Livestrong Foundation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a significant global health threat because of its rapid evolution and high mutation rate, which limits the performance of existing molecular diagnostics. This study presents a dual-mode, aptamer-based detection platform that combines high sensitivity with mutation resilience. Using a computer-assisted X-aptamer Systematic Evolution of Ligands by EXponential enrichment (SELEX) approach, we identified NP14, a high-affinity, dual-target DNA aptamer that specifically binds to the SARS-CoV-2 nucleocapsid (N) protein at its N-terminal domain. Analyses via molecular docking, aptamer truncation, and targeted mutagenesis revealed that NP14 interacted with both SARS-CoV-2 and SARS-CoV N proteins and identified key nucleotides C24 and G27 of the P1 region and structural determinants critical for its high-affinity binding. Building on this discovery, we engineered a dual-mode biosensing system by integrating NP14 into a multicolor dynamic light scattering-enhanced enzyme-linked aptamer-antibody assay (MD ELAAA). MD ELAAA synergistically combines two complementary detection strategies: i) non-aggregative plasmonic colorimetry for visual signal detection and ii) dynamic light scattering for ultrasensitive quantitative analysis, in which Au/Ag nanomaterials are used to amplify optical and scattering signals. This system achieves a sensitivity of 0.43 TCID50/mL, representing a 47-fold improvement over standard methods. By integrating high sensitivity, specificity, variant recognition, and dual-mode signal output, the MD ELAAA platform enables reliable detection of low-abundance SARS-CoV-2 antigens. Its robust performance supports early-stage diagnostics and high-throughput variant monitoring, establishing MD ELAAA as a robust platform for next-generation viral detection and surveillance.

Nanoparticles (NPs) are known to enhance the activity of enzymes, but such findings remain largely empirical, lacking predictive design principles. Here, the first high‐throughput platform for the discovery of surface‐engineered nanoparticles (SENs) that modulate enzyme function is introduced. Guided by the hypothesis that surface ligands are primary drivers of activity enhancement, a library of 194 gold‐ and palladium‐based SENs functionalized with diverse peptide ligands is synthesized. These SENs are screened against three model enzymes: cytochrome c, lactoperoxidase (LPO), and lipase. Multiple SENs substantially increased enzymatic activity, with the most effective achieving ≈19‐fold increase. The resulting dataset enabled the training of a machine learning model that identified key ligand features associated with high‐performing SENs, establishing a predictive framework for designing activity‐enhancing NPs. Mechanistic studies confirm that the ligand shell plays a dominant role in driving enhancement, suggesting that effective ligands identified via this approach can be readily transferred across NP platforms. To demonstrate functional relevance, it is shown that an optimized SEN/LPO pair outperforms LPO in inhibiting the growth of multidrug‐resistant bacteria and disrupting biofilm formation. Collectively, this work offers a scalable and generalizable method to map and harness nanoscale structure‐function relationships at biointerfaces, with applications in biocatalysis, biosensing, and beyond.

DNA damage promotes mutations that fuel cancer, ageing and neurodegenerative diseases1-3, but surprisingly, the causes and types of damage remain largely unknown. There are three identified mechanisms that damage DNA during transcription: collision of RNA polymerase (RNAP) with the DNA-replication machinery head-on and co-directionally4-6, and R-loop-induced DNA breakage7-10. Here we identify novel DNA damage reaction intermediates11,12 and uncover a fourth transcription-related source of DNA damage: endogenous DNA damage at sites of terminated transcripts. We engineered proteins to capture single-stranded DNA (ssDNA) ends with 3' polarity in bacterial and human cells. In Escherichia coli, spontaneous 3'-ssDNA-end foci were unexpectedly frequent, at one or more per cell division, and arose via two identifiable pathways, both of which were dependent on DNA replication. A pathway associated with double-strand breaks was suppressed by overexpression of replicative DNA polymerase (pol) III, suggesting competition between pol III and DNA damage-promoting proteins. Mapping of recurrent 3'-ssDNA-ends identified distinct 3'-ssDNA-end-hotspots, mostly unrelated to double-strand breaks, next to the 5'-CCTTTTTT transcription-terminator-like sequence. These 3'-ssDNA-termini coincide with RNA 3'-termini identified by DirectRNA sequencing13 or simultaneous 5' and 3' end RNA sequencing (SEnd-seq)14 and were prevented by a mutant RNAP that readsthrough terminators. Our findings reveal that transcription termination or pausing can promote DNA damage and subsequent genomic instability.

