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From commensal to pathobiont: The emergence of virulence-enhanced Escherichia coli in China's food-animal systems - insights with future implications.

A fundamental shift in Escherichia coli epidemiology is being driven by convergence of virulence determinants and antimicrobial resistance within linked human-animal-environment systems. In China, the rapid growth of food-animal production, extensive antimicrobial use, and complex food networks are accelerating the emergence and dissemination of virulence-enhanced E. coli pathobionts. This review synthesizes recent epidemiological, genomics, and outbreak data to characterize China's evolving landscape of food-animal-associated E. coli. We highlight a significant shift from classical pathotypes to hybrid lineages that simultaneously carry virulence factors and last-resort antibiotic resistance determinants, including mcr-1, tet(X4), and blaNDM. These traits disseminate rapidly via plasmid-mediated horizontal gene transfer, facilitating rapid adaptation and enabling cross-sectoral One Health transmission. National surveillance, foodborne outbreak investigations, and whole-genome sequencing data show that food-animal reservoirs are active evolutionary niches that drive pathogen diversity and fitness, rather than serving merely as contamination sources. Whole-genome sequencing also pinpoints high-risk clones (e.g., ST394) and plasmid-mediated co-selection of virulence and AMR. The emergence of hybrid pathotypes (e.g., STEC/ETEC) and AMR-virulence co-selection challenges traditional classification and limits the effectiveness of conventional surveillance approaches. The 2017 colistin ban reduced mcr-1, yet ongoing resistance and emerging tet(X4) demand integrated surveillance. Collectively, these findings call for reconceptualizing E. coli as a dynamic genomic entity embedded within a unified ecological network. Addressing this threat requires an integrated One Health strategy including genomic surveillance, agricultural antimicrobial stewardship, and coordinated food-environment-clinical monitoring to prevent high-risk clone emergence and global spread.

Animals

An Overview of Red Breast Syndrome: A Qualitative Systematic Review of the Literature and a Single-Center Case Series.

Red breast syndrome (RBS) is an uncommon inflammatory complication that may occur following implant-based breast reconstruction and can clinically mimic surgical-site infection. This qualitative systematic review, based on comprehensive PubMed and Scopus searches, summarizes the existing literature on RBS, focusing on its etiology, clinical presentation, diagnostic characteristics, and therapeutic approaches following breast reconstruction using acellular dermal matrices (ADMs). A management protocol is proposed based on available data, and a single-center case series is presented from our Hospital, including patients who developed RBS after direct-to-implant reconstruction with ADM between January 2022 and December 2024. Twenty-nine studies met the inclusion criteria, comprising case reports, case series, and retrospective or prospective cohort studies. The reported incidence of RBS ranged from 0% to 29.6%. Proposed etiologies include endotoxin contamination, residual cellular debris, delayed hypersensitivity reactions, and lymphatic or vascular impairment of mastectomy flaps. Most reports described localized erythema confined to the area of the ADM, with normal inflammatory markers and negative imaging findings, whereas antibiotic therapy frequently failed to achieve improvement. Corticosteroids represented the most consistently effective treatment, although some cases required ADM removal or replacement. In our institutional case series (n = 8), symptom onset occurred between 4 weeks and 7 months postsurgery. Inflammatory markers remained within normal limits, imaging rarely demonstrated fluid collections, and symptoms resolved within days to weeks with corticosteroid therapy or conservative management. This review consolidates current evidence, proposes a diagnostic-therapeutic algorithm and highlights the need for prospective investigations and manufacturer-level endotoxin testing to elucidate pathogenesis and optimize clinical management. Level of Evidence: 2 (Risk) For image description, please refer to the figure legend and surrounding text.

Humans

Illicium verum polysaccharide targets fimbriae and flagella to disrupt biofilm and inhibit multidrug-resistant Escherichia coli proliferation.

