OECD TG 489 recognizes that some modifications of the in vivo comet assay (e.g., longer electrophoresis times) can detect DNA crosslink inductions expressed as DNA migration decreases. But the application of these methods in regulated safety testing has been limited because identifying an in vivo crosslinking positive control for every tissue that can be evaluated with the comet assay can be very challenging. Most crosslinking agents induce crosslinks in just one tissue (e.g., site of contact) with the agent’s toxicity limiting exposure and effects induced in other tissues. This complication can require different positive control compounds with additional animals for each compound to adequately evaluate crosslinks in the multiple tissues typically evaluated with the comet assay. Our objective was to develop a method for generating concurrent in vivo crosslinking positive control comet data for any tissue without using additional animals. We accomplished this by preparing for each tissue evaluated extra comet slides from the conventional positive control (EMS) dosed animals and ex vivo crosslinking the heavily damaged cells on these slides with 10% neutral buffered formalin (NBF) immediately before lysis. These ex vivo crosslinked slides were then electrophoresed with the rest of the study slides with the same standard conditions and electrophoresis time. The conventional comet study slides prepared from the liver, duodenum, glandular stomach, and lung tissues collected from the EMS dosed animals and lysed without ex vivo crosslinking expressed a statistically significant DNA migration increase when compared to the concurrent vehicle control dose group. The ex vivo crosslinked slides from the EMS dose group tissue samples expressed a statistically significant decrease in DNA migration when compared to the concurrent vehicle control group. Although no statistical analysis was conducted, it is clear by the data that the ex vivo crosslinked slides from the EMS dose group tissue samples also expressed a significant decrease compared to the same samples from the EMS dose group without the ex vivo NBF treatment. This data demonstrate that the method can be easily incorporated into any existing comet study design to evaluate crosslink induction in any comet assay tissue with minimal effort or cost and without the use of any additional animals.
BACKGROUND:Antibiotic resistance in Helicobacter pylori poses a significant challenge to the effective eradication of infection worldwide. Understanding molecular mechanisms of resistance is essential for guiding treatment strategies. This study aimed to investigate the molecular basis of antimicrobial resistance in Helicobacter pylori isolates and their associated mutation frequencies. METHODS:In this cross-sectional study, gastric biopsy specimens were collected from 203 patients at Rizgary Hospital in Erbil, Kurdistan Region, Iraq, who underwent endoscopy for dyspepsia-related symptoms. Of the 137 positive patients, 91 Helicobacter pylori isolates were confirmed by colony morphology, Gram staining, and biochemical tests; 63 were successfully subcultured for antimicrobial susceptibility testing (culture success rate: 69.2%). Antimicrobial susceptibility testing was performed by the agar dilution method to determine the minimum inhibitory concentrations. The sequences of specific genes were examined and analysed by next-generation sequencing. Multiple sequence comparisons were performed to identify resistance-related genes and mutations, using 26695 (NC_000915.1) as the reference genome. RESULTS:Only two isolates (3.17%) were susceptible to all antibiotics examined. The frequency of metronidazole resistance was highest (85.71%), followed by levofloxacin (55.55%), clarithromycin (52.38%), amoxicillin (26.98%), tetracycline (6.35%), and rifabutin (4.76%). Mutations in the rdxA and frxA genes correlated with metronidazole resistance, while GyrA protein mutations at positions 87 and 91 were linked to levofloxacin resistance. Clarithromycin resistance was mainly associated with A2142G and A2143G mutations in 23S rRNA. Amoxicillin resistance (26.98%) was associated with mutations in the pbp1A gene, whereas resistance to tetracycline and rifabutin was infrequent. CONCLUSIONS:This study provides the first molecular surveillance data on antimicrobial resistance in Helicobacter pylori in northern Iraq, offering valuable regional evidence to guide local eradication strategies. The relatively high amoxicillin resistance, together with the elevated resistance to metronidazole, levofloxacin, and clarithromycin, underscores the need for susceptibility-guided therapy and continuous local antimicrobial resistance surveillance.