Aberrations in the immunoglobulin heavy chain (IgH) locus are associated with poor prognosis in pediatric precursor B-cell acute lymphoblastic leukemia (BCP-ALL) patients. The primary objective of this pilot study is to enhance our understanding of the IgH phenotype by exploring the intracellular chiral metabolome. Leukemia cells were isolated from the bone marrow of BCP-ALL pediatric patients at diagnosis. The samples' metabolome and transcriptome were characterized using untargeted chiral metabolomic and next-generation sequencing transcriptomic analyses. For the first time D- amino acids were identified in the leukemic cells' intracellular metabolome from the bone marrow niche. Chiral metabolic signatures at diagnosis was indicative of a resistant phenotype. Through integrated network analysis and Pearson correlation, confirmation was obtained regarding the association of the IgH phenotype with several genes linked to poor prognosis. The findings of this study have contributed to the understanding that the chiral metabolome plays a role in the poor prognosis observed in an exceptionally rare patient cohort. The findings include elevated D-amino acid incorporation in the IgH group, the emergence of several unknown, potentially enantiomeric, metabolites, and insights into metabolic pathways that all warrant further exploration.

Background: Pancreatic ductal adenocarcinoma (PDAC) presents significant challenges in diagnosis, staging, and appropriate treatment. Furthermore, patients with PDAC often experience complex symptomatology and psychosocial implications that require multi-disciplinary and inter-professional supportive care management from health professionals. Despite these hurdles, the implementation of inter-professional clinic approaches showed promise in enhancing clinical outcomes. To assess the effectiveness of such an approach, we examined the impact of the Wallace McCain Centre for Pancreatic Cancer (WMCPC), an inter-professional clinic for patients with PDAC at the Princess Margaret Cancer Centre (PM). Methods: This retrospective cohort study included all patients diagnosed with PDAC who were seen at the PM before (July 2012-June 2014) and after (July 2014-June 2016) the establishment of the WMCPC. Standard therapies such as surgery, chemotherapy, and radiation therapy remained consistent across both time periods. The cohorts were compared in terms of survival rates, disease stage, referral patterns, time to treatment, symptoms, and the proportion of patients assessed and supported by nursing and allied health professionals. Results: A total of 993 patients were included in the review, comprising 482 patients pre-WMCPC and 511 patients post-WMCPC. In the multivariate analysis, adjusting for ECOG (Eastern Cooperative Oncology Group) and stage, it was found that post-WMCPC patients experienced longer median overall survival (mOS, HR 0.84, 95% CI 0.72-0.98, p = 0.023). Furthermore, the time from referral to initial consultation date decreased significantly from 13.4 to 8.8 days in the post-WMCPC cohort (p < 0.001), along with a reduction in the time from the first clinic appointment to biopsy (14 vs. 8 days, p = 0.022). Additionally, patient-reported well-being scores showed improvement in the post-WMCPC cohort (p = 0.02), and these patients were more frequently attended to by nursing and allied health professionals (p < 0.001). Conclusions: The implementation of an inter-professional clinic for patients diagnosed with PDAC led to improvements in overall survival, patient-reported well-being, time to initial assessment visit and pathological diagnosis, and symptom management. These findings advocate for the adoption of an inter-professional clinic model in the treatment of patients with PDAC.

ABSTRACT Tumor heterogeneity contributes significantly to chemoresistance, a leading cause of treatment failure. To better personalize therapies, it is essential to develop tools capable of identifying and predicting intra- and inter-tumor heterogeneities. Biology-inspired mathematical models are capable of attacking this problem, but tumor heterogeneity is often overlooked in in-vivo modeling studies, while phenotypic considerations capturing spatial dynamics are not typically included in in-vitro modeling studies. We present a data assimilation-prediction pipeline with a two-phenotype model that includes a spatiotemporal component to characterize and predict the evolution of in-vitro breast cancer cells and their heterogeneous response to chemotherapy. Our model assumes that the cells can be divided into two subpopulations: surviving cells unaffected by the treatment, and irreversibly damaged cells undergoing treatment-induced death. MCF7 breast cancer cells were previously cultivated in wells for up to 1000 hours, treated with various concentrations of doxorubicin and imaged with time-resolved microscopy to record spatiotemporally-resolved cell count data. Images were used to generate cell density maps. Treatment response predictions were initialized by a training set and updated by weekly measurements. Our mathematical model successfully calibrated the spatiotemporal cell growth dynamics, achieving median [range] concordance correlation coefficients of > .99 [.88, >.99] and .73 [.58, .85] across the whole well and individual pixels, respectively. Our proposed data assimilation-prediction approach achieved values of .97 [.44, >.99] and .69 [.35, .79] for the whole well and individual pixels, respectively. Thus, our model can capture and predict the spatiotemporal dynamics of MCF7 cells treated with doxorubicin in an in-vitro setting.

