The Journal of Pathology最新文献

Human tumors likely differ in their mitotic ages, reflecting how many divisions elapse between the final tumor progenitor cell and surgical removal. We used a rapidly fluctuating CpG (fCpG) methylation clock to infer relative endometrial adenocarcinomas (EAC) mitotic ages. Experimentally, young tumors initiated from single cells show low-diversity, high-variance fCpG distributions with trimodal peaks near 0%, 50%, and 100%, reflecting inherited progenitor methylation states. fCpG methylation becomes polymorphic with divisions, and older tumors exhibit higher diversity, lower variance, and unimodal distributions centered around 50%. Mitotic ages varied across EAC samples. Synchronous hyperplasia and invasive regions generally shared similar ages, and primary–metastatic EAC pairs showed both synchronous and stepwise progression. The Cancer Genome Atlas (TCGA) EACs also showed variable mitotic ages: younger tumors were enriched for proliferation pathways, whereas older tumors showed more immune infiltration, immune-pathway activation, and evidence of T-cell exhaustion. These results show that human tumors can be ranked by mitotic age and suggest that the growth of older cancers is restrained by immune surveillance. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Platelet-derived microparticles (PMPs) constitute the majority of circulating microparticles in blood. PMPs carry cargo including RNA, protein, and miRNA, and play key pathophysiologic intercellular signaling roles in cardiovascular, autoimmune, and liver diseases. Most methods use fresh platelets treated with an agonist to generate PMPs, which has restricted the size and feasibility of human studies. With the rise of large biobanks, such as the UK Biobank (https://www.ukbiobank.ac.uk/), and because microparticles are retained in cryopreserved plasma, this study aimed to develop an efficient and reproducible method to isolate PMPs from banked cryopreserved human plasma to investigate their communication with target cells. We employed flow cytometry using 180–1,300 nm size calibration beads and the platelet-specific marker CD41 to identify and sort PMPs based on size and CD41 positivity. Following isolation, microparticle size and morphology were validated by electron microscopy and nanoparticle tracking analysis. To assess the utility of the microparticles for studies of cell–cell interactions, we visualized microparticle uptake into human umbilical vein endothelial cells and THP-1 cells. Our method enables the isolation and downstream analysis of human PMPs in cell–cell interactions, facilitating translational studies in large populations and rare diseases. © 2026 The Pathological Society of Great Britain and Ireland.

Colon cancer progression is closely associated with the tumor microenvironment, where cancer-associated fibroblasts (CAFs) play a pivotal role. Exosomal long non-coding RNAs (lncRNAs) are known to modulate the tumor stroma, but the role of lncRNA PVT1 (plasmacytoma variant translocation 1) in exosome-mediated fibroblast activation in colon cancer remains poorly understood. This study demonstrated significantly elevated PVT1 levels in colon cancer tissues. Mechanistically, hypoxia/reoxygenation (H/R) induced the recruitment of HIF-1α to the PVT1 promoter, directly activating its transcription and subsequent exosomal loading. Exosomes derived from H/R-treated colon cancer cells promoted fibroblast activation into a CAF phenotype. PVT1 was found to sponge miR-23b-5p, thereby upregulating a network of target genes. Importantly, silencing of MAPK13, a key downstream target, significantly abrogated the PVT1-mediated fibroblast-to-CAF transformation. In vivo experiments confirmed that exosomal PVT1 enhanced CAF infiltration and tumor growth, whereas these effects were reversed by either restoring miR-23b-5p expression or knocking out PVT1. These findings uncover a novel mechanism whereby H/R-induced exosomal PVT1 promotes fibroblast activation and CAF transformation via the miR-23b-5p signaling axis, providing potential diagnostic biomarkers and therapeutic targets for modulating the tumor stroma in colon cancer. © 2026 The Pathological Society of Great Britain and Ireland.

