935 resultados para Colon (Anatomia) - Cancer - Prevenção
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Background: Recent attention on chemotherapeutic intervention against cancer has been focused on discovering and developing phytochemicals as anticancer agents with improved efficacy, low drug resistance and toxicity, low cost and limited adverse side effects. In this study, we investigated the effects of Curcuma C20-dialdehyde on growth, apoptosis and cell cycle arrest in colon and cervical cancer cell lines. Materials and Methods: Antiproliferative, apoptosis induction, and cell cycle arrest activities of Curcuma C20-dialdehyde were determined by WST cell proliferation assay, flow cytometric Alexa fluor 488-annexin V/propidium iodide (PI) staining and PI staining, respectively. Results: Curcuma C20 dialdehyde suppressed the proliferation of HCT116, HT29 and HeLa cells, with IC50 values of 65.4±1.74 μg/ml, 58.4±5.20 μg/ml and 72.0±0.03 μg/ml, respectively, with 72 h exposure. Flow cytometric analysis revealed that percentages of early apoptotic cells increased in a dose-dependent manner upon exposure to Curcuma C20-dialdehyde. Furthermore, exposure to lower concentrations of this compound significantly induced cell cycle arrest at G1 phase for both HCT116 and HT29 cells, while higher concentrations increased sub-G1 populations. However, the concentrations used in this study could not induce cell cycle arrest but rather induced apoptotic cell death in HeLa cells. Conclusions: Our findings suggest that the phytochemical Curcuma C20-dialdehyde may be a potential antineoplastic agent for colon and cervical cancer chemotherapy and/or chemoprevention. Further studies are needed to characterize the drug target or mode of action of the Curcuma C20-dialdehyde as an anticancer agent.
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Peer reviewed
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The roles of long non-coding RNAs (lncRNAs) in regulating cancer and stem cells are being increasingly appreciated. Its diverse mechanisms provide the regulatory network with a bigger repertoire to increase complexity. Here we report a novel LncRNA, Lnc34a, that is enriched in colon cancer stem cells (CCSCs) and initiates asymmetric division by directly targeting the microRNA miR-34a to cause its spatial imbalance. Lnc34a recruits Dnmt3a via PHB2 and HDAC1 to methylate and deacetylate the miR-34a promoter simultaneously, hence epigenetically silencing miR-34a expression independent of its upstream regulator, p53. Lnc34a levels affect CCSC self-renewal and colorectal cancer (CRC) growth in xenograft models. Lnc34a is upregulated in late-stage CRCs, contributing to epigenetic miR-34a silencing and CRC proliferation. The fact that lncRNA targets microRNA highlights the regulatory complexity of non-coding RNAs (ncRNAs), which occupy the bulk of the genome.
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PURPOSE: Conventional staging methods are inadequate to identify patients with stage II colon cancer (CC) who are at high risk of recurrence after surgery with curative intent. ColDx is a gene expression, microarray-based assay shown to be independently prognostic for recurrence-free interval (RFI) and overall survival in CC. The objective of this study was to further validate ColDx using formalin-fixed, paraffin-embedded specimens collected as part of the Alliance phase III trial, C9581.
PATIENTS AND METHODS: C9581 evaluated edrecolomab versus observation in patients with stage II CC and reported no survival benefit. Under an initial case-cohort sampling design, a randomly selected subcohort (RS) comprised 514 patients from 901 eligible patients with available tissue. Forty-nine additional patients with recurrence events were included in the analysis. Final analysis comprised 393 patients: 360 RS (58 events) and 33 non-RS events. Risk status was determined for each patient by ColDx. The Self-Prentice method was used to test the association between the resulting ColDx risk score and RFI adjusting for standard prognostic variables.
RESULTS: Fifty-five percent of patients (216 of 393) were classified as high risk. After adjustment for prognostic variables that included mismatch repair (MMR) deficiency, ColDx high-risk patients exhibited significantly worse RFI (multivariable hazard ratio, 2.13; 95% CI, 1.3 to 3.5; P < .01). Age and MMR status were marginally significant. RFI at 5 years for patients classified as high risk was 82% (95% CI, 79% to 85%), compared with 91% (95% CI, 89% to 93%) for patients classified as low risk.
CONCLUSION: ColDx is associated with RFI in the C9581 subsample in the presence of other prognostic factors, including MMR deficiency. ColDx could be incorporated with the traditional clinical markers of risk to refine patient prognosis.
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Bisphenol A (BPA) is capable of mimicking endogenous hormones with potential consequences for human health and BPA exposure has been associated with several human diseases including neuropsychiatric disorders. Here, quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) results show that BPA at low concentrations (10 ng/mL and 1 μg/mL) induces differential transcript levels of four biomarker genes for Major Depressive Disorder (MDD) in HT29 human colon adenocarcinona cell line and Human Umbilical Vein Endothelial Cells (HUVEC). These results substantiate increasing concerns of BPA exposure in levels currently detected in humans.