The widespread dissemination of multidrug-resistant (MDR) E. coli has led to a decrease in the efficacy of antibiotics, posing severe challenges to clinical anti-infective therapy. Owing to their safety, multitarget activities, and low risk of inducing drug resistance, plant polysaccharides represent a promising alternative strategy. In this study, an acidic polysaccharide (IVP-3) was isolated and purified from the medicinal and edible plant Illicium verum, and it was found to inhibit MDR E. coli colonization by disrupting its biofilm. The Mw of IVP-3 was determined to be 35.566 kDa. Its backbone consists of →4)-α-D-GalpA-6-OMe-(1→, →4)-α-D-GalpA-(1→, →4)-β-D-Galp-(1→, and →3,4)-α-D-GalpA-(1 → residues, whereas the branched chain is composed of α-L-Araf-(1 → 5)-α-L-Araf-(1 → attached to the O-5 position of →2,5)-α-L-Araf-(1→, which is further linked to the O-3 position of the backbone. Mechanistically, IVP-3 disrupts the structure of fimbriae and flagella, inhibits bacterial motility, effectively prevents initial biofilm adhesion, and eradicates preformed mature biofilms. Additionally, IVP-3 damages cell membrane integrity, disrupts the proton motive force, and induces energy metabolism disorder, efflux pump inhibition, and oxidative stress, ultimately leading to bacterial lysis. This study provides a theoretical basis for the development of natural antibacterial agents targeting MDR E. coli biofilms and for the high-value utilization of Illicium verum.

Biofilms

Genomic epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli across humans, poultry and wastewater sectors in Douala, Cameroon.

BACKGROUND: The global health threat of antimicrobial resistance involves the human, animal and environmental sectors. Data from Cameroon are scarce. OBJECTIVES: This study aimed to define extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) rates and associated risk factors across the three sectors in Douala, Cameroon, and to define molecular characteristics of isolates. METHODS: From June 2022 to May 2023, we collected blood cultures from hospitalized patients, rectal swabs from healthy pregnant women, caeca from broiler chickens and environmental wastewater. Samples were screened for ESBL-Ec using CHROMAgar™ ESBL and cefotaxime-supplemented Tryptone Bile X-glucuronide agar. Antimicrobial susceptibility testing was performed by disk diffusion following EUCAST guidelines. Whole-genome sequencing was carried out using Illumina technology. RESULTS: Of 628 samples, 374 yielded ESBL-Ec. Prevalence was 54.6% (131/240) in pregnant women, 70.4% (169/240) in chickens and 93.1% (67/72) in wastewater. The proportion of ESBL-Ec among E. coli-positive-blood cultures was 9.2% (7/76). Multi-family household living was independently associated with ESBL-Ec carriage among pregnant women (adjusted odds ratio = 1.7, 95% CI 1.0-3.1, P = 0.03). High co-resistance (>70%) was observed for tetracycline, ciprofloxacin and trimethoprim/sulfamethoxazole. Sequencing of 32 isolates revealed 45 distinct resistance genes, including blaCTX-M-15 (n = 13, 40.6%), blaCTX-M-55 (n = 11, 34.4%) and last-resort antibiotic resistance genes mcr-1 and bla OXA-181. High-risk sequence types included ST131 (pregnant women) and ST10 (chickens). Notably, ST48 was shared between pregnant women and chickens, and ST155 between pregnant women and wastewater. CONCLUSION: Cross-sectoral ESBL-Ec in Douala exhibits high genomic diversity and alarming resistance. The occurrence of last-resort genes requires immediate One Health surveillance and coordinated interventions.

Journal Article

Maternal disease control and pregnancy outcomes with anti-CD20 therapy versus natalizumab in multiple sclerosis: a systematic review.