Prostate cancer (PCa) is the second most common type of neoplasm, currently treated with a variety of therapeutic agents. Although advances in treatment over the past decade have improved overall survival, patients with advanced PCa eventually progress from hormone-sensitive PCa to metastatic castration-resistant PCa. For this reason, other therapeutic strategies, including immunotherapy, are being investigated. Despite initial enthusiasm, these approaches have not yet produced significant improvements in either progression free survival or overall survival. Several factors may have contributed to the consistently disappointing results of immune checkpoint inhibitors in PCa, despite their more successful results in other tumor types. In this review, we discuss the potential reasons for these disappointing clinical results. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Uveal melanoma (UM) is a deadly ocular malignancy with well-described genetic alterations that predict disease outcome. However, our current understanding of the biological underpinnings of high-risk uveal melanoma progression remains relatively limited. Using RNA expression profiles from 250 patients with UM, we identified 12 novel biomarkers associated with high-risk UM, with protein expression level validation of the top two candidates: the transcriptional regulator RBFOX2 and matrix protein COL9A3. Moreover, we investigated the functional contribution of COL9A3 via its overexpression in EIF1AX^mut and BAP1^mut UM cell lines. Our data suggest that COL9A3 enhances cell motility and cell proliferation and alters morphology specifically in BAP1^mut UM cells. Furthermore, zebrafish xenograft studies revealed increased cell dissemination in a EIF1AX^mut UM cell line upon overexpression of COL9A3, whereas a BAP1^mut UM cell line remained unchanged under wild-type conditions. Interestingly, RNA sequencing revealed a high-stress profile by upregulated metabolic activity and loss of protein translation due to COL9A3 overexpression. BAP1^mut UM appears to adapt to this stress by upregulation of plasticity markers, such as CD44, Nestin, EZH2, ABCB5, PAX3 and CD166, as a coping mechanism. These markers are known as differentiation markers during the development of melanocyte biogenesis and are implicated in plasticity in other high-risk cancers. The relationship between COL9A3 and plasticity was validated by multiplex immunohistochemistry of formalin-fixed paraffin-embedded (FFPE) tissue, which demonstrated colocalization of COL9A3, CD44 and Nestin. BAP1^mut-UM samples presented higher levels of COL9A3, CD44 and Nestin expression than EIF1AX^mut or SF3B1^mut UM samples based on the mean fluorescent intensity of each marker. A positive correlation between COL9A3 and Nestin expression in triple-positive cells, irrespective of the UM subtype, was observed. Collectively, our findings suggest that COL9A3 is a novel high-risk biomarker that may contribute to UM cell plasticity and is most prevalent in BAP1^mut UM. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

The cellular composition and disease susceptibilities of the distinct zones of the human prostate remain incompletely understood. Benign prostatic hyperplasia (BPH) is a common condition that causes widespread morbidity and is nearly exclusively localized to the transition zone (TZ). Through extensive single-cell RNA sequencing (scRNA-seq) of benign regions from prostatectomy specimens, we identified a basal cell population expressing WIF1, VCAN, and NRG1, among other genes, that was significantly enriched in the TZ. Analysis of previously published scRNA-seq datasets further confirmed that WIF1⁺ basal cells were significantly enriched in BPH compared with normal prostate. Pathway and cell-cell communication analyses revealed that this basal subtype is associated with programs related to cell proliferation, epithelial-mesenchymal transition, immune regulation, angiogenesis, and hormone response. Together, the molecular signature, zonal distribution, and pathway enrichment suggest that TZ-enriched WIF1⁺ basal cells may contribute to BPH pathogenesis by promoting epithelial and stromal remodeling. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Fibroblast growth factor receptor 1 (FGFR1) amplification, a significant cancer alteration with both prognostic and therapeutic relevance, lacks a standardized definition. The relationship between FGFR1 copy number (CN) variations and tumour microenvironment (TME) characteristics also remains poorly understood. This study defined FGFR1 amplification and investigated TME features across FGFR1 CN subtypes in triple-negative breast cancer (TNBC) to guide precise treatment. We analysed 182 TNBC tumour specimens. FGFR1 CN status was assessed using fluorescence in situ hybridization (FISH). Next-generation sequencing (NGS) was performed on 88 samples to explore biological differences. Immunohistochemical (IHC) results for CD3, CD4, and CD8 along with clinical data were analysed. Samples were categorized into four groups based on the FGFR1/CEN8 ratio and the mean FGFR1 signals per cell. Groups 1 (ratio ≥ 2.0, signals ≥ 4.0) and 2 (ratio ≥ 2.0, signals < 4.0) exhibited robust tumour proliferation, increased FGFR signalling, and an immunosuppressive TME. Conversely, group 4 (ratio < 2.0, signals < 4.0) showed significantly enhanced immune cell infiltration (e.g. CD8⁺ T cells, NK cells), supported by elevated CD3⁺/CD8⁺ T-cell densities. Group 3 (ratio < 2.0, signals ≥ 4.0) was heterogeneous: tumours with FGFR1 CN ≥ 5 resembled groups 1/2, while those with CN < 5 mirrored group 4. Thus, FGFR1 amplification (FGFR1-Amp) was defined as FGFR1/CEN8 ratio ≥ 2.0 or CN ≥ 5.0 (14.29% prevalence, 26/182). Remaining cases were FGFR1-neutral (FGFR1-Neu). Immune profiling revealed that FGFR1-Amp & HER2-low TNBC had reduced immune cell infiltration but heightened oncogenic signalling (including epithelial-mesenchymal transition, angiogenesis) compared with other subgroups. In contrast, FGFR1-Neu tumours, especially HER2-zero, displayed increased immune cell infiltration (NK cells, effector cells), MHC I/II molecules, activation markers, and elevated immune checkpoint expression (e.g. PD-L1, CTLA4, LAG3). This study defines FGFR1 amplification in TNBC and characterizes its TME. FGFR1-Amp in HER2-low TNBC correlates with an immunosuppressive environment, potentially hindering HER2-ADC efficacy and suggesting combined FGFR inhibition. Conversely, FGFR1-Neu & HER2-zero tumours with immune activation may respond better to immunotherapy. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Germline variations contribute to esophageal squamous cell carcinoma (ESCC) susceptibility. We identified a germline deletion (exons 7-8) in HIF3A in an ESCC family and investigated its functional impact using CRISPR/Cas9-engineered cells and Hif3a-eKO1 mice (heterozygous for exons 7-8 deletion). Multi-omics analysis of Hif3a-eKO1 and WT mice revealed dysregulated pathways in normal esophagus and during 4NQO-induced carcinogenesis, with key biomarkers validated by immunohistochemistry. Hif3a deficiency enhanced ESCC cell proliferation and invasion in vitro and accelerated 4NQO-induced tumorigenesis in vivo, with Hif3a-eKO1 mice developing more and larger neoplastic lesions. Multi-omics analysis revealed downregulation of cytokeratin-related genes (notably Krt17) and γδ T cells in normal esophagus of Hif3a-eKO1 compared with WT. Consistently reduced Krt17 expression in Hif3a-eKO1 was confirmed by both esophageal immunohistochemistry and cellular Western blot analyses. During 4NQO-induced carcinogenesis, Hif3a deficiency upregulated DNA damage response markers, including Krüppel-like factor 4 (Klf4) and ATR serine/threonine kinase (Atr). Notably, epithelial cells with abundant γH₂AX foci lacked Krt17 expression, while Krt17-positive cells showed minimal γH₂AX foci. Heterozygous germline Hif3a deletion (exons 7-8) may promote ESCC by disrupting esophageal barrier function-impairing Krt17-mediated epithelial integrity and reducing γδ T cells-while exacerbating genomic instability. These findings reveal ESCC predisposition mechanisms and therapeutic targets. © 2026 The Pathological Society of Great Britain and Ireland.

