Search Results (1,560)

Solitary living is an evolutionarily widespread yet comparatively under-theorized social system, despite its occurrence across diverse animal taxa. Shrikes (family Laniidae) are small predatory passerines that combine raptorial behavior, strong territoriality, and predominantly solitary space use, making them a powerful model for examining the ecology and evolution of solitary living. Here, I synthesize published work on shrike behavioral ecology and explicitly link these traits to the costs and benefits of a solitary lifestyle. I argue that shrikes exemplify how solitary species can offset the absence of social buffering through cognitive innovation, finetuned habitat selection, and flexible yet tightly bounded sociality. I then compare shrike ecology to solitary mammals and reptiles, highlighting convergent patterns in resource dispersion, spatial memory, risk management, and juvenile dispersal. I further examine how anthropogenic pressures, such as habitat fragmentation, climatic instability, and urbanization, interact with solitary life histories and review evidence from management interventions in both European farmland and North American systems that demographic recovery is achievable but remains contingent on addressing broader land-use conflicts and sources of adult mortality. Finally, I outline five interconnected research priorities—spanning cognitive ecology, trophic interactions, movement ecology, genomics, and formal comparative analyses—that would move shrike research from its current observational foundation toward a more experimental, mechanistic, and phylogenetically informed programme. By reframing shrikes as a model taxon for solitary living, this review aims to integrate avian behavioral ecology into broader comparative frameworks of social organization, cognition, and resilience under global change. Full article

The Fukushima nuclear accident highlighted that evacuation-related psychosocial harm can outweigh direct radiation risks, underscoring the need to define the health impacts of chronic low-dose-rate (LDR) radiation and evidence-based thresholds for intervention. This study investigated the effects of continuous, postnatal LDR gamma irradiation (1.2 mGy/h, cumulative dose: 5 Gy) in male mice. While no changes in body weight, hippocampal neurogenesis, or major glial and neuronal populations were observed, persistent DNA damage (γ-H2AX foci) in dentate gyrus granule cells occurred in both irradiated male and female mice. Irradiated male mice developed anxiety-like behaviour, a phenotype not observed in a previously published study of female mice subjected to an identical irradiation protocol. Molecular profiling revealed two novel, dysregulated miRNA/mRNA axes in the hippocampus linking DNA damage to behaviour: a maladaptive miR-466i-5p/Tfcp2l1 pathway associated with genomic instability, and a potentially adaptive miR-101a-5p/BMP6 pathway promoting neuronal survival. Venn analysis further identified miR-124b-3p and novel-miR489-3p as conserved exposure biomarkers, altered in both the hippocampus and blood of irradiated animals. Our results show that a high cumulative dose of chronic LDR induces markedly less severe hippocampal pathology than has been reported for equivalent acute doses. These findings support the concept of dose-rate-dependent threshold dose and contribute to the evidence base for developing countermeasures following nuclear incidents or other radiation exposures. Full article

Endometrial cancer (EC) is the sixth most common cancer in women. Its overall incidence has increased by 132% over the past 30 years, reflecting an increase in the prevalence of risk factors. The mortality rate decreased by 15% in the last 30 years, despite the high number of endometrial cancer-related deaths occurring world-wide. An inverse relationship has been observed between the incidence of EC, mortality and socio-economic status: more patients living in low-income countries die from EC because they do not have access to timely and effective treatment. About 80% of EC cases are diagnosed in an early stage and have a good prognosis. However, about 20% of cases present in advanced stages and are characterized by a poor prognosis. The molecular classification proposed by The Cancer Genome Atlas (TGCA) and its surrogate for clinical use allowed the adoption of personalized treatments. The assessment of the status of the MMR has revolutionized the treatment of advanced ECs, leading to significant results both in terms of PFS and OS. In this review we will focus on MMR deficiency (dMMR)/microsatellite instability-hypermutated (MSI-H) tumors, which globally account for 20–30% of ECs. The dMMR group encompasses multiple etiologies, including sporadic defects in MMR genes, germline mutations, and hypermethylation of the MLH1 promoter. Currently, the combination of immunotherapy (I-O) with standard chemotherapy has become the new standard first-line treatment for dMMR advanced or recurrent ECs. Although the main clinical trials involving patients with MMRd/MSI-H ECs treated with I-O and chemotherapy have demonstrated efficacy and long-term control of the disease, a significant number of patients do not respond to treatment (intrinsic or primary resistance) and others develop progression during treatment (acquired or secondary resistance). In this narrative approach the biological and molecular bases of these tumors have been integrated with recent advances involving diagnostic techniques, therapeutic opportunities and the genomic and phenotypical alterations underpinning the mechanisms of resistance. Special attention was given to the need for robust, clinically affordable biomarkers to promptly identify responders and non-responders to the current treatment regimens. Full article

