Search Results (794)

Background and Objectives: The aim of this study is to assess the mismatch repair (MMR) status and immunohistochemical changes in cases of recurrent endometrial cancer following primary surgery and to evaluate the impact of these changes on prognosis. Materials and Methods: Thirty-one patients diagnosed with endometrial cancer who underwent surgery and had pathologically confirmed recurrences were evaluated. Changes in MMR protein expression, estrogen receptor (ER)/progesterone receptor (PR), and p53 expression in primary surgery and recurrent tumor tissues were assessed using immunohistochemical methods. Prognostic factors influencing these parameters and survival data were investigated. Results: In the assessment of recurrent materials, there were four cases where the MLH-1&PMS-2 staining status changed from intact to loss and four cases that changed from loss to intact. No changes were observed in regard to MSH-2 &MSH-6 staining. The ratios of pMMR and dMMR following the primary surgery were 55% (n = 17) and 45% (n = 14), respectively. Four cases transitioned from pMMR to dMMR, and four cases transitioned from dMMR to pMMR. After recurrence, changes in the ER, PR, and P53 status were observed in seven, three, and three patients, respectively. Conclusions: Changes in the MMR status, receptors, and P53 were observed. It is necessary to re-evaluate prognostic parameters via biopsies in recurring cases and to adjust rescue treatments accordingly. Full article

Gene amplification resulting from double strand breaks (DSBs) is a typical genetic alteration in tumorigenesis and drug-resistant progression. Amplified oncogenes and drug-resistant genes are present on extrachromosomal DNAs (ecDNAs), or chromosomal homogeneously staining regions (HSRs). Considering the role of mismatch repair (MMR) as a sensor of DSBs, we hypothesized that MMR may be involved in gene amplification. We used two MTX-resistant HT-29 colorectal cancer cell lines, which served as models with amplified genes mainly in HSRs or ecDNAs. Expression of MSH2, a key protein in MMR, was increased following the acquisition of MTX-resistant. MMR inhibition was achieved by depleting MSH2. Suppression of MMR led to decreased copy numbers of amplified genes as well as the quantity of ecDNAs and HSR. This was caused by the decreased efficiency of DSBs repair, which resulted from the reduced ability of MMR to recruit DSBs repair proteins. Additionally, it accelerated the formation of micronuclei (MN)/nuclear buds (NBUDs), which functioned to eliminate the amplified genes. Furthermore, the suppression of MMR was capable of inhibiting cell proliferation and enhancing MTX-sensitivity in ecDNA-containing cells. Conversely, suppression of MMR had no effect on gene amplification in HSR-containing cells. Our findings demonstrate that MMR plays a pivotal role in gene amplification through mediating DSBs repair pathways and facilitating the formation of MN/NBUDs in ecDNA-containing cells. MMR is likely to emerge as a prime therapeutic target worthy of in-depth exploration in future clinical investigations. 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

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

Background: POLE-mutated endometrial carcinomas are associated with exceptionally favorable outcomes, forming the basis for treatment de-escalation in early-stage disease. Nevertheless, rare adverse clinical courses have been reported. This study describes an unusual case of late metastatic recurrence in a POLE-mutated tumor and provides a review of similar cases in the literature. Methods: We present a detailed clinical, radiological, pathological, and molecular description of a patient who developed metastatic recurrence 16 years after initial surgery. A systematic literature search was conducted to identify reports of recurrence, progression, or cancer-related death in POLE-mutated endometrial carcinoma, with extraction of recurrence patterns, genomic features, treatment, and outcomes. Results: The patient experienced sequential pulmonary, cerebral, and leptomeningeal metastases despite harboring a canonical POLE hotspot mutation, proficient mismatch repair status, wild-type TP53, no additional known driver mutation beyond PTEN alterations. The literature review identified a small number of similarly adverse cases. Reported recurrences were heterogeneous, though distant and occasionally central nervous system involvement were noted. Conclusions: While POLE-mutated tumors overall retain an excellent prognosis, rare cases may follow an atypical and aggressive course. Improved molecular annotation and integrated risk-stratification models are needed to better identify this minority of higher-risk patients. Full article

