Identification of Achaete-scute complex-like 1 (ASCL1) target genes and evaluation of DKK1 and TPH1 expression in pancreatic endocrine tumours

<p>Abstract</p> <p>Background</p> <p><it>ASCL1 </it>role in pancreatic endocrine tumourigenesis has not been established. Recently it was suggested that ASCL1 negatively controls expression of the Wnt signalling antagonist <it>DKK1</it>. Notch signalling regulates expression of TPH1, the rate limiting enzyme in the biosyntesis of serotonin. Understanding the development and proliferation of pancreatic endocrine tumours (PETs) is essential for the development of new therapies.</p> <p>Methods</p> <p><it>ASCL1 </it>target genes in the pancreatic endocrine tumour cell line BON1 were identified by RNA interference and microarray expression analysis. Protein expressions of selected target genes in PETs were evaluated by immunohistochemistry.</p> <p>Results</p> <p>158 annotated <it>ASCL1 </it>target genes were identified in BON1 cells, among them DKK1 and TPH1 that were negatively regulated by ASCL1. An inverse relation of ASCL1 to DKK1 protein expression was observed for 15 out of 22 tumours (68%). Nine tumours displayed low ASCL1/high DKK1 and six tumours high ASCL1/low DKK1 expression. Remaining PETs showed high ASCL1/high DKK1 (n = 4) or low ASCL1/low DKK1 (n = 3) expression. Nine of twelve analysed PETs (75%) showed TPH1 expression with no relation to ASCL1.</p> <p>Conclusion</p> <p>A number of genes with potential importance for PET tumourigenesis have been identified. <it>ASCL1 </it>negatively regulated the Wnt signalling antagonist <it>DKK1</it>, and <it>TPH1 </it>expression in BON1 cells. In concordance with these findings DKK1 showed an inverse relation to ASCL1 expression in a subset of PETs, which may affect growth control by the Wnt signalling pathway.</p

Evasion of anti-growth signaling: a key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally-occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally-occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting

The mediterranean dietary pattern and breast cancer risk in Greek-Cypriot women: a case-control study

Background: Diet has long been suspected to impact on breast cancer risk. In this study we evaluated whether the degree of adherence to a Mediterranean diet pattern modifies breast cancer risk amongst Greek-Cypriot women. Methods: Subjects included 935 cases and 817 controls, all participating in the MASTOS case-control study in Cyprus. The study was approved by the Cyprus National Bioethics Committee. Information on dietary intakes was collected using an interviewer administered 32-item Food Frequency Questionnaire. Information on demographic, anthropometric, lifestyle, and other confounding factors was also collected. Adherence to the Mediterranean Diet pattern was assessed using two a-priory defined diet scores. In addition, dietary patterns specific to our population were derived using Principal Component Analysis (PCA). Logistic regression models were used to assess the association between the dietary patters and breast cancer risk. Results: There was no association with breast cancer risk for either score, however, higher consumptions of vegetables, fish and olive oil, were independently associated with decreased risk. In addition, the PCA derived component which included vegetables, fruit, fish and legumes was shown to significantly reduce risk of breast cancer (ORs across quartiles of increasing levels of consumption: 0.89 95%CI: 0.65-1.22, 0.64 95%CI: 0.47-0.88, 0.67 95%CI: 0.49-0.92, P trend < 0.0001), even after adjustment for relevant confounders. Conclusions: Our results suggest that adherence to a diet pattern rich in vegetables, fish, legumes and olive oil may favorably influence the risk of breast cancer. This study is the first investigation of dietary effects on breast cancer risk in Cyprus, a country whose population has traditionally adhered to the Mediterranean diet

Nutritional profile and obesity: results from a random‑sample population‑based study in Córdoba, Argentina