BACKGROUND: Management of multiple sclerosis (MS) during pregnancy requires balancing maternal disease control with fetal safety. Among high-efficacy disease-modifying therapies, anti-CD20 monoclonal antibodies and natalizumab are commonly used in women with active disease, yet their comparative effectiveness and safety during pregnancy remain incompletely defined. This systematic review evaluated maternal disease activity and pregnancy-related outcomes associated with anti-CD20 exposure compared with natalizumab in pregnant women with MS. METHODS: PubMed/MEDLINE, Web of Science, Scopus, and the Cochrane Library were searched from inception through February 2026. Eligible studies included pregnant women with MS exposed to anti-CD20 before or during pregnancy and reporting maternal disease activity compared to natalizumab. RESULTS: Seven studies were included, comprising six observational cohort studies and one pharmacovigilance disproportionality analysis. Across studies, anti-CD20 exposure was consistently associated with lower relapse activity than natalizumab, particularly in the postpartum period. Anti-CD20 strategies were also associated with markedly lower postpartum MRI activity and more favorable disability-related outcomes where reported. Meta-analysis of three studies demonstrated a significant reduction in postpartum MRI activity with anti-CD20 therapy compared with natalizumab (RR 0.06, 95% CI 0.02-0.24; I² = 0%). No clear increase in major congenital anomalies was identified, although some data suggested higher odds of small for gestational age and maternal antibiotic use with anti-CD20 exposure. CONCLUSIONS: Anti-CD20 therapy was associated with lower maternal disease activity than natalizumab during pregnancy, especially for relapse prevention and postpartum MRI suppression. However, evidence regarding fetal and neonatal safety remains limited, warranting cautious individualized treatment decisions and further comparative research.

Humans

Base editing reversal of radiation sensitivity in NHEJ1 immunodeficiency.

Inherited defects of DNA double-stranded break (DSB) repair can result in radiosensitive/radiation-sensitive (RS) SCID (RS-SCID). We applied base editing to reverse NHEJ1 mutations in patient fibroblasts, exemplifying how this technology can help interrogate RS sequence variants.

Journal Article

Influence of Immediate Post-Bleaching Polishing on Enamel Color, Morphology, and Sensitivity: A Randomized Clinical Trial.

OBJECTIVE: This study evaluated the influence of polishing on enamel color change after in-office bleaching treatment on tooth morphology and sensitivity. MATERIALS AND METHODS: A total of 50 volunteers were randomized into two groups (n = 25): in-office bleaching with 35% hydrogen peroxide gel for 45 min without polishing (GSEM) or with polishing (GP). Color analysis was performed four times, at the beginning of the starting line and immediately after the first, second, and third bleaching sessions with a spectrophotometer. A qualitative analysis of enamel morphology was performed under a scanning electron microscope. Tooth sensitivity was assessed daily using the Visual Analog Scale (α = 0.05). RESULTS: There was no statistically significant difference (p > 0.05) in tooth color change when comparing ΔE, ΔE00, and ΔWID between the groups. The enamel surface showed larger areas of irregularities and depressions in the GP group than in the GSEM group. There was no difference in tooth sensitivity (p > 0.05) between the groups. CONCLUSIONS: Polishing after whitening in the office does not change the color and sensitivity of the tooth but promotes greater changes in the morphology of the enamel, such as increased surface roughness. CLINICAL RELEVANCE: Polishing immediately after teeth whitening causes greater changes in enamel surface morphology.

Humans

An automated geometric modeling framework in GATE for the design and optimization of high-sensitivity converging-beam SPECT collimators.

Objective.The trade-off between detection sensitivity and spatial resolution is a fundamental challenge in designing organ-dedicated Single-photon emission computed tomography (SPECT) collimators. While converging-hole geometries offer a solution, their optimization is often hindered by the lack of flexible computational tools capable of modeling large-scale, non-parallel hole arrays. This study aims to develop an automated geometric modeling framework to facilitate the design and evaluation of complex converging- and diverging-hole collimators within standard Monte Carlo environments.Approach.We developed a specialized modeling framework by implementing custom C++ classes and a vector-based alignment algorithm within GATE. This platform enables automated, orientation-consistent construction of large-scale converging arrays not natively supported by standard implementations. A high-sensitivity pure cone-beam collimator (CBC) was designed using this framework. The evaluation used hot-rod, disc, and Jaszczak phantoms for physical characterization, while XCAT and dedicated brain models were employed for clinical tasks, including cardiac, brain perfusion, and DaTscan SPECT simulations.Main results.The CBC achieved a nearly fourfold sensitivity increase compared to a conventional low-energy high-resolution parallel-hole collimator at a 20 cm radius of rotation, while maintaining comparable spatial resolution. Despite a 52.3% field of view reduction, the CBC yielded a 2.2-fold noise reduction (CV: 11.7% vs 25.9%) and mitigated partial volume effects via geometric magnification. XCAT and brain phantom simulations confirmed enhanced anatomical definition and contrast recovery in cardiac, perfusion, and DaTscan tasks.Significance.This work provides an efficient computational tool for rapid design space exploration of advanced collimator geometries. The results demonstrate that the proposed CBC design offers a significant sensitivity advantage, making it highly suitable for high-performance, small-volume clinical applications such as brain and cardiac molecular imaging.

