferation and apoptosis as compared to controls, whereas cell-cell aggregation was decreased. No significant differences were found in terms of migration and invasion between the downregulated clones and the controls. Expression of TCN1, KLK6, ADAM29, LGAL4, TSPAN8 and SHPS-1 was found to be significantly different between MUC1 downregulated clones and the control cells. In vivo assays have shown that mice injected with MUC1 downregulated cells develop smaller tumours when compared to mice injected with the control cells. CONCLUSIONS: These results indicate that MUC1 downregulation alters the phenotype and tumorigenicity of MKN45 gastric carcinoma cells and also the expression of several molecules that can be involved in tumorigenic events. Therefore, MUC1 should be further studied to better clarify its potential as a novel therapeutic target for gastric cancer.


Assuntos
Regulação para Baixo , Mucina-1/metabolismo , Neoplasias Gástricas/patologia , Animais , Sequência de Bases , Western Blotting , Linhagem Celular Tumoral , Primers do DNA , Feminino , Imunofluorescência , Humanos , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Nus , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real
14.
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
15.
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
17.
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
18.
Cancer Lett ; 242(2): 191-7, 2006 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-16427187

RESUMO

Aberrant expression of Lewis antigens has been demonstrated in gastric lesions, namely gastritis, intestinal metaplasia (IM) and gastric carcinoma (GC), and can be partly due to overexpression of the Lewis (FUT3) enzyme. Our aim was to evaluate the role of promoter methylation in FUT3 and Le(a) expression in gastric carcinoma cell lines. MKN45 cell line showed low amounts of Le(a), in the absence of FUT3; GP220 expressed high levels of Le(a) and FUT3. After 5aza-2'deoxycytidine MKN45 showed increased levels of FUT3 and Le(a), by immunohistochemistry and Real-Time PCR, whereas GP220 showed an increase in FUT3 without increase of Le(a). Enzyme activity assays confirmed an increase in alpha-1,4 fucosyltransferase activity in both cell lines by 5aza-2'deoxycytidine. Luciferase reporter gene assays, using methylated and unmethylated deletion constructs of FUT3 promoter, showed that FUT3 expression is regulated by methylation. Summing up, we showed that FUT3 overexpression in gastric cells depends upon promoter hypomethylation and that FUT3 is responsible for overexpression of Le(a) in gastric cells, in vitro. FUT3, Lea, Methylation.


Assuntos
Antígenos de Neoplasias/biossíntese , Fucosiltransferases/biossíntese , Regulação Neoplásica da Expressão Gênica , Regiões Promotoras Genéticas , Neoplasias Gástricas/metabolismo , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Linhagem Celular Tumoral , Metilação de DNA , Primers do DNA/química , Decitabina , Humanos , Imuno-Histoquímica , Luciferases/metabolismo , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
J Pathol ; 207(4): 396-401, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16278805

RESUMO

Intestinal metaplasia (IM) is a preneoplastic lesion of the stomach in which there is transdifferentiation of the gastric mucosa to an intestinal phenotype. The caudal-related homeobox gene CDX2 encodes an intestine-specific transcription factor crucial for the regulation of proliferation and differentiation of intestinal cells. In addition, CDX2 is involved in the induction of IM in the stomach. The aim of this study was to access the putative involvement of OCT-1 in the induction of CDX2 expression de novo in gastric mucosa leading to the onset of IM. OCT-1 protein expression was evaluated by immunohistochemistry in 31 biopsies with chronic gastritis, 15 biopsies with foci of IM and adjacent gastric mucosa and 42 gastric carcinomas. Furthermore, we evaluated OCT-1 binding by electrophoretic mobility shift assay and activation of the CDX2 promoter by co-transfecting a CDX2 promoter/reporter construct with an OCT-1 expression vector in two gastric carcinoma cell lines, GP220 and MKN45. Our results show that OCT-1 is expressed in chronic gastritis, particularly when it is adjacent to IM and is expressed in 87% of IM foci. Furthermore, 74% of the gastric carcinomas were positive for OCT-1 and a strong association was observed between OCT-1 expression and intestinal-type carcinoma. We identified that OCT-1 binds to the CDX2 promoter, although we could not see a transactivation effect in gastric carcinoma cell lines. In conclusion, we observed increased OCT-1 expression in IM and in intestinal gastric carcinomas and identified the capacity of OCT-1 to bind to the CDX2 promoter, although we could not demonstrate a direct effect of OCT-1 in the transactivation of CDX2.


Assuntos
Proteínas de Homeodomínio/metabolismo , Fator 1 de Transcrição de Octâmero/metabolismo , Lesões Pré-Cancerosas/metabolismo , Neoplasias Gástricas/metabolismo , Estômago/patologia , Transativadores/metabolismo , Fator de Transcrição CDX2 , Doença Crônica , Ensaio de Desvio de Mobilidade Eletroforética , Mucosa Gástrica/metabolismo , Gastrite/metabolismo , Proteínas de Homeodomínio/genética , Humanos , Metaplasia/genética , Metaplasia/metabolismo , Proteínas de Neoplasias/metabolismo , Lesões Pré-Cancerosas/genética , Regiões Promotoras Genéticas , Neoplasias Gástricas/genética , Transativadores/genética , Transfecção , Células Tumorais Cultivadas
20.
J Pathol ; 199(1): 36-40, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12474224

RESUMO

Intestinal metaplasia (IM) is part of a stepwise sequence of alterations of the gastric mucosa, leading ultimately to gastric cancer, and is strongly associated with chronic Helicobacter pylori infection. The molecular mechanisms underlying the onset of IM remain elusive. The aim of this study was to assess the putative involvement of two intestine-specific transcription factors, CDX1 and CDX2, in the pathogenesis of gastric IM and gastric carcinoma. Eighteen foci of IM and 46 cases of gastric carcinoma were evaluated by immunohistochemistry for CDX1 and CDX2 expression. CDX1 was expressed in all foci of IM and in 41% of gastric carcinomas; CDX2 was expressed in 17/18 foci of IM and in 54% of gastric carcinomas. In gastric carcinomas, a strong association was observed between the expression of CDX1 and CDX2, as well as between the intestinal mucin MUC2 and CDX1 and CDX2. No association was observed between the expression of CDX1 and CDX2 and the histological type of gastric carcinoma. In conclusion, these results show that aberrant expression of CDX1 and CDX2 is consistently observed in IM and in a subset of gastric carcinomas. The association of CDX1 and CDX2 with expression of the intestinal mucin MUC2, both in IM and in gastric carcinoma, indirectly implies that CDX1 and CDX2 may be involved in intestinal differentiation along the gastric carcinogenesis pathway.


Assuntos
Proteínas de Homeodomínio/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/metabolismo , Estômago/patologia , Biomarcadores Tumorais/metabolismo , Fator de Transcrição CDX2 , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Imuno-Histoquímica/métodos , Metaplasia/metabolismo , Metaplasia/patologia , Mucina-5AC , Mucina-2 , Mucinas/metabolismo , Neoplasias Gástricas/patologia , Transativadores/metabolismo
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