The American Journal of Pathology

In clinical trials for ulcerative colitis (UC), pathologists assess disease severity through standardized histological indices, including the Geboes Score, Robarts Histopathology Index (RHI), and Nancy Histologic Index (NHI). Despite strong associations with clinical outcomes, histologic scoring suffers from inter- and intra-reader variability, and consensus criteria for histologic remission remain uncertain. Through a consortium approach, we developed an artificial intelligence-based measurement (AIM) tool for scoring histology in UC mucosal biopsies (AIM-HI UC). This model, trained on a large dataset of UC biopsies (N=10,230), utilizes additive multiple instance learning models leveraging PLUTO, a pathology foundation model, that predict each of the Geboes subgrades, from which the Geboes grade-level score, RHI, and NHI can be calculated. Evaluation of this model on a standalone verification set including clinical trial specimens established algorithm non-inferiority and/or superiority relative to standard qualified pathologists through comparison of algorithm-consensus and pathologist-consensus agreement metrics (non-inferior if difference >-0.1, superior if difference >0, inclusive of confidence intervals). AIM-HI UC was determined to be non-inferior to pathologists (N=3) for the prediction of all seven Geboes subgrades, grade-level Geboes, RHI, NHI, histologic improvement (GS<3.1), 2A histologic remission (GS<2A.0), and 2B histologic remission (GS<2B.0). AIM-HI UC was superior to pathologists for several Geboes subgrades (GS 0, GS 1, GS 2B, and GS 5), as well as grade-level Geboes, RHI, and positive percent agreement of 2A histologic remission. The model was shown to be greater than 99% repeatable for all histologic scoring metrics examined. Model-derived scores were shown to strongly correlate with canonical histologic features of inflammation, including the proportion of total epithelium that is inflamed (Spearman r=0.83; p<0.01), the proportion of neutrophils localized within crypt epithelium (Spearman r=0.83, p<0.01), and the amount of mucosal area classified as erosion or ulceration (Spearman r=0.80, p<0.01). Overall, these results suggest that AIM-HI UC has the potential to improve consistency of UC histology interpretation, providing a path toward standardization of UC histology scoring in clinical trials.

Background: Diabetic kidney disease (DKD) remains a leading cause of end-stage renal disease worldwide, characterized by progressive structural and metabolic alterations secondary to chronic hyperglycemia. While numerous type 1 and type 2 rodent models have been developed to study the pathophysiology of DKD, no single model perfectly recapitulates the full clinical spectrum of human disease. The selection of an optimal model depends deeply on the specific research objective, as phenotypic expression and histopathological severity vary significantly across different strains and induction methods. The present study provides a comparative analysis of the renal histological of three widely utilized murine models: the chemically induced streptozotocin (STZ) model and the genetic Akita (type 1) and db/db (type 2) models. Methods: Male STZ-induced (28 weeks post-induction), heterozygous Akita (28 weeks old), and db/db mice at two different age intervals (18-21 and 16-24 weeks old) were assessed. Renal injury was quantified using four light-microscopic parameters: glomerulomegaly, mesangial hypercellularity, tubular vacuolization and arteriolar hyalinosis. Due to observed discrepancies between metabolic and structural findings in the db/db strain, transmission electron microscopy (TEM) was employed for subcellular characterization. Results: All models exhibited significant hyperglycemia and albuminuria. At the light-microscopic level, STZ and Akita mice demonstrated consistent and pronounced renal lesions. In contrast, db/db mice despite increasing albuminuria and obesity, light microscopy revealed heterogeneous and inconsistent histopathological changes. However, TEM analysis of db/db mice kidneys successfully captured early ultrastructural injury, including irregular glomerular basement membrane (GBM) thickening and focal podocyte foot process effacement, which were undetectable by light microscopy. Conclusions: Our findings indicate that the Akita and STZ-induced models exhibit prominent structural alterations detectable by conventional light microscopy, whereas the db/db model requires ultrastructural evaluation by TEM to reliably confirm renal injury. This study underscores the limitation of routine histology in certain type 2 diabetes models and highlights the complementary value of TEM for accurate histopathological characterization. Collectively, the alternative histopathological markers identified herein offer sensitive and readily accessible indices for monitoring early-to-moderate DKD progression, providing a more robust framework for preclinical model selection and therapeutic evaluation in future studies.