Endometriosis is a chronic estrogen-dependent disorder affecting approximately 10% of women of reproductive age. Increasing epidemiological and molecular evidence indicates that it may represent a precursor condition for a subset of ovarian malignancies collectively defined as endometriosis-associated ovarian cancer (EAOC), predominantly endometrioid and clear cell carcinomas. Malignant transformation is driven by the interplay between chronic inflammation, oxidative stress, and local hyperestrogenism within the endometriotic microenvironment. Recurrent hemorrhage and persistent immune activation further promote genomic instability and clonal expansion. Shared somatic mutations have been identified in both atypical endometriosis and adjacent carcinomas, supporting a model of stepwise tumorigenesis. Dysregulation of signaling pathways and epigenetic mechanisms, including microRNA alterations, further contribute to tumor development. Although the absolute risk of malignant transformation remains low, women with ovarian endometriosis and deep infiltrating disease show an increased risk of ovarian cancer. EAOC is frequently diagnosed at earlier stages and generally demonstrates a more favorable prognosis than high-grade serous carcinoma, although clear cell histotypes may exhibit chemoresistance and distinct molecular vulnerabilities. This review summarizes current evidence on the pathogenesis, molecular mechanisms, and clinical implications of EAOC, highlighting future strategies for risk stratification and personalized surveillance. Full article

Inflammatory bowel diseases (IBD), encompassing ulcerative colitis and Crohn’s disease, are associated with an increased risk of colorectal cancer through mechanisms driven by persistent mucosal inflammation. Chronic inflammatory signaling, recurrent epithelial injury, and altered tissue repair processes progressively reshape the intestinal microenvironment, promoting genomic instability and facilitating the development of colitis-associated colorectal cancer (CAC). Despite the well-established link between inflammation and tumorigenesis, only a subset of patients with long-standing IBD develops malignancy, highlighting the complexity of the regulatory effects of the ongoing inflammation on the tumor initiation and progression. This review discusses the multifaceted roles of innate and adaptive immune responses in CAC pathogenesis. Innate immune signaling mediated by pattern recognition receptors, particularly Toll-like receptors, integrates microbial and damage-associated signals to activate inflammatory pathways that regulate epithelial proliferation, survival, and tumor-promoting cytokine networks. Tumor-associated macrophages, neutrophils, and myeloid-derived suppressor cells contribute to carcinogenesis by sustaining chronic inflammation, promoting immunosuppression, and remodeling the tumor microenvironment, although under specific conditions these cells can also support antitumor immunity. Innate lymphocyte subsets participate in immune surveillance and epithelial homeostasis, yet may also amplify inflammatory circuits that influence tumor development. Adaptive immune populations further shape CAC evolution, as CD4⁺ T-helper subsets, CD8⁺ cytotoxic T lymphocytes, regulatory T cells, and B cells exert divergent effects depending on cytokine milieu, immune context, and disease stage. Understanding immune-cell plasticity and the molecular pathways governing these processes may facilitate the identification of predictive biomarkers and the development of targeted immunomodulatory strategies aimed at preventing CAC. Full article