Genetic instability has been reported in several neurodegenerative diseases, such as Alzheimer's and Parkinson's, but only a few studies have addressed sclerosis. Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. Micronuclei (MNi) and nuclear buds (NBUDs) are established markers of chromosomal instability, yet no data are available regarding a possible link between genetic instability and ALS. The novelty of this case-control study lies in the assessment of genetic instability in oral exfoliated cells from ALS patients (n = 20) and matched controls (n = 20), contributing to the identification of potential novel markers related to the molecular pathogenesis of this severe disorder. Groups were matched for age, sex, and lifestyle (p > 0.05). No significant differences were observed in MNi or NBUD frequencies between groups (p > 0.05). These findings suggest no association between ALS and MN/NBUD frequencies in oral cells.
The in vitro genotoxicity testing battery comprising a bacterial gene mutation test (Ames test) and an in vitro micronucleus (MNvit) test is widely recommended by regulatory authorities since it detects the 3 key modes of genotoxic action (gene mutations, clastogenicity and aneuploidy). The recommendations that this battery is acceptable for regulatory use are based on its ability to effectively detect in vivo genotoxins and carcinogens. However, substances inducing gene mutations are a particular concern (representing stable genetic change and a key step in the carcinogenic process), and more in vivo gene mutation data have been published in recent years due to the wider use of transgenic rodent gene mutation (TGR) and Pig-a assays. It is appropriate to question whether the Ames + MNvit battery is efficient at detecting substances that induce gene mutations in vivo. A review of several compilations of genotoxicity studies revealed 26 substances that were reported positive in TGR and/or Pig-a but negative in the Ames test. A detailed analysis showed that 25 of these results were questionable for various reasons, and not robust examples of the failure of the 2-test in vitro battery. Only procarbazine was convincingly positive in vivo but predominantly negative in vitro, and this is mainly due to its complex metabolism which is probably not optimal with standard in vitro metabolic activation systems. The analysis shows no evidence that adding a mammalian cell gene mutation test to the in vitro battery would improve the detection of in vivo gene mutagens.
The health consequences of cigarette smoking and its commercial variants have been extensively investigated for more than three decades. However, despite substantial evidence demonstrating the detrimental effects of tobacco use, including respiratory and cardiovascular diseases and several types of cancer, the global number of users remains alarmingly high. This scientometric review mapped the scientific literature on the health impacts of cigarettes and commercial tobacco products, focusing on studies employing biomarkers of toxicological effects, including the comet assay, micronucleus test, redox status assessment, and telomere length analysis. Of 1990 retrieved records, 155 articles met the inclusion criteria and were analyzed. Redox status assessment and the comet assay were the most frequently applied biomarkers. In vivo studies primarily analyzed blood samples, whereas in vitro investigations exposed diverse cell types to cigarette smoke. Although the adverse effects of conventional cigarettes are well established, the health impacts of alternative products, including e-cigarettes, pods, and vapes, remain insufficiently investigated. This review provides a focused scientometric overview of biomarker-based research on tobacco-related toxicological effects and highlights the need for broader future studies incorporating additional biomarkers, health outcomes, and emerging tobacco and nicotine products.
This article reviews the evolution of radioprotection research in major Indian laboratories over the past seventy years, tracing a systematic progression in the exploration of various protective agents. The significant contribution of premier Indian institutions dedicated to ‘Radioprotection Development Programme’ is highlighted. Early investigations focused on synthetic radiopro-tectors, particularly sulphydryl compounds, which demonstrated strong radioprotective effects in laboratory settings. However, their clinical application was limited due to severe tissue toxicity. Subsequent research shifted toward natural thiols, novel synthetic compounds, and antioxidant nutrients. While these approaches produced encouraging experimental results, only a few showed real promise in clinical contexts. In recent decades, there has been a marked increase in studies on phytochemicals and herbal extracts, especially in Asian countries, driven by rich biodiversity and traditional medicinal systems such as Ayurveda in India. These phyto-products have shown high potential as effective radioprotectors with minimal toxicity. India has emerged as a key contributor in this domain, with extensive indigenous research efforts. Using databases such as PubMed and Google Scholar, this review identifies and compiles 46 Indian medicinal plants investigated for their radioprotective properties. Extract-based studies reveal promising efficacy through multiple mechanisms, including antioxidant activity and tissue protection. Preclinical findings demonstrate the ability of plant-derived bioactive compounds to mitigate radiation-induced damage. Notable examples include orientin and vicinin (Ocimum sanctum), podophyllin (Podophyllum hexandrum), curcumin (Curcuma longa), phyllanthin and flavonoids (Phyllanthus niruri) and polyphenol rich Rhodiola imbricata. Despite promising efficacy, clinical translation remains limited due to issues like poor bioavailability, low solubility, and formulation instability. This review concludes addressing the various pharmacological limitations, advanced delivery strategies, and the need for validated biomarkers for radiation damage to improve therapeutic effectiveness.