Background Diagnostic interpretation of kidney allograft biopsies using the Banff classification remains variable, but the determinants of this variability are not fully defined. We performed a global, fully digital multi-reader study to identify the principal drivers of disagreement in Banff-based assessment. Methods Thirty six kidney transplant biopsies were independently scored by 67 renal pathologists on a standardized digital platform. Readers assessed Banff lesions on hematoxylin and eosin, periodic acid Schiff, and Jones' silver stains; final diagnostic categories were assigned using prespecified Banff-based decision rules. Interobserver agreement was quantified with Gwet's agreement coefficient (AC) statistics. Determinants of diagnostic agreement were evaluated) using pairwise mixed-effects logistic regression, and reader similarity was examined by principal component analysis (PCA) with post hoc molecular annotation. Results Agreement for final diagnostic categories was moderate (Gwet's AC1, 0.55; 95% CI, 0.47 - 0.63). Lesion-level agreement varied substantially, with lowest agreement for selected threshold-dependent inflammatory or semi-quantitative lesions, including interstitial inflammation in areas of IFTA, peritubular capillaritis and arteriolar hyalinosis. Diagnostic concordance differed markedly across biopsies, indicating strong case-level heterogeneity. In pairwise models, differences in active inflammatory and vascular lesion scoring were the strongest correlates of diagnostic disagreement; reader experience and geography contributed minimally. Principal component analysis showed reader variation was organized along two dominant axes: a rejection-calling threshold axis linked mainly to tubulointerstitial inflammatory injury, and a T cell-mediated (TCMR/TI) and antibody-mediated/microvascular (AMR/MVI) inflammation-oriented phenotypic classification axis. Conclusion Interobserver variation in Banff-based kidney transplant biopsy assessment is structured rather than random and driven mainly by how readers threshold and integrate key inflammatory lesion compartments rather than experience or geographic location.

P2Y12 receptor (P2RY12), mainly expressed on platelets, is known for its central role in hemostasis. P2RY12 activation is also involved in cancer development through platelet adhesion to cancer cells supporting immune-evasion, promoting tumor angiogenesis and metastasis, among others. P2RY12 is known as an actionable target, and P2RY12 antagonists are in clinical use for cardiovascular diseases. However, very little data are available regarding the protein expression of P2RY12 in lung carcinomas. We performed immunohistochemical staining for P2RY12 in a cohort of non-small cell lung cancer (NSCLC) samples comprising 320 adenocarcinomas (LUAD) and 158 squamous cell carcinomas (LUSC). Results were evaluated using a dual approach combining microscopic assessment and digital image analysis (QuPath). Results were correlated with clinical-pathological data. We found significantly higher P2RY12 protein expression in LUSC compared to LUAD (p<0.001) via eyeballing (absent/low expression in 21.7% (34/158) and moderate/high expression in 78.3% (124/158) of LUSC cases versus absent/low expression in 98.4% (315/320) and moderate/high expression in 1.6% (5/320) of LUAD cases). Digital analysis yielded similar results. High P2RY12 expression was associated with a significantly better 5-year overall survival rate for the entire cohort (p=0.0048) as well as for the LUAD (p=0.015) and LUSC (p=0.05) subgroups. Furthermore, P2RY12 showed excellent discriminatory performance for classifying carcinomas as LUAD or LUSC, with an AUC of 0.916 in ROC-analysis. High P2RY12 expression is linked to a better prognosis and might serve as a promising novel prognostic biomarker for NSCLC. Its assessment could be implemented in future routine diagnostic workup. At the same time, the data suggest that P2RY12 could also serve as a diagnostic marker for LUSC.

Lung adenocarcinoma a progress from preinvasive lesions to invasive cancer; however, early evolutionary events in adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) remain poorly defined, particularly in East Asian populations enriched for EGFR mutations. We performed whole-exome sequencing on 67 Japanese patients (38 AIS, 29 MIA), including multiregion sampling in 13 cases to identify EGFR as predominant driver (61.2%), followed by RBM10 (19.4%) and TP53 (9.0%). Two evolutionary trajectories emerged: age-related and smoking-driven pathways. In the former, EGFR-mutant tumors frequently exhibited early whole-genome doubling (WGD) (24.4%) with clock-like signature. The smoking-driven pathway, typically involving KRAS mutations, displayed a tobacco-associated signature. Multiregion sequencing revealed that driver mutations (EGFR, KRAS, and MET) were shared trunk events across in situ and invasive regions, while secondary alterations arose subclonally. This study defines the genomic evolution of early lung adenocarcinoma in Japanese patients, identifying two evolutionary trajectories: an age-related pathway with EGFR-linked genome doubling and a smoking-driven pathway involving KRAS mutations. These findings elucidate mechanisms underlying progression from preinvasive lesions to invasive cancer in Asian populations.