Background/Objectives: Accurate ploidy determination is essential for understanding population structure and evolutionary history for breeding and domestication. The Chrysanthemum arcticum (Arctic daisy) complex, comprising C. arcticum and subspecies arcticum and polaré, exhibits variability in ploidy variation with reports ranging from diploid (2n = 2x = 18) to octoploid (2n = 8x = 72). Methods: The objective of this study was to assess ploidy levels in n = 225 genotypes from n = 46 wild, native populations of the three taxa collected across mainland Alaska, Attu Island (Alaska), and Hudson Bay (Canada) using flow cytometry, and using C. nankingense (2n = 2x = 18) as the diploid reference. Results: Genome sizes were from 5.27 to 20.69 pg (2C), corresponding to diploid through hexaploid. Triploids were the most frequent (64%) before, as well as after, applying the reference standard bias (10% correction). All ploidy levels were present in multiple geographic regions, with no clear spatial, taxonomic, or latitudinal segregation. The high incidence of triploids, most of which were self-compatible and highly fertile, may reflect genetic instability, underlying aneuploidy (which is common in several Chrysanthemum polyploids), or systematic bias from reference standard differences. Inconsistencies between flow cytometry estimates and observed reproductive compatibility, such as successful crossings with known diploids, suggest additional genomic complexity. Potential historical influences creating genomic instability, including environmental disturbances (chemical, radiation warfare remnants) from World War II military activities at Attu Island and Hudson Bay, are discussed. Conclusions: This study shows the challenges of accurately determining ploidy levels in the C. arcticum trifecta complex and highlights the need for other approaches, including high-density SNP genotyping and chromosome imaging, to resolve ploidy questions and guide future breeding strategies. Full article

Recombinogenic DNA damage can initiate chromosomal rearrangements that can alter gene expression or accelerate cancer progression in higher eukaryotes. Thus, there is a critical need to identify genes that suppress chromosomal rearrangements and environmental exposures that promote genetic instability. Cell cycle checkpoints modulate the cell cycle so that DNA repair occurs before the replication or segregation of damaged chromosomes. Saccharomyces cerevisiae (budding yeast) RAD9 was the first cell cycle checkpoint gene identified, which initiated intensive research studies into the mechanisms of checkpoint activation and the phenotypes of checkpoint mutants. The budding yeast Rad9 protein serves as both an adaptor and scaffold that facilitates downstream effector activation to orchestrate a DNA damage response at multiple stages of the cell cycle, which facilitates double-strand break (DSB) repair by sister chromatid recombination. However, the role of RAD9 in homologous recombination and in suppressing gross chromosomal rearrangements (GCRs) is not completely understood. In this review we discuss how RAD9 can promote genome instability resulting from aberrant DNA replication intermediates, while suppressing DSB-associated rearrangements. We also discuss possible mechanisms accounting for the synergistic increase in genomic instability in double mutants defective in both RAD9 and recombinational repair. We emphasize that while there is an overlap between checkpoint and recombinational repair pathways, RAD9 and checkpoint pathways can function independently to suppress chromosomal instability. These studies thus elucidate checkpoint mechanisms that control homologous recombination between repeated sequences. Full article

Background/Objectives: Lung cancer remains the leading cause of cancer-related mortality globally. Approximately 45% of these tumors harbor oncogenic mutations that drive carcinogenesis and are amenable to targeted therapies. Other predictive biomarkers—e.g., PD-L1, TMB, and MSI—play a crucial role in patients’ management. This study aims to investigate the existence of mutation clusters (co-mutations) and evaluate the correlation of these clusters with various clinical and laboratory parameters. Methods: A retrospective study was conducted utilizing pathological samples from lung cancer patients harboring mutations in EGFR, KRAS, ALK, BRAF, MET, HER2, ROS1, NTRK, and NRG1. Data were collected from the Institute of Pathology at Carmel Medical Center between the years 2022 and 2024. Patients were stratified using a Two-Step Cluster Analysis algorithm based on actionable mutations and co-mutations. Heatmaps and dendrograms were generated to assess the correlation between these genomic clusters, clinical metrics, and predictive biomarkers. Results: The study cohort included 129 patients with actionable mutations. Five distinct clusters were identified: Clusters 1, 2, and 3 exhibited a high expression of STK11 and TP53 co-mutations alongside KRAS drivers (n = 38, n = 12, and n = 23, respectively). Clusters 4 and 5 demonstrated high expression of ALK alterations and tumor suppressor gene mutations (n = 31 and n = 25, respectively). Cluster comparisons demonstrated statistically significant differences between clusters regarding age, gender, PD-L1 expression, and tumor mutational burden. No significant associations were found regarding ethnicity or microsatellite instability status. Conclusions: By constructing clusters based on the aggregate of genomic alterations in patients with actionable mutations, it is possible to predict associations with distinct demographic and clinical characteristics. Future research should apply this analytical approach to larger cohorts to further characterize these subgroups and investigate potential correlations with therapeutic efficacy. Full article