Cytogenetic studies in populations chronically exposed to mutagens are challenging due to a number of methodological constraints. The aim of the study was to demonstrate the applicability of dicentric assay, combined with advanced data interpretation, for radiation biodosimetry in chronically exposed medical staff. Dicentric frequencies were measured in cultured blood lymphocytes from 12 interventional radiologists with 5-42 years of professional exposure and 14 unexposed controls. The data processing methodology included a mathematical "unfolding" of observed aberration yields, a robust linear dose-response coefficient derived from in vitro low-dose calibration curve for dicentrics, and a Bayesian-type statistical framework for calculating posterior probability densities for "true" aberration yields and corresponding dose estimates. The mean dicentric frequency in radiologists significantly exceeded the control level, but individual yields showed no dependence on the years of service (r = 0.268). After "unfolding", a strong positive correlation emerged (r = 0.843). "Unfolded" dicentric yields were converted into cumulative dose estimates of 49 - 595 mGy. Bayesian posterior probability densities of "true" aberration yields corresponded to the most probable annual doses of 3.7 - 27.9 mGy. Confidence intervals of annual doses, which are "more probable to be true than non-true", ranged from 0.8 to 39.3 mGy, and their upper limits exceeded 20 mGy in eleven cases out of twelve. The proposed approach substantially enhances the accuracy and interpretative power of cytogenetic biodosimetry of chronic irradiation. The resulting dose estimates can be used for assessment of radiation-associated health risks and support individual radiation protection measures for occupationally exposed individuals.
Oral melanoma is a rare and aggressive subtype of melanoma that presents significant challenges in terms of delayed diagnosis and treatment. One promising clinical outcome is the detection of KIT gene mutations, which play a key role in tumor proliferation and resistance to therapy. The KIT gene encodes a receptor tyrosine kinase critical for cell survival and proliferation, and its mutations are associated with more aggressive tumor behavior. Detection of KIT mutations can be achieved through techniques such as tissue biopsy, next-generation sequencing (NGS), RT-PCR, and immunohistochemistry, providing comprehensive genomic profiling and insights into potential therapeutic targets. Precision therapies, including small-molecule inhibitors like imatinib and sunitinib, as well as combination therapies involving immune checkpoint inhibitors, offer personalized treatment strategies. Despite the potential, the rarity of oral melanoma limits clinical trials, and understanding resistance mechanisms remains a significant challenge for effective treatments for oral melanoma patients. This article highlights the critical role of KIT mutations in oral melanoma, offering insights into how molecular diagnostics can pave the way for personalized treatment approaches by focusing on advanced detection techniques and targeted therapies.
Chromosomal instability (CIN) is a pervasive feature of cancer and a major driver of tumor heterogeneity, evolution, and therapeutic resistance. Arising predominantly from defects in chromosome segregation, DNA repair, and mitotic fidelity, CIN promotes continuous genomic diversification within tumor cell populations, enabling adaptive responses to intrinsic and extrinsic selective pressures. While clonal chromosomal alterations reflect stabilized genomic configurations selected during tumor evolution, non-clonal interphase markers of chromosomal instability represent transient, low-frequency events that capture ongoing microevolutionary dynamics and genomic plasticity. This review provides a comprehensive synthesis of current knowledge regarding both classical and non-classical markers of CIN evaluated during interphase, including micronuclei, nucleoplasmic bridges, nuclear buds, cytoplasmic chromatin, massive chromosomal segregation errors, chromosomal fragmentation, and genomic chaos-related phenomena. We discuss the cellular mechanisms underlying their formation, their contribution to structural and numerical chromosomal alterations, and their role in shaping intratumoral heterogeneity, adaptive potential, malignancy acquisition, and cancer progression. Particular emphasis is placed on the "just-right" dual nature of CIN, which can either drive tumor aggressiveness or precipitate mitotic catastrophe and cell death, depending on its magnitude and cellular context. By integrating cytogenetic, molecular, and evolutionary perspectives, this review highlights the relevance of these non-clonal interphase cytogenetic markers as sensitive indicators of genome instability and tumor dynamics. Understanding the interplay between clonal and non-clonal chromosomal alterations may provide valuable insights for the development of prognostic tools and therapeutic strategies aimed at exploiting the vulnerabilities of genomically unstable cancers.