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer accounting for most cancer-related deaths worldwide. Despite substantial recent advances in targeted therapies and immunotherapy, the prognosis for advanced-stage disease remains comparably poor, which is why the identification of novel molecular biomarkers as well as therapeutic targets influencing tumor development, progression, and metastasis remain important. This study focusses on SERPINB13, a serine-protease inhibitor expressed in selected tissues that is dysregulated in several tumor entities. However, its role in NSCLC still remains largely unclear. We analyzed SERPINB13 transcription in a cohort of non-small cell lung cancer (NSCLC) cases including both lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) by transcriptome profiling. Epigenetic modifications were assessed via Methylation BeadChips. Additionally, SERPINB13 protein expression was assessed by immunohistochemistry (IHC) in an independent cohort of NSCLC comprising 126 LUSC patients. Correlation analyses were performed to associate SERPINB13 expression with key clinico-pathological parameters, including overall survival and extent of tumor-infiltrating immune cells. To functionally investigate the regulatory influence of peripheral blood mononuclear cells (PBMCs) on SERPINB13 expression in LUSC tumor cells in vitro, we utilized the SERPINB13-expressing LUSC cell line LUDLU-1. Here, gene transcription was analyzed by quantitative real-time PCR (RT-qPCR), confirmed by Western blot on the protein level. Transcriptome analysis revealed a significant upregulation of SERPINB13 in lung squamous cell carcinoma (LUSC) compared to lung adenocarcinoma (LUAD), highlighting a subtype-specific expression pattern. This differential expression was further associated with a distinct epigenetic DNA methylation signature at the SERPINB13 loci in LUSC, suggesting transcriptional regulation via hypomethylation. IHC analysis demonstrated that high SERPINB13 protein expression is significantly associated with prolonged overall survival in LUSC. Notably, SERPINB13 expression was enriched in immune-inflamed ("hot") tumors, characterized by elevated infiltrating lymphocytes and immune activation. Mechanistically, co-culture experiments with PBMCs induced SERPINB13 expression in a LUSC cell line in a dose- and time-dependent manner in the absence of direct cell contact. This suggests that soluble factors secreted by immune cells might play a key role in regulating SERPINB13 expression in the tumor microenvironment. Taken together, SERPINB13 is a novel prognostic indicator in LUSC that is modulated by Immune cells. Further studies are necessary to decipher the crosstalk of Immune cells on the Serpin B13 expressing tumor cells in depth, with regard to a possible interventional strategy. immunomodulatory potential strategies and personalized therapeutic approaches in NSCLC.

We have previously shown that fresh frozen plasma (FFP) and fibrinogen have protective effects in mice with hemorrhagic shock through restoration of endothelial syndecan-1 and reversal of endothelial injury. In the current study, we tested the hypothesis that a combined model of abdominal sepsis and hemorrhagic shock would induce endothelial syndecan-1 shedding and lung injury which could be attenuated by both FFP and fibrinogen. C57BL/6 mice underwent cecal ligation and puncture (CLP) followed by hemorrhagic shock (HS) and fluid resuscitation with lactated Ringers (LR), fibrinogen (5 mg/mouse), and FFP, all at 1X shed blood volume. After 24 hours, lung tissues and plasma were harvested for assays. CLP+HS induced an increase in alveolar thickness and decreases in lung syndecan-1 and lung neutrophil granule-enzymes (myeloperoxidase, neutrophil elastase, and MMP9), with reciprocal elevations in plasma syndecan-1 and plasma neutrophil granule-enzymes (myeloperoxidase, neutrophil elastase, and MMP9). All these alterations were significantly attenuated by FFP but not by fibrinogen. Additionally, CLP+HS-induced hypotension at 24 hours was partially reversed by FFP but not by fibrinogen. FFP administration inhibits CLP+HS-induced neutrophil degranulation to prevent syndecan-1 shedding and lung injury. The current study supports that FFP has therapeutic benefit in a combined septic and hemorrhage shock model.