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O presente projeto educativo consiste na recolha, estudo e implementação de estratégias de correção postural e qualidade do movimento na performance num conjunto de sessões individuais feito com quatro alunos de piano do Conservatório de Música de Cascais. No início de cada sessão foi gravado um momento performativo, avaliado em matriz própria, que serviu para monitorizar o progresso de cada aluno e para orientar a planificação específica de cada aula, garantindo um acompanhamento individualizado. De forma a recolher dados relativos à consciência e à incidência de problemas médicos em músicos profissionais em Portugal, e assim averiguar a pertinência da implementação de medidas de prevenção em escolas de música, foi feita uma sondagem a nível nacional com a adaptação de um questionário de música e saúde preexistente.
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Colorectal cancer (CRC) results from histologic and gene alterations can lead to a massive cellular proliferation. Most of the authors assume multifactorial causes to CRC genesis. Low physical activity, a fat diet poor in fibers and smoking habits seems to have an important role in CRC. However, there are also genetic causes associated with CRC risk. It has been described that oxidative stress levels could influence CRC development. Thus, cellular balance reactive species and defense enzymes involved in oxidative stress are crucial to maintain a good tissue function and avoid neoplasic process. Therefore, genome variations on these defense enzymes, such as MNSOD, SOD3, GSTP1, GSTT1 and GSTM1, could be important biomarkers to colorectal adenocarcinomas. We intend to determine frequencies distribution of most common polymorphisms involved on oxidative stress regulation (MNSOD, SOD3, GSTP1, GSTT1 and GSTM1) in patients with sporadic colorectal adenocarcinoma (SCA) and in healthy controls, evaluation their possible correlation with SCA risk. Samples common polymorphisms of antioxidant and detoxify genes (MNSOD T175C, SOD3 R213G, GSTP1 A105G, GSTP1 C114T, GSTT1del and GSTM1del) analysis was done by PCR-SSP techniques. In this study we found a higher prevalence of MNSOD 175CC (55% vs 2%; p<0.0001; OR: 58.5; CI 13.3 to 256.7), SOD3 213GG (31% vs 2%; p<0.0001; OR: 21.89; CI 4.93 to 97.29), GSTP1 105GG (46% vs 12%; p<0.0001; OR: 6.14; CI 2.85 to 13.26), GSTP1 114TT (38% vs 0%; p<0.0001; OR: Infinity) and GSTT1 null (75% vs 28%; p<0.0001; OR: 7.71; CI 3.83 to 15.56) mutated genotypes among SCA patients, while the normal genotypes were associated with SCA absence. Furthermore, we found GSTP1 114TT mutated genotype (52% vs 27%; p=0.003; OR: 2.88; CI: 1.41 to 5.89) and GSTT1 null genotype (87% vs 65%; p=0.003; OR: 3.66; CI 1.51 to 8.84) associated with colon samples. These findings suggest a positive association between most of common polymorphisms involved on oxidative stress regulation and SCA prevalence. Dysregulation of MNSOD, SOD3, GSTP1, GSTT1 and GSTM1 genes could be associated with an increase of ROS in colon and rectum tissue and p53 pathway deregulation, induced by oxidative stress on colonic and rectal cells. The present study also provides preliminary evidence that MNSOD 175C, SOD3 213G, GSTP1 105G, GSTP1 114T and GSTT1 null polymorphisms, may be involved in SCA risk and could be useful to clarify this multifactorial disorder.
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Objetivo: Analisar o conhecimento das mulheres em relação à prevenção do câncer de colo de útero e os fatores dificultadores acerca da realização da prática do exame preventivo. Métodos: Trata-se de um estudo do tipo observacional, de corte transversal e descritivo, com 110 mulheres entre 25 e 64 anos, atendidas em uma unidade de saúde, entre os meses de janeiro e março de 2014. Coletaram-se dados sociodemográficos e econômicos, aspectos ginecológicos e comportamento sobre o exame. Analisaram-se os dados através da estatística descritiva, apresentando valores absolutos e relativos. Resultados: Dados referentes ao significado do câncer uterino mostraram que 65 (59,1%) desconheciam seu significado, 69 (62,7%) sabiam como preveni-lo, 104 (94,5%) já realizaram o Papanicolau, 59 (53,6%) realizaram o Papanicolau há 1 ano, 62 (56,4%) realizam o exame preventivo anualmente e 88 (80%) sabiam a importância dessa realização. Quanto aos fatores encontrados referentes à dificuldade na realização do exame preventivo, 49 (44,5%) relataram ser a vergonha o fator mais impactante. Conclusão: Apesar de a maioria das mulheres realizar o exame periodicamente, muitas desconhecem a sua verdadeira finalidade, sentindo-se envergonhadas e constrangidas durante a realização do exame.