Tomography, Emission-Computed, Single-Photon

Effectiveness of STK Spray® for semen stain localization on solid surfaces: A specificity and sensitivity study.

Semen identification is a crucial step in sexual assault cases. The aim of this study was to assess STK Spray®, a presumptive test for semen, under controlled conditions including, simulated crime scene stains detection. Easy to use, it can be sprayed directly onto different surfaces and visualized under UV light. Several tests were performed on five different substrates (ceramic tile, drywall, metal, wood, and faux leather). The spray was able to enhance semen fluorescence, especially in diluted samples, with characteristic "globular" spots. Although it showed good specificity, false positives could be obtained with 10% bleach. The fluorescence signals were quantified using ImageJ™ and showed a statistically significant substrate-dependent variability. Mixture analysis indicated that saliva did not interfere with detection of semen, while urine partially suppressed the signal and blood markedly affected its interpretation. Simulation tests with UV lamp comparisons confirmed the importance of choosing the right detection method and the utility of this presumptive test in combination with additional immunochromatographic tests. A preliminary signal retention test showed stable fluorescence for up to two years when stains were stored appropriately. Finally, complete DNA profiles (100% of alleles) were obtained from all samples (n = 24) after exposure to the reagent and UV light. Because of its ability to enhance semen signal, especially on specific surfaces, and its rapidity of use and detection, STK Spray® may represent a useful aid in the preliminary screening phase.

Humans

Application of Perioperative Real-Time Fluorescence Imaging to Achieve High-Quality Debridement: A Randomized Control Trial.

OBJECTIVE: To investigate the effectiveness of real-time fluorescence imaging (RTFI)-assisted debridement in managing chronic wounds compared with standard surgical debridement. APPROACH: This study was a patient-blinded, randomized clinical trial conducted from February 17, 2021, to July 30, 2021, on patients with chronic wounds. Patients were randomized to an RTFI group (M group) or conventional group (C group). The primary outcomes were as follows: percentage of residual bacterial area (preoperative and postoperative), number of debridements, high-quality debridement ratio, operation duration, and wound healing duration. RESULTS: A total of 100 patients were enrolled in both groups. No significant difference in the percentage of preoperative residual bacterial area or high-quality debridement ratio was seen. The M group underwent debridement an average of 2.6 times and had a significantly longer duration of operation (33.5 &#xb1; 12.7 min) than the C group (29.9 &#xb1; 10.4 min; p = 0.031). The postoperative residual bacterial area was significantly lower in the M than in the C group (6.83% &#xb1; 1.39% vs. 30.0% &#xb1; 12.37%, respectively; p < 0.001). The M group required significantly fewer wound healing days (49.2 &#xb1; 25.3 vs. 63.0 &#xb1; 27.9, p < 0.001). Secondary outcomes also demonstrated statistically significant differences in total hospitalized days (17.5 &#xb1; 9.3 vs. 21.5 &#xb1; 12.5, p < 0.01), days of antibiotic use (15.5 &#xb1; 8.7 vs. 18.7 &#xb1; 6.7, p < 0.01), and reinfection rates (4 of 100 vs. 22 of 100, p < 0.001). INNOVATION: RTFI can detect signals from normal skin components and bacterial metabolites. Therefore, interpretation of RTFI results should be correlated with the clinical condition. RTFI is associated with high-quality debridement. This technique can also be applied in targeted biopsy and in training young staff to mature debridement procedures. CONCLUSION: RTFI in debridement is associated with favorable clinical outcomes and may have a positive influence on chronic wound healing.