Banff acute lesion scores underpin histologic classification of kidney allograft biopsies; however, biomarker studies rely on second-order associations with diagnostic categories that introduce confounding. We quantified the first-order relationships between Banff acute lesion scores and the validated urinary cell three-gene rejection signature. In 354 biopsy-urine pairs, three-gene signature scores computed using a locked regression equation incorporating absolute copy numbers of CD3E mRNA, CXCL10 mRNA, and 18S rRNA in urinary cell RNA-were related to glomerulitis (g), peritubular capillaritis (ptc), interstitial inflammation (i), and tubulitis (t). Signature scores rose monotonically with Banff acute lesion severity, with 1.5 to 1.8-fold higher odds of more severed g, ptc, i, and t (all P<0.0001), and showed good calibration. Associations remained robust for composite microvascular (g+ptc) and tubulointerstitial (i+t) indices and were strongest for severe g and t, supporting this signature as a noninvasive, quantitative readout of acute rejection pathology with immediate diagnostic applicability.

BackgroundDuctal carcinoma in situ (DCIS) is a noninvasive breast lesion with variable risk of progression to invasive breast cancer (IBC). Current transcription and cell marker investigations suggest ECM decreases in later events but are limited in details of ECM proteomic composition, including post-translational modifications. We investigated whether the extracellular matrix (ECM) proteome alters with later breast events of DCIS or IBC. MethodsECM-targeted mass spectrometry imaging and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were applied to ten tissue microarrays from the Resource of Archival Human Breast Tissue cohort (RAHBT). Primary DCIS specimens (n=136) were analyzed in relation to later events of DCIS (n=40) or IBC(n=30), with a mean follow-up of 192.1 months 95% CI [179.1,205.1]. Statistical modeling, survival analyses, and exploratory machine learning approaches were used to identify ECM peptide signatures associated with later events. ResultsDistinct ECM peptide profiles were associated with later events of DCIS or IBC. Fifteen peptides derived from fibrillar collagens (COL1A1, COL1A2, COL3A1) and elastin, showed significantly reduced abundance in patients who developed IBC. Lower expression of specific collagen peptides associated with overall 19.9% 95% CI [17.92, 21.81] decreased disease-free survival for IBC. Lower expression of these peptides was significantly associated with reduced disease-free survival (age-adjusted hazard ratio [HR] = 2.45, 95% CI: 2.33-2.57; P < 0.05). Patient-matched samples of primary DCIS, later DCIS, and later invasive breast cancer further demonstrated reduction in ECM peptide detection. Exploratory predictive modeling from patient-matched samples achieved high performance (AUROC >0.98, accuracy >93%) in distinguishing primary from later events. Following prior work in the RAHBT cohort, reduction of certain collagen peptides was also observed in primary DCIS samples from higher risk patient groups. ConclusionsECM proteomic remodeling, particularly decreases of specific collagen domains, is strongly associated with later events of DCIS and IBC. These findings highlight ECM proteome as a critical regulator of breast cancer emergence with potential as a prognosticator of risk stratification to guide clinical management of DCIS.

