Search Results (963)

Objective: This review provides an overview of the current knowledge regarding the mechanisms of action of AGuIX, a clinical-stage theranostic nano-radiosensitizer composed of gadolinium. It covers the steps following the administration, from the internalization in tumor cells to the interaction with X-rays and the subsequent physical, chemical, biological, and immunological events. Results: After intravenous injection, AGuIX accumulates in tumors through the enhanced permeability and retention (EPR) effect, and its specific retention properties allow its persistence in tumors for several days. At the cellular level, the nanomedicine is internalized by endocytic processes and mainly located in the cytoplasm, especially in lysosomes. AGuIX enhances the effects of radiotherapy (RT) at several levels, starting from radiation–matter interactions to a chemical stage of reactive oxygen species (ROS) production, followed by a cascade of biological events leading to tumor cell death and immune response. Indeed, AGuIX induces a local increase in radiation dose deposition through the emission of Auger electrons, leading to a subsequent increase in ROS generation. AGuIX also impacts RT-induced biological mechanisms, including DNA damage and cell death mechanisms such as apoptosis, autophagic cell death, and ferroptosis. Last, the combination of AGuIX and RT stimulates an antitumor immune response through the induction of immunogenic cell death (ICD), the activation of dendritic and T cells, and the reprogramming of tumor-associated macrophages (TAMs) into a pro-inflammatory phenotype. Conclusions: AGuIX is a clinical-stage nanoparticle (NP) intravenously administered with pan-cancer potential due to its specific biodistribution properties and a strong ability to amplify RT-induced mechanisms. Full article

For nearly three decades, interspecies somatic cell nuclear transfer (iSCNT) has been explored as a potential tool for cloning, regenerative medicine, and wildlife conservation. However, developmental inefficiencies remain a major challenge, largely due to persistent barriers in nucleocytoplasmic transport, mitonuclear communication, and epigenome crosstalk. This review synthesized peer-reviewed English articles from PubMed, Web of Science, and Scopus, spanning nearly three decades, using relevant keywords to explore the molecular mechanisms underlying iSCNT inefficiencies and potential improvement strategies. We highlight recent findings deepening the understanding of interspecies barriers in iSCNT, emphasizing their interconnected complexities, including the following: (1) nucleocytoplasmic incompatibility may disrupt nuclear pore complex (NPC) assembly and maturation, impairing the nuclear transport of essential transcription factors (TFs), embryonic genome activation (EGA), and nuclear reprogramming; (2) mitonuclear incompatibility could lead to nuclear and mitochondrial DNA (nDNA-mtDNA) mismatches, affecting electron transport chain (ETC) assembly, oxidative phosphorylation, and energy metabolism; (3) these interrelated incompatibilities can further influence epigenetic regulation, potentially leading to incomplete epigenetic reprogramming in iSCNT embryos. Addressing these challenges requires a multifaceted, species-specific approach that balances multiple incompatibilities rather than isolating a single factor. Gaining insight into the molecular interactions between the donor nucleus and recipient cytoplast, coupled with optimizing strategies tailored to specific pairings, could significantly enhance iSCNT efficiency, ultimately transforming experimental breakthroughs into real-world applications in reproductive biotechnology, regenerative medicine, and species conservation. Full article

Strongyloidiasis, caused by the soil-transmitted helminth Strongyloides stercoralis, is estimated to infect around 600 million people worldwide. Ivermectin is the current first-line treatment. This prospective study evaluated long-term treatment response in patients with chronic strongyloidiasis. Conducted from 2019 to 2022 at Vega Baja Hospital in Alicante, Spain, this study enrolled 28 patients diagnosed with S. stercoralis infection. Patients received ivermectin at a dosage of 200 mcg/kg for one or two days and were followed for at least 12 months, with evaluations at 3, 6, 12, and 18 months post-treatment. Assessments included hemogram, IgE, Strongyloides serology, larvae culture and direct visualization and Strongyloides PCR in stool. Twenty-three patients completed at least 12 months of follow-up. Twenty-one patients (91.3%) achieved treatment response. Two patients (8.6%) experienced parasitological treatment failure, with detectable Strongyloides stercoralis DNA during follow-up. Ivermectin is highly effective in treating strongyloidiasis, with serology aiding in monitoring treatment efficacy. However, PCR detected an additional case of persistent infection, underscoring its complementary role. Full article

