Challenging Future Generations: A Qualitative Study of Students’ Attitudes toward the Transition to Animal-Free Innovations in Education and Research

In 2016, the Dutch government declared its commitment to phasing out animal experiments by 2025. Although a high number of animal experiments are still performed and the 2025 target will not be met, the commitment remains. Efforts are being made to identify levers that might foster the transition to animal-free science. Education has been found to play a key role in the future of animal-free science and young generations are increasingly seen as key stakeholders. However, their attitudes toward the transition to animal-free innovations have not been investigated. The present article focuses on the values and beliefs held by students, who in 2022, participated in the course ‘Replacing Animal Testing’ (RAT) Challenge, organized by a consortium of Dutch universities. Contextually, students’ motivations to follow the course were investigated. The research was based on a qualitative study, including semi-structured interviews and a literature review. Our analysis of the findings revealed that students feel aligned with the social, ethical, and scientific reasons that support the transition to animal-free innovations. Moreover, the participants identified a series of regulatory, educational, cultural, and political obstacles to the transition that align with those identified in recent literature. From the discussion of these findings, we extrapolated six fundamental challenges that need to be addressed to foster the transition to animal-free science in an acceptable and responsible way

Distinct cardiotoxic effects by venoms of a spitting cobra (Naja pallida) and a rattlesnake (Crotalus atrox) revealed using an ex vivo Langendorff heart model

Here we describe the acute myocardial effects of an elapid (red spitting cobra, Naja pallida) and a viper (western diamondback rattlesnake, Crotalus atrox) venom using an ex vivo heart model. Our results reveal two different pathophysiological trajectories that influence heart function and morphology. While cobra venom causes a drop in contractile force, rattlesnake venom causes enhanced contractility and frequency that coincides with differences in myocellular morphology. This highlights the medical complexity of snake venom-induced cardiotoxicity

BRCA1-deficient mammary tumor cells are dependent on EZH2 expression and sensitive to Polycomb Repressive Complex 2-inhibitor 3-deazaneplanocin A

10.1186/bcr2354Breast Cancer Research114R6

Challenging Future Generations: A Qualitative Study of Students’ Attitudes toward the Transition to Animal-Free Innovations in Education and Research

In 2016, the Dutch government declared its commitment to phasing out animal experiments by 2025. Although a high number of animal experiments are still performed and the 2025 target will not be met, the commitment remains. Efforts are being made to identify levers that might foster the transition to animal-free science. Education has been found to play a key role in the future of animal-free science and young generations are increasingly seen as key stakeholders. However, their attitudes toward the transition to animal-free innovations have not been investigated. The present article focuses on the values and beliefs held by students, who in 2022, participated in the course ‘Replacing Animal Testing’ (RAT) Challenge, organized by a consortium of Dutch universities. Contextually, students’ motivations to follow the course were investigated. The research was based on a qualitative study, including semi-structured interviews and a literature review. Our analysis of the findings revealed that students feel aligned with the social, ethical, and scientific reasons that support the transition to animal-free innovations. Moreover, the participants identified a series of regulatory, educational, cultural, and political obstacles to the transition that align with those identified in recent literature. From the discussion of these findings, we extrapolated six fundamental challenges that need to be addressed to foster the transition to animal-free science in an acceptable and responsible way

Selected Alkylating Agents Can Overcome Drug Tolerance of G-like Tumor Cells and Eradicate BRCA1-Deficient Mammary Tumors in Mice.

We aimed to characterize and target drug-tolerant BRCA1-deficient tumor cells that cause residual disease and subsequent tumor relapse.We studied responses to various mono- and bifunctional alkylating agents in a genetically engineered mouse model for-mutant breast cancer. Because of the large intragenic deletion of thegene, no restoration of BRCA1 function is possible, and therefore, no BRCA1-dependent acquired resistance occurs. To characterize the cell-cycle stage from whichmammary tumors arise after cisplatin treatment, we introduced the fluorescent ubiquitination-based cell-cycle indicator (FUCCI) construct into the tumor cells.Despite repeated sensitivity to the MTD of platinum drugs, the-mutated mammary tumors are not eradicated, not even by a frequent dosing schedule. We show that relapse comes from single-nucleated cells delaying entry into the S-phase. Such slowly cycling cells, which are present within the drug-naïve tumors, are enriched in tumor remnants. Using the FUCCI construct, we identified nonfluorescent G-like cells as the population most tolerant to platinum drugs. Intriguingly, these cells are more sensitive to the DNA-crosslinking agent nimustine, resulting in an increased number of multinucleated cells that lack clonogenicity. This is consistent with ourfinding that the nimustine MTD, among several alkylating agents, is the most effective in eradicating-mutated mouse mammary tumors.Our data show that targeting G-like cells is crucial for the eradication of BRCA1/p53-deficient tumor cells. This can be achieved with selected alkylating agents such as nimustine.

