51 research outputs found
Mechanistic insight into RET kinase inhibitors targeting the DFG-out conformation in RET-rearranged cancer
Oncogenic fusion events have been identified in a broad range of tumors. Among them, RET rearrangements represent distinct and potentially druggable targets that are recurrently found in lung adenocarcinomas. Here, we provide further evidence that current anti-RET drugs may not be potent enough to induce durable responses in such tumors. We report that potent inhibitors such as AD80 or ponatinib that stably bind in the DFG-out conformation of RET may overcome these limitations and selectively kill RET-rearranged tumors. Using chemical genomics in conjunction with phosphoproteomic analyses in RET-rearranged cells we identify the CCDC6-RETI788N mutation and drug-induced MAPK pathway reactivation as possible mechanisms, by which tumors may escape the activity of RET inhibitors. Our data provide mechanistic insight into the druggability of RET kinase fusions that may be of help for the development of effective therapies targeting such tumors
Risk-Adjusted Cancer Screening and Prevention (RiskAP): Complementing Screening for Early Disease Detection by a Learning Screening Based on Risk Factors
Background: Risk-adjusted cancer screening and prevention is a promising and continuously emerging option for improving cancer prevention. It is driven by increasing knowledge of risk factors and the ability to determine them for individual risk prediction. However, there is a knowledge gap between evidence of increased risk and evidence of the effectiveness and efficiency of clinical preventive interventions based on increased risk. This gap is, in particular, aggravated by the extensive availability of genetic risk factor diagnostics, since the question of appropriate preventive measures immediately arises when an increased risk is identified. However, collecting proof of effective preventive measures, ideally by prospective randomized preventive studies, typically requires very long periods of time, while the knowledge about an increased risk immediately creates a high demand for action. Summary: Therefore, we propose a risk-adjusted prevention concept that is based on the best current evidence making needed and appropriate preventive measures available, and which is constantly evaluated through outcome evaluation, and continuously improved based on these results. We further discuss the structural and procedural requirements as well as legal and socioeconomical aspects relevant for the implementation of this concept
Expression, localization and polymorphisms of the nuclear receptor PXR in Barrett's esophagus and esophageal adenocarcinoma
Background: The continuous exposure of esophageal epithelium to refluxate may induce ectopic expression of bile-responsive genes and contribute to the development of Barrett's esophagus (BE) and esophageal adenocarcinoma. In normal physiology of the gut and liver, the nuclear receptor Pregnane × Receptor (PXR) is an important factor in the detoxification of xenobiotics and bile acid homeostasis. This study aimed to investigate the expression and genetic variation of PXR in reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma.Methods: PXR mRNA levels and protein expression were determined in biopsies from patients with adenocarcinoma, BE, or RE, and healthy controls. Esophageal cell lines were stimulated with lithocholic acid and rifampicin. PXR polymorphisms 25385C/T, 7635A/G, and 8055C/T were genotyped in 249 BE patients, 233 RE patients, and 201 controls matched for age and gender.Results: PXR mRNA levels were significantly higher in adenocarcinoma tissue and columnar Barrett's epithelium, compared to squamous epithelium of these BE patients (P < 0.001), and RE patients (P = 0.003). Immunohistochemical staining of PXR showed predominantly cytoplasmic expression in BE tissue, whereas nuclear expression was found in adenocarcinoma tissue. In cell lines, stimulation with lithocholic acid did not increase PXR mRNA levels, but did induce nuclear translocation of PXR protein. Genotyping of the PXR 7635A/G polymorphism revealed that the G allele was significantly more prevalent in BE than in RE or controls (P = 0.037).Conclusions: PXR expresses in BE and adenocarcinoma tissue, and showed nuclear localization in adenocarcinoma tissue. Upon stimulation with lithocholic acid, PXR translocates to the nuclei of OE19 adenocarcinoma cells. Together with the observed association of a PXR polymorphism and BE, this data implies that PXR may have a function in prediction and treatment of esophageal disease
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial
Background:
Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke.
Methods:
We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515.
Findings:
Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group.
Interpretation:
In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes.
Funding:
GlaxoSmithKline
Reconciliation Opportunities for Ethnic Chinese in Cambodia through Non-Judicial Reparations at the ECCC
The Extraordinary Chambers in the Courts of Cambodia (ECCC) have been tasked with bringing justice to the survivors of the Khmer Rouge genocide. Almost ten years later, three people have been sentenced to life imprisonment. This study examines the perceptions of justice and opportunities of reconciliation from somewhat neglected perspective of Chinese-Cambodian genocide survivors. Through the unique tool of non-judicial measures (NJMs), I am exploring opportunities and chances that might arise for a broader victim support in the future.
I have conducted two focus groups in Kampot and Battambang, as well as eleven semi-structured interviews in Battambang and Phnom Penh with Chinese-Cambodian survivors of the Khmer Rouge. As a bridge to the quantitative research, I additionally have conducted a Qualitative Comparative Analysis (QCA) with existing surveys and studies
Extending product lifetimes: a reuse network for ICT hardware
This paper examines how a network of small/medium-sized enterprises was developed to enable reuse and resource conservation in the information and communications technology sector by exchange of used equipment over a resource exchange internet platform. The network’s effectiveness and potential for expansion is also examined. The results demonstrate that it is possible and in many cases economically viable to increase the reuse stream of equipment and to extend the network’s activities to a European level. The expectation of doubling the amount of traded appliances within the network was greatly exceeded. The successful development of technical, legal and financial guidance led to its incorporation into an accredited industry guideline
Is bodyweight-based dosing truly better than flat dosing for panitumumab? [Response to Letter]
Synthesis and Structure–Activity Relationships of Substituted Urea Derivatives on Mouse Melanocortin Receptors
The
melanocortin system is involved in the regulation of several
complex physiological functions. In particular, the melanocortin-3
and -4 receptors (MC3R/MC4R) have been demonstrated to regulate body
weight, energy homeostasis, and feeding behavior. Synthetic and endogenous
melanocortin agonists have been shown to be anorexigenic in rodent
models. Herein, we report synthesis and structure–activity
relationship (SAR) studies of 27 nonpeptide small molecule ligands
based on an unsymmetrical substituted urea core. Three templates containing
key residues from the lead compounds, showing diversity at three positions
(R<sup>1</sup>, R<sup>2</sup>, R<sup>3</sup>), were designed and synthesized.
The syntheses were optimized for efficient microwave-assisted chemistry
that significantly reduced total syntheses time compared to a previously
reported room temperature method. The pharmacological characterization
of the compounds on the mouse melanocortin receptors identified compounds <b>1</b> and <b>12</b> with full agonist activity at the mMC4R,
but no activity was observed at the mMC3R when tested up to 100 μM
concentrations. The SAR identified compounds possessing aliphatic
or saturated cyclic amines at the R<sup>1</sup> position, bulky aromatic
groups at the R<sup>2</sup> position, and benzyl group at the R<sup>3</sup> position resulted in mMC4R selectivity over the mMC3R. The
small molecule template and SAR knowledge from this series may be
helpful in further design of MC3R/MC4R selective small molecule ligands
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