7196 research outputs found
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RNF43 mutations predict response to anti-BRAF/EGFR combinatory therapies in BRAFV600E metastatic colorectal cancer
No full textAnti-BRAF/EGFR therapy was recently approved for the treatment of metastatic BRAFV600E colorectal cancer (mCRCBRAF-V600E). However, a large fraction of patients do not respond, underscoring the need to identify molecular determinants of treatment response. Using whole-exome sequencing in a discovery cohort of patients with mCRCBRAF-V600E treated with anti-BRAF/EGFR therapy, we found that inactivating mutations in RNF43, a negative regulator of WNT, predict improved response rates and survival outcomes in patients with microsatellite-stable (MSS) tumors. Analysis of an independent validation cohort confirmed the relevance of RNF43 mutations to predicting clinical benefit (72.7% versus 30.8%; P = 0.03), as well as longer progression-free survival (hazard ratio (HR), 0.30; 95% confidence interval (CI), 0.12–0.75; P = 0.01) and overall survival (HR, 0.26; 95% CI, 0.10–0.71; P = 0.008), in patients with MSS-RNF43mutated versus MSS-RNF43wild-type tumors. Microsatellite-instable tumors invariably carried a wild-type-like RNF43 genotype encoding p.G659fs and presented an intermediate response profile. We found no association of RNF43 mutations with patient outcomes in a control cohort of patients with MSS-mCRCBRAF-V600E tumors not exposed to anti-BRAF targeted therapies. Overall, our findings suggest a cross-talk between the MAPK and WNT pathways that may modulate the antitumor activity of anti-BRAF/EGFR therapy and uncover predictive biomarkers to optimize the clinical management of these patients
3D printed PLGA implants: APF DDM vs. FDM.
No full text3D Printing offers a considerable potential for personalized medicines. This is especially true for customized biodegradable implants, matching the specific needs of each patient. Poly(lactic-co-glycolic acid) (PLGA) is frequently used as matrix former in biodegradable implants. However, yet relatively little is known on the technologies, which can be used for the 3D printing of PLGA implants. The aim of this study was to compare: (i) Arburg Plastic Freeforming Droplet Deposition Modeling (APF DDM), and (ii) Fused Deposition Modeling (FDM) to print mesh-shaped, ibuprofen-loaded PLGA implants. During APF DDM, individual drug-polymer droplets are deposited, fusing together to form filaments, which build up the implants. During FDM, continuous drug-polymer filaments are deposited to form the meshes. The implants were thoroughly characterized before and after exposure to phosphate buffer pH 7.4 using optical and scanning electron microscopy, GPC, DSC, drug release measurements and monitoring dynamic changes in the systems' dry & wet mass and pH of the bulk fluid. Interestingly, the mesh structures were significantly differed, although the device design (composition & theoretical geometry) were the same. This could be explained by the fact that the deposition of individual droplets during APF DDM led to curved and rather thick filaments, resulting in a much lower mesh porosity. In contrast, FDM printing generated straight and thinner filaments: The open spaces between them were much larger and allowed convective mass transport during drug release. Consequently, most of the drug was already released after 4 d, when substantial PLGA set on. In the case of APF DDM printed implants, most of the drug was still entrapped at that time point and substantial polymer swelling transformed the meshes into more or less continuous PLGA gels. Hence, the diffusion pathways became much longer and ibuprofen release was controlled over 2 weeks
Assessing the effect of compounds from plantar foot sweat, nesting material, and urine on social behavior in male mice, Mus musculus
No full textHome cage aggression causes poor welfare in male laboratory mice and reduces data quality. One of the few proven strategies to reduce aggression involves preserving used nesting material at cage change. Volatile organic compounds from the nesting material and several body fluids not only correlate with less home cage aggression, but with more affiliative allo-grooming behavior. To date, these compounds have not been tested for a direct influence on male mouse social behavior. This study aimed to determine if 4 previously identified volatile compounds impact home cage interactions. A factorial design was used with cages equally split between C57BL/6N and SJL male mice (N = 40). Treatments were randomly assigned across cages and administered by spraying one compound solution on each cage’s nesting material. Treatments were refreshed after day 3 and during cage change on day 7. Home cage social behavior was observed throughout the study week and immediately after cage change. Several hours after cage change, feces were collected from individual mice to measure corticosterone metabolites as an index of social stress. Wound severity was also assessed after euthanasia. Measures were analyzed with mixed models. Compound treatments did not impact most study measures. For behavior, SJL mice performed more aggression and submission, and C57BL/6N mice performed more allo-grooming. Wound severity was highest in the posterior region of both strains, and the middle back region of C57BL/6N mice. Posterior wounding also increased with more observed aggression. Corticosterone metabolites were higher in C57BL/6N mice and in mice treated with 3,4-dimethyl-1,2-cyclopentanedione with more wounding. These data confirm previous strain patterns in social behavior and further validates wound assessment as a measure of escalated aggression. The lack of observed treatment effects could be due to limitations in the compound administration procedure and/or the previous correlation study, which is further discussed
Context-dependent reversal of odorant preference is driven by inversion of the response in a single sensory neuron type.
