Mammary Gland Structures Are Not Affected by an Increased Growth Rate of Yearling Ewes Post-Weaning but Are Associated with Growth Rates of Singletons

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Reduced risk of synovial sarcoma in females: X-chromosome inactivation?

Synovial sarcoma shows a characteristic t(X;18) translocation but not the expected female predominance in incidence. We speculate that, among females, one X-chromosome is inactivated and that only the translocation to an active X-chromosome leads to development of synovial sarcoma. Population-based cancer registry data from the SEER program support this hypothesis

A Full Pharmacological Analysis of the Three Turkey β-Adrenoceptors and Comparison with the Human β-Adrenoceptors

There are three turkey β-adrenoceptors: the original turkey β-adrenoceptor from erythrocytes (tβtrunc, for which the X-ray crystal structure has recently been determined), tβ3C and tβ4C-receptors. This study examined the similarities and differences between these avian receptors and mammalian receptors with regards to binding characteristics and functional high and low affinity agonist conformations.Stable cell lines were constructed with each of the turkey β-adrenoceptors and 3H-CGP12177 whole cell binding, CRE-SPAP production and (3)H-cAMP accumulation assays performed. It was confirmed that the three turkey β-adrenoceptors are distinct from each other in terms of amino acid sequence and binding characteristics. The greatest similarity of any of the turkey β-adrenoceptors to human β-adrenoceptors is between the turkey β3C-receptor and the human β2-adrenoceptor. There are pharmacologically distinct differences between the binding of ligands for the tβtrunc and tβ4C and the human β-adrenoceptors (e.g. with CGP20712A and ICI118551). The tβtrunc and tβ4C-adrenoceptors appear to exist in at least two different agonist conformations in a similar manner to that seen at both the human and rat β1-adrenoceptor and human β3-adrenoceptors. The tβ3C-receptor, similar to the human β2-adrenoceptor, does not, at least so far, appear to exist in more than one agonist conformation.There are several similarities, but also several important differences, between the recently crystallised turkey β-adrenoceptor and the human β-adrenoceptors. These findings are important for those the field of drug discovery using the recently structural information from crystallised receptors to aid drug design. Furthermore, comparison of the amino-acid sequence for the turkey and human adrenoceptors may therefore shed more light on the residues involved in the existence of the secondary β-adrenoceptor conformation

Antiproliferative and pro-apoptotic effects afforded by novel Src-kinase inhibitors in human neuroblastoma cells

<p>Abstract</p> <p>Background</p> <p>Neuroblastoma (NB) is the second most common solid malignancy of childhood that usually undergoes rapid progression with a poor prognosis upon metastasis. The Src-family tyrosine kinases (SFKs) are a group of proteins involved in cancer development and invasiveness that seem to play an important role in the NB carcinogenesis.</p> <p>Methods</p> <p>To determine cell proliferation, the growth rate was evaluated by both MTT test and cells counted. Analysis of DNA content was performed for the evaluation of the cell cycle and apoptosis. To characterize the mechanisms underlying the antiproliferative effects induced by SI 34, a novel pyrazolo-pyrimidine derivative provided with Src inhibitory activity, the involvement of some cellular pathways that are important for cell proliferation and survival was investigated by western blot assays. In particular, the contribution of cyclins, Src and ERK were examined. Finally, experiments of cell adhesion and invasiveness were performed.</p> <p>Results</p> <p>Treatment of SH-SY5Y human NB cells and CHP100 human neuroepithelioma (NE) cultures with three novel pyrazolo[3,4-<it>d</it>]pyrimidine derivatives, namely SI 34, SI 35 and SI 83, inhibits the cell proliferation in a time and concentration-dependent manner. The maximal effect was obtained after 72 hours incubation with SI 34 10 μM. Fluorescence microscopy experiments, flow cytometry analysis and determination of caspase-3 activity by fluorimetric assays showed that SI 34 induced SH-SY5Y apoptosis. Moreover, SI 34 determined cell cycle arrest at the G0/G1 phase, paralleled by a decreased expression of cyclin D1. Furthermore, our data indicate that SI 34 reduces the SH-SY5Y cells adhesion and invasiveness. Evidence that SI 34 inhibits the Src and the ERK-phosphorylation, suggests the mechanism through which it exerts its effects in SH-SY5Y cells.</p> <p>Conclusions</p> <p>Our study shows the ability of this pyrazolo-pyrimidine Src inhibitor in reducing the growth and the invasiveness of human NB cells, suggesting a promising role as novel drug in the treatment of neuroblastoma.</p