BACKGROUND:Curcumin exhibits significant antitumor activity, inhibiting proliferation, angiogenesis, invasion, and metastasis, highlighting its potential for cancer treatment. However, its mechanisms in Laryngeal and Pharyngeal Carcinoma remain unclear. Therefore, this study aims to elucidate these mechanisms through in vitro and in vivo experiments. METHODS:Cell functions were examined using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-Ethynyl-2'-deoxyuridine (EdU) staining, tube formation assay, flow cytometry, and Transwell assays. Laryngeal and Pharyngeal Carcinoma-related genes were screened using GeneCards database, while curcumin-related genes were predicted using TCMSP and Swiss Target Prediction databases. Enrichment analysis of overlapping genes was performed using KEGG and GO analysis. Additionally, the core genes from common target genes were analyzed using Cytoscape and its plugins Cytohubba and MCODE. Gene expression was detected using reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and western blot. Molecular docking was used to computationally predict the binding affinity between curcumin and EP300, followed by normal mode analysis (NMA)-based simulation to hypothetically explore complex stability under equilibrium conditions as a static approximation. Xenograft tumor models were constructed to investigate the role of curcumin and EP300. RESULTS:Curcumin suppressed Laryngeal and Pharyngeal Carcinoma cell proliferation, migration, and invasion, and HUVEC tube formation, and promoted cancer cell apoptosis. Six of the eight curcumin-targeted genes were overexpressed in Laryngeal cancer (in both datasets), with NFE2L2 non-significantly upregulated and BCL2 showing heterogeneous expression. EP300 expression was increased in Laryngeal and Pharyngeal Carcinoma tissues and cells, and curcumin inhibited EP300 expression. Molecular docking, coupled with NMA, predicted favorable binding affinity and suggested that the curcumin and EP300 histone acetyltransferase (HAT) domain complex forms a stable binding mode. Notably, curcumin suppressed Laryngeal and Pharyngeal Carcinoma cell proliferation, migration, invasion, and HUVEC tube formation, and promoted cancer cell apoptosis in a process involving EP300, as demonstrated by rescue experiments with EP300 overexpression. In addition, EP300 overexpression reversed the inhibitory effect of curcumin on tumor growth. CONCLUSION:Curcumin inhibits FaDu and AMC-HN-8 cell proliferation, HUVEC tube formation, cancer cell migration, and invasion and promotes cell apoptosis in a process involving EP300, as demonstrated by EP300 overexpression rescue experiments.
Acromegaly is characterized by the hypersecretion of growth hormone (GH) and insulin-like growth factor (IGF-1). Individuals with acromegaly have a higher risk of developing certain cancers, and the mitogenic and anti-apoptotic effects of GH and IGF-1 may heighten their predisposition to tumorigenesis. The presence of micronuclei (MN) and nuclear buds (NBs) in buccal mucosa cells is a marker of DNA damage, and high levels have been linked to carcinogenesis. The aims of this study were i) to comparatively analyze the proportions of buccal mucosa cells with MN and NBs in patients with acromegaly and controls, and ii) to identify associations between increased levels of such cells and patient and clinical factors. MN- and NB-containing cells were quantified using fluorescence microscopy. Data on the following demographic and clinical characteristics were collected: age, sex, smoking, alcohol consumption, time since acromegaly, GH and IGF-1 levels, radiation exposure, diabetes, body mass index, blood pressure, and cancer history. The patients with acromegaly (n = 42; 17 male, 25 female) had higher proportions of MN- and NB-containing cells than the controls, although only the levels of the MN-containing cells significantly differed (p = 0.023). The levels of MN-containing cells significantly differed with age (< 45 vs. ≥ 45 years). A significant inverse correlation was observed between the frequency of MN-containing cells and the IGF-1/upper limit of normal ratio. In conclusion, the patients with acromegaly exhibited relatively higher proportions of buccal mucosa cells with MN, a marker of genomic instability.