Introduction Obesity is a chronic, heterogeneous, multifactorial disease, which has sharply increased in prevalence in both developed and developing countries. This study aimed to estimate the prevalence of obesity and to identify socio-demographic risk factors associated with it, with special emphasis on diet. Methods Nutritional status, demographic characteristics, lifestyle habits, and food consumption patterns derived from a Food Frequency Questionnaire were investigated. Exhaustive exploratory analyses were performed in order to describe dietary patterns, and logistic regression models were used for odds ratio estimation. Results The study included 4328 subjects, over 18 years old and resident in Cordoba city. The prevalence of overweight and obesity was 34 and 17 %, respectively, with 60 % in men and 45 % in women of BMI ≥ 25. Obesity risk factors were high intake of sodium, refined grains, starchy vegetables, and snacks. A lower risk of overweight and obesity was associated with an adequate, moderate intake of meats, eggs, alcoholic beverages, sugar and sweets, milk, yogurt, and pulses. Conclusions A high intake of snacks, refined grains, starchy vegetables and sodium and low intake of yogurt, milk, pulses, and whole grains seem to be associated with the emergence and high prevalence of obesity in Cordoba, Argentina.publishedVersionFil: Aballay, Laura Rosana. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición. Estadística y Bioestadística; ArgentinaFil: Aballay, Laura Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: De la Quintana, Ana Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: Díaz, María del Pilar. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición. Estadística y Bioestadística; Argentina.Fil: Díaz, María del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Osella, Alberto R. Hospital Saverio de Bellis. Laboratorio de Epidemiologia y Bioestadística; Italia

Enhanced Notch Activation Is Advantageous but Not Essential for T Cell Lymphomagenesis in Id1 Transgenic Mice

T cell lymphoblastic leukemia (T-ALL) is known to be associated with chromosomal abnormalities that lead to aberrant expression of a number of transcription factors such as TAL1, which dimerizes with basic helix-loop-helix (bHLH) E proteins and inhibits their function. Activated Notch receptors also efficiently induce T cell leukemogenesis in mouse models. Interestingly, gain-of-function mutations or cryptic transcription initiation of the Notch1 gene have been frequently found in both human and mouse T-ALL. However, the correlations between these alterations and overall Notch activities or leukemogenesis have not been thoroughly evaluated. Therefore, we made use of our collection of T cell lymphomas developed in transgenic mice expressing Id1, which like TAL1, inhibits E protein function. By comparing expression levels of Notch target genes in Id1-expressing tumors to those in tumors induced by a constitutively active form of Notch1, N1C, we were able to assess the overall activities of Notch pathways and conclude that the majority of Id1-expressing tumors had elevated Notch function to a varying degree. However, 26% of the Id1-expressing tumors had no evidence of enhanced Notch activation, but that did not delay the onset of tumorigenesis. Furthermore, we examined the genetic or epigenetic alterations thought to contribute to ligand-independent activation or protein stabilization of Notch1 and found that some of the Id1-expressing tumors acquired these changes, but they are not uniformly associated with elevated Notch activities in Id1 tumor samples. In contrast, N1C-expressing tumors do not harbor any PEST domain mutations nor exhibit intragenic transcription initiation. Taken together, it appears that Notch activation provides Id1-expressing tumor cells with selective advantages in growth and survival. However, this may not be absolutely essential for lymphomagenesis in Id1 transgenic mice and additional factors could also cooperate with Id1 to induce T cell lymphoma. Therefore, a broad approach is necessary in designing T-ALL therapy

Pdx1 and Ngn3 Overexpression Enhances Pancreatic Differentiation of Mouse ES Cell-Derived Endoderm Population