Type D personality is associated with increased metabolic syndrome prevalence and an unhealthy lifestyle in a cross-sectional Dutch community sample

<p>Abstract</p> <p>Background</p> <p>People with Type D-Distressed-personality have a general tendency towards increased negative affectivity (NA), while at the same time inhibiting these emotions in social situations (SI). Type D personality is associated with an increased risk of adverse outcomes in patients with cardiovascular disease. Whether Type D personality is a cardiovascular risk factor in healthy populations remains to be investigated. In the present study, the relations between Type D personality and classical cardiovascular risk factors, i.e. metabolic syndrome and lifestyle were investigated in a Dutch community sample.</p> <p>Methods</p> <p>In a cross-sectional study 1592 participants were included, aged 20-80 years. Metabolic syndrome was defined by self-report, following the International Diabetes Federation-IDF-guidelines including an increased waist circumference, dyslipidemia, hypertension, and diabetes. In addition lifestyle factors smoking, alcohol use, exercise and dietary habits were examined. Metabolic syndrome prevalence was stratified by Type D personality (a high score on both NA and SI), lifestyle and confounders age, gender, having a partner, higher education level, cardiac history, family history of cardiovascular disease.</p> <p>Results</p> <p>Metabolic syndrome was more prevalent in persons with a Type D personality (13% vs. 6%). Persons with Type D personality made poorer lifestyle choices, adhered less to the physical activity norm (OR = 1.5, 95%CI = 1.1-2.0, <it>p </it>= .02), had a less varied diet (OR = 0.50, 95%CI = 0.40-0.70, <it>p </it>< .0005), and were less likely to restrict their fat intake (OR = 0.70, 95%CI = 0.50-0.90, <it>p </it>= .01). Type D personality was related to a twofold increased risk of metabolic syndrome (OR = 2.2, 95%CI = 1.2-4.0, <it>p </it>= .011), independent of lifestyle factors and confounders.</p> <p>Conclusions</p> <p>Type D personality is related to an increased prevalence of metabolic syndrome and unhealthy lifestyle, which suggests both behavioral and biological vulnerability for development of cardiovascular disorders and diabetes.</p

Machine Learning Methods for Prediction of CDK-Inhibitors

Progression through the cell cycle involves the coordinated activities of a suite of cyclin/cyclin-dependent kinase (CDK) complexes. The activities of the complexes are regulated by CDK inhibitors (CDKIs). Apart from its role as cell cycle regulators, CDKIs are involved in apoptosis, transcriptional regulation, cell fate determination, cell migration and cytoskeletal dynamics. As the complexes perform crucial and diverse functions, these are important drug targets for tumour and stem cell therapeutic interventions. However, CDKIs are represented by proteins with considerable sequence heterogeneity and may fail to be identified by simple similarity search methods. In this work we have evaluated and developed machine learning methods for identification of CDKIs. We used different compositional features and evolutionary information in the form of PSSMs, from CDKIs and non-CDKIs for generating SVM and ANN classifiers. In the first stage, both the ANN and SVM models were evaluated using Leave-One-Out Cross-Validation and in the second stage these were tested on independent data sets. The PSSM-based SVM model emerged as the best classifier in both the stages and is publicly available through a user-friendly web interface at http://bioinfo.icgeb.res.in/cdkipred

A Targeted Constitutive Mutation in the Apc Tumor Suppressor Gene Underlies Mammary But Not Intestinal Tumorigenesis