Although periodontal disease (PD) is reported to be associated with changes in various genes and proteins in both invading bacteria and the host, its molecular mechanism of pathogenesis remains unclear. Changes in immune and inflammatory genes play a significant role in PD pathogenesis. Some reports relate alterations in cellular epigenetic patterns to PD characteristics, while several high-throughput analyses indicate thousands of differentially methylated genes in both PD patients and controls. Furthermore, changes in DNA methylation patterns in inflammation-related genes have been linked to the efficacy of periodontal therapy, as demonstrated by findings related to the cytochrome C oxidase II gene. Distinct DNA methylation patterns in mesenchymal stem cells from PD patients and controls persisted despite the reversal of phenotypic PD. Methyl groups for DNA methylation are supplied by S-adenosylmethionine, which is synthesized with the involvement of folate, an essential nutrient known to play a role in maintaining mitochondrial homeostasis, reported to be compromised in PD. Folate may benefit PD through its antioxidant action against reactive oxygen and nitrogen species that are overproduced by dysfunctional mitochondria. As such, DNA methylation, dietary folate, and mitochondrial quality control may interact in PD pathogenesis. In this narrative/hypothesis review, we demonstrate how PD is associated with changes in mitochondrial homeostasis, which may, in turn, be improved by folate, potentially altering the epigenetic patterns of immune and inflammatory genes in both the nucleus and mitochondria. Therefore, a folate-based dietary intervention is recommended for PD prevention and as an adjunct therapy. At the same time, further research is needed on the involvement of epigenetic mechanisms in the beneficial effects of folate on PD studies. Full article

Parvoviruses are small, single-stranded DNA viruses that have evolved sophisticated mechanisms to hijack host cell machinery for replication and persistence. One critical aspect of this interaction involves the manipulation of the host’s DNA Damage Response (DDR) pathways. While the viral genome is comparatively simple, parvoviruses have developed strategies that cause significant DNA damage, activate DDR pathways, and disrupt the host cell cycle. This review will explore the impact of parvovirus infections on host genome stability, focusing on key viral species such as Adeno-Associated Virus (AAV), Minute Virus of Mice (MVM), and Human Bocavirus (HBoV), and their interactions with DDR proteins. Since parvoviruses are used as oncolytic agents and gene therapy vectors, a better understanding of cellular DDR pathways will aid in engineering potent anti-cancer agents and gene therapies for chronic diseases. Full article

Forensic age estimation is crucial for identifying unknown individuals and narrowing suspect pools in criminal investigations. Over the past 15 years, significant progress has been made in using biochemical, genetic, and epigenetic markers to estimate chronological age. Methods: From research on PubMed a total of 155 studies, related to advancements in age prediction techniques, were selected following PRISMA guidelines. Studies considered eligible dealt with radiocarbon dating, aspartic acid racemization, mitochondrial DNA analysis, signal joint T-cell receptor excision circles, RNA analysis, telomeres, and DNA methylation in the last 15 years and were summarized in a table. Results: Despite these advancements, challenges persist, including variability in prediction accuracy, sample degradation, and the lack of standardization and reproducibility. DNA methylation emerged as the most promising approach capable of high accuracy across diverse populations and age ranges. Multimodal methods integrating several biomarkers show promise in improving reliability and addressing these limitations. Conclusion: While significant progress has been made, further standardization, validation, and technological integration are needed to enhance forensic age estimation. These efforts are essential for meeting the growing demands of forensic science while addressing ethical and legal considerations. Full article

Colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer-related mortality worldwide, with prognosis significantly deteriorating at advanced stages. While current diagnostic methods, such as colonoscopy and tissue biopsy, are widely employed in clinical practice, they are invasive, expensive, and limited in assessing tumor heterogeneity and monitoring disease processes, including therapy response. Therefore, early and accurate detection, coupled with minimal invasion and cost-effective strategies, are critical for improving patient outcomes. Liquid biopsy has emerged as a promising, minimally invasive alternative, enabling the detection of tumor-derived components. This approach is increasingly utilized in clinical settings. The current key liquid biopsy modalities in CRC include circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and RNA-based biomarkers such as long non-coding RNAs (lncRNAs), microRNAs(miRNAs), and circular RNAs (circRNAs), and tumor-educated platelets (TEPs). These methods provide valuable insights into genetic and epigenetic tumor alterations, and serve as indicators for early detection, treatment monitoring, and recurrence prediction. However, challenges such as assay standardization and variability in sensitivity persist. This review delves into the clinical applications of liquid biopsy in CRC management, highlighting the transformative roles of ctDNA, CTCs, and non-coding RNAs, TEPs in early detection, prognostic assessment, and personalized therapy. In addition, it addresses current limitations and explores potential advancements to facilitate their integration into routine clinical practice. Full article