In order to define the molecular mechanisms regulating the specification and differentiation of pancreatic β-islet cells, we investigated the effect of upregulating Pdx1 and Ngn3 during the differentiation of the β-islet-like cells from murine embryonic stem (ES) cell-derived activin induced-endoderm. Induced overexpression of Pdx1 resulted in a significant upregulation of insulin (Ins1 and Ins2), and other pancreas-related genes. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we induced the overexpression express of Ngn3 together with Pdx1. This combination dramatically increased the level and timing of maximal Ins1 mRNA expression to approximately 100% of that found in the βTC6 insulinoma cell line. Insulin protein and C-peptide expression was confirmed by immunohistochemistry staining. These inductive effects were restricted to c-kit+ endoderm enriched EB-derived populations suggesting that Pdx1/Ngn3 functions after the specification of pancreatic endoderm. Although insulin secretion was stimulated by various insulin secretagogues, these cells had only limited glucose response. Microarray analysis was used to evaluate the expression of a broad spectrum of pancreatic endocrine cell-related genes as well as genes associated with glucose responses. Taken together, these findings demonstrate the utility of manipulating Pdx1 and Ngn3 expression in a stage-specific manner as an important new strategy for the efficient generation of functionally immature insulin-producing β-islet cells from ES cells

Case-Control Study of Vitamin D, dickkopf homolog 1 (DKK1) Gene Methylation, VDR Gene Polymorphism and the Risk of Colon Adenoma in African Americans

There are sparse data on genetic, epigenetic and vitamin D exposure in African Americans (AA) with colon polyp. Consequently, we evaluated serum 25(OH) D levels, vitamin D receptor (VDR) polymorphisms and the methylation status of the tumor suppressor gene dickkopf homolog 1 (DKK1) as risk factors for colon polyp in this population.The case-control study consisted of 93 patients with colon polyp (cases) and 187 healthy individuals (controls) at Howard University Hospital. Serum levels of 25(OH)D (including D3, D2, and total) were measured by liquid chromatography-mass spectrometry. DNA analysis focused on 49 single nucleotide polymorphisms (SNPs) in the VDR gene. Promoter methylation analysis of DKK1 was also performed. The resulting data were processed in unadjusted and multivariable logistic regression analyses.Cases and controls differed in vitamin D status (D(3)<50 nmol/L: Median of 35.5 in cases vs. 36.8 in controls nmol/L; P = 0.05). Low levels of 25(OH)D(3) (<50 nmol/L) were observed in 86% of cases and 68% of controls and it was associated with higher risks of colon polyp (odds ratio of 2.7, 95% confidence interval 1.3-3.4). The SNP analysis showed no association between 46 VDR polymorphisms and colon polyp. The promoter of the DKK1 gene was unmethylated in 96% of the samples.We found an inverse association between serum 25(OH)D(3) and colon polyp in AAs. VDR SNPs and DKK1 methylation were not associated with colon polyp. Vitamin D levels may in part explain the higher incidence of polyp in AAs

The effectiveness of computerized clinical guidelines in the process of care: a systematic review

<p>Abstract</p> <p>Background</p> <p>Clinical practice guidelines have been developed aiming to improve the quality of care. The implementation of the computerized clinical guidelines (CCG) has been supported by the development of computerized clinical decision support systems.</p> <p>This systematic review assesses the impact of CCG on the process of care compared with non-computerized clinical guidelines.</p> <p>Methods</p> <p>Specific features of CCG were studied through an extensive search of scientific literature, querying electronic databases: Pubmed/Medline, Embase and Cochrane Controlled Trials Register. A multivariable logistic regression was carried out to evaluate the association of CCG's features with positive effect on the process of care.</p> <p>Results</p> <p>Forty-five articles were selected. The logistic model showed that Automatic provision of recommendation in electronic version as part of clinician workflow (Odds Ratio [OR]= 17.5; 95% confidence interval [CI]: 1.6-193.7) and Publication Year (OR = 6.7; 95%CI: 1.3-34.3) were statistically significant predictors.</p> <p>Conclusions</p> <p>From the research that has been carried out, we can conclude that after implementation of CCG significant improvements in process of care are shown. Our findings also suggest clinicians, managers and other health care decision makers which features of CCG might improve the structure of computerized system.</p

Expression of the "stem cell marker" CD133 in pancreas and pancreatic ductal adenocarcinomas

