pH-sensitive K⁺ channel TREK-1 is a novel target in pancreatic cancer

AbstractPancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and new therapeutic targets are urgently needed. One of the hallmarks of cancer is changed pH-homeostasis and potentially pH-sensors may play an important role in cancer cell behavior. Two-pore potassium channels (K2P) are pH-regulated channels that conduct a background K+ current, which is involved in setting the plasma membrane potential (Vm). Some members of the K2P superfamily were reported as crucial players in driving tumor progression. The aim of this study was to investigate pH-regulated K+ currents in PDAC cells and determine possible effects on their pathological phenotype. Using a planar high-throughput patch-clamp system (SyncroPatch 384PE) we identified a pH-regulated K+ current in the PDAC cell line BxPC-3. The current was inhibited by extracellular acidification and intracellular alkalization. Exposure to a set of different K+ channel inhibitors, and the TREK-1 (K2P2.1)–specific activator BL1249, TREK-1 was identified as the main component of pH-regulated current. A voltage-sensor dye (VF2.1.Cl) was used to monitor effects of pH and BL1249 on Vm in more physiological conditions and TREK-1–mediated current was found as critical player in setting Vm. We assessed a possible role of TREK-1 in PDAC progression using cell proliferation and migration assays and observed similar trends with attenuated proliferation/migration rates in acidic (pH<7.0) and alkaline (pH>7.4) conditions. Notably, BL1249 inhibited both PDAC cell proliferation and migration indicating that hyperpolarization of Vm attenuates cancer cell behavior. TREK-1 may therefore be a promising novel target for PDAC therapy

The role of TMEM16A (ANO1) and TMEM16F (ANO6) in cell migration

Members of the TMEM16 family have recently been described as Ca(2+)-activated Cl(−) channels. They have been implicated in cancer and appear to be associated with poor patient prognosis. Here, we investigate the role of TMEM16 channels in cell migration, which is largely unknown. We focused on TMEM16A and TMEM16F channels that have the highest expression of TMEM16 channels in Ehrlich Lettre ascites (ELA) cells. Due to the lack of specific pharmacological modulators, we employed a miRNA approach and stably knocked down the expression of TMEM16A and TMEM16F channels, respectively. Migration analysis shows that TMEM16A KD clones are affected in their directional migration, whereas TMEM16F KD clones show a 40 % reduced rate of cell migration. Moreover, TMEM16A KD clones have a smaller projected cell area, and they are rounder than TMEM16F KD clones. The morphological changes are linearly correlated with the directionality of cells. TMEM16A and TMEM16F, thus, have an important function in cell migration—TMEM16A in directional migration, TMEM16F in determination of the speed of migration. We conclude that TMEM16A and TMEM16F channels have a distinct impact on the steering and motor mechanisms of migrating ELA cells

Exploring objective measures for assessing team performance in healthcare: an interview study.

INTRODUCTION Effective teamwork plays a critical role in achieving high-performance outcomes in healthcare. Consequently, conducting a comprehensive assessment of team performance is essential for providing meaningful feedback during team trainings and enabling comparisons in scientific studies. However, traditional methods like self-reports or behavior observations have limitations such as susceptibility to bias or being resource consuming. To overcome these limitations and gain a more comprehensive understanding of team processes and performance, the assessment of objective measures, such as physiological parameters, can be valuable. These objective measures can complement traditional methods and provide a more holistic view of team performance. The aim of this study was to explore the potential of the use of objective measures for evaluating team performance for research and training purposes. For this, experts in the field of research and medical simulation training were interviewed to gather their opinions, ideas, and concerns regarding this novel approach. METHODS A total of 34 medical and research experts participated in this exploratory qualitative study, engaging in semi-structured interviews. During the interview, experts were asked for (a) their opinion on measuring team performance with objective measures, (b) their ideas concerning potential objective measures suitable for measuring team performance of healthcare teams, and (c) their concerns regarding the use of objective measures for evaluating team performance. During data analysis responses were categorized per question. RESULTS The findings from the 34 interviews revealed a predominantly positive reception of the idea of utilizing objective measures for evaluating team performance. However, the experts reported limited experience in actively incorporating objective measures into their training and research. Nevertheless, they identified various potential objective measures, including acoustical, visual, physiological, and endocrinological measures and a time layer. Concerns were raised regarding feasibility, complexity, cost, and privacy issues associated with the use of objective measures. DISCUSSION The study highlights the opportunities and challenges associated with employing objective measures to assess healthcare team performance. It particularly emphasizes the concerns expressed by medical simulation experts and team researchers, providing valuable insights for developers, trainers, researchers, and healthcare professionals involved in the design, planning or utilization of objective measures in team training or research

ANO1 (TMEM16A) in pancreatic ductal adenocarcinoma (PDAC)

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst survival rates of all cancers. ANO1 (TMEM16A) is a recently identified Ca(2+)-activated Cl(−) channel (CaCC) that is upregulated in several tumors. Although ANO1 was subject to extensive studies in the recent years, its pathophysiological function has only been poorly understood. The aim of the present study is to establish the significance of ANO1 in PDAC behavior and demarcate its roles in PDAC from those of the volume-regulated anion channel (VRAC). We performed qPCR and Western blot measurements on different PDAC cell lines (Panc-1, Mia PaCa 2, Capan-1, AsPC-1, BxPC-3) and compared the results to those obtained in a human pancreatic ductal epithelium (HPDE) cell line. All cancer cell lines showed an upregulation of ANO1 on mRNA and protein levels. Whole-cell patch-clamp recordings identified large Ca(2+) and voltage-dependent Cl(−) currents in PDAC cells. Using siRNA knockdown of ANO1 and three ANO1 inhibitors (T16A(inh)-A01, CaCC(inh)-A01, and NS3728), we found that ANO1 is the main constituent of CaCC current in PDAC cells. We further characterized these three inhibitors and found that they had unspecific effects on the free intracellular calcium concentration. Functional studies on PDAC behavior showed that surprisingly inhibition of ANO1 did not influence cellular proliferation. On the other hand, we found ANO1 channel to be pivotal in PDAC cell migration as assessed in wound healing experiments. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00424-014-1598-8) contains supplementary material, which is available to authorized users

Preparing medical first responders for crises: a systematic literature review of disaster training programs and their effectiveness.