Deltamethrin (Del), a widely utilized pyrethroid pesticide, exhibits significant risks to human health due to its persistent environmental residues. This study aims to develop an efficient sensing detector for rapid Del detection through aptamer-based recognition. A modified Capture-SELEX strategy successfully identified Del-1, a high-affinity DNA aptamer demonstrating specific binding to Del with a dissociation constant (Kd) of 82.90 ± 6.272 nM. Molecular docking analysis revealed strong intermolecular interactions between Del-1 and Del, exhibiting a favorable binding energy of −7.35 kcal·mol⁻¹. Leveraging these findings, we constructed a colorimetric detector using gold nanoparticles (AuNPs) and poly dimethyl diallyl ammonium chloride (PDDA)-mediated aggregation modulation. The sensing detector employed dual detection parameters: (1) a characteristic color transition from red to blue and (2) a quantitative ∆A650/A520 ratio measurement. This optimized system achieved a detection limit of 54.57 ng·mL⁻¹ with exceptional specificity against other competitive pesticides. Practical validation using spiked fruit samples (apples and pears) yielded satisfactory recoveries of 74–118%, demonstrating the sensor’s reliability in real-sample analysis. The developed methodology presents a promising approach for the on-site monitoring of pyrethroid contaminants in agricultural products. Full article

A proviral reservoir persists within the central nervous system (CNS) of people with HIV, but its characteristics remain poorly understood. Research has primarily focused on cerebrospinal fluid (CSF), as acquiring brain tissue is challenging. We examined size, cellular tropism, and infection-dynamics of the viral reservoir in post-mortem brain tissue from five individuals on and off antiretroviral therapy (ART) across three brain regions. Microglia-enriched fractions (CD11b⁺) were isolated and levels of intact proviral DNA were quantified (IPDA). Full-length envelope reporter viruses were generated and characterized in CD4⁺ T cells and monocyte-derived microglia. HIV DNA was observed in microglia-enriched fractions of all individuals, but intact proviruses were identified only in one ART-treated individual, representing 15% of the total proviruses. Phenotypic analyses of clones from this individual showed that 80% replicated efficiently in microglia and CD4⁺ T cells, while the remaining viruses replicated only in CD4⁺ T cells. No region-specific effects were observed. These results indicate a distinct HIV brain reservoir in microglia for all individuals, although intact proviruses were detected in only one. Given the unique immune environment of the CNS, the characteristics of microglia, and the challenges associated with targeting these cells, the CNS reservoir should be considered in cure strategies. Full article

Oxidative stress is prevalent in organisms, and excessive oxidative damage can trigger cell death. Bacteria have evolved multiple pathways to cope with adverse stress, including the regulation of the cell cycle. Previous studies show that non-lethal exposure to H₂O₂ and mutations in antioxidant enzymes suppress replication initiation in Escherichia coli. The existence of common regulatory factors governing replication initiation across diverse causes-induced oxidative stress remains unclear. In this study, we utilized flow cytometry to determine the replication pattern of E. coli, and found that oxidative stress also participated in the inhibition of replication initiation by a defective iron regulation (fur-bfr-dps deletion). Adding a certain level of ATP promoted replication initiation in various antioxidant enzyme-deficient mutants and the ΔfurΔbfrΔdps mutant, suggesting that low ATP levels could be a common factor in the inhibition of replication initiation by different causes-induced oxidative stress. More potential common factors were screened using proteomics, followed by genetic validation with H₂O₂ stress. We found that oxidative stress might mediate the inhibition of replication initiation by interfering with the metabolism of glycine, glutamate, ornithine, and aspartate. Blocking CcmA-dependent cytochrome c biosynthesis, deleting the efflux pump proteins MdtABCD and TolC, or the arabinose transporter AraFHG eliminated the replication initiation inhibition by H₂O₂. In conclusion, this study uncovers a common multifactorial pathway of different causes-induced oxidative stress inhibiting replication initiation. Dormant and persistent bacteria exhibit an arrested or slow cell cycle, and non-lethal oxidative stress promotes their formation. Our findings contribute to exploring strategies to limit dormant and persistent bacterial formation by maintaining faster DNA replication initiation (cell cycle progression). Full article

