Search Results (2,707)

Background/Objectives: Loss of heterozygosity (LOH) in meningioma has been known for more than two decades. It has been shown that LOH on chromosome 1p36 is an independent marker of meningioma recurrence and progression. ARID1A, a tumor suppressor gene located on chromosome 1p36.11, is part of the chromatin-regulating SWI/SNF complex whose subunits are altered in 20% of cases across all tumor entities. Methods: Using our newly developed indirect enzyme-linked immunosorbent assay (ELISA), we investigated whether tumors with or without LOH 1p differ in ARID1A expression in 61 meningiomas. To study possible links between ARID1A and ARID1B, we tested for LOH 6q in association with LOH 1p using a PCR-based microsatellite approach. ARID1B, another member of the SWI/SNF complex, is located on 6q25.3. Additionally, we compared our ELISA results with immunohistochemistry data staining of ARID1A in tissue sections known to harbor LOH 1p. Results: Our results indicate that meningiomas harboring LOH 1p have significantly lower ARID1A levels compared to tumors without LOH 1p. In free nuclear protein fractions, reductions were up to 32% (CI: 6–58.7%). Interestingly, we found that ARID1A levels were significantly lower in tumors with recurrence and/or multiple localizations. In addition, our analysis of chromosome 6q uncovered a significantly strong correlation between LOH 1p and LOH 6q (p < 0.0001). Conclusions: These results highlight the importance of ARID1A in meningioma malignization and indicate for the first time functional evidence for LOH 1p. Full article

The objectives of this paper were to assess the genetic diversity, population structure, genetic differentiation, and phylogenetic relationships among seven duck populations using 14 microsatellite (MS) markers. This paper included 176 individuals representing seven duck populations of Bangladesh: indigenous duck (BLD), Nageswari (NAG), Rupali (RUP), Jinding (JIN), Pekin (PEK), BAU Black and White (BWC), and BAU White (WHC). A total of 133 alleles were observed with a mean of 9.50 alleles per locus. Genetic diversity was evaluated using measures such as allele frequency, observed and expected heterozygosity, and Shannon’s information index with average values of 5.44 ± 0.31, 0.59 ± 0.02, 0.64 ± 0.02, and 1.28 ± 0.05, respectively. Population differentiation and inbreeding analysis (F-statistics) indicated moderate genetic diversity and a slight degree of inbreeding across populations. Analysis of molecular variance indicated that 75% of the total genetic diversity was attributable to the within-population variation, whereas 9% and 16% were attributed to the variation among individuals and population differentiation, respectively. Indigenous duck populations (BLD, NAG, and RUP) had a close genetic relationship with JIN ducks and an intermediate relationship with two crossbreds (BWC and WHC), and the highest genetic distance was observed with PEK ducks. Neighbor-joining phylogenetic analysis revealed that the Bangladeshi indigenous duck populations formed a single cluster, while the two crossbreds (BWC and WHC) and PEK exhibited their distinct genetic identities in separate clusters. Furthermore, structure analysis at K = 2 to 5 confirmed the distinct genetic architecture (ΔK = 4.00) of the studied duck populations. This paper provides important insights into genetic diversity measures and population differentiation that will be helpful in future genetic improvement, conservation initiatives, and the design of appropriate breeding programs. Full article

Populations of several billfish species are declining due to overfishing and bycatch, and fundamental aspects of their biology and population dynamics remain poorly understood. We provide the first assessment of the population genetic structure of longbill spearfish (Tetrapturus pfluegeri) in the western Atlantic Ocean. We screened variation at 12 nuclear microsatellite loci (n = 144) and mitochondrial DNA control region sequences (mtCR, n = 177). Both marker types revealed three genetically differentiated clusters, with mean values for microsatellites showing differentiation of F_ST = 0.136 and D_EST = 0.201, and for mtCR F_ST = 0.645. Microsatellite markers demonstrated moderate-to-high genetic diversity, with a mean allelic richness of 6.73 alleles per locus, moderate heterozygosities (Ho = 0.446, He = 0.604), and a positive inbreeding coefficient (F_IS = 0.22) across the three sample collection sites. The overall estimated effective population size was 789.2 (95% CI: 246.7–∞). The mtCR exhibited 96 haplotypes, with high haplotype (0.989 ± 0.003) and nucleotide (0.025 ± 1.3%) diversities. We found higher mean relatedness within clusters than among them, supporting the interpretation of population subdivision and the Wahlund effect. Tajima’s D and Fu’s Fs were negative across all localities, with significant values observed along the Brazilian coast but not in the Caribbean Sea. These neutrality test results, together with low Harpending’s raggedness indices from DNA sequence mismatch distributions, are consistent with historical demographic expansion. Our findings establish a genetic baseline for fishery monitoring and management, contributing to the conservation of T. pfluegeri populations in the western Atlantic Ocean. Full article