Background/Objectives: The treatment of gynecologic malignancies has moved towards a precision medicine model with an approach to prognostication and management based on biomarker testing. The objective of this review is to describe the current landscape of biomarker testing in gynecologic cancer including clinical implications and the approach to testing. Methods: A review of the literature was performed that included published clinical trials which utilized biomarker testing as part of inclusion/exclusion criteria, prospective trials that addressed the application and scoring of biomarkers utilized in gynecologic cancers, prospective clinical trials that utilized biomarker findings to determine management, and national or society guidelines for the scoring of biomarkers and treatment of gynecologic cancers. Findings: The use of biomarker testing as part of the management of gynecologic cancers is the standard of care for both treatment and prognostication. In endometrial cancer, biomarker testing has been incorporated into the staging system and impacts treatment in both the upfront and recurrent setting. Specific biomarkers of interest for endometrial cancer include estrogen receptor (ER), progesterone receptor (PR), DNA Polymerase Epsilon (POLE), mismatch repair proteins (MMR), and Human Epidermal growth factor Receptor-2 (HER2). In ovarian cancer, biomarker testing is primarily utilized in the recurrent setting to guide management of platinum-resistant ovarian cancer with a specific focus on targeted therapy utilizing antibody drug conjugates (ADCs) and immunotherapy. Immunotherapy has become an important component of therapy for cervical cancer and Programmed death-ligand 1 (PD-L1) testing is a key biomarker in determining treatment. Conclusions: The utilization of appropriate assays and processes to accurately assess the status of biomarkers in the pathology laboratory is crucial to the treatment of gynecologic malignancies in the precision medicine era. 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

Carcinoma showing thymus-like differentiation (CASTLE) is a rare malignancy arising in the thyroid or neck, with an uncertain cellular origin that complicates both diagnosis and treatment. To better understand its molecular underpinnings and identify potential therapeutic avenues, we conducted integrated whole-exome and transcriptome sequencing on six CASTLE and six thymic carcinoma samples. Whole-exome sequencing (WES) was performed on all 12 samples, while RNA sequencing was successful for 1 CASTLE and 6 thymic carcinoma samples. Our analysis included somatic mutation profiling, mutational signature deconvolution, differential gene expression, and characterization of tumor microenvironment for the cases with available data, with comparisons to genomic data from other thyroid cancers. CASTLE tumors demonstrated a higher median tumor mutational burden than thymic carcinoma and lacked the common BRAF and RAS mutations typically found in thyroid cancers. They harbored alterations in genes such as TRHDE, cilia-associated genes (ANKS6, CFAP46, DNAH6), and Wnt signaling components (TRRAP, BCL9L), as well as mutational signatures suggestive of mismatch repair deficiency and oxidative damage. MSIsensor-pro analysis of the WES data provided support for the potential for mismatch repair deficiency in a subset of CASTLE samples. Exploratory transcriptomic analysis from a single CASTLE case showed downregulation of thyroid follicular markers and an “immune-hot”, lymphocyte-rich microenvironment, closely resembling that of thymic carcinoma. While these findings require validation in larger cohorts, they support a thymic origin for CASTLE and establish its molecular distinction from follicular-derived thyroid cancers. The immunogenic tumor landscape suggests that immune checkpoint inhibitors, particularly those targeting PD-1/PD-L1, may be a promising therapeutic strategy, alongside emerging targets for precision oncology. Full article

Chronic wounds are ulcers unable to heal due to vascular insufficiency, diabetes, or obesity. Adipose-derived stromal cells (ASCs) are promising candidates for regenerative therapies owing to their pro-healing and angiogenic properties. Compared with autologous approaches, allogeneic ASC therapies offer the opportunity for off-the-shelf use, enabling immediate availability, standardized qualification, and consistent potency. Gelatin sponges have been shown to reprogram ASCs toward a highly angiogenic phenotype. However, because this activation also modulates some immune-related genes, including MHC, its impact on immunogenicity is unknown and could be critical for allogeneic applications. This study evaluated whether ASCs embedded in a gelatin sponge could be used in an allogeneic setting for ischemic wound repair. To mimic clinical allogeneic conditions, a controlled MHC mismatch was introduced in a rat ischemic wound model: donor ASCs carrying RT1^n or RT1^l haplotypes were implanted into outbred RT1^a recipients. Embedding ASCs within the gelatin sponge upregulated MHC class I but not class II expression, without inducing systemic or local alloreactivity. Serum acute-phase proteins remained unchanged, and no CD3⁺ T-cell infiltration was detected. Histology confirmed efficacy on ischemic wounds, with increased granulation tissue thickness, red blood cell infiltration, and enhanced vessel density versus controls. Allogeneic ASCs activated by a gelatin scaffold promote wound revascularization without eliciting immune rejection, supporting their development as standardized, off-the-shelf therapies for chronic ischemic wounds. Full article