BACKGROUND Adequate training and preparation of medical first responders (MFRs) are essential for an optimal performance in highly demanding situations like disasters (e.g., mass accidents, natural catastrophes). The training needs to be as effective as possible, because precise and effective behavior of MFRs under stress is central for ensuring patients' survival and recovery. This systematic review offers an overview of scientifically evaluated training methods used to prepare MFRs for disasters. It identifies different effectiveness indicators and provides an additional analysis of how and to what extent the innovative training technologies virtual (VR) and mixed reality (MR) are included in disaster training research. METHODS The systematic review was conducted according to the PRISMA guidelines and focused specifically on (quasi-)experimental studies published between January 2010 and September 2021. The literature search was conducted via Web of Science and PubMed and led to the inclusion of 55 articles. RESULTS The search identified several types of training, including traditional (e.g., lectures, real-life scenario training) and technology-based training (e.g., computer-based learning, educational videos). Most trainings consisted of more than one method. The effectiveness of the trainings was mainly assessed through pre-post comparisons of knowledge tests or self-reported measures although some studies also used behavioral performance measures (e.g., triage accuracy). While all methods demonstrated effectiveness, the literature indicates that technology-based methods often lead to similar or greater training outcomes than traditional trainings. Currently, few studies systematically evaluated immersive VR and MR training. CONCLUSION To determine the success of a training, proper and scientifically sound evaluation is necessary. Of the effectiveness indicators found, performance assessments in simulated scenarios are closest to the target behavior during real disasters. For valid yet inexpensive evaluations, objectively assessible performance measures, such as accuracy, time, and order of actions could be used. However, performance assessments have not been applied often. Furthermore, we found that technology-based training methods represent a promising approach to train many MFRs repeatedly and efficiently. These technologies offer great potential to supplement or partially replace traditional training. Further research is needed on those methods that have been underrepresented, especially serious gaming, immersive VR, and MR

Integrin β₁, osmosensing, and chemoresistance in mouse ehrlich carcinoma cells

Background/Aims: Altered expression of the integrin family of cell adhesion receptors has been associated with initiation, progression, and metastasis of solid tumors as well as in the development of chemoresistance. Here, we investigated the role of integrins, in particular integrin β1, in cell volume regulation and drug-induced apoptosis in adherent and non-adherent Ehrlich ascites cell lines. Methods: Adhesion phenotypes were verified by colorimetric cell-adhesion-assay. Quantitative real-time PCR and western blot were used to compare expression levels of integrin subunits. Small interfering RNA was used to silence integrin β1 expression. Regulatory volume decrease (RVD) after cell swelling was studied with calcein-fluorescence-self-quenching and Coulter counter analysis. Taurine efflux was estimated with tracer technique. Caspase assay was used to determine apoptosis. Results: We show that adherent cells have stronger fibronectin binding and a significantly increased expression of integrin α5, αv, and β1 at mRNA and protein level, compared to non-adherent cells. Knockdown of integrin β1 reduced RVD of the adherent but not of the non-adherent cells. Efflux of taurine was unaffected. In contrast to non-adherent, adherent cells exhibited chemoresistance to chemotherapeutic drugs (cisplatin and gemcitabine). However, knockdown of integrin β1 promoted cisplatin-induced caspase activity in adherent cells. Conclusion: Our data identifies integrin β1 as a part of the osmosensing machinery and regulator of cisplatin resistance in adherent Ehrlich cells

Long-Term Increase of Radiographic Damage and Disability in Patients with RA in Relation to Disease Duration in the Era of Biologics. Results from the SCQM Cohort

Objectives: There is little information on the relation between disease duration, disability and radiographic outcome since the introduction of biologics into the therapy of rheumatoid arthritis (RA). No long-term cohort studies have been conducted on this subject so far. To analyse radiographic damage, disability, and disease activity in RA-patients dependent on disease duration in the Swiss national RA cohort (SCQM). Methods: The primary outcome was the association between the radiographic destruction, assessed by Ratingen scores, and disease duration. All patients with at least one clinical visit were analysed with polynomial and multiple negative binomial models. Results: The disease duration in the 8678 patients with available radiographs analysed ranged between less than 1 and more than 65 years (median 8.3). Disease duration and radiographic destruction were significantly associated with an average increase of Ratingen scores by 8.3% per year. Apart from disease duration, positive rheumatoid factor was the strongest predictor for radiographic destruction. While DAS28-scores remained stable in patients with a disease duration of more than 5 years (median DAS28 2.8), HAQ-DI scores increased continuously by 0.018 for each additional year. Conclusion: In this RA cohort, patients show a continuous increase of articular destruction and physical disability in parallel with disease duration. Even when nowadays a satisfactory control of disease activity can be achieved in most patients, RA remains a destructive disease leading to joint destruction and physical disability in many patients