Colorectal cancer (CRC) shows consistent sex-related differences in incidence, anatomic distribution, molecular subtype, immune context, and clinical outcome. However, these differences are often discussed through broad parallel themes such as hormones, genetics, or the microbiome, rather than through the biological settings in which sex meaningfully modifies tumor behavior. This review argues that sex is most informative in CRC when treated as a contextual modifier whose relevance emerges only after integrating tumor sidedness, mismatch repair status, oncogenic background, immune ecology, and age at onset. The clearest signals arise from interaction-based contexts, particularly when sex is interpreted together with tumor sidedness and dMMR/MSI-H or BRAF-linked disease states. Current evidence indicates that women are enriched for proximal or right-sided, microsatellite instability-high, mismatch repair-deficient, CpG island methylator phenotype-high, and BRAF-associated CRC, whereas men more often present with distal disease and a higher overall burden. Mechanistic studies further show that sex-related differences extend beyond hormone exposure to include KRAS–STAT4–KDM5D signaling, site-specific immune-checkpoint programs, metabolic phenotypes, epigenetic biomarker variation, and microbiota–hormone crosstalk. These effects are most evident in defined clinical niches, particularly right-sided CRC, mismatch repair-deficient disease, BRAF-mutated metastatic CRC, and early-onset CRC. A sex-aware, subtype-aware, and location-aware framework therefore offers a more clinically useful interpretation of CRC heterogeneity than descriptive male-versus-female comparisons alone. Full article

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy worldwide, with molecular heterogeneity complicating early detection and treatment stratification. The insulin-like growth factor (IGF) axis interacts bidirectionally with immune regulatory mechanisms in ways that shape tumor phenotype and therapeutic vulnerability. This review synthesizes evidence on how IGF signaling orchestrates immunosuppression through effects on tumor-associated macrophages, regulatory T cells, and myeloid-derived suppressor cells, while inflammatory cytokines reciprocally modulate IGF bioavailability. Three mechanistic principles emerge: IGF binding protein 2 (IGFBP-2) functions as a central coordinator linking growth factor signaling to immune evasion through STAT3-dependent pathways driving M2 macrophage polarization and regulatory T cell differentiation; IGF–immune crosstalk varies considerably across molecular subtypes, with microsatellite-stable tumors exhibiting high reliance on IGF-I receptor-mediated immune silencing; and local paracrine IGF production increasingly dominates over systemic regulation as disease progresses. These bidirectional connections establish self-reinforcing circuits that determine whether tumors remain immunologically responsive or develop immune exclusion. Multi-marker panels incorporating IGFBP-2 alongside complementary biomarkers have shown improved diagnostic performances for early CRC detection, underscoring the need for the large-scale prospective clinical evaluation of IGF network components as biomarkers for CRC in diverse populations. The convergence of IGF signaling with checkpoint regulation suggests that combined targeting warrants investigation for resistance in tumors lacking effective immunotherapy options. Full article

Background/Objectives: MSS-CRC comprises a heterogeneous group of tumors generally considered “immune cold” due to limited neoantigen generation and T-cell exclusion or inactivation. Current evidence indicates that the composition of T and B immune cells within the tumor microenvironment represents a prognostically relevant factor, significantly associated with both tumor expression profiles and molecular subtypes. Methods: We conducted an exploratory analysis to identify prognostically relevant immune cell components in this group of tumors and to investigate corresponding differences in RNA-based bulk expression and high-resolution spatial transcriptomic profiles. Results: A total of 254 localized mismatch repair-proficient colorectal cancer cases were evaluated. Our findings revealed PD-L1 expression as a robust independent prognostic biomarker associated with favorable outcomes in this specific population. Bulk RNA expression analysis showed that PD-L1-negative tumors exhibited an expression profile consistent with abundant cancer-associated fibroblast infiltration, increased matrix stiffness, and impaired immune activation—features consistent with tumor progression and poorer clinical outcomes. In contrast, PD-L1-positive tumors displayed stromal programs enriched in immune activation and controlled remodeling, consistent with an immunologically active microenvironment. Spatial transcriptomics added an additional layer of evidence, revealing that epithelial to mesenchymal transition-related programs can dominate stromal niches in PD-L1-negative tumors, particularly within macrophage-enriched stromal regions. Conclusions: Our observations suggest an association between PD-L1 expression on immune cells and immune-activated versus mesenchymal-dominant states, potentially occurring within macrophage-enriched stromal niches. These results provide insight into the biological mechanisms underlying disease progression and highlight tumor-associated macrophages as a potential therapeutic target to overcome immune resistance, particularly in PD-L1-negative MSS-CRC tumors. Full article