No full textThe valence and salience of individual odorants are modulated by an animal's innate preferences, learned associations, and internal state, as well as by the context of odorant presentation. The mechanisms underlying context-dependent flexibility in odor valence are not fully understood. Here, we show that the behavioral response of Caenorhabditis elegans to bacterially produced medium-chain alcohols switches from attraction to avoidance when presented in the background of a subset of additional attractive chemicals. This context-dependent reversal of odorant preference is driven by cell-autonomous inversion of the response to these alcohols in the single AWC olfactory neuron pair. We find that while medium-chain alcohols inhibit the AWC olfactory neurons to drive attraction, these alcohols instead activate AWC to promote avoidance when presented in the background of a second AWC-sensed odorant. We show that these opposing responses are driven via engagement of distinct odorant-directed signal transduction pathways within AWC. Our results indicate that context-dependent recruitment of alternative intracellular signaling pathways within a single sensory neuron type conveys opposite hedonic valences, thereby providing a robust mechanism for odorant encoding and discrimination at the periphery
Transient JAK/STAT pathway inhibition prevents natural occurring B-ALL development in genetically predisposed Pax5+/- mice
No full textPreventing development of childhood B-cell acute lymphoblastic leukemia (B-ALL), a disease with devastating effects, is a longstanding and unsolved challenge. Heterozygous germline alterations in the PAX5 gene can lead to B-ALL upon accumulation of secondary mutations affecting the JAK/STAT signaling pathway. Preclinical studies have shown that this malignant transformation occurs only under immune stress such as exposure to infectious pathogens. Here we show in Pax5+/- mice that transient, early-life administration of clinically relevant doses of ruxolitinib, a JAK1/2 inhibitor, significantly mitigates the risk of B-ALL following exposure to infection; 1 of 29 animals treated with ruxolitinib developed B-ALL versus 8 of 34 untreated mice. Ruxolitinib treatment preferentially targeted Pax5+/- versus wild-type B-cell progenitors and exerted unique effects on the Pax5+/- B-cell progenitor transcriptional program. These findings provide the first in vivo evidence for a potential strategy to prevent B-ALL development
Lightning Fast and Highly Sensitive Full-Length Single-cell sequencing using FLASH-Seq
No full textIn the last 10 years, single-cell RNA-sequencing (scRNA-seq) has undergone
exponential growth. Emulsion droplets methods1–3, such as those commercialized by 10x
Genomics, have allowed researchers to analyze tens of thousands of cells in parallel in a
robust and reproducible way. However, in contrast to SMART-based full-length
sequencing protocols4,5, these methods interrogate only the outer portion of the
transcripts and still lack the required sensitivity for analyzing comprehensively the
transcriptome of individual cells. Building upon the existing SMART-seq forerunners
protocols4,5, we developed FLASH-Seq (FS), a new scRNA-seq method which displays
greater sensitivity while decreasing incubation times and reducing the number of
processing steps compared to its predecessors. The entire FS protocol - from lysed cells
to pooled cDNA libraries - can be performed in ~4.5 hours, is automation-friendly and can
be easily miniaturized to decrease costs
Measuring Health-Related Quality of Life With Multimodal Data: Viewpoint
No full textThe ability to objectively measure aspects of performance and behavior is a fundamental pillar of digital health, enabling digital wellness products, decentralized trial concepts, evidence generation, digital therapeutics, and more. Emerging multimodal technologies capable of measuring several modalities simultaneously and efforts to integrate inputs across several sources are further expanding the limits of what digital measures can assess. Experts from the field of digital health were convened as part of a multi-stakeholder workshop to examine the progress of multimodal digital measures in two key areas: detection of disease and the measurement of meaningful aspects of health relevant to the quality of life. Here we present a meeting report, summarizing key discussion points, relevant literature, and finally a vision for the immediate future, including how multimodal measures can provide value to stakeholders across drug development and care delivery, as well as three key areas where headway will need to be made if we are to continue to build on the encouraging progress so far: collaboration and data sharing, removal of barriers to data integration, and alignment around robust modular evaluation of new measurement capabilities
Current Practices, Gap Analysis and Proposed Roadmaps for PBPK Modeling of Cytochrome P450 Induction: An Industry Perspective