Humans

Ecotoxicological responses of aquatic macrophytes to 2,4-D: A global synthesis of species sensitivity and ecological risk.

The widespread use of 2,4-dichlorophenoxyacetic acid (2,4-D) has raised concern about its persistence, mobility, and effects on non-target aquatic vegetation in freshwater ecosystems. Here, we provide a global synthesis of the ecotoxicological responses of aquatic macrophytes to 2,4-D based on a PRISMA-guided systematic review of 86 peer-reviewed studies published between 1947 and 2025. A consistent gradient of species-specific sensitivity was observed across macrophyte growth forms. The submerged species Myriophyllum spicatum showed high susceptibility, with EC&#x2085;&#x2080; values of 0.04-0.182 mg/L and marked growth inhibition at low concentrations, whereas floating species such as Lemna minor and Pontederia crassipes were more tolerant, requiring higher concentrations (7.08 to >100 and 8.1 mg/L, respectively) to produce comparable effects. Importantly, this sensitivity ranking was consistent across laboratory and field experimental settings. These interspecific differences likely reflect variation in herbicide uptake, translocation, and detoxification capacity associated with growth form. The overlap between EC&#x2085;&#x2080; values for M. spicatum and regulatory thresholds for 2,4-D in surface waters suggests that current limits may be insufficient to protect sensitive submerged macrophyte communities. Regarding remediation, L. minor and Salvinia natans emerged as the most promising candidates for phytoremediation, while P. crassipes showed limited capacity to reduce herbicide concentrations in water. Despite advances, no study directly compared oxidative stress biomarkers between submerged and floating species, representing a critical gap in understanding the biochemical basis of the sensitivity gradient. Overall, this synthesis highlights the need to account for taxon-dependent sensitivity when evaluating the ecological risks of 2,4-D and provides a basis for improving regulatory frameworks and management of herbicide contamination in freshwater ecosystems.

2,4-Dichlorophenoxyacetic Acid

Dual signal-enhanced immunochromatographic test strip based on Au@PtNPs: From sensitive detection of thiamethoxam to multiplex pesticide screening in vegetables.

Immunochromatographic test strip (ICTS) is a rapid analytical technique widely used in environmental and food detection owing to its merits of simple operation and short analysis time. Herein, three-dimensional nanoflower-structured gold&#x2011;platinum nanoparticles (Au@PtNPs) were synthesized via a seed-growth method. Compared with conventional gold nanoparticles (AuNPs), Au@PtNPs exhibited stronger signal intensity, excellent catalytic performance, and efficient antibody binding efficiency. Colorimetric Au@PtNPs-ICTS and catalytic colorimetric Au@PtNPs-ICTS were developed for the sensitive detection of thiamethoxam (THI) in vegetables. The limits of detection (LODs) for colorimetric Au@PtNPs-ICTS and catalytic colorimetric Au@PtNPs-ICTS quantitative analysis were 0.18&#xa0;ng/mL and 0.093&#xa0;ng/mL, respectively, representing approximately 3-fold and 6-fold improvement compared to AuNPs-ICTS (0.56&#xa0;ng/mL). Furthermore, highly sensitive detection of multiple pesticide residues (chlorpyrifos, acetamiprid, and imidacloprid) was achieved by replacing the corresponding target antigens and antibodies, which further verified the universality of this immunochromatographic strategy.

Thiamethoxam

List randomization for prevalence estimation of sensitive behavioral data among women with HIV of reproductive age in Lilongwe, Malawi.

Self-reported data are subject to reporting biases, including social desirability bias. List randomization is one method that can help mitigate the impact of such biases. Here, we examined the utility of list randomization among women of reproductive age living with HIV in sub-Saharan Africa. In the Family Planning and Antiretroviral Therapy study, participants were randomized to answer 5 blocks of true/false statements via either direct or list response. Each block contained 3 nonsensitive statements and 1 sensitive statement related to either condom use or HIV disclosure. For each sensitive statement, we calculated the prevalence difference (PD) comparing list response to direct response overall and stratified by socioeconomic status. The PD for 4 of the sensitive statements was negligible. However, we found that self-report of always using a condom was reported by 53.1% at list response visits vs 34.7% at direct response visits (PD, 18.5%; 95% CI, 6.2%-30.7%), a difference that was attenuated among those with higher socioeconomic status. In this setting, list randomization did not meaningfully change the estimated prevalence for most questions, except for one question, which unexpectedly produced a higher estimate for a positive behavior. Examining this method in other settings and populations is warranted.