<p>Abstract</p> <p>Background</p> <p>It has been suggested that a small population of cells with unique self-renewal properties and malignant potential exists in solid tumors. Such "cancer stem cells" have been isolated by flow cytometry, followed by xenograft studies of their tumor-initiating properties. A frequently used sorting marker in these experiments is the cell surface protein CD133 (prominin-1). The aim of this work was to examine the distribution of CD133 in pancreatic exocrine cancer.</p> <p>Methods</p> <p>Fifty-one cases of pancreatic ductal adenocarcinomas were clinically and histopathologically evaluated, and immunohistochemically investigated for expression of CD133, cytokeratin 19 and chromogranin A. The results were interpreted on the background of CD133 expression in normal pancreas and other normal and malignant human tissues.</p> <p>Results</p> <p>CD133 positivity could not be related to a specific embryonic layer of organ origin and was seen mainly at the apical/endoluminal surface of non-squamous, glandular epithelia and of malignant cells in ductal arrangement. Cytoplasmic CD133 staining was observed in some non-epithelial malignancies. In the pancreas, we found CD133 expressed on the apical membrane of ductal cells. In a small subset of ductal cells and in cells in centroacinar position, we also observed expression in the cytoplasm. Pancreatic ductal adenocarcinomas showed a varying degree of apical cell surface CD133 expression, and cytoplasmic staining in a few tumor cells was noted. There was no correlation between the level of CD133 expression and patient survival.</p> <p>Conclusion</p> <p>Neither in the pancreas nor in the other investigated organs can CD133 membrane expression alone be a criterion for "stemness". However, there was an interesting difference in subcellular localization with a minor cell population in normal and malignant pancreatic tissue showing cytoplasmic expression. Moreover, since CD133 was expressed in shed ductal cells of pancreatic tumors and was found on the surface of tumor cells in vessels, this molecule may have a potential as clinical marker in patients suffering from pancreatic cancer.</p

Spanish Mediterranean diet and other dietary patterns and breast cancer risk: case–control EpiGEICAM study

Background:Although there are solid findings regarding the detrimental effect of alcohol consumption, the existing evidence on the effect of other dietary factors on breast cancer (BC) risk is inconclusive. This study aimed to evaluate the association between dietary patterns and risk of BC in Spanish women, stratifying by menopausal status and tumour subtype, and to compare the results with those of Alternate Healthy Index (AHEI) and Alternate Mediterranean Diet Score (aMED).Methods:We recruited 1017 incident BC cases and 1017 matched healthy controls of similar age (±5 years) without a history of BC. The association between ‘a priori' and ‘a posteriori' developed dietary patterns and BC in general and according to menopausal status and intrinsic tumour subtypes (ER+/PR+ and HER2− HER2+ and ER−/PR− and HER2−) was evaluated using logistic and multinomial regression models.Results:Adherence to the Western dietary pattern was related to higher risk of BC (OR for the top vs the bottom quartile 1.46 (95% CI 1.06–2.01)), especially in premenopausal women (OR=1.75; 95% CI 1.14–2.67). In contrast, the Mediterranean pattern was related to a lower risk (OR for the top quartile vs the bottom quartile 0.56 (95% CI 0.40–0.79)). Although the deleterious effect of the Western pattern was similarly observed in all tumour subtypes, the protective effect of our Mediterranean pattern was stronger for triple-negative tumours (OR=0.32; 95% CI 0.15–0.66 and Pheterogeneity=0.04). No association was found between adherence to the Prudent pattern and BC risk. The associations between ‘a priori' indices and BC risk were less marked (OR for the top vs the bottom quartile of AHEI=0.69; 95% CI 0.51–0.94 and aMED=0.74; 95% CI 0.46–1.18)).Conclusions:Our results confirm the harmful effect of a Western diet on BC risk, and add new evidence on the benefits of a diet rich in fruits, vegetables, legumes, oily fish and vegetable oils for preventing all BC subtypes, and particularly triple-negative tumours