Search Results (336)

Background/Objectives: Glioblastoma multiforme (GBM) is the most infiltrative, treatment-resistant, and deadly brain tumor in adults. Given the extremely malignant phenotype of the GBM cells, the high intratumoral heterogeneity, and the limited efficacy of the vast majority of chemotherapeutics due to the restrictive nature of the blood–brain barrier, GBM remains largely incurable. Methods: Utilizing the U87, U251, and T98G GBM cell lines, diverse in vitro approaches (Western blotting, quantitative real-time PCR, flow cytometry, immunofluorescence, Luc-reporter analysis, microscopic examination, and scanning electron microscopy), and pharmacological inhibition, we investigated for the first time the cell death decisions in the GBM cells in response to the LCS1269 treatment. Results: We showed that LCS1269 collapsed the mitochondrial potential and triggered both intrinsic and extrinsic apoptosis. Importantly, our findings demonstrated that LCS1269-mediated apoptosis was paralleled by an induction of both MLKL-dependent necroptosis and caspase-3/GSDME-dependent pyroptosis. Using a combination of specific inhibitors, we further demonstrated that apoptosis, necroptosis, and pyroptosis provoked by LCS1269 occur simultaneously and orchestrate a peculiar form of programmed cell death, which is known as PANoptosis. We subsequently found that LCS1269-induced PANoptosis may be initiated either through the RIPK1-PANoptosome alone or through the integrated ZBP1-, AIM2-, and RIPK1-PANoptosomes. Additionally, we revealed that LCS1269-mediated PANoptosis may be closely related to micronuclei formation. Conclusions: Taken together, our results confirm that LCS1269 is a promising anti-glioblastoma agent that is capable of effectively promoting GBM cell death via PANoptosis. Full article

The objective of this study was to use plant models, Allium cepa and Lepidium sativum, to assess the genotoxic effects of the urban particulate matter (PM) collected in a Northern Italian town. Aqueous extracts of different particle sizes (PM_10–3, PM_3–0.5, PM_0.5) were tested alongside the organic extracts through the standard Ames test. The organic particulate matter extracts were subjected to mutagenicity testing in the Salmonella typhimurium strains TA98 and TA100 (without and with metabolic activation), whereas the aqueous extracts were evaluated for genotoxicity in the emerging seedlings of L. sativum and in the root tips of A. cepa bulbs using the comet test to detect the primary DNA damage. Furthermore, the micronuclei frequency was assessed in the bulbs of A. cepa. As expected, the organic extracts of PM_3–0.5 and PM_0.5 induced point mutations in bacteria. The aqueous extracts of the finest fractions caused a significant increase in genotoxic damage in both plant models. These findings indicate that the two plant models (L. sativum seeds and A. cepa bulbs) are able to detect the genotoxicity of aqueous extracts of air pollutants, with many potential advantages as screening-level tools to complement Ames testing for an easier assessment of urban air quality in terms of DNA toxicity. Full article

Background/Objectives: SETD2 is a dual-function methyltransferase important for methylation of histone H3 at lysine 36 and α-tubulin in spindle microtubules. Genetic inactivation of SETD2 during oncogenesis drives loss of H3K36me3, genomic instability, and cancer progression. This study asked if disruption of genomic stability was a canonical feature of SETD2 inactivation via different pathways. Methods: We evaluated the impact of EPZ-719, a pharmacologic SETD2 inhibitor, and an H3.3K36M mutant histone (“oncohistone”) that binds and sequesters SETD2, on methylation activity and genomic stability in human cell lines. SETD2 activity was measured using in vitro methylation assays, H3K36me3 loss confirmed by Western analysis, and mitotic defects, specifically micronuclei and chromatin bridges, quantified with cytogenetic analysis. Results: EPZ-719 caused a dose- and time-dependent reduction in SETD2 activity on both histone and tubulin substrates, accompanied by significant increases in chromatin bridges and micronuclei in retinal pigmented epithelial (RPE-1) and 786-O ccRCC cells. Similarly, oncohistone expression markedly decreased SETD2 function, as determined by H3K36me3 levels, and induced comparable mitotic defects in 786-O cells, and aneuploidy in two chondrocyte cell lines expressing the H3.3K36M oncohistone. Combining EPZ-719 with H3.3K36M expression did not exacerbate mitotic defects beyond either oncohistone or pharmacologic inhibition alone, consistent with inhibition of SETD2 as their shared underlying mechanism of action. Conclusions: Pharmacologic inhibition and oncohistone-mediated sequestration of SETD2 converge on the induction of mitotic defects, underscoring SETD2’s essential role in maintaining genomic stability. Identification of loss of genomic stability as a canonical feature of SETD2 inactivation points to a potential therapeutic liability associated with targeting SETD2 in cancers where it is overexpressed and reveals a mechanism that could contribute to the progression of cancers expressing oncohistone mutations. Full article