Humans

A MIL-88@Ru-based molecularly imprinted electrochemiluminescence sensor for highly selective and sensitive detection of enrofloxacin residues in animal-derived foods.

Using a metal-organic framework (MOF) - supported Ru(bpy)32+ (MIL-88@Ru) composite luminescent material, this study innovatively adopted electropolymerization to fabricate a molecularly imprinted polymer-based electrochemiluminescent (MIP-ECL) sensor for enrofloxacin (ENR) detection in animal-derived foods. Systematic investigation of the ECL luminescence and ENR's quenching mechanism confirmed that the sensor integrates ECL's high sensitivity and MIP's high specificity, enabling rapid and accurate recognition of ENR. Experimental results show a good linear response in the range of 1&#xa0;nmol/L-20&#xa0;&#x3bc;mol/L (R2&#xa0;=&#xa0;0.99), a limit of detection (LOD) as low as 0.28&#xa0;nmol/L, as well as excellent selectivity and stability. Recoveries of ENR in all investigated matrices ranged from 97.7% to 106.4%, confirming the reliability of the established method. This ECL-MIP coupling strategy provides a new technical approach and application references for the efficient detection of trace pollutants in food safety and environmental monitoring fields.

Enrofloxacin

Proteomic profiling reveals that DPP4 overexpression increases cell adhesion, inhibits cell migration, and restores androgen sensitivity in prostate cancer.

Dipeptidyl peptidase-4 (DPP4), a serine protease with both enzymatic and non-enzymatic roles, has emerged as a context-dependent modulator of tumor progression. In the present study, we investigated the expression and function of DPP4 in androgen-sensitive and castration-resistant prostate cancer (CRPC) models. Proteomic analysis of androgen-resistant prostate cells overexpressing DPP4 identified the involvement of the cellular adhesion molecules pathway. In prostate cells, lentiviral-mediated DPP4 overexpression restored androgen receptor signaling, inhibited epithelial-to-mesenchymal transition, and reduced cell migration, whereas DPP4 silencing produced the opposite effects. We demonstrate that DPP4 expression is down-regulated in CRPC cells and that treatment with capsaicin (CAP), a bioactive compound derived from red peppers, restores DPP4 expression. Moreover, DPP4 restoration by CAP suppresses prostate tumorigenesis in the TRAMP mice in vivo model of prostate cancer. Our results suggest that DPP4 could be a new target for CRPC.

Male

Repeated scoring with the adult appendicitis score improves the sensitivity and the specificity of appendicitis diagnosis in patients with early equivocal signs of appendicitis: a secondary analysis.

PURPOSE: The utilization of computed tomography in the early stage of acute appendicitis may result in overdiagnosis and unnecessarily expose patients to ionising radiation. The Adult Appendicitis Score (AAS) can be used to select patients for imaging. Observation and re-scoring in the DIAMOND trial reduced the need for imaging. Now, we wanted to determine if the change in AAS (&#x2206;AAS) can serve as a diagnostic tool to select patients for imaging even more precisely. METHODS: Eighty-eight patients with early equivocal appendicitis participated in the observation arm of the DIAMOND trial. The data for these patients were reanalysed, and &#x2206;AAS during the observation was calculated. The baseline AAS, final AAS, and the change in C-reactive protein (&#x2206;CRP) were selected as reference standards. RESULTS: Eighty-three patients with complete data were included in the analysis. The AUROC (Area Under the Receiver Operating Characteristic) values are as follows: &#x2206;AAS, 0.932 (95% CI 0.868-0.996); baseline AAS, 0.629 (95% CI 0.498-0.760); final AAS, 0.936 (95% CI 0.886-0.987); and &#x2206;CRP, 0.796 (95% CI 0.696-0.897). Using receiver operating characteristic curves, we established the thresholds for low (AAS&#x2009;&#x2264;&#x2009;-2), intermediate (AAS -1 to 0), and high (AAS&#x2009;&#x2265;&#x2009;1) probability of appendicitis. The negative predictive value for the low-probability group and the positive predictive value for the high-probability group concerning acute appendicitis were 97% and 94%, respectively. CONCLUSION: Patients with equivocal signs of appendicitis may benefit from short observation and the calculation of &#x2206;AAS to reduce overdiagnosis and exposure to excessive imaging. REGISTRATION: The DIAMOND trial was officially registered on ClinicalTrials.gov (NCT02742402) on April 13, 2016.