In Africa, hares (Lepus spp.) show a high variability in external phenotypes. Species identification, delimitation, and distinction are difficult, due to the generally shallow evolutionary divergence of species, high intraspecific phenotypic variability, potentially complex reticulate evolutionary scenarios, and absence of relevant data across large areas. Our microsatellite and mitochondrial (mt) CR1 sequence data of hares from Tunisia with four different coat color morphs revealed high levels of gene flow both in nuclear and mt gene pools but no relevant partitioning of genetic variability parallel to the four coat color types. Nuclear and mt gene pool correspondence was at a very low level, and no phylogenetic gaps were observed in the mtDNA. Our results indicate only one hare species with different coat colors in Tunisia that shows no signals of reticulate evolution or incipient speciation. Because of potential reticulate evolutionary signals, especially in the mtDNA and the probably high adaptive significance of coat colors and patterns, external phenotypes combined with mtDNA alone may not serve as good proxies for species delimitation in hares from wide ranges in Africa. Combined nuclear and mtDNA population genetic and phylogenetic data allow more complex inferences on current and ancestral evolutionary processes for species identification and delimitation. Full article

Understanding the genetic diversity and population structure of Cucurbita species is essential for effective germplasm conservation and the development of improved cultivars. This study aimed to evaluate the genetic diversity, population structure, and genetic relationships among accessions of C. pepo, C. moschata and C. maxima and their interspecific hybrids (Tetsukabuto hybrid C. maxima × C. moschata). A total of 92 accessions were analyzed using 22 polymorphic simple sequence repeat (SSR) markers selected from previous studies due to their high polymorphic information content (PIC). Genetic diversity parameters were estimated, and population structure was inferred using Bayesian clustering, complemented by dendrogram and principal component analysis (PCA). All markers were successfully amplified in C. pepo, C. moschata, C. maxima, and the hybrids, with polymorphic information content (PIC) values ranging from 0.191 (CMTm232) to 0.448 (CMTm48) and average of 0.274. The AMOVA analysis showed that 50% of the total variation was attributed to differences both within and among groups. PCA revealed clear genetic differentiation among the analyzed species, with C. maxima and hybrid accessions clustering closely and exhibiting lower genetic dissimilarity. In contrast, C. pepo displayed greater genetic divergence, supporting its distinct evolutionary trajectory. According STRUCTURE analysis the accessions can be divided into four subpopulations, which are closely related to the species. PCA and dendrogram showed similar results for genetic structure of Cucurbita germplasm; C. maxima and hybrid accessions clustering closely and C. pepo as a distinct group. These findings provide valuable insights for breeding programs, germplasm management, and conservation strategies aimed at preserving genetic diversity and exploiting interspecific variation. Full article

Tilia cordata Mill. is a long-lived, ecologically important broadleaved tree species that maintains high genetic diversity despite habitat fragmentation and historical range shifts. In this study, we assessed genetic diversity, clonal structure, and population differentiation in six genetic conservation units (GCUs) in Lithuania using nuclear microsatellite markers. A total of 1109 individuals were successfully genotyped, revealing 979 unique multi-locus genotypes, with 17% of individuals assigned to clonal lineages. Clonal groups were generally small and spatially restricted, indicating localized vegetative regeneration. Genetic diversity was high across all populations, with similar levels of observed and expected heterozygosity, consistent with predominantly outcrossing reproduction. Juvenile cohorts exhibited slightly higher allelic richness and latent genetic potential compared to mature trees, suggesting effective regeneration and maintenance of genetic variation. Genetic differentiation among populations was low but significant (F_ST = 0.013; G″_ST = 0.051), with evidence of clustering corresponding to provenance regions. High gene flow (Nm ≈ 10) likely contributes to weak population structure, although regional differentiation persists. The results demonstrate that Lithuanian T. cordata populations retain a robust genetic framework, combining high within-population diversity with moderate structuring. These findings highlight the importance of conserving multiple GCUs and implementing genetic monitoring to ensure long-term population viability under changing environmental conditions. Full article