The widespread occurrence of macrolide antibiotics (MLs) in aquatic environments poses potential ecological risks; however, the interactive effects of MLs, especially combined MLs on microalgae and their removal mechanisms, remain poorly understood. This study investigated the removal efficiency, physiological–biochemical responses, and molecular mechanisms of Chlorella pyrenoidosa under single and combined exposure to erythromycin (ERY) and roxithromycin (ROX) over 14 days. The results demonstrated that antibiotic removal efficiency was concentration-dependent and higher in low-concentration treatment. The removal rates of ERY (0.15 mg/L) and ROX (0.02 mg/L) reached 100% and 66.86%, respectively. Notably, in the combined low-concentration group, the presence of ROX promoted the degradation of ERY, with the removal being 11.06–14.77% higher than in single treatment. Conversely, in high-concentration combined treatments (1.63 mg/L ERY + 0.5 mg/L ROX), the removal of ERY was inhibited and the removal of ROX was comparable with the corresponding single treatment. High-concentration treatment groups and combined-treatment groups significantly inhibited microalgae growth and total chlorophyll content, modified the chlorophyll composition, and induced severe oxidative stress. Correlation analysis revealed that antibiotic removal was positively correlated with cell density, chlorophyll content, CAT, CYP450, and GST activities while negatively correlated with SOD, ROS, and MDA. Transcriptomic analysis revealed significant disruption of xenobiotic metabolism pathways, photosynthesis-related processes, and DNA replication/mismatch repair pathways. Key genes involved in stress signaling (e.g., MKK3, MPK3), detoxification (e.g., CYP97, GSTP), and photosynthesis (e.g., HemL) were differentially regulated, providing molecular evidence for the observed physiological responses and removal behaviors. These findings provide valuable insights for the ecological risk assessment of antibiotic mixtures and the development of microalgae-based wastewater treatment technologies. Full article

Chlorinated paraffins (CPs) are widely used, structurally complex mixtures of chlorinated alkanes whose ecological risks in aquatic ecosystems have raised increasing concern. However, the toxic effects and molecular mechanisms of CPs on primary aquatic producers remain poorly understood. In this study, we used the eukaryotic green algae Chlorella sp. and the prokaryotic cyanobacterium Microcystis aeruginosa (M. aeruginosa) as test organisms to systematically investigate the effects of CPs with different carbon chain lengths, namely short-chain CPs (SCCPs), medium-chain CPs (MCCPs), and long-chain CPs (LCCPs), on algal growth, photosynthetic pigment content, antioxidant systems, cellular ultrastructure, and the underlying molecular responses. Our results showed that CPs toxicity to algae is significantly dependent on both CPs carbon-chain length and algal species. Exposure to 1.0 mg/L SCCPs for 96 h produced a growth inhibition of Chlorella sp. of 14.45%. CPs’ exposure significantly altered algal Chl-a content and elicited antioxidant defense responses, and affected the synthesis and extracellular release of MC-RR and MC-LR in M. aeruginosa. Ultrastructural observations revealed cell surface wrinkling and deformation in both Chlorella sp. and M. aeruginosa. Chlorella sp. additionally exhibited thylakoid disintegration and plasmolysis. Transcriptomic analysis indicated that CPs with different chain lengths significantly downregulated genes in Chlorella sp. associated with DNA replication and mismatch repair, suggesting impairment of replication initiation and elongation and compromised genome stability. Concurrently, genes encoding photosynthetic antenna proteins and carbon fixation were upregulated. In M. aeruginosa, CPs exposure markedly disturbed energy metabolism pathways, including glycolysis/gluconeogenesis and oxidative phosphorylation, which were generally downregulated. This study provides a comparative assessment of CPs’ toxicity between the eukaryotic algae Chlorella sp. and the prokaryotic algae M. aeruginosa, revealing that toxicity is co-determined by carbon chain length and algal species. Additionally, it provides critical toxicological data and establishes a theoretical foundation for the scientific assessment of the aquatic ecological risks posed by CPs with different carbon chain lengths. Full article

Background and Objectives: Immunohistochemistry (IHC) is a keystone in gastric cancer (GC) management, allowing treatment customization, including for advanced or metastatic diseases. This review aims to evaluate the critical role of IHC markers, analyzing their efficiency in molecular subclassification and prediction of response to gastric cancer-targeted therapies, while also describing state-of-the-art IHC techniques and perspectives. Results: The major challenges for the GC management were structured in two main sections, as follows: (i) the current paradigm of gastric neoplasia diagnosis, which includes subsections related to the methodological and morphological foundations, the epidemiological dynamics, and risk factors, as well as differential diagnosis of poorly differentiated tumors; and (ii) the progress in 3,3′-diaminobenzidine (DAB) application and advanced reagents in gastric cancer immunohistochemistry. Discussion: Considering the role of IHC and DAB, the following topics were successively addressed in seven sections: GC key biomarkers, such as human epidermal growth factor receptor 2 (HER2), programmed death-ligand 1 (PD-L1), and DNA replication mismatch repair (MMR) system, allow direct correlation between tissue morphology and protein expression; intestinal and gastrointestinal differentiation markers; emerging and aggressive histological subtypes; epithelial–mesenchymal transition, E-cadherin, and the process of tumor budding; implementation of innovative procedures in gastric cancer immunohistochemistry; and automation, quality control, and sustainability in the pathology laboratory. Perspectives: The main directions were focused on the integration of artificial intelligence (AI) algorithms for digital quantification of the IHC signal and also on the expansion of panels to new targets, such as Claudin 18.2 (CLDN 18.2), which redefines treatment approaches in advanced stages. Conclusions: Although faced with technical and biological limitations, immunohistochemistry remains indispensable in modern gastric oncology. The evolution towards digital pathology and the refinement of scoring criteria will transform IHC from a complementary test into a visual tool that is essential for personalizing oncological treatment. Full article