Adult

A machine learning-derived and functionally validated circadian rhythm signature predicts clinical outcomes and in silico drug sensitivity in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) displays considerable heterogeneity in clinical outcomes, highlighting the need for reliable prognostic biomarkers. While the aberrant expression of circadian rhythm-related genes has been implicated in cancer pathogenesis, its comprehensive role in CRC progression and predicted therapeutic vulnerabilities remains inadequately characterized. METHODS: Bulk and single-cell RNA-sequencing data were integrated from multiple CRC cohorts. A circadian rhythm signature (CRS) was developed through machine learning algorithms and validated for prognostic value. Comprehensive analyses of tumor microenvironment, genomic alterations, and drug sensitivity were performed. Furthermore, the biological function of the core gene, BHLHE40, was validated in CRC cell lines through CCK-8, EdU, and wound healing assays. RESULTS: Single-cell analysis demonstrated an elevated expression signature of circadian rhythm-related genes in dendritic cells. The optimized CRS, comprising 14 circadian rhythm-related genes, successfully categorized patients into high- and low-risk groups. Patients with a high CRS showed markedly poorer overall survival and computationally inferred immunosuppressive features, including reduced CD8+ T cell infiltration and increased M2 macrophage polarization. Genomic analysis revealed enhanced mutation burden in TP53 and alterations in RTK-RAS/WNT pathways. Notably, in vitro assays confirmed that BHLHE40 is significantly overexpressed in CRC cells. Knockdown of BHLHE40 markedly inhibited tumor cell proliferation and migration. Drug sensitivity profiling identified bexarotene and SMER-3 as potential therapeutic options for high-CRS patients. A nomogram integrating CRS with clinical parameters demonstrated superior predictive accuracy for 1-, 3-, and 5-year survival. CONCLUSIONS: The CRS represents a promising prognostic biomarker that reflects tumor immune status and genomic features, providing valuable insights for personalized treatment strategies in CRC.

Circadian rhythm

Engineering bubble structures as Cas12a activators for highly sensitive monitoring of WRN helicase function.

The Werner syndrome helicase (WRN) is a critical synthetic lethal target in microsatellite instability cancers, essential for resolving complex genomic structures like replication bubbles and R-loops. However, strategies to simultaneously discriminate WRN activity on DNA versus DNA-RNA substrates in living cells are lacking. Here, we developed a structure-specific CRISPR/Cas12a biosensing strategy to visualize WRN functional activity by engineering bubble-structure probes. These probes were rationally designed to structurally mimic DNA replication bubbles and R-loop associated DNA-RNA hybrids. Upon specific unwinding by WRN, the probes release a sequestered activator strand that triggers Cas12a trans-cleavage, effectively converting the unwinding event into an amplified fluorescent signal. This assay achieves low picomolar sensitivity (LODs: 5.6-6.0 pM) and exceptional selectivity against homologous RecQ helicases. Uniquely, this strategy enables the parallel quantification of WRN activity on both substrate types, providing insights into distinct WRN-mediated pathways for resolving genomic stress. We further demonstrated the strategy's utility by visualizing endogenous WRN dynamics in living cells and profiling the efficacy of small-molecule inhibitors. This work offers a powerful molecular toolkit for dissecting WRN biology and facilitating high-throughput drug screening in targeted cancer therapy.

Werner Syndrome Helicase