3,986 research outputs found
Developing a Model System to Study the Mechanisms of Resveratrol Inhibition of AR-V7 Transcriptional Activity
Prostate cancer is one of the biggest threats to men’s health in the western world and it accounts for the second largest number of male cancer-related deaths in the United States. It is well established that prostate cancer cells depend on the androgen/androgen receptor pathway. Therefore, androgen deprivation therapy (ADT) has become the primary treatment option for prostate cancer. Patients with metastatic prostate cancer who receive (ADT) have shown increased quality of life. However, survival benefit with ADT is reduced dramatically in castration-resistant prostate cancer (CRPC). Androgen receptor (AR) continues to be functional in CRPC through various mechanisms. It is becoming evident that AR-V7, an AR variant with constitutive transcriptional activity, plays crucial roles in the development of CRPC. In order to study the mechanism of AR-V7’s actions and the ability of resveratrol to repress AR-V7, we ectopically expressed AR-V7 in PC3 cells and treated the cells with different concentrations of resveratrol. Resveratrol represses AR-V7 transcriptional activity in a dose-dependent manner evidenced by levels of the AR target gene PSA. Mechanistically, we found that under our specific experimental conditions resveratrol down-regulates AR-V7 protein levels post-transcriptionally without affecting AR-V7 subcellular location. Given the fact that resveratrol potentially represses endogenous AR-V7 transcriptional activity at the transcriptional level, resveratrol could become an option in CPRC treatment
A pharmacological cocktail for arresting actin dynamics in living cells.
The actin cytoskeleton is regulated by factors that influence polymer assembly, disassembly, and network rearrangement. Drugs that inhibit these events have been used to test the role of actin dynamics in a wide range of cellular processes. Previous methods of arresting actin rearrangements take minutes to act and work well in some contexts, but can lead to significant actin reorganization in cells with rapid actin dynamics, such as neutrophils. In this paper, we report a pharmacological cocktail that not only arrests actin dynamics but also preserves the structure of the existing actin network in neutrophil-like HL-60 cells, human fibrosarcoma HT1080 cells, and mouse NIH 3T3 fibroblast cells. Our cocktail induces an arrest of actin dynamics that initiates within seconds and persists for longer than 10 min, during which time cells maintain their responsivity to external stimuli. With this cocktail, we demonstrate that actin dynamics, and not simply morphological polarity or actin accumulation at the leading edge, are required for the spatial persistence of Rac activation in HL-60 cells. Our drug combination preserves the structure of the existing cytoskeleton while blocking actin assembly, disassembly, and rearrangement, and should prove useful for investigating the role of actin dynamics in a wide range of cellular signaling contexts
May the Best Molecule Win: Competition ESI Mass Spectrometry
Electrospray ionization mass spectrometry has become invaluable in the characterization of macromolecular biological systems such as nucleic acids and proteins. Recent advances in the field of mass spectrometry and the soft conditions characteristic of electrospray ionization allow for the investigation of non-covalent interactions among large biomolecules and ligands. Modulation of genetic processes through the use of small molecule inhibitors with the DNA minor groove is gaining attention as a potential therapeutic approach. In this review, we discuss the development of a competition method using electrospray ionization mass spectrometry to probe the interactions of multiple DNA sequences with libraries of minor groove binding molecules. Such an approach acts as a high-throughput screening method to determine important information including the stoichiometry, binding mode, cooperativity, and relative binding affinity. In addition to small molecule-DNA complexes, we highlight other applications in which competition mass spectrometry has been used. A competitive approach to simultaneously investigate complex interactions promises to be a powerful tool in the discovery of small molecule inhibitors with high specificity and for specific, important DNA sequences
Impact of automation: measurement of performance, workload and behaviour in a complex control environment
This paper describes an experiment that was undertaken to compare three levels of automation in rail signalling; a high level in which an automated agent set routes for trains using timetable information, a medium level in which trains were routed along pre-defined paths, and a low level where the operator (signaller) was responsible for the movement of all trains. These levels are described in terms of a Rail Automation Model based on previous automation theory (Parasuraman et al., 2000). Performance, subjective workload, and signaller activity were measured for each level of automation running under both normal operating conditions and abnormal, or disrupted, conditions. The results indicate that perceived workload, during both normal and disrupted phases of the experiment, decreased as the level of automation increased and performance was most consistent (i.e. showed the least variation between participants) with the highest level of automation. The results give a strong case in favour of automation, particularly in terms of demonstrating the potential for automation to reduce workload, but also suggest much benefit can achieved from a mid-level of automation potentially at a lower cost and complexity
A framework to support human factors of automation in railway intelligent infrastructure
Technological and organisational advances have increased the potential for remote access and proactive monitoring of the infrastructure in various domains and sectors – water and sewage, oil and gas and transport. Intelligent Infrastructure (II) is an architecture that potentially enables the generation of timely and relevant information about the state of any type of infrastructure asset, providing a basis for reliable decision-making. This paper reports an exploratory study to understand the concepts and human factors associated with II in the railway, largely drawing from structured interviews with key industry decision-makers and attachment to pilot projects. Outputs from the study include a data-processing framework defining the key human factors at different levels of the data structure within a railway II system and a system-level representation. The framework and other study findings will form a basis for human factors contributions to systems design elements such as information interfaces and role specifications
On the scale-height of the molecular gas disc in Milky Way-like galaxies
We study the relationship between the scale-height of the molecular gas disc
and the turbulent velocity dispersion of the molecular interstellar medium
within a simulation of a Milky Way-like galaxy in the moving-mesh code Arepo.
We find that the vertical distribution of molecular gas can be described by a
Gaussian function with a uniform scale-height of ~50 pc. We investigate whether
this scale-height is consistent with a state of hydrostatic balance between
gravity and turbulent pressure. We find that the hydrostatic prediction using
the total turbulent velocity dispersion (as one would measure from kpc-scale
observations) gives an over-estimate of the true molecular disc scale-height.
The hydrostatic prediction using the velocity dispersion between the centroids
of discrete giant molecular clouds (cloud-cloud velocity dispersion) leads to
more-accurate estimates. The velocity dispersion internal to molecular clouds
is elevated by the locally-enhanced gravitational field. Our results suggest
that observations of molecular gas need to reach the scale of individual
molecular clouds in order to accurately determine the molecular disc
scale-height.Comment: MNRAS accepted, comments welcome. 14 pages, 10 figure
A Course-Based Research Experience: How Benefits Change with Increased Investment in Instructional Time
There is widespread agreement that science, technology, engineering, and mathematics programs should provide undergraduates with research experience. Practical issues and limited resources, however, make this a challenge. We have developed a bioinformatics project that provides a course-based research experience for students at a diverse group of schools and offers the opportunity to tailor this experience to local curriculum and institution-specific student needs. We assessed both attitude and knowledge gains, looking for insights into how students respond given this wide range of curricular and institutional variables. While different approaches all appear to result in learning gains, we find that a significant investment of course time is required to enable students to show gains commensurate to a summer research experience. An alumni survey revealed that time spent on a research project is also a significant factor in the value former students assign to the experience one or more years later. We conclude: 1) implementation of a bioinformatics project within the biology curriculum provides a mechanism for successfully engaging large numbers of students in undergraduate research; 2) benefits to students are achievable at a wide variety of academic institutions; and 3) successful implementation of course-based research experiences requires significant investment of instructional time for students to gain full benefit
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