Early-onset colorectal cancer (EOCRC), defined as diagnosis before the age of 50 years, is increasing globally and is frequently characterized by aggressive biology and a disproportionate burden of liver metastases. This review synthesizes emerging evidence on the distinct molecular, immunologic and clinical features that differentiate EOCRC liver metastases from those arising in older adults. Genomic studies revealed increased chromosomal instability, increased copy number variation burden and unique amplification patterns involving MYC, RAD21, GNAS and MAPK1, alongside altered frequencies of classical driver mutations and increased germline predisposition. EOCRC liver metastases also exhibit a progenitor-like transcriptional state and an immune-cold microenvironment marked by reduced myeloid infiltration, impaired antigen presentation and profound resistance to immunotherapy, particularly in microsatellite-stable disease. Mechanistic insights into ferroptosis highlight therapeutic vulnerabilities, especially in PIK3CA-mutant tumors, where aspirin and ferroptosis inducers show synergistic potential. Clinically, high-risk EOCRC patients often present with left-sided primary tumors, synchronous metastases, adverse histology, elevated CEA levels and a hereditary predisposition, with prognostic models incorporating these variables outperforming traditional staging. Collectively, accumulating evidence suggests that EOCRC liver metastases may represent a biologically and clinically distinct entity, although ongoing debates regarding the extent of this distinction underscore the need for age-specific molecular profiling and prospectively validated therapeutic strategies. Full article

Cutaneous T-cell lymphoma (CTCL) comprises a heterogeneous group of extranodal non-Hodgkin lymphomas. With the publication of the fifth edition of the World Health Organization Classification of Hematolymphoid Tumors, the diagnostic framework for CTCL has shifted from primarily morphologic phenotypes toward an emphasis on molecular drivers. Current research suggests that malignant clones may arise from somatic mutations at the hematopoietic stem cell stage and may follow a continuous hematogenous dissemination model with bidirectional trafficking between the skin and systemic circulation. At the molecular level, genomic instability, often associated with somatic copy-number variations, may promote activation of the janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway through gene-dosage effects. In parallel, chromatin remodeling linked to EZH2 overexpression and reduced special SATB1 expression may support a Th2-polarized program. This phenotype may contribute to epidermal barrier impairment via cytokines such as Interleukins-4 (IL-4) and IL-13, potentially creating conditions permissive for Staphylococcus aureus colonization. Microbial superantigens and exotoxins may further contribute to tumor progression and therapeutic resistance by reinforcing JAK/STAT signaling, particularly STAT3, and reducing CD8+ T-cell–mediated immune surveillance. In the dermis, reprogramming of cancer-associated fibroblasts and polarization of macrophages toward an M2 phenotype may collectively contribute to an immunosuppressive niche. Emerging biomarkers, including CD74, and acquired resistance mechanisms after anti-C-C chemokine receptor 4 therapy further extend the translational relevance of recent pathologic findings. Overall, CTCL evolution appears to be a systemic process shaped by interactions between tumor-intrinsic genetic alterations and the skin microenvironment. Full article