Defects in homologous recombination repair genes contribute to hereditary cancer susceptibility beyond BRCA1 and BRCA2, yet clinical interpretation of intermediate-penetrance genes remains challenging. We retrospectively evaluated unrelated carriers of pathogenic or likely pathogenic germline variants in RAD51C, RAD51D, and BRIP1 identified through hereditary cancer multigene panel testing in a real-world cohort of approximately 8000 individuals. Fifty-two carriers were included (RAD51C n = 14, RAD51D n = 15, BRIP1 n = 23). Ovarian cancer represented the predominant malignancy, followed by breast cancer, consistent with established gene-phenotype associations. Most detected variants were predicted loss-of-function alterations. Six previously unreported variants were identified, expanding the mutational spectrum of RAD51C and RAD51D. Recurrent variants were observed in unrelated individuals, including BRIP1 c.2992_2995del, which demonstrated higher frequency in regional population data compared with global datasets, suggesting possible population enrichment. Additional pathogenic variants in ATM and BRCA1 were identified in two individuals, highlighting the complexity of multigene testing. Although non-classical tumour types were occasionally observed, including colorectal cancer in BRIP1 carriers, causal associations remain uncertain. These findings emphasize the importance of population-aware variant interpretation and individualized genetic counseling aligned with contemporary ACMG and ESMO recommendations for moderate-penetrance hereditary cancer genes.
This paper is part of a series of publications developed by the Latin America-Comet assay (LA-COMET) group, which emerged in 2021, during the Asociacion Latinoamericana de Mutagenesis, Carcinogenesis y Teratogenesis Ambiental Congress, to organize the LA-COMET initiative. A total of 104 alkaline comet assay publications in animal (aquatic and terrestrial) and plant models, authored by members of this group, were analyzed to determine how DNA damage under experimental and environmental exposure conditions is assessed. The manuscript reflects the broad use and versatility of the comet assay in diverse taxonomic groups (invertebrates and vertebrates), in vivo research models, and cell types (e.g., erythrocytes, branchia cells, retinal epithelial cells, peripheral blood, liver, kidney, lung, bone marrow, testicle and nasal cells). Application of the comet assay in diverse biological systems requires careful methodological standardization to ensure reproducibility and allow for comparability of results. In order to unify the evaluations of the papers, a quality score system was developed, the 'quality score comet assay' (QSca), providing values reflecting the methodological rigor of the execution of the assay. The group identified key elements when performing the comet assay and uses them as the focus for the QSca score. The LA-COMET initiative will provide opportunities to strengthen collaborative networks among Latin American countries, promoting more integrative and regionally connected research where the comet assay can be used as a reliable and reproducible tool for the assessment of DNA damage in diverse biological models.
The increasing application of nanotechnology has raised concerns regarding the genotoxic potential of engineered nanoparticles due to their unique physicochemical properties and biological interactions. The present study evaluated the genotoxic effects of four oxide nanoparticles-aluminium oxide (Al₂O₃NPs), iron oxide (Fe₃O₄NPs), silicon dioxide (SiO₂NPs), and titanium dioxide (TiO₂NPs)-in human peripheral blood cells using the alkaline comet and cytokinesis-block micronucleus (CBMN) assays. Sublethal concentrations were selected based on IC₅₀ values determined by a resazurin-based cell viability assay. The comet assay revealed a significant dose-dependent increase in DNA strand breaks for all nanoparticles, with TiO₂NPs inducing the highest levels of primary DNA damage, as reflected by the percentage of tail DNA. In contrast, SiO₂NPs produced the highest frequency of micronuclei in the CBMN assay, indicating pronounced chromosomal instability. Fe₃O₄NPs showed a significant increase in nucleoplasmic bridge formation at higher concentrations, while Al₂O₃NPs exhibited comparatively lower genotoxic effects. Overall, these findings demonstrate differential genotoxic responses among oxide nanoparticles, influenced by particle size and composition, and highlight their potential to induce genome instability even at sublethal exposure levels.