Background: Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death in women worldwide, and the great majority of these deaths are caused by metastatic disease. Whether the immunohistochemical (IHC) phenotype of breast cancer is associated with the anatomical site of metastasis has been characterized mainly in high-income, registry-based populations, while data from ecologically stressed and medically under-served regions such as the Lower Aral Sea basin are lacking. Methods: We retrospectively reviewed 652 women diagnosed with breast cancer at the Khorezm Branch of the Republican Specialized Scientific-Practical Medical Center of Oncology and Radiology (Uzbekistan) between 2020 and 2024, of whom 213 had metastatic disease (306 metastatic foci). Histological type was assessed on hematoxylin-eosin and van Gieson-stained sections; quantitative morphometry was performed in Fiji/ImageJ; and HER2, estrogen receptor (ER), progesterone receptor (PR) and Ki-67 were assessed by IHC. The association between marker expression and metastatic site (liver, lung, lymph node) was tested in 187 foci with adequate tissue using the chi-square test, with significance at p < 0.05. Results: Invasive ductal carcinoma predominated. Metastatic site was significantly associated with the IHC phenotype. Liver metastases showed the highest frequency of HER2 3+ (45.7%), ER-negativity (65.2%), PR-negativity (69.6%) and high proliferation (Ki-67 [&ge;] 60%; 47.8%), whereas lymph-node metastases were more often hormone-receptor-positive (ER+ 58.7%; PR+ 52.4%) with lower HER2 3+ (22.2%); lung metastases were intermediate (all p < 0.05). The combination of HER2 3+ and Ki-67 [&ge;] 60% was associated with multi-organ spread. Morphometry corroborated these patterns: liver lesions had larger atypical cells (up to 132.8 m), a higher nuclear-to-cytoplasmic ratio (0.76 vs 0.51) and more extensive necrosis and microvascularity than lymph-node lesions. A pragmatic 5-criterion morphological score (histological type, Ki-67, HER2, ER/PR status, atypical-cell size) stratified metastatic risk into three tiers. Conclusions: In this regional cohort, the IHC phenotype of breast cancer tracked the anatomical site of metastasis, with an aggressive HER2-driven, hormone-receptor-negative profile concentrated in liver metastases and a hormone-receptor-positive profile in lymph-node metastases. These findings reproduce established organotropism patterns in a previously uncharacterized population and support phenotype-aware, site-specific surveillance together with a low-cost morphological risk score for resource-limited settings.

BackgroundTraditional immunohistochemistry (IHC) with chromogen detection has limited multiplex capacity, detecting at most 4 protein markers per tissue section simultaneously, thereby restricting comprehensive spatial analysis of valuable human biopsies. We developed and validated a robust serial IHC (sIHC) staining method to detect multiple antigens on a single kidney biopsy slide, maximizing data yield for diagnosing and studying complex kidney diseases. MethodsFormalin-fixed, paraffin-embedded kidney biopsy sections were subjected to repeated IHC/imaging cycles with antibody removal using an optimized sodium dodecyl sulfate-glycerol buffer stripping protocol. Images were then co-registered, and analysis was performed using a variety of methodologies, including color deconvolution, cell segmentation, and spatial clustering. ResultsThis optimized sIHC method successfully detected up to 20 antigens on a single slide. Combining image analysis and artificial intelligence software, for example with HALO (Indica Labs), the assay assembles high-dimensional images and enables quantitative histology and single-cell spatial analysis. Using this advanced method, we were able to identify rare cell populations, such as double-negative T cells, that are challenging to detect conventionally. ConclusionWe have developed a validated, high-capacity sIHC protocol that uses standard IHC procedures with commercially available, clinically validated off-the-shelf antibodies. This method is a valuable, cost-effective tool for obtaining extensive, high-dimensional single-cell-resolved spatial data from limited pathology samples, such as a human kidney biopsy.

The kidney is a highly energetic organ, requiring substantial ATP production through mitochondrial oxidative phosphorylation to support tubular reabsorption. Metabolic reprogramming and impaired mitochondrial function are implicated in diabetic kidney disease, yet direct assessment of mitochondrial respiratory flux in the human kidney has been constrained by limited access to freshly obtained tissue. Consequently, much of the evidence supporting altered renal mitochondrial function in diabetes derives from animal models that do not fully recapitulate the human condition. We established a workflow for real-time bioenergetic profiling of fresh kidney cortex obtained during nephrectomy from living individuals with diabetes and preserved kidney function. Mitochondrial respiration, electron transport system activity and tubular mitochondrial morphology were compared with age- and sex-matched, histopathologically normal non-diabetic controls. High-resolution respirometry revealed increased mitochondrial respiratory flux in permeabilised diabetic kidney cortex. In contrast, mitochondria isolated from the same tissue exhibited reduced respiratory capacity and impaired complex I activity. Quantitative analysis of tubular cells demonstrated increased mitochondrial volume density together with greater mitochondrial fragmentation in diabetes. These findings reveal that the human kidney undergoes substantial metabolic adaptation early in diabetes, before measurable loss of kidney function. Increased tissue-level respiratory flux despite intrinsic mitochondrial impairment suggests that expansion and remodelling of the mitochondrial network may initially compensate for reduced organelle efficiency and sustain the kidneys high energetic demands. This compensatory state may, however, increase metabolic stress and vulnerability to subsequent kidney injury. To our knowledge, this study provides the first direct tissue-level functional evidence that mitochondrial metabolism is reprogrammed in the human kidney in diabetes before measurable kidney dysfunction develops. It defines an early bioenergetic signature characterised by tissue hypermetabolism despite impaired mitochondria-specific respiratory capacity, challenging the concept that diabetes produces a uniform decline in renal mitochondrial function. Failure to sustain this adaptive state may represent a critical transition towards diabetic kidney disease. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/740003v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1a147a2org.highwire.dtl.DTLVardef@16614e8org.highwire.dtl.DTLVardef@e6c895org.highwire.dtl.DTLVardef@17ad6ab_HPS_FORMAT_FIGEXP M_FIG C_FIG One Sentence SummaryDiabetes drives early metabolic reprogramming of the human kidney before measurable kidney dysfunction