Background/Objectives: Placental vascular malperfusion, on both the maternal (MVM) and fetal (FVM) side, is a key mechanism linking hypertensive disorders of pregnancy, fetal growth restriction (FGR), stillbirth, preterm neonatal death and neonatal encephalopathy. Nevertheless, clinical use and medico-legal interpretation of placental findings remain inconsistent. To summarize recent evidence on the relationship between placental vascular malperfusion, perinatal mortality and neonatal brain injury, integrating standardized placental pathology with Doppler and angiogenic biomarkers, and to outline the main medico-legal implications. Methods: A PubMed search using the string “((placenta OR placental pathology) AND (stillbirth OR fetal death) AND (maternal vascular malperfusion OR fetal vascular malperfusion))” yielded 118 records. After excluding reviews, meta-analyses, case reports (except one illustrative SARS-CoV-2 placentitis case), non-human studies and papers without original histopathology, 33 studies were included: observational cohorts and case–control studies with standardized placental assessment, autopsy series, biomarker/Doppler cohorts, mechanistic work, one randomized trial protocol and a small number of focused clinical commentaries. Results: Across these studies, MVM emerges as the dominant placental lesion in pre-eclampsia, FGR and a large proportion of stillbirths, especially in early-onset disease and in association with maternal hypertension. FVM is strongly linked to stillbirth and term neonatal encephalopathy, and specific combinations of MVM, FVM and inflammatory lesions correspond to distinct patterns of brain injury. Large population-based cohorts confirm that maternal hypertensive disorders and placental malperfusion are major upstream causes of intrauterine hypoxia and preterm neonatal death. Doppler velocimetry and angiogenic biomarkers (PlGF, sFlt-1 and their ratio) are strongly associated with an increased likelihood of underlying MVM and adverse neonatal outcomes, although their predictive performance remains probabilistic and context-dependent rather than diagnostic. Mechanistic studies suggest roles for placental genomic instability and altered decidual immunity in defective placentation. Conclusions: Maternal and fetal vascular malperfusion represent converging pathways to FGR, stillbirth, preterm neonatal death and neonatal encephalopathy. Routine, standardized placental examination, interpreted together with Doppler and biomarker data, substantially improves causal attribution and timing of injury, with direct consequences for counselling, prevention and medico-legal assessment. Full article

Oxidative stress is one of the major contributors to DNA damage and genomic instability, emphasizing the importance of identifying natural compounds with antioxidant genoprotective potential. Cedrus atlantica essential oil (EO) has been widely reported to possess antioxidant properties and potential genoprotective effects due to the presence of a cohort of antioxidant compounds, including polyphenols and terpenes. Nevertheless, its effects on DNA integrity remain poorly understood. The present study aimed to evaluate the genotoxic and antigenotoxic effects of C. atlantica EO in human peripheral blood mononuclear cells (PBMCs) using the alkaline Comet assay. PBMCs were exposed to increasing concentrations of the EO (0.2–3% w/v) under basal conditions and in the presence of hydrogen peroxide (H₂O₂, 25 µM) as an oxidative DNA-damaging agent. Genetic damage was quantified by visual score, and arbitrary units were converted into a percentage of DNA in the comet tail. The EO was characterized by gas chromatography–mass spectrometry. The results showed that C. atlantica EO did not induce detectable genotoxic effects under the experimental conditions and within the tested concentration range (0.2–3% w/v). H₂O₂ exposure markedly increased DNA strand breaks, whereas co-treatment with the EO significantly attenuated H₂O₂-induced oxidative DNA damage, particularly at intermediate concentrations. The chemical characterization analysis revealed a sesquiterpene-rich profile dominated by cedrene- and himachalene-type compounds. Overall, these findings indicate that C. atlantica EO exerts antigenotoxic effects against oxidative DNA damage, supporting its genoprotective potential in moderate concentrations. Full article

Chronic lymphocytic leukemia (CLL) exhibits marked clinical heterogeneity that is closely associated with genomic instability. Although cytogenetic abnormalities are widely used for risk stratification, they do not fully capture the biological complexity of the disease. Telomere dysfunction and alterations in DNA damage response pathways have been implicated in disease progression, but their relationship with cytogenetic risk in CLL remains incompletely characterized. In this study, peripheral blood mononuclear cells (PBMCs) from 48 CLL patients were analyzed. The analyzed PBMC fractions were enriched in leukemic B cells, with an estimated median tumor content above 85–90%. Cytogenetic profiles were obtained by conventional karyotyping following in vitro immunostimulation with DSP30 and interleukin-2 and classified according to ERIC and Döhner criteria. Telomere length was assessed by quantitative PCR, and CHEK1 and CHEK2 expression levels were quantified by RT–qPCR. Molecular parameters were compared across cytogenetic risk groups. Distinct molecular profiles were observed across cytogenetic categories. Favorable-risk CLL cases showed preserved telomere length, low CHEK1 expression, and maintained CHEK2 levels. Intermediate-risk cases, predominantly characterized by trisomy 12, exhibited moderate telomere shortening accompanied by increased CHEK1 expression and partial reduction of CHEK2. High-risk CLL cases, defined by del(11q), del(17p), or complex karyotypes, displayed pronounced telomere shortening, marked CHEK1 upregulation, and strong suppression of CHEK2. Telomere length was inversely correlated with cytogenetic risk (Spearman’s ρ = −0.68, p < 0.0001), and the CHEK1/CHEK2 expression ratio increased progressively with genomic complexity. These findings indicate that telomere length and CHEK1/CHEK2 expression patterns are closely associated with cytogenetic risk in CLL and may provide complementary biological information for risk stratification. Full article