Microsatellite instability (MSI) testing is frequently used to screen patients for the early detection of Lynch syndrome, the most common hereditary colorectal cancer syndrome. MSI testing compares microsatellite repeat lengths in tumor DNA with those in matched normal tissue from the same patient. Therefore, precise sample identification is critical for obtaining reliable test results. The Penta-C and Penta-D pentanucleotide markers are widely used for sample identification in MSI testing. We investigated instability, defined as allelic mismatches or shifts, discordant fragment sizes, or the appearance of alleles in tumor DNA that were absent in the corresponding normal DNA, in the Penta-C and Penta-D loci across 2609 paired colorectal tumor and matched normal tissue or blood DNA samples. The allele sizes of both markers did not match in 0.3% of microsatellite-stable (MSS) and 12.3% of microsatellite instability-high (MSI-H) patients (p < 0.001, difference in proportions, 12.0% (95% CI, 8.9–15.1%)). Non-matching allele sizes in 12.3% of the MSI-H tumors suggest that other repeat markers may also be unstable and not suitable for sample identification in these tumors. Full article

Climate change has transformed extreme heat from a transient environmental perturbation into a persistent threat that worsens cardiovascular outcomes. Epidemiological studies show a lag between heat exposure and peaks in acute myocardial infarction (AMI) mortality, indicating a subclinical, latent vulnerability. This latent vulnerability likely originates at the level of the microvasculature, as cardiac microvascular endothelial cells (CMECs)—the heart’s primary “thermal sensors”—are uniquely susceptible to proteotoxic stress. The existing literature suggests that this sensitivity may be mediated by thermodynamically gated activation of the activating transcription factor 6 (ATF6) branch of the unfolded protein response (UPR), which could function as a master switch that reprograms endothelial cells from a pro-repair to a maladaptive, anti-angiogenic phenotype. However, this mechanism is derived primarily from preclinical studies and lacks direct validation in humans. The resulting “endothelial memory” is sustained by epigenetic modifications and organelle uncoupling; it persists beyond the initial insult and impairs subsequent neovascularization. As a result, ischemia occurs later in a compromised microenvironment, promoting a fibrosis–conduction mismatch that drives infarct expansion and arrhythmic risk. Thus, the post-exposure latent phase emerges as a novel therapeutic window: Precision targeting of the ER stress–angiogenesis axis during this period offers a focused strategy to protect heat-vulnerable individuals Full article

Urachal carcinoma is a rare and aggressive malignancy for which standardized management remains limited, particularly in patients with locally advanced and node-positive disease. We report the case of a 34-year-old woman with urachal adenocarcinoma involving the bladder dome and radiographically suspicious pelvic lymph nodes who underwent robot-assisted partial cystectomy with urachal resection and extended bilateral pelvic lymph node dissection. Because there was no clinical, radiologic, or intraoperative evidence of umbilical involvement, the umbilicus was preserved after preoperative counseling and intraoperative confirmation of a negative proximal margin. Final pathology demonstrated a 4.5 cm enteric-type urachal adenocarcinoma, pT3a pN2 (2/17), with lymphovascular invasion, perineural invasion, and negative surgical margins. Immunohistochemistry and DNA- and RNA-based next-generation sequencing showed microsatellite stability, mismatch-repair proficiency, low tumor mutational burden, and no actionable genomic alteration. Given the absence of an established adjuvant standard, the multidisciplinary tumor board selected adjuvant FOLFOX as a non-standard postoperative strategy based on the overall clinicopathologic context. The patient remained continent, experienced no postoperative complications or treatment-limiting toxicity, and showed normalization of carcinoembryonic antigen and carbohydrate antigen 19-9 levels. This case provides a carefully contextualized example of transparent surgical reasoning and restrained multidisciplinary management in a rare malignancy with limited prospective evidence. Full article