Under homeostatic conditions, the cornea is avascular and contains few immune cells, but this changes rapidly following injury. Although the long-term consequences of corneal damage are well characterized, the earliest vascular and immune responses remain poorly understood. Here, we used a murine corneal alkali-burn model to examine limbal vascular activation and leukocyte recruitment immediately and at 2, 6, and 24 hours after injury. Limbal blood vessels underwent immediate dilation; however, vascular leakage into the corneal stroma occurred only in males. Lymphatic capillaries rapidly formed directed extensions toward the injury without significantly increasing their total vascular area, with males exhibiting longer extensions than females. Fluorescent dextran uptake provided evidence that these lymphatic vessels were functionally engaged in early tracer drainage. Despite pronounced vascular activation, early recruitment of neutrophils, monocytes, dendritic cells, macrophages, T cells, B cells, and natural killer cells remained limited. Thus, limbal blood and lymphatic vessels initiate the earliest response to corneal alkali injury before substantial leukocyte infiltration. These findings reveal sex-dependent differences in vascular permeability and lymphatic remodeling and identify the limbal vasculature as an early regulator of corneal inflammation and tissue repair.

Background. Breast cancer treatment depends on histopathological features, such as grade and receptor-defined subtype; however, specialist pathologist access is constrained when the workforce is limited. Commercial multimodal large language models (MLLMs) accept hematoxylin and eosin (H&E) image tiles through paid interfaces without local hardware or fine-tuning. However, prior pathology evaluations addressed only coarse tasks. Whether they reach treatment-determining accuracy and whether vendors agree remain unclear. Methods. We aimed to evaluate three vendor-designated flagship MLLMs (Claude Sonnet 4.6, Gemini 2.5 Pro, GPT-5.5) in 427 invasive breast cancer cases. Each case went to all three with identical H&E tiles and prompts, and the subtype was inferred in the second call. The reference was an institutional sign-out report of an immunohistochemistry-derived subtype. We calculated the concordance, sensitivity, specificity, Cohen's kappa, and pairwise McNemar and Bowker tests. Findings. Claude ranked highest by raw histologic-type concordance but lowest by kappa, classifying all 23 lobular and seven micropapillary carcinomas as invasive breast carcinoma of no special type. The models anchored the Nottingham grade to three modal grades. None of the models reliably identified human epidermal growth factor receptor 2-positive disease. The failure direction was vendor-specific: Claude and GPT-5.5 were under-detected, whereas Gemini was over-called. Twelve prompt variants (4,056 calls) did not recover sensitivity. Interpretation. No current commercial MLLM reaches deployment-ready accuracy for any treatment-determining feature of breast pathology. As each vendor fails in its own fixed direction, changing vendors alters the type of error rather than removing it; therefore, the value of these models is assistive rather than autonomous. At USD 0.20-0.50 per case, they may serve as supervised draft generators that leave the diagnosis with the pathologist.