Background and Objectives: Although conventional semen analysis remains central in male infertility evaluation, the biological relationship between sperm morphology and genomic integrity remains incompletely defined. Sperm DNA fragmentation (SDF) has emerged as a clinically relevant marker of genomic instability; however, its relationship with composite morphological indices of spermatogenic dysfunction remains debated. This study aimed to evaluate the relationship between sperm DNA fragmentation assessed in the post-swim-up fraction and composite sperm morphological indices derived from raw semen, using a multivariable analytical framework that accounts for conventional semen parameters. Materials and Methods: This observational study included 183 semen samples from men undergoing fertility evaluation. SDF was assessed using a sperm chromatin dispersion (SCD)-based assay in the post-swim-up fraction. Sperm morphology was evaluated in raw semen according to World Health Organization criteria, and composite morphological indices, namely the Teratozoospermia Index (TZI), Sperm Deformity Index (SDI), and Multiple Anomalies Index (MAI), were calculated. Associations were examined using Spearman correlation and multivariable linear regression models adjusted for sperm concentration and progressive motility. Exploratory distributional analyses were performed across clinically defined SDF categories. Results: Bivariate analyses demonstrated weak, non-significant positive correlations between SDF and all composite morphological indices. None of the morphological indices independently predicted SDF after adjustment for sperm concentration and progressive motility in multivariable regression models. In contrast, sperm concentration showed a consistent inverse association with SDF. Distributional analyses revealed substantial overlap between morphological severity and SDF categories, indicating heterogeneity in the co-occurrence of structural abnormalities and DNA fragmentation at the individual sample level. Conclusions: Composite sperm morphological indices were not independently associated with sperm DNA fragmentation after adjusting for quantitative semen parameters in the present analytical framework. These findings suggest that structural abnormalities and genomic instability may capture complementary aspects of male infertility rather than representing interchangeable markers. SDF assessment may therefore provide complementary diagnostic information beyond morphology-based evaluation, particularly in assisted reproductive contexts. Full article

Background/Objectives: Exposure of cells to ionizing radiation induces isolated DNA lesions, including single-strand breaks, apurinic/apyrimidinic sites, and oxidized bases, as well as clustered damages of different complexity. The latter types of damage are difficult to repair, and the failure to process them accurately and efficiently is related to the induction of mutagenesis, genomic instability, cancer, and aging. Since various types of clustered lesions may occur simultaneously after radiation exposure, leading to a complex architecture of DNA damage, the study of the concomitant formation and the removal kinetics of clustered DNA damage is important to determine the mutagenic and, consequently, the carcinogenic potential of ionizing radiation. Methods: With the aim of capturing real-time coexisting lesion types and assessing the repair kinetics of clustered damages, the simultaneous determination of double-strand breaks, apurinic/apyrimidinic site clusters, and oxypurine clusters induced by γ-irradiation of Saccharomyces cerevisiae yeast cells was performed immediately after exposure and at time intervals during incubation in Liquid Holding Recovery conditions. Results: Ionizing radiation induced lethal and mutagenic events, leading to a dose-dependent linear increase in double-strand breaks, apurinic/apyrimidinic site clusters, and oxypurine clusters. The kinetic study showed that double-strand break frequencies declined during Liquid Holding Recovery, although a transient increase was detected at early time points. At 160 Gy, apurinic/apyrimidinic site clusters repair was evident, whereas at 400 Gy the frequency of damage increased before returning to the initial value at 24 h. In contrast, oxypurine clusters showed no net increase in repaired lesions over 24 h. Conclusions: The complex nature and topological characteristics of ionizing radiation-induced clustered DNA damage may influence lesion processing. Also, ionizing radiation may disrupt redox cellular homeostasis, leading to DNA damage and delayed effects. Full article