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This review evaluated the strength of the evidence for a causal relationship between physical activity (PA) and colorectal cancer (CRC). A systematic review of databases through February 2008 was conducted to identify studies that assessed the association between total or recreational PA and incidence or mortality of CRC (including CRC, rectal cancer, colon cancer, and proximal or distal colon cancer). Studies were evaluated for significant associations between PA and risk of CRC endpoints and for evidence of dose–response relationships in the highest quality studies. Twenty cohort studies were evaluated; 11 were high-quality. Fifty percent of all studies and 64%of highest quality studies reported at least one significant association between PA and risk of a CRC endpoint (Po0.05).However, only 28%of all analyses (31% of analyses of highest quality studies) were significant (Po0.05). Only 40% of analyses of highest quality studies resulted in a significant P for trend (Po0.05); however, a non-significant inverse linear association between PA and colon cancer riskwas apparent.Heterogeneity in the evidence from all studies and from the highest quality studies was evident. Evidence from cohort studies is not sufficient to claim a convincing relationship exists between PA and CRC risk.
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Purpose: Colorectal cancer patients diagnosed with stage I or II disease are not routinely offered adjuvant chemotherapy following resection of the primary tumor. However, up to 10% of stage I and 30% of stage II patients relapse within 5 years of surgery from recurrent or metastatic disease. The aim of this study was to determine if tumor-associated markers could detect disseminated malignant cells and so identify a subgroup of patients with early-stage colorectal cancer that were at risk of relapse. Experimental Design: We recruited consecutive patients undergoing curative resection for early-stage colorectal cancer. Immunobead reverse transcription-PCR of five tumor-associated markers (carcinoembryonic antigen, laminin γ2, ephrin B4, matrilysin, and cytokeratin 20) was used to detect the presence of colon tumor cells in peripheral blood and within the peritoneal cavity of colon cancer patients perioperatively. Clinicopathologic variables were tested for their effect on survival outcomes in univariate analyses using the Kaplan-Meier method. A multivariate Cox proportional hazards regression analysis was done to determine whether detection of tumor cells was an independent prognostic marker for disease relapse. Results: Overall, 41 of 125 (32.8%) early-stage patients were positive for disseminated tumor cells. Patients who were marker positive for disseminated cells in post-resection lavage samples showed a significantly poorer prognosis (hazard ratio, 6.2; 95% confidence interval, 1.9-19.6; P = 0.002), and this was independent of other risk factors. Conclusion: The markers used in this study identified a subgroup of early-stage patients at increased risk of relapse post-resection for primary colorectal cancer. This method may be considered as a new diagnostic tool to improve the staging and management of colorectal cancer. © 2006 American Association for Cancer Research.
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Circulating tumour cells (CTCs) have attracted much recent interest in cancer research as a potential biomarker and as a means of studying the process of metastasis. It has long been understood that metastasis is a hallmark of malignancy, and conceptual theories on the basis of metastasis from the nineteenth century foretold the existence of a tumour "seed" which is capable of establishing discrete tumours in the "soil" of distant organs. This prescient "seed and soil" hypothesis accurately predicted the existence of CTCs; microscopic tumour fragments in the blood, at least some of which are capable of forming metastases. However, it is only in recent years that reliable, reproducible methods of CTC detection and analysis have been developed. To date, the majority of studies have employed the CellSearch™ system (Veridex LLC), which is an immunomagnetic purification method. Other promising techniques include microfluidic filters, isolation of tumour cells by size using microporous polycarbonate filters and flow cytometry-based approaches. While many challenges still exist, the detection of CTCs in blood is becoming increasingly feasible, giving rise to some tantalizing questions about the use of CTCs as a potential biomarker. CTC enumeration has been used to guide prognosis in patients with metastatic disease, and to act as a surrogate marker for disease response during therapy. Other possible uses for CTC detection include prognostication in early stage patients, identifying patients requiring adjuvant therapy, or in surveillance, for the detection of relapsing disease. Another exciting possible use for CTC detection assays is the molecular and genetic characterization of CTCs to act as a "liquid biopsy" representative of the primary tumour. Indeed it has already been demonstrated that it is possible to detect HER2, KRAS and EGFR mutation status in breast, colon and lung cancer CTCs respectively. In the course of this review, we shall discuss the biology of CTCs and their role in metastagenesis, the most commonly used techniques for their detection and the evidence to date of their clinical utility, with particular reference to lung cancer.