Germline mutations in the adenomatous polyposis coli (APC) gene are responsible for familial adenomatous polyposis (FAP), an autosomal dominant hereditary predisposition to the development of multiple colorectal adenomas and of a broad spectrum of extra-intestinal tumors. Moreover, somatic APC mutations play a rate-limiting and initiating role in the majority of sporadic colorectal cancers. Notwithstanding its multifunctional nature, the main tumor suppressing activity of the APC gene resides in its ability to regulate Wnt/β-catenin signaling. Notably, genotype–phenotype correlations have been established at the APC gene between the length and stability of the truncated proteins encoded by different mutant alleles, the corresponding levels of Wnt/β-catenin signaling activity they encode for, and the incidence and distribution of intestinal and extra-intestinal tumors. Here, we report a novel mouse model, Apc1572T, obtained by targeting a truncated mutation at codon 1572 in the endogenous Apc gene. This hypomorphic mutant allele results in intermediate levels of Wnt/β-catenin signaling activation when compared with other Apc mutations associated with multifocal intestinal tumors. Notwithstanding the constitutive nature of the mutation, Apc+/1572T mice have no predisposition to intestinal cancer but develop multifocal mammary adenocarcinomas and subsequent pulmonary metastases in both genders. The histology of the Apc1572T primary mammary tumours is highly heterogeneous with luminal, myoepithelial, and squamous lineages and is reminiscent of metaplastic carcinoma of the breast in humans. The striking phenotype of Apc+/1572T mice suggests that specific dosages of Wnt/β-catenin signaling activity differentially affect tissue homeostasis and initiate tumorigenesis in an organ-specific fashion

Genome-Scale Metabolic Modeling Elucidates the Role of Proliferative Adaptation in Causing the Warburg Effect

The Warburg effect - a classical hallmark of cancer metabolism - is a counter-intuitive phenomenon in which rapidly proliferating cancer cells resort to inefficient ATP production via glycolysis leading to lactate secretion, instead of relying primarily on more efficient energy production through mitochondrial oxidative phosphorylation, as most normal cells do. The causes for the Warburg effect have remained a subject of considerable controversy since its discovery over 80 years ago, with several competing hypotheses. Here, utilizing a genome-scale human metabolic network model accounting for stoichiometric and enzyme solvent capacity considerations, we show that the Warburg effect is a direct consequence of the metabolic adaptation of cancer cells to increase biomass production rate. The analysis is shown to accurately capture a three phase metabolic behavior that is observed experimentally during oncogenic progression, as well as a prominent characteristic of cancer cells involving their preference for glutamine uptake over other amino acids

A Common Role for Various Human Truncated Adenomatous Polyposis Coli Isoforms in the Control of Beta-Catenin Activity and Cell Proliferation

The tumour suppressor gene adenomatous polyposis coli (APC) is mutated in most colorectal cancer cases, leading to the synthesis of truncated APC products and the stabilization of β-catenin. Truncated APC is almost always retained in tumour cells, suggesting that it serves an essential function. Here, RNA interference has been used to down-regulate truncated APC in several colorectal cancer cell lines expressing truncated APCs of different lengths, thereby performing an analysis covering most of the mutation cluster region (MCR). The consequences on proliferation in vitro, tumour formation in vivo and the level and transcriptional activity of β-catenin have been investigated. Down-regulation of truncated APC results in an inhibition of tumour cell population expansion in vitro in 6 cell lines out of 6 and inhibition of tumour outgrowth in vivo as analysed in one of these cell lines, HT29. This provides a general rule explaining the retention of truncated APC in colorectal tumours and defines it as a suitable target for therapeutic intervention. Actually, we also show that it is possible to design a shRNA that targets a specific truncated isoform of APC without altering the expression of wild-type APC. Down-regulation of truncated APC is accompanied by an up-regulation of the transcriptional activity of β-catenin in 5 out of 6 cell lines. Surprisingly, the increased signalling is associated in most cases (4 out of 5) with an up-regulation of β-catenin levels, indicating that truncated APC can still modulate wnt signalling through controlling the level of β-catenin. This control can happen even when truncated APC lacks the β-catenin inhibiting domain (CiD) involved in targeting β-catenin for proteasomal degradation. Thus, truncated APC is an essential component of colorectal cancer cells, required for cell proliferation, possibly by adjusting β-catenin signalling to the “just right” level

Prediction of Cellular Burden with Host--Circuit Models

Heterologous gene expression draws resources from host cells. These resources include vital components to sustain growth and replication, and the resulting cellular burden is a widely recognised bottleneck in the design of robust circuits. In this tutorial we discuss the use of computational models that integrate gene circuits and the physiology of host cells. Through various use cases, we illustrate the power of host-circuit models to predict the impact of design parameters on both burden and circuit functionality. Our approach relies on a new generation of computational models for microbial growth that can flexibly accommodate resource bottlenecks encountered in gene circuit design. Adoption of this modelling paradigm can facilitate fast and robust design cycles in synthetic biology