Simple SummaryHistone deacetylase (HDAC) inhibitors are anti-cancer agents that have demonstrated efficacy in hematologic malignancies; however, the utility of available agents is limited, owing to narrow therapeutic indices and suboptimal isoform selectivity. Bocodepsin (OKI-179) is a novel, orally bioavailable, Class I-targeting depsipeptide HDAC inhibitor with promising anti-cancer activity in preclinical solid tumor models. In this first-in-human phase I clinical study, we report the safety and tolerability of OKI-179 administered orally daily with intermittent and continuous dosing schedules. OKI-179 was well tolerated with low rates of high-grade adverse events, supporting the potential for the successful combination of OKI-179 with other targeted anti-cancer agents. OKI-179 is currently being investigated in combination with the MEK inhibitor binimetinib in patients with NRAS-mutated melanoma.(1) Background: Histone deacetylases (HDACs) play a critical role in epigenetic signaling in cancer; however, available HDAC inhibitors have limited therapeutic windows and suboptimal pharmacokinetics (PK). This first-in-human phase I dose escalation study evaluated the safety, PK, pharmacodynamics (PDx), and efficacy of the oral Class I-targeting HDAC inhibitor bocodepsin (OKI-179). (2) Patients and Methods: Patients (n = 34) with advanced solid tumors were treated with OKI-179 orally once daily in three schedules: 4 days on 3 days off (4:3), 5 days on 2 days off (5:2), or continuous in 21-day cycles until disease progression or unacceptable toxicity. Single-patient escalation cohorts followed a standard 3 + 3 design. (3) Results: The mean duration of treatment was 81.2 (range 11–447) days. The most frequent adverse events in all patients were nausea (70.6%), fatigue (47.1%), and thrombocytopenia (41.2%). The maximum tolerated dose (MTD) of OKI-179 was 450 mg with 4:3 and 200 mg with continuous dosing. Dose-limiting toxicities included decreased platelet count and nausea. Prolonged disease control was observed, including two patients with platinum-resistant ovarian cancer. Systemic exposure to the active metabolite exceeded the preclinical efficacy threshold at doses lower than the MTD and was temporally associated with increased histone acetylation in circulating T cells. (4) Conclusions: OKI-179 has a manageable safety profile at the recommended phase 2 dose (RP2D) of 300 mg daily on a 4:3 schedule with prophylactic oral antiemetics. OKI-179 is currently being investigated with the MEK inhibitor binimetinib in patients with NRAS-mutated melanoma in the phase 2 Nautilus trial.

Cutaneous squamous cell carcinoma (cSCC) represents an important clinical problem requiring novel approaches for both prevention and treatment. The transcription factor, Twist-related protein 1 (Twist1), has been identified as having a key mechanistic role in the development and progression of cSCC. Studies in relevant mouse models of cSCC have shown that Twist1 regulates epithelial-mesenchymal transition (EMT) and stemness driving progression and metastasis of cSCC. In addition, further research has shown that Twist1 regulates the balance between keratinocyte proliferation and differentiation and therefore impacts earlier stages of cSCC development. Through use of keratinocyte specific Twist1 knockout models, a role for this gene in keratinocyte stem cell homeostasis has been revealed. As a transcription factor, Twist1 regulates a large number of genes both in a positive, as well as a negative manner across several interdependent pathways. Studies in keratinocyte specific knockout models have shown that Twist1 upregulates the expression of genes involved in proliferation, stemness, and EMT while downregulating the expression of genes associated with differentiation. Furthermore, a number of compounds, including naturally occurring compounds, have been identified that target Twist1 and can block its effects in cancer cells and in keratinocytes in vivo. Collectively, the current understanding of Twist1 function in cSCC development and progression suggests that it represents a potential target for prevention and treatment of cSCC.