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy. Next-generation sequencing (NGS) enables molecular characterization and may identify clinically actionable alterations; however, real-world multicenter data linking genomic subgroups to survival outcomes remain limited. We aimed to characterize the molecular landscape of NGS-tested PDAC in a Turkish multicenter cohort and evaluate the association of key molecular alterations, including KRAS status and KRAS variant subgroups, with survival outcomes. Methods: We conducted a multicenter retrospective cohort study including patients with pathologically diagnosed PDAC between 2017 and 2025 who underwent tumor-based NGS in routine clinical practice. Overall survival (OS) was calculated from the date of metastasis, defined as the date of diagnosis for de novo metastatic disease and the date of first documented distant recurrence for recurrent cases. Progression-free survival (PFS) was calculated from the initiation of first-line systemic therapy for metastatic disease to progression or death. Survival was estimated using the Kaplan–Meier method and compared using the log-rank test. Multivariable Cox proportional hazards models were constructed for OS and PFS using clinically relevant covariates selected a priori. Results: A total of 98 patients underwent molecular profiling, and survival analyses were performed in 92 patients with available OS/PFS data. KRAS mutations were detected in 83.7% (82/98) of patients, with predominant variants G12D (47.6%), G12V (30.5%), and G12R (12.2%). TP53 mutations were present in 59.2% (58/98) of tumors, and all tumors were microsatellite stable. Tumor mutational burden data were available for 72 patients; the median TMB was 3.83 mutations/Mb, and 15.3% of evaluable tumors had a TMB ≥ 10 mutations/Mb. Excluding KRAS, clinically actionable alterations were identified in 4.1% of patients, whereas an additional 32.7% harbored potentially actionable or investigational alterations. Median OS was 14.0 months (95% CI, 11.7–16.3), and median PFS was 6.0 months (95% CI, 4.3–7.7). In unadjusted analyses, OS and PFS did not differ significantly according to KRAS mutation status (OS, p = 0.967; PFS, p = 0.652), TP53 mutation status (OS, p = 0.404; PFS, p = 0.510), or KRAS variant subgroup (OS, p = 0.332; PFS, p = 0.194). In multivariable Cox analyses, KRAS mutation status was not independently associated with OS (aHR 1.13, 95% CI 0.56–2.28; p = 0.727) or PFS (aHR 1.09, 95% CI 0.59–2.01; p = 0.780), whereas ECOG performance status remained the strongest adverse clinical factor. Conclusions: In this multicenter real-world PDAC cohort, the molecular landscape was dominated by KRAS and TP53 alterations, whereas clinically actionable non-KRAS alterations were identified in only a minority of patients. After adjustment for major clinical covariates, KRAS mutation status was not independently associated with OS or PFS. Molecular profiling may still be useful for identifying uncommon potentially targetable alterations; however, larger clinically annotated multicenter studies are needed to better define its prognostic and treatment-directing value in routine practice. 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

Colorectal cancer is a heterogeneous malignancy characterized by alterations in oncogenic signaling pathways and epigenetic mechanisms involved in gene regulation. Aberrant activation of the Wnt/β-catenin pathway represents a central molecular event in colorectal tumorigenesis, while histone-associated epigenetic modifications may contribute to tumor progression and variability. This study aimed to investigate the relationship between Wnt pathway activation and histone H3 lysine 27 trimethylation in colorectal cancer and to examine their associations with clinicopathological and molecular characteristics. A retrospective observational study was performed on 83 colorectal adenocarcinoma cases using immunohistochemical evaluation of nuclear β-catenin and H3K27me3 expression in formalin-fixed, paraffin-embedded tumor samples, together with molecular analysis of KRAS, NRAS, and BRAF mutations and microsatellite instability status. Nuclear β-catenin expression was observed in 39.8% of cases, while H3K27me3 exhibited negative, mosaic, or diffuse nuclear staining patterns. Nuclear β-catenin expression was significantly associated with patient sex and age, whereas H3K27me3 expression patterns were significantly associated with tumor location, histological grade, disease stage, and metastatic status. These results indicate that Wnt pathway activation and H3K27me3-associated epigenetic alterations frequently coexist in colorectal cancer and support the value of integrated molecular and epigenetic assessment. Full article

Erythema gyratum repens (EGR) is a rare figurate erythema strongly associated with internal malignancy and recognized as one of the most specific cutaneous paraneoplastic syndromes. Its recognition is clinically important, as it frequently precedes the diagnosis of an underlying neoplasm. We report the case of an 80-year-old woman who presented to the emergency department with a rapidly progressive, intensely pruritic eruption displaying a characteristic concentric “wood-grain” pattern. Laboratory evaluation revealed iron-deficiency anemia. Contrast-enhanced computed tomography identified a right-sided colonic mass, and colonoscopy with biopsy confirmed adenocarcinoma of the cecum. The patient underwent elective laparoscopic right hemicolectomy with complete tumor resection (pT3N0, microsatellite stable). Following surgery, the cutaneous lesions resolved completely and did not recur during follow-up. This case highlights erythema gyratum repens as a clinically relevant early marker of colorectal cancer and emphasizes the importance of prompt recognition of this distinctive dermatosis to trigger urgent and comprehensive malignancy screening, enabling timely diagnosis and definitive treatment. 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