Abstract Objective Commercially available next-generation sequencing (NGS) platforms in China routinely adopt a lung cancer-derived tumor microenvironment (TME) subtyping signature from a European cohort to classify colorectal cancer (CRC), yet its diagnostic performance in Chinese CRC patients remains unvalidated. This study aimed to evaluate the subtyping efficiency of the lung cancer TME signature in a Chinese CRC cohort, screen CRC-specific immune mRNA biomarkers for TME subtyping, and explore the clinical utility of IRF1, CD8A and LAG3 for distinguishing immune-enriched (IE) and immune-desert plus fibrotic (D+F) subtypes. Methods A total of 87 FFPE CRC specimens with complete NGS and clinicopathological data were retrospectively enrolled, including 15 IE subtype and 72 D+F subtype patients. Thirty-one mRNA transcripts covering 13 immune-metabolic homeostasis genes and 18 immune checkpoint/infiltration-related genes were divided into two functional modules. Spearman correlation analysis was performed to assess co-expression patterns among candidate genes. Receiver operating characteristic (ROC) curves combined with five-fold cross-validation were used to compare the discriminatory efficacy of single-gene markers and the three-gene combined panel. Results Strong positive co-expression was observed between IRF1, CD8A and LAG3 (IRF1-CD8A: r=0.93; IRF1-LAG3: r=0.84; CD8A-LAG3: r=0.73). Nominal P-values indicated elevated expression of IRF1, CD8A and LAG3 in IE subtype, though no intergroup significance remained after Benjamini-Hochberg FDR correction, largely attributed to the limited sample size of IE cases. Single-gene ROC analysis showed AUC values of 0.763 (IRF1), 0.752 (CD8A) and 0.771 (LAG3), with LAG3 exhibiting the best individual discriminatory capacity. The three-gene combined panel yielded a cross-validated AUC of 0.717, inferior to single LAG3, due to severe collinearity that generated redundant predictive information. Conclusions The lung cancer-originated TME subtyping system cannot be directly extrapolated to Chinese CRC patients. LAG3 serves as a promising independent transcriptomic candidate marker for distinguishing CRC TME subtypes. The robust collinearity among IRF1, CD8A and LAG3 eliminates additional predictive benefits of the combined signature. Large independent multi-center Chinese CRC cohorts are required to construct population-specific immune transcriptomic biomarkers for standardized clinical NGS TME stratification.

Thymosin {beta}4 (T{beta}4) is a conserved acidic polypeptide with 43-amino acids participating in multiple pathophysiological processes. In this study in vivo effects of T{beta}4 on liver regeneration are investigated in carbon-tetrachloride (CCL4) induced rodent animal liver jury models. Results illustrate that exogenous T{beta}4 treatment significantly reduced CCL4-rendered liver necrosis around central vein. At 48 hours after CCL4 insults hepatocytes proliferation occur mainly around the periportal area, while hepatocytes proliferation around the necrosis area is prominently increased by exogenous T{beta}4 treatment. The holistic proliferation level of liver tissues are also enhanced by exogenous T{beta}4. Hepatocyte proliferation activities negatively correlate with the necrosis extent of the liver tissue. These results suggested firstly exogenous T{beta}4 treatment could enhance liver regeneration and exhibit prosperous potential for application in clinical conditions such as liver transplantation.

H&E whole-slide images capture prognostic information encoded in tumor morphology and the surrounding microenvironment, but these signals remain difficult to extract and interpret at scale. Here, we developed a self-supervised computational pathology framework to predict disease-free survival in colorectal cancer and link model-derived risk to interpretable histomorphology and spatial tumor biology. Using a multicenter developmental cohort spanning colorectal adenomas and invasive colorectal cancer, we trained HPL-PanColon, a self-supervised representation model, to extract tile-level embeddings and identify recurrent histomorphological phenotype clusters across the adenoma-carcinoma spectrum. Compared with general-purpose pathology foundation models, HPL-PanColon yielded representations with reduced institution- and dataset-specific batch effects. We then applied HPL-PanColon to a global survival cohort of 1,024 colorectal cancer patients in a leave-one-institution-out framework, using tile embeddings to train an attention-based survival model and derive the Colon Histomorphology Prognostic Score (CHiPS). CHiPS stratified patients by disease-free survival and provided complementary prognostic information to a UICC TNM-informed clinicopathological model, increasing the c-index from 0.683 to 0.706. Integrating model attention with phenotype assignments traced CHiPS-associated risk to pathologist-recognizable tissue patterns, with high-risk regions enriched for desmoplastic, stromal, and fibroinflammatory morphologies and low-risk regions reflecting tumor-rich epithelial glandular patterns. Spatial transcriptomic analysis further linked high-risk morphologies to fibroblastic, perivascular, myofibroblastic, and immune-reactive tumor microenvironment programs, while low-risk morphologies mapped to epithelial and tumor-enriched regions. These findings establish a scalable framework for interpretable histology-based prognosis and spatial biological discovery in colorectal cancer.