Microplastics (MPs) and nanoplastics (NPs) are environmental pollutants with paramount implications for aquatic ecosystems and, through that route, human health, particularly due to their oxidative stress-mediated genotoxic potential. This review is a synthesis of findings from recent studies, with emphasis on the scenario in India, on the bioavailability, toxicological risks, and cellular mechanisms of MPs and NPs (MNPs) in various organisms, separately addressing evidence from aquatic models, including marine mussels, common carp, zebrafish, rotifers, etc., and mammalian systems relying essentially on in vitro studies. Key evidence indicates that MPs adsorb persistent organic pollutants like Polycyclic Aromatic Hydrocarbons (PAHs), enhancing their bioavailability and inducing oxidative stress, immunological alterations, and developmental toxicity, which are closely associated with DNA damage and chromosome instability. As regards aquatic organisms, combined exposure to MPs and heavy metals to fish models exacerbates biochemical disruptions and immune suppression, along with oxidative stress-linked genotoxic responses such as DNA strand breaks and micronucleus formation. Zebrafish embryos exhibit microcirculation dysfunction and pathological angiogenesis upon NP exposure. Mammalian cell studies reveal size-dependent cytotoxicity, with smaller NPs causing greater oxidative damage and membrane disruption, which triggers mitochondrial dysfunction, excessive ROS production, cell-cycle arrest, and activation of DNA damage response pathways, evidenced by micronucleus formation, chromosomal abnormalities, and oxidative DNA lesions. Overall, toxicity is influenced by particle size, charge and co-contaminants, with oxidative stress emerging as the central mechanism that connects cellular toxicity to genetic damage. This review underscores the urgent need for integrated, multidisciplinary approaches to assess the environmental and toxicological risks of MNPs with special emphasis on standardized genotoxicity assessment, while informing regulatory and mitigation strategies for the future.
The repeated-dose liver micronucleus (RDLMN) assay is an in vivo genotoxicity test that is useful for detecting hepatocarcinogens and is anticipated to be incorporated into general toxicity studies. Although many RDLMN studies have been reported, further investigation is necessary to demonstrate age-related sensitivity and to evaluate compounds with cytostatic properties.In this study, a repeated oral dose study of 2,6-dinitrotoluene (2,6-DNT), a substance known to have cytostatic properties, was conducted in Crl:CD(SD) rats starting at 6 or 8 weeks of age for 28 days. Liver micronucleus (LMN) frequency, mitotic index (MI), and cell proliferation markers, Ki-67 and PCNA, were subsequently evaluated. As a result, LMN frequency increased significantly at all dose levels, showing a reverse dose-response relationship, and there were little differences between age groups. The number of Ki-67-positive cells increased in both age groups, and it was considered compensatory cell proliferation following toxicity at higher doses. Histopathological evaluation revealed prominent anisokaryosis, particularly at 8 weeks of age at start of dosing, and DNA content analysis confirmed that these cells were polyploid, suggesting endoreduplication.This study confirmed that LMN detection sensitivity in the RDLMN assay did not differ between rats aged 6 or 8 weeks at the start of dosing, and that micronucleus-inducing ability was detected even in compounds with cytostatic properties. For appropriate interpretation of the results, histopathological assessment, the analysis of cell proliferation markers and DNA content analysis are useful.
India's rapid population growth positively correlates with solid waste generation. Indiscriminate disposal in unsanitary landfills is dominant, and releases hazardous contaminants, that pose genotoxic risks to humans and biota. This study evaluated DNA damage and genome instability induced by solid waste emissions of Indian origin. Following PRISMA guidelines, 36 peer-reviewed studies published until 2025 were selected. These studies reported 40 bioindicators and 56 genotoxic biomarkers, with cell lines and comet assay most frequently reported. Significant DNA strand breaks, micronucleus formation, chromosomal aberrations, nuclear abnormalities, and sperm defects in exposed models were consistently reported, often in dose- and time-dependent patterns. Random-effects meta-analysis using pooled standardized mean differences showed significant positive effect sizes for micronucleus and comet endpoints (p ≤ 0.0001), confirming increased genetic damage in exposed groups. Although substantial heterogeneity was observed (I² = 95.73% for micronucleus; 87.66% for comet), the direction of effect remained consistently positive. Risk-of-bias assessment indicated overall moderate to high methodological quality, with common reporting gaps in exposure characterization and blinding procedures. Oxidative stress and ROS generation are dominant drivers of genome instability. Signaling pathways causing DNA adduct, DNA repair impairment, epigenetic dysregulation, and mitochondrial-mediated apoptosis were other mechanisms. Despite strong evidence of somatic and germline genotoxicity, epidemiological data and quantitative exposure assessments remain inadequate. Integrated exposure monitoring, advanced molecular and epigenetic biomarkers, dose-response characterization and long-term population-level biomonitoring are needed to strengthen causal inference and human health risk assessment. Emissions from solid waste facilities in India represent a credible genotoxic hazard warranting improved waste management, and regulatory enforcement.