Background: The Allium cepa test is a widely used, cost-effective, and versatile model for assessing cytogenotoxicity. Cytotoxicity is determined through changes in root growth and the mitotic index, while genotoxicity is identified through chromosomal aberrations such as breaks, bridges, and micronuclei. Objective: To synthesize the methodological principles, applications, and interpretation of the assay’s endpoints, with emphasis on environmental monitoring, nanotoxicology, and the evaluation of emerging materials. Methods: An exploratory analytical approach was applied to identify and compare studies employing the Allium cepa assay across different contexts. The literature, selected from scientific databases, was organized to highlight methodological diversity and biomarker performance. Conclusions: Compared with other models, Allium cepa stands out for its simplicity, the availability of multiple cytogenotoxic markers, and its minimal ethical constraints, making it especially suitable for research in low-infrastructure settings. Future studies should work toward the international standardization of methodologies, the integration of this model with molecular and omics-based approaches, and its incorporation into predictive frameworks for environmental and human health risk assessment. In an increasingly complex toxicological landscape, Allium cepa emerges as a pivotal tool for enhancing toxicological surveillance and safeguarding biological systems. Full article

The unicellular ciliate Paramecium caudatum undergoes a developmental transition from asexual binary fission to sexual reproduction during its mature stage. This transition is triggered by mating interactions between cells of complementary mating types, leading to aggregate formation, mating pairs, and the meiotic division of micronuclei. Although calcium-driven EF-hand kinases have been implicated as mating type proteins, the spatiotemporal dynamics of calcium signaling during conjugation have not been comprehensively characterized. In this study, we established a behavioral assay to isolate committed cells from aggregates immediately after mating onset, and developed an experimental system to monitor intracellular calcium fluctuations specifically expressed in these cells. By combining Ca²⁺/EGTA buffering and microinjection approaches, we manipulated extracellular and intracellular calcium levels and confirmed the continuous requirement of calcium ions for conjugation-specific functions. Two significant findings emerged. First, we identified, for the first time, a calcium atlas covering the entire cell, with ascending centers localized in the anterior, oral apparatus, and posterior regions. The calcium/Indo-1-AM fluorescence peaked at 6 h after mating initiation and declined gradually, but persisted until conjugation was completed at ~48 h. Second, we demonstrated that distinct intracellular calcium thresholds are required for each stage of mating, including maintenance of mating activity, commitment of micronuclei to meiosis, and two-stepwise formation of mating pairs. These thresholds function as regulatory checkpoints that coordinate subcellular localization and stage synchronization. Collectively, our findings highlight calcium ions as pivotal regulators of conjugation in Paramecium and propose a novel framework, the Paramecium calcium atlas, for understanding the cellular and molecular mechanisms underlying sexual reproduction in ciliates. Full article

The buccal micronucleus cytome assay (BMCyt) is a validated, non-invasive biomonitoring method used to detect early genotoxic and cytotoxic changes linked to environmental and occupational exposures. Healthcare workers, especially nurses and dentists, are routinely exposed to genotoxic agents such as anesthetic gases, cytotoxic drugs, ionizing radiation, and heavy metals. This study compared seven cytological biomarkers in exfoliated buccal cells from female nurses, dentists, and teachers to assess multivariate cytogenetic differences and potential occupational influences. Samples were collected from 32 nurses, 41 dentists, and 47 teachers, and 3000 cells per participant were evaluated for micronuclei (MN) and six additional nuclear abnormalities. Group differences were examined using MANOVA and permutation MANOVA, followed by pairwise tests, and visualized with Principal Component Analysis (PCA). Significant multivariate differences were found between nurses and both dentists and teachers (p = 0.003), supported by permutation tests, while dentists and teachers did not differ. PCA explained 56% of the variance and showed apparent clustering of nurses. Chromatin condensation and MN were the main contributors to group separation. Nurses had significantly higher MN (p ≤ 0.001) and karyorrhexis (p ≤ 0.0004) than dentist and teachers. Overall, nurses showed a distinct cytogenetic profile consistent with greater genotoxic susceptibility. Full article