(Objective) In our previous research, we identified latent chronic pancreatitis in the normal tissue surrounding pancreatic cancer. We also discovered the presence of Enterococcus faecalis (E. faecalis), a type of intestinal bacterium, in the pancreatic fluid and tissue of pancreatic cancer patients, suggesting it may be one of the factors contributing to the development of latent chronic pancreatitis. In this study, we performed pathological analyses to investigate its characteristics and investigate a possibility of E. faecalis infection. (Methods) Pathological analyses were performed, using 16 cases of pancreatic cancer and intraductal papillary mucinous neoplasia (IPMN) involving lesions in the pancreas tail. The involvement of E. faecalis was investigated with immunohistochemical analysis and serological methods. (Results) All cases exhibited inflammatory changes in pancreatic tissue without a clinical diagnosis of chronic pancreatitis, along with macrophage infiltration. These changes did not significantly differ according to preoperative treatment. DNA encoding E. faecalis 16s ribosomal RNA was detected in many cases, however, a positive immunostaining to E. faecalis was observed in only a few cases. Serum capsular polysaccharide (CPS) antibody levels exceeding the mean values were observed in patients with established chronic pancreatitis, while the level was not correlated with E. faecalis immunostaining. (Conclusion) These results suggest the E. faecalis infection is involved in the early stage of the progression of chronic latent pancreatitis and the diagnostic technology incorporating novel multi-biomarkers may be useful for identifying high-risk individuals for future pancreatic cancer development.

Following aortic dissection (AD), there is a sustained risk of vascular complications, progressive false lumen aneurysm formation, and rupture. However, no effective therapy exists to prevent these complications, highlighting the need to elucidate the pathophysiology following AD. Elastic fibers are crucial for maintaining aortic wall integrity but are thought to have limited regenerative capacity once disrupted during AD. This study defined that elastic fibers were newly generated in the false lumen wall following AD in humans and mice. In human ADs, new elastic fibers were observed in the false lumen wall 6 months after onset. In mice with descending AD induced by {beta}-aminopropionitrile (BAPN), elastin mRNA was markedly upregulated in the chronic phase following AD, accompanied by elastic fiber formation. These fibers coincided with smooth muscle cell (SMC) markers within the false lumen wall. Of note, lineage tracing studies demonstrated that these cells were not derived from resident SMCs but adventitial progenitor cells. In vitro experiments further demonstrated that adventitial progenitor cells produced elastic fibers while expressing SMC markers. Collectively, these findings suggest that adventitial progenitor cells differentiate into elastogenic SMC-like cells, contributing to false lumen remodeling through de novo elastic fiber formation following AD.

Metastasis is the leading cause of death in breast cancer, yet the mechanisms controlling organotropism are not well defined. Coagulation has emerged as a biologically relevant contributor to metastatic progression, but mechanisms linking pro-thrombotic phenotypes to organ-specific metastasis remain unresolved, significantly hindering the development of novel treatments. Here, a serial transplantation approach was used to enrich for liver organotropism from a spontaneous mouse mammary tumor model with occasional liver and lymph node metastasis. Comparative transcriptomics between the enriched liver and lymph node metastases revealed strong upregulation of coagulation in liver metastases, due in part to loss of repression of FXII with knockout of the E2F5 transcription factor. In vitro clotting assays demonstrated that tumor-derived FXII was sufficient to induce fibrin(ogen) clot formation. Moreover, liver metastatic cells exhibit elevated lipid peroxide levels and impaired lipid droplet formation associated with a pro-coagulant phenotype. Inhibition of coagulation with low molecular weight heparin reduced the presence of circulating tumor cells and suppressed liver metastasis in the mouse model. Human electronic health record data supported the translational relevance of these findings. Together, these data reveal a new mouse model where loss of E2F5 has resulted in tumors with elevated expression of FXII that have a propensity for liver metastasis and illustrates that anti-coagulation dramatically reduces the liver-specific metastasis in breast cancer. HighlightsE2F5 conditional knockout model develops breast tumors with liver tropism Liver metastasis hijacks the intrinsic coagulation cascade mediated by tumor-derived FXII Liver metastatic cells displayed lipid metabolic alterations that contributed to a pro-coagulant phenotype Low molecular weight heparin blocks liver metastasis and significantly reduces circulating tumor cells