Distinct cardiotoxic effects by venoms of a spitting cobra (Naja pallida) and a rattlesnake (Crotalus atrox) revealed using an ex vivo Langendorff heart model

Here we describe the acute myocardial effects of an elapid (red spitting cobra, Naja pallida) and a viper (western diamondback rattlesnake, Crotalus atrox) venom using an ex vivo heart model. Our results reveal two different pathophysiological trajectories that influence heart function and morphology. While cobra venom causes a drop in contractile force, rattlesnake venom causes enhanced contractility and frequency that coincides with differences in myocellular morphology. This highlights the medical complexity of snake venom-induced cardiotoxicity.</p

Each of the four intracellular cysteines of CD36 is essential for insulin- or AMP-activated protein kinase-induced CD36 translocation

Stimulation of cellular fatty acid uptake by induction of insulin signalling or AMP-kinase (AMPK) activation is due to translocation of the fatty acid-transporter CD36 from intracellular stores to the plasma membrane (PM). For investigating the role of the four Cys-residues within CD36's cytoplasmic tails in CD36 translocation, we constructed CHO-cells expressing CD36 mutants in which all four, two, or one of the intracellular Cys were replaced by Ser. Intracellular and PM localization of all mutants was similar to wild-type CD36 (CD36wt). Hence, the four Cys do not regulate sub-cellular CD36 localization. However, in contrast to CD36wt, insulin or AMPK activation failed to induce translocation of any of the mutants, indicating that all four intracellular Cys residues are essential for CD36 translocation. The mechanism of defective translocation of mutant CD36 is unknown, but appears not due to loss of S-palmitoylation of the cytoplasmic tails or to aberrant oligomerization of the mutants

BRCA1 RING Function Is Essential for Tumor Suppression but Dispensable for Therapy Resistance

SummaryHereditary breast cancers are frequently caused by germline BRCA1 mutations. The BRCA1C61G mutation in the BRCA1 RING domain is a common pathogenic missense variant, which reduces BRCA1/BARD1 heterodimerization and abrogates its ubiquitin ligase activity. To investigate the role of BRCA1 RING function in tumor suppression and therapy response, we introduced the Brca1C61G mutation in a conditional mouse model for BRCA1-associated breast cancer. In contrast to BRCA1-deficient mammary carcinomas, tumors carrying the Brca1C61G mutation responded poorly to platinum drugs and PARP inhibition and rapidly developed resistance while retaining the Brca1C61G mutation. These findings point to hypomorphic activity of the BRCA1-C61G protein that, although unable to prevent tumor development, affects response to therapy

Loss of 53BP1 causes PARP inhibitor resistance in Brca1-mutated mouse mammary tumors

Inhibition of PARP is a promising therapeutic strategy for homologous recombination-deficient tumors, such as BRCA1-associated cancers. We previously reported that BRCA1-deficient mouse mammary tumors may acquire resistance to the clinical PARP inhibitor (PARPi) olaparib through activation of the P-glycoprotein drug efflux transporter. Here, we show that tumor-specific genetic inactivation of P-glycoprotein increases the long-term response of BRCA1-deficient mouse mammary tumors to olaparib, but these tumors eventually developed PARPi resistance. In a fraction of cases, this resistance is caused by partial restoration of homologous recombination due to somatic loss of 53BP1. Importantly, PARPi resistance was minimized by long-term treatment with the novel PARP inhibitor AZD2461, which is a poor P-glycoprotein substrate. Together, our data suggest that restoration of homologous recombination is an important mechanism for PARPi resistance in BRCA1-deficient mammary tumors and that the risk of relapse of BRCA1-deficient tumors can be effectively minimized by using optimized PARP inhibitors. In this study, we show that loss of 53BP1 causes resistance to PARP inhibition in mouse mammary tumors that are deficient in BRCA1. We hypothesize that low expression or absence of 53BP1 also reduces the response of patients with BRCA1-deficient tumors to PARP inhibitor