Ionizing radiation remains the primary approach for treating brain cancer and is frequently used in combination with chemotherapy. However, when it comes to gliomas, the effective delivery of therapeutic agents is hindered by the limited permeability of the blood–brain barrier (BBB). Consequently, selecting the most suitable and least harmful type of ionizing radiation is essential, given its potential side effects on healthy cells within the tumor microenvironment. In this study, we explored the impact of X-ray exposure on two in vitro BBB endothelial cell models—murine and human. Post-irradiation, we evaluated cell viability, clonogenic capacity, cell cycle progression, reactive oxygen species (ROS) levels, formation of micronuclei and γ-H2AX foci, as well as alterations in cytoskeletal organization, cell migration, and intracellular calcium dynamics. The results demonstrate notable differences between the two endothelial cell lines, suggesting the human cell line is more sensitive to X-rays. In conclusion, our study provides valuable insights into the brain microvascular endothelial cells’ response to radiation, laying the groundwork for strategies to protect healthy brain tissue. Full article

Background/Objectives: Systemic sclerosis (SSc) is a rare, complex autoimmune disease characterized by fibrosis of the skin and internal organs. While its pathogenesis is not fully understood, chromosomal instability and telomere attrition have emerged as significant areas of investigation. Methods: This review provides a historical narrative perspective and synthesizes current findings on the role of these genomic anomalies in SSc pathogenesis. We synthesized findings from foundational and recent research articles investigating genotoxic factors, chromosomal aberrations, and telomere biology in SSc. Results: There is a strong historical basis for chromosomal instability in SSc, manifesting as micronuclei, translocations, and breaks. This instability is driven by clastogenic factors and oxidative stress. SSc-specific autoantibodies are implicated; anti-centromere antibodies correlate with aneuploidy and micronuclei, while anti-topoisomerase I may inhibit DNA repair. SSc is also characterized by significant telomere attrition, first reported in 1996 and now confirmed by additional genetic studies. This telomere loss is associated with reduced telomerase activity and the presence of autoantibodies against telomere-associated proteins, including shelterin components. Conclusions: We conclude that inflammation, telomere attrition, and chromosomal instability are linked in a self-perpetuating cycle that drives SSc pathogenesis. We propose that an initial inflammatory stimulus leads to reactive oxygen species production, causing telomere damage and attrition. Critically short telomeres trigger faulty DNA repair mechanisms, such as breakage–fusion–bridge cycles, resulting in chromosomal instability. This genomic damage, in turn, acts as a danger signal, further activating inflammatory pathways and creating a feedback loop that perpetuates fibrosis. Full article

Regulatory changes in the EU for safety purposes require strict control and high safety standards for essential oils obtained by steam distillation, as they are classified as chemical mixtures with potential toxic effects. Subcritical water extracts (SWEs) are considered safer. This study evaluated the cytotoxicity and genotoxicity of SWEs from Rosa damascena Mill. and Rosa alba L. in three test systems at different hierarchical levels: higher plants (root meristems of Hordeum vulgare), somatic cells of Mus musculus ICR strain, and human lymphocytes in vitro. The chromatographic fingerprint of the extracts revealed the presence of key components such as flavonoids, phenolic acids, and glycoside derivatives, with species-dependent variations and concentrations. No significant cytotoxicity was detected in the concentration range of 6–20%. SWE from R. alba showed a higher level of safety at high doses. Genotoxicity tests showed a weak, dose-dependent induction of chromosomal aberrations and micronuclei in barley and lymphocytes (greater in R. alba), a lack of genotoxicity in mouse bone marrow, and a slight increase in micronuclei in mouse erythrocytes after exposure to R. alba extract. The results highlight the suitability of SWEs from R. damascena and R. alba for safe application in the medical, food, and cosmetic industries. Full article