TP53 mutation is one of the most frequently altered genetic variants leading to hepatocellular carcinoma (HCC). Single nucleotide polymorphisms (SNPs) in this gene play a crucial role in predicting the risk of HCC development. This study aimed to analyze how SNPs in the human TP53 gene affect protein stability, structure, localization, and other physicochemical properties. The coding sequence (CDS) and SNP data of TP53 were retrieved from the Ensembl database. CDS were translated using the ExPASy Translate tool. Mutated protein sequences were analyzed using ProtParam, I-MUTANT, CELLO2, SOPMA, SWISS-MODEL, SAVES v6.0, and the HDOCK server to evaluate physicochemical properties, stability, subcellular localization, secondary and tertiary structures, structure validation, and docking behavior. Among 30 SNPs analyzed, three SNPs (rs1555526997 in exon 15, rs1567556784 in exon 59, and rs869054324 in exon 66) showed complete alterations in physicochemical properties, subcellular localization, 2D and 3D structures, and ERRAT and PROCHECK values. The study identified 21 missense, 3 frameshift, and 6 stop-gained mutations. Of the missense mutations, seven SNPs showed a decreasing effect on protein stability. This study demonstrates the effectiveness of in silico approaches in predicting HCC associated biomarkers and assessing the functional impact of TP53 mutations.
On a global scale, the versatility and high sensitivity of the comet assay have promoted its use from different perspectives to determine genotoxic damage. With this in mind and through the formation of a Latin American group denominated "LA-COMET", a review of the manuscripts published by the group is proposed from the perspective of in vitro studies, using the alkaline comet assay. To facilitate the analysis of the 81 manuscripts published between 1996 and 2022, they were classified into four categories based on the type of agents evaluated by the assay: 1) environmental pollutants; 2) pesticides and their mixtures; 3) radiation and drugs; and 4) natural products. The objective of this review was to describe the strengths and versatility of in vitro studies reflected by cellular models, putative DNA damaging agents, and the use of specific enzymes to identify particular DNA lesions. In addition, an in vitro QS (quality score) was established, taking into consideration the data provided in the publications regarding the cellular model, the method of disaggregation and the cell suspension obtention. Other considerations included the clarity of the description of the treatments, the use of negative and positive reference controls, and the use of specific enzymes and/or the functional evaluation of DNA repair. The analysis demonstrated that the publications of the LA-COMET group of in vitro models exhibited a high score with respect to the important parameters established in the OECD agreements.
Glial tumors are the most common malignant brain tumors, and IDH1 serves as an important diagnostic and prognostic molecular marker in gliomas. The mutation status of IDH1 influences prognosis, patient survival, and treatment response in glial tumors. However, the effects of the IDH1 mutation on the angiogenic potential of glial tumors have yet to be thoroughly elucidated. Our aim was to investigate the impact of the IDH1 mutation on the angiogenic potential of glial tumors by overexpressing both mutant and wild-type IDH1 genes in these tumors. Furthermore, we examined how the signaling pathways affecting the angiogenic behavior of glial tumors differ based on IDH1 mutation status by evaluating the mRNA expressions of VEGF, EGF, PDGF, and FGF signaling pathways in the U87MG cell line as well as in patient-derived tumor samples. The IDH1 mutation induced proliferation and tube-formation potential in U87MG cells while suppressing these activities in HUVEC cells. Considering angiogenesis-associated signaling pathways, we found that mutant IDH1 expression indirectly upregulates angiogenesis-associated pathways via HIF1A. The genes VEGFC, ERBB3, PDGFB, and PDGFC may serve as potential markers for the prognosis of glial tumors and for anti-angiogenic therapy.