The persistence of human immunodeficiency virus (HIV) within viral reservoirs poses significant challenges to eradication efforts. Epigenetic alterations, including DNA methylation, are potential factors influencing the latency and persistence of HIV. This study details the development and application of techniques to assess CpG methylation in the promoter regions of the CCR5 and CXCR4 genes, which are key HIV-1 coreceptors. Using both Sanger sequencing and pyrosequencing methods, we examined 51 biological samples from 17 people living with HIV at three time points: baseline (week 0) and post-antiretroviral therapy (ART) at weeks 24 and 48. Our results revealed that CXCR4 promoter CpG sites were largely unmethylated, while CCR5 promoter CpGs exhibited significant variability in methylation levels. Specifically, CCR5 CpG 1 showed a significant decrease in methylation from week 0 to week 48, while CXCR4 CpG 3 displayed a significant decrease between week 0 and week 24. These differences were statistically significant when compared with non-HIV-infected controls. These findings demonstrate distinct methylation patterns between CCR5 and CXCR4 promoters in people living with HIV over time, suggesting that epigenetic modifications may play a role in regulating the persistence of HIV-1. Our techniques provide a reliable framework for assessing gene promoter methylation and could be applied in further research on the epigenetics of HIV. Full article

Background/Objectives: In metastatic colorectal cancer (mCRC), liquid biopsy has enabled the identification of “neo-RAS-Wild-Type (WT)”, a transient phase characterized by the disappearance of RAS mutations, with significant clinical implications for re-sensitization to EGFR blockade. This study aimed to prospectively track the kinetics of neo-RAS-WT in circulating tumor DNA (ctDNA) among RAS-mutant mCRC patients receiving first-line and subsequent systemic therapies. Methods: A total of 380 serial blood samples from 35 patients were analyzed. Each patient provided a median of 10 ctDNA samples at three-month intervals during first-line and subsequent therapies. The patients were categorized into three groups: neo-RAS-WT, non-shedding, and persistent mutant. Results: During first-line treatment, 68% of patients transitioned to RAS-WT. Of these, 17% were neo-RAS-WT, while the majority were classified as non-shedding. In the second-line setting, the percentage of neo-RAS-WT increased to 34%, which dropped to 8.5% during the third-line setting. The duration of the neo-RAS-WT window was significantly longer in neo-RAS-WT patients compared to non-shedding patients (p = 0.037). Patients who achieved RAS-WT status had improved progression-free survival (PFS) compared to those with persistent mutant, with significant differences observed across all treatment lines: first-line (p = 0.004), second-line (p < 0.0001), and third-line (p = 0.001). Multivariate analysis revealed that the duration of the RAS-WT window correlated with extended first-line PFS (HR: 0.78; 95% CI: 0.69–0.89; p < 0.0001), second-line PFS (HR: 0.66; 95% CI: 0.52–0.84; p = 0.001), and overall survival (OS) (HR: 0.82; 95% CI: 0.72–0.95; p = 0.006). Conclusions: While the neo-RAS-WT window is transient in non-shedding, it is durable in neo-RAS-WT patients, persisting until disease progression. These findings highlight the potential utility of ctDNA testing in refining treatment strategies for RAS-mutant mCR. Full article

Background: Cervical cancer is highly prevalent among women in Amazonas, Brazil, mainly due to low screening coverage, and is diagnosed at a late stage, which compromises the treatment efficacy and survival rates. After treatment, recurrence is frequent, and there are few follow-up options to detect it. This highlights the urgent need for less-invasive biomarkers to monitor affected patients. Methods: This study employed real-time PCR, targeting the E7 gene of HPV types 16 and 18 to analyze cell-free DNA from plasma samples from 39 cervical cancer patients treated at the Oncology Control Center Foundation in Amazonas, Brazil. Results: cf-HPV 16 DNA was detected in 54% of the samples before treatment. The socioeconomic and behavioral data showed that 46.2% of the patients had low educational levels, 77% reported having a low income, 79.5% experienced an early sexual activity onset, and 15.4% had never undergone cytological screening. Persistence or recurrence occurred in 30.8% of cases over 4–33 months of follow-up, with cf-HPV DNA detectable in 75% of these cases. Conclusions: cf-HPV DNA in plasma is a promising biomarker for post-treatment surveillance, facilitating the earlier detection of persistence/recurrence. Incorporating this biomarker into clinical protocols could enhance outcomes and survival, particularly in underserved regions like the Amazon, where the access to healthcare is limited. Full article