Birds have played a crucial role as environmental monitors throughout history, ranging from the use of canaries to detect methane and carbon monoxide in mines to the decline of raptors and seabirds during the DDT era due to widespread organochlorine pesticide contamination. Owing to their high diversity and capacity for bioaccumulation, birds are widely recognized as effective indicators of environmental change and pollutant exposure. Cytogenetic techniques have been increasingly applied over the past two decades to assess micronuclei formation resulting from interactions with clastogenic and aneugenic chemical compounds. The main goals of this study were (a) to evaluate a subset of the bird community in the southeastern Brazilian Cerrado as potential environmental indicators of pesticide exposure using the erythrocyte micronucleus test and (b) to investigate possible associations between bird morphometric traits and micronuclei frequency. Birds were sampled from three groups of coffee farms in the Brazilian Cerrado. Blood samples were collected from 152 individuals (122 on farms and 30 at the reference site) via the metatarsal vein, followed by slide preparation for micronucleus analysis. Two slides were prepared per bird; each slide was scored for 10,000 erythrocytes, and MN frequency was reported as the mean across slides. The species Leptotila rufaxilla, Volatinia jacarina, Galbula ruficauda, Gnorimopsar chopi, Molothrus bonariensis, Passer domesticus, Turdus leucomelas, and Turdus rufiventris exhibited six or more micronuclei per 10,000 erythrocytes, indicating the highest potential as bioindicators of environmental contamination. Micronuclei frequency in erythrocytes was positively correlated with the use of mixed pesticides, with variation depending on the size of the coffee farms. Although a slight negative biological trend was observed between micronuclei frequency and certain morphometric traits, particularly bill length, no statistically significant correlations were found. Similarly, birds from large farms exhibited a slight reduction in certain morphometric features, though these differences were also not statistically significant. These results highlight the utility of selected bird species as early-warning bioindicators for pesticide exposure in tropical agroecosystems. Full article

Gametogenesis is a fundamental biological process that ensures both genetic recombination and the continuity of successive generations. Interspecific hybrids can reproduce through modified mechanisms, such as hybridogenesis, by transmitting clonal, unrecombined genomes of only one of the parental species via their gametes. Pelophylax grafi (RP) is a natural hybrid frog composed of mixed genomes (subgenomes) of two related species, Pelophylax perezi (P) and Pelophylax ridibundus (R), and coexists in populations with P. perezi. This study tested the involvement of programmed genome elimination in gamete production of P. grafi, providing new insight into reproductive mechanisms of hybrid vertebrates. Using comparative genomic hybridization (CGH) and fluorescent in situ hybridization (FISH), we examined the genomic constitution of germline cells in tadpoles and adult male and female P. grafi. Controlled crosses between P. perezi and P. grafi produced F1 hybrid tadpoles, whose genotypes confirmed that P. grafi parents transmitted the R subgenome through their gametes. In the early germline cells (gonocytes) of these tadpoles, P chromosomes were selectively eliminated via micronuclei formation during interphase. The occasional presence of the R genome and mixed R/P genome micronuclei suggests variability and imperfect fidelity in the elimination process. In adult hybrids, the majority of diplotene oocytes, spermatogonial stem cells (SSC) and spermatocytes carried R subgenomes. We demonstrated that programmed genome rearrangement in Pelophylax hybrids is an evolutionarily conserved mechanism underlying this unique reproductive strategy. Full article

This study’s objective was to evaluate genotoxic effects on automotive paint workers who are exposed to a complex mixture of VOCs, heavy metals, and solvents. Biological samples, including blood, urine, and buccal epithelial cells, were collected from 80 exposed workers and 80 demographically matched control subjects. DNA damage was assessed using the alkaline COMET assay in lymphocytes and whole blood. The Buccal Micronucleus Cytome (BMCyt) assay was also employed to identify cytogenetic abnormalities. Additionally, trichloroacetic acid (TCA), hippuric acid (HA), phenol, and lead (Pb) levels were measured as biomarkers of exposure. A significant increase in DNA damage was observed in the lymphocytes and whole blood of exposed workers (p < 0.05) BMCyt analysis also revealed higher frequencies of micronuclei (MN), binucleated cells, condensed chromatin (CC), and karyorrhectic (KHC) and pyknotic cells (PYC) in buccal cells (p < 0.05). Elevated levels of urinary HA, phenol, TCA, and blood lead indicated systemic chemical exposure. DNA damage positively correlated with these biomarkers, supporting a strong link between chronic occupational exposure and genotoxicity. The findings from this study highlight the critical importance of implementing effective safety measures and consistent biomonitoring for paint workers to prevent adverse health effects. Full article