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Arachidonic acid metabolism through cyclooxygenase (COX) pathways leads to the generation of biologically active eicosanoids. Eicosanoid expression levels vary during development and progression of gastrointestinal (GI) malignancies. COX-2 is the major COX-isoform responsible for G.I. cancer development/progression. COX-2 expression increases during progression from a normal to cancerous state. Evidence from observational studies has demonstrated that chronic NSAID use reduces the risk of cancer development, while both incidence and risk of death due to G.I. cancers were significantly reduced by daily aspirin intake. A number of randomized controlled trials (APC trial, Prevention of Sporadic Adenomatous Polyps trial, APPROVe trial) have also shown a significant protective effect in patients receiving selective COX-2 inhibitors. However, chronic use of selective COX-2 inhibitors at high doses was associated with increased cardiovascular risk, while NSAIDs have also been associated with increased risk. More recently, downstream effectors of COX-signaling have been investigated in cancer development/progression. PGE 2, which binds to both EP and PPAR receptors, is the major prostanoid implicated in the carcinogenesis of G.I. cancers. The role of TXA 2 in G.I. cancers has also been examined, although further studies are required to uncover its role in carcinogenesis. Other prostanoids investigated include PGD 2 and its metabolite 15d-PGJ2, PGF 1α and PGI 2. Targeting these prostanoids in G.I. cancers has the promise of avoiding cardiovascular toxicity associated with chronic selective COX-2 inhibition, while maintaining anti-tumor reactivity.A progressive sequence from normal to pre-malignant to a malignant state has been identified in G.I. cancers. In this review, we will discuss the role of the COX-derived prostanoids in G.I. cancer development and progression. Targeting these downstream prostanoids for chemoprevention and/or treatment of G.I. cancers will also be discussed. Finally, we will highlight the latest pre-clinical technologies as well as avenues for future investigation in this highly topical research field. © 2011 Elsevier B.V.
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The level of 67 kDa laminin receptor (67LR) expression on breast and colon tumor cell surfaces was previously shown to be correlated with the capacity of tumor cells to metastasize. In the present work we investigate the effects of progestins and estrogen on the expression of 67LR in two sublines of the T47D human breast cancer cells: weakly tumorigenic, poorly invasive parental T47D cells and a highly tumorigenic, more invasive T47Dco subclone. Inmmunoblotting with an affinity purified antibody directed against a synthetic peptide recognizes the 67LR in these cells. 67LR expression in the T47Dco subclone is 5,5-fold higher than in their parental T47D cells. Treatment of T47D cells with 1 nM of the synthetic progestin R5020 results in a 4-fold increase in 67LR protein expression. Estrogen also induced 67LR expression, but only by 1.5-fold. The progestin-stimulated expression of the 67LR correlates with a 4.3-fold increase in attachment of T47D cells to laminin. A monoclonal antibody, mAb 13, directed against β1 integrin, completely blocks the attachment of T47D cells to fibronectin, only partially inhibits the attachment of T47D cells to laminin, and appears not to affect the progestin-stimulated laminin attachment of T47D cells. A new antiprogestin, ZK 112.993, significantly inhibits both progestin-stimulated 67LR expression and the increased attachment to laminin. These results suggest a possible role for progestin in mediating one of the multiple events thought to be important in metastasis of steroid receptor positive human breast cancer cells.
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The aims of the present study are to investigate the clinicopathological correlations of JK-1(FAM134B) expression and its relationship to carcinogenesis in a colorectal adenoma-adenocarcinoma model. JK-1(FAM134B) protein expression was studied in a colon cancer cell line by Western blot and immunocytochemistry. JK-1(FAM134B) expression profiles at mRNA and protein levels were investigated in cancer tissues from 236 patients with colorectal adenocarcinoma and 32 patients with colorectal adenoma using real-time polymerase chain reaction and immunohistochemistry. The findings were then correlated with the clinicopathological features of these tumours. JK-1(FAM134B) protein was demonstrated in the colon cancer cells by Western blot. The protein was located in the nuclei of the tumour cells at both cellular and tissue levels. In colorectal adenocarcinomas, lower levels of JK-1(FAM134B) protein expression were associated with younger age (p=0.032), larger tumour size (p=0.004), advanced cancer stages (p=0.016) and higher rates of cancer recurrence (p=0.04). Also, lower levels of JK-1(FAM134B) mRNA expression were associated with advanced cancer stages (p=0.02) and presence of lymphovascular invasion (p=0.014). Higher JK-1(FAM134B) mRNA and protein expression levels were identified in adenomas and non-neoplastic mucosae, compared to carcinomas (p=0.005). To conclude, JK-1(FAM134B) mRNA expression and JK1 (FAM134B) protein levels varied with the different stages of progression of colorectal tumours. The expression levels of the gene were associated with clinicopathological features in patients with colorectal adenocarcinoma suggesting that JK-1(FAM134B) gene has roles in controlling some steps in the development of the invasive phenotypes from colorectal adenoma to early staged as well as advanced staged colorectal adenocarcinomas.