Background/Objectives: Tumor necrosis factor alpha (TNF-α) is the key inflammatory cytokine involved in the pathogenesis of inflammatory bowel diseases (IBDs). Anti-TNF-α therapy has been successfully used for IBD treatment, although the therapeutic response differs among patients due to the genetic background. The aim of this study was to investigate whether the presence of single nucleotide polymorphisms (SNPs) on TNFA, TNFRSF1A, and TNFRSF1B genes could affect anti-TNF-α treatment effectiveness in IBD patients. Methods: In this prospective cohort study, 83 European IBD patients treated with infliximab or adalimumab (with or without steroid bridge therapy) as first-line therapy were enrolled. Genomic DNA was extracted from peripheral blood, and TNF-α (rs1800629, rs361525, rs1799724), TNFRSF1A (rs767455), and TNFRSF1B (rs1061622, rs1061624, rs3397, rs976881) SNPs were assessed. Steroid-free remission (SFR) (clinical remission together with steroid interruption) and anti-TNF-α therapy persistence after 12 months of follow-up were evaluated. Patients who stopped anti-TNF-α therapy before the end of follow-up, due to side effects or treatment failure, were defined as discontinuers. Results: A higher frequency of the G/G genotype in rs1800629 and the A/A genotype in rs1061624 was observed in the SFR group compared to non-SFR (97.7% vs. 82.8%; p = 0.025 and 32.6% vs. 10.3%; p = 0.029, respectively). Moreover, carriers of the A/A genotype in rs361525 and the C/C genotype in rs767455 had a lower probability of achieving SFR than wild-type patients (OR = 0.14; 95% CI= 0.03–0.69; p = 0.016 and OR = 0.10; 95% CI = 0.02–0.60; p = 0.012, respectively). Furthermore, an increased frequency of rs1800629 A allele was observed in patients who discontinued treatment compared to completers (27.3% vs. 6.9%; p = 0.033), as well as a high risk of interrupting therapy (HR = 6.47; 95% CI = 1.15–36.38). Conclusions: These results suggest that the evaluation of SNPs in TNF-α, TNFR1A, and TNFR1B genes could improve the management of IBD, leading to more effective, individualized treatment plans and a reduction in healthcare costs associated with ineffective therapies and disease complications. Full article

Introduction: Liquid biopsies provide a less-invasive option to tissue biopsies for the early diagnosis, prognosis, and tailored therapy of colorectal cancer (CRC). CRC is a major cause of cancer-related death, and early identification is essential for improving patient outcomes. Review: Conventional diagnostic techniques, including colonoscopy and tissue biopsy, may be enhanced by liquid biopsies that examine circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), extracellular vesicles (EVs), and other indicators present in body fluids. These markers provide significant insights into tumor biology, heterogeneity, and therapeutic response. CTCs detected in early-stage CRC have prognostic significance for disease recurrence and survival, while ctDNA investigation may uncover genetic mutations, epigenetic alterations, and tumor development. The identification of ctDNA in minimal residual disease (MRD) postsurgery correlates with an elevated risk of recurrence and unfavorable prognosis, underscoring its use in assessing treatment effectiveness. Furthermore, non-coding RNAs (ncRNAs) contained inside EVs provide potential prospective biomarkers and therapeutic targets, facilitating diagnosis and treatment assessment. Notwithstanding the potential of liquid biopsies, obstacles persist in assay standardization, sensitivity enhancement, and the management of tumor heterogeneity. Additional extensive research is required to determine their function in clinical practice. Conclusion: Overall, liquid biopsies serve as a potential instrument for real-time monitoring, evaluating therapy responses, and directing individualized therapeutic strategies in CRC patients. Full article