The global population constantly breathes particulate matter with an aerodynamic diameter of ≤10 µm (PM₁₀)—a human carcinogen linked to lung cancer. Previous studies have indicated that PM₁₀ causes DNA damage, including double-strand breaks (DSBs). In particular, DSBs are primarily repaired by the non-homologous end joining (NHEJ) pathway, which is essential for maintaining genomic stability; however, the effects of PM₁₀ exposure on this pathway are unknown. To address this, A549 lung epithelial cells were exposed to 10 µg/cm² of PM₁₀ for 6, 12, and 24 h. We determined that DSBs increased with prolonged exposure, and an increase in the frequency of micronuclei was found. Despite the accumulated DNA damage, no changes in the cell cycle were observed. Reductions in the levels of the Ku80 gene and protein, as well as the Ku70–Ku80 heterodimer—which is essential for initiating NHEJ-mediated repair—were observed. Levels of Artemis (which is responsible for processing DNA damage) remained stable, while levels of the XRCC4 gene and protein (responsible for completing repair) decreased. We conclude that PM₁₀ disrupts two key proteins in the NHEJ pathway, impairing the capacity for DSB repair. This could promote the accumulation of DNA damage and induce genomic instability, contributing to the development of cancer. Full article

Essential oils are increasingly recognized as promising agents for sustainable weed control due to their selectivity and complex modes of action. This study evaluated the effects of Acorus calamus essential oil (SEO) on mitosis in two Fabaceae species (Vicia faba, Lupinus luteus) and two Brassicaceae species (Brassica napus, Arabidopsis thaliana) treated with species-specific IC₅₀ concentrations (0.03%, 0.025%, 0.01%, and 0.005%, respectively). Previous research showed that SEO induces oxidative stress and S-phase delay via genome instability. Here, SEO consistently disrupted mitosis across all species, reducing mitotic index by 50–60%, decreasing Cdc2 (CDKA homolog) levels, and causing chromosomal aberrations, including uneven chromatin condensation, sticky chromosomes, bridges, and micronuclei. Cells accumulated in metaphase and exhibited abnormal karyokinetic and cytokinetic spindles. Immunolabeling revealed thick, tightly packed microtubules and actin filaments, indicating excessive stabilization and impaired reorganization. Epigenetic regulation was also affected: H3T3 phosphorylation was abnormally strong, widely distributed, and persistent into anaphase/telophase, while H3S10Ph intensity was weakened. These results suggest that SEO targets multiple components of mitotic machinery and epigenetic control, regardless of species. The observed selectivity depends on dosage, not mechanism. This multi-targeted action may limit the development of plant resistance, supporting the potential of SEO as a bioherbicide in sustainable agriculture. Full article

Cyanobacterial blooms in aquatic ecosystems are a major global environmental concern. While the mutagenic and mitosis-disrupting properties of isolated cyanobacterial toxins are well documented, evidence of cytogenotoxic effects resulting from cyanobacterial blooms in natural aquatic ecosystems remains limited. In this study, water genotoxicity was evaluated in microcosms simulating cyanobacterial blooms of varying abundance. In microcosms with initially high cyanobacterial abundances (4.6 × 10⁷ and 2.2 × 10⁷ cells L⁻¹) and biomass (58 mg L⁻¹ and 20 mg L⁻¹), significant toxic, cytotoxic, mitosis-disrupting, and mutagenic effects were observed: root elongation was inhibited by up to 49.6% (Day 1), the mitotic index decreased by ~33% (Treatment I, Day 42) vs. Control, and total chromosomal aberrations and lagging chromosomes increased by ~2.5-fold on Day 1 (Treatment I) and ~4.7-fold on Day 42 (Treatment I) vs. Control; micronuclei increased ~10-fold on Day 42 in Treatment I and II. In microcosms with lower cyanobacterial abundance (1.2 × 10⁷ cells L⁻¹) and biomass (9 mg L⁻¹), significant reductions were observed only in root growth and in the mitotic index compared with Control. Future research should aim to identify a broader spectrum of cyanobacterial toxins and to investigate their environmental fate and persistence in aquatic ecosystems, particularly since genotoxic effects were detected even during the post-bloom period: on Day 42 extracellular microcystins in water were <LOQ in Treatments I and III (and 0.025 µg L⁻¹ in Treatment II), yet chromosome lagging and micronuclei remained elevated. The observed genotoxicity associated with cyanobacterial metabolites underscores the need for thorough risk assessments of cyanobacterial blooms in aquatic environments. Full article