No full textThe International Consortium for Innovation and Quality (IQ) Physiologically Based Pharmacokinetic modeling (PBPK) Induction Working Group (IWG) conducted a survey across participating companies around general strategies for PBPK modeling of induction, including experience with; its utility to address various questions, regulatory interactions, and regulatory acceptance. The results highlight areas where PBPK modeling is used with high confidence and identify opportunities where confidence is lower and further evaluation is needed. To enhance the survey results, the PBPK-IWG also collected case studies and analyzed recent literature examples where PBPK models were applied to address CYP3A induction-mediated drug-drug interactions. PBPK modeling of induction has evolved and progressed significantly and has great potential to accelerate drug discovery and development. With the aim of enabling optimal use for new molecular entities that are either substrates and/or inducers of CYP3A, the PBPK-IWG proposes initial roadmaps for PBPK application, discusses future trends, and identifies gaps that need to be addressed
Science-based approach to harmonize contraception recommendations in clinical trials and pharmaceutical labels.
No full textThis review presents an EFPIA-PDEG topic group consensus on a data-driven approach to harmonized contraception recommendations for clinical trial protocols and product labeling. There is no international agreement in pharmaceutical clinical trial protocols or product labeling on when/if female and/or male contraception is warranted and for how long after the last dose. This absence of consensus has resulted in different recommendations among regions. For most pharmaceuticals, contraception recommendations are generally based exclusively on nonclinical data and/or mechanism. For clinical trials, contraception is the default position and is maintained for females throughout clinical development, whereas appropriate information can justify removing male contraception. Conversely, contraception is only recommended in product labeling when warranted. A base case rationale is proposed for whether or not female and/or male contraception is warranted, using available genotoxicity and developmental toxicity data. Contraception is generally warranted for both male and female subjects treated with mutagenic pharmaceuticals. We propose as a starting point that contraception is not typically warranted when the margin is 10-fold or greater between clinical exposure at the maximum recommended human dose and exposure at the no-observed-adverse-effect-level (NOAEL) for purely aneugenic pharmaceuticals and for pharmaceuticals that induce fetal malformations or embryo-fetal lethality. Other factors are discussed, including contraception methods, pregnancy testing, drug clearance, options for managing the absence of a developmental toxicity NOAEL, drug-drug interactions, radiopharmaceuticals, and other drug modalities. Overall, we present a data-driven rationale that can serve as a basis for consistent contraception recommendations in clinical trials and in product labeling across regions
Donor-Acceptor Pyridinium Salts for Photo-Induced Electron-Transfer-Driven Modification of Tryptophan in Peptides, Proteins, and Proteomes Using Visible Light.
No full textTryptophan (Trp) plays a variety of critical functional roles in protein biochemistry; however, owing to its low natural frequency and poor nucleophilicity, the design of effective methods for both single protein bioconjugation at Trp as well as for in situ chemoproteomic profiling remains a challenge. Here, we report a method for covalent Trp modification that is suitable for both scenarios by invoking photo-induced electron transfer (PET) as a means of driving efficient reactivity. We have engineered biaryl N-carbamoyl pyridinium salts that possess a donor-acceptor relationship that enables optical triggering with visible light whilst simultaneously attenuating the probe's photo-oxidation potential in order to prevent photodegradation. This probe was assayed against a small bank of eight peptides and proteins, where it was found that micromolar concentrations of the probe and short irradiation times (10-60 min) with violet light enabled efficient reactivity toward surface exposed Trp residues. The carbamate transferring group can be used to transfer useful functional groups to proteins including affinity tags and click handles. DFT calculations and other mechanistic analyses reveal correlations between excited state lifetimes, relative fluorescence quantum yields, and chemical reactivity. Biotinylated and azide-functionalized pyridinium salts were used for Trp profiling in HEK293T lysates and in situ in HEK293T cells using 440 nm LED irradiation. Peptide-level enrichment from live cell labeling experiments identified 290 Trp modifications, with 82% selectivity for Trp modification over other π-amino acids, demonstrating the ability of this method to identify and quantify reactive Trp residues from live cells