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor originating from calcitonin producing C-cells and accounts for 1-5% of thyroid cancers. Total thyroidectomy is curative in localized disease (N0), whereas lymph node metastases (N1) are associated with poorer prognosis. However, the molecular mechanisms driving the metastatic shift remain poorly understood. This study aimed to identify miRNA features linked to metastatic spread in MTC, focusing on the transition from N0 to N1. Co-expression networks were constructed for N0 and N1 tumors, and differential connectivity analysis was used to identify key miRNAs acting as regulatory hubs. Functional annotation of their target genes was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Reactome pathway analyses. Validation experiments were carried out in MTC cells to evaluate the effects of selected miRNAs on cell proliferation, survival, and MAPK pathway activation. Network analysis revealed distinct miRNA co-expression patterns between N0 and N1 tumors. Differential network analysis highlighted miR-145-3p as a central regulatory hub, exhibiting 29 altered co-expression changes and a marked loss of connectivity in N1. Target enrichment identified 59 validated genes, including key oncogenic drivers such as MYC, PTEN, BCL2, PIK3CA, AKT1, and MAPK7. In MTC cells, simultaneous inhibition of miR-145-3p together with its top co-expressed miRNAs increased proliferation and survival, and enhanced ERK phosphorylation, indicating MAPK pathway activation and a shift toward a more aggressive phenotype. In conclusion, this study identifies a miRNA regulatory hub centered on miR-145-3p that is associated with metastatic progression and highlights the value of network-based approaches in uncovering mechanisms of cancer dissemination. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Invasive mucinous adenocarcinoma (IMA) of the lung is a distinct subtype of lung adenocarcinoma with unique clinicopathologic features; however, its histogenesis remains incompletely understood. Although mucinous metaplasia has been suspected as a precursor lesion, direct molecular evidence supporting this progression is limited. In this study, we applied morphology-guided spatial transcriptomics to investigate epithelial lineage relationships across the mucinous spectrum of lung lesions. Formalin-fixed, paraffin-embedded lung tissues from 26 patients were analyzed using the GeoMx digital spatial profiling platform. A total of 118 cytokeratin-positive regions of interest representing normal bronchioles, bronchiolar metaplasia, mucinous metaplasia, mucinous dysplasia, IMA, nonmucinous terminal respiratory unit-type adenocarcinoma, squamous metaplasia/dysplasia, and squamous cell carcinoma were profiled. Spatial transcriptomic data were integrated with two independent public cohorts and mapped to the Human Lung Cell Atlas for epithelial cell-type assignment. Unsupervised clustering identified a distinct mucinous cluster comprising IMA and most mucinous dysplasia regions, characterized by enrichment of gastric-type differentiation markers, including MUC5AC, MUC6, TFF1, TFF2, and CLDN18. Label-transfer analysis demonstrated that mucinous metaplasia and dysplasia were predominantly associated with club and goblet cell identities, whereas IMAs showed enrichment of club and goblet signatures. In contrast, nonmucinous adenocarcinomas consistently aligned with alveolar type 2 cell identity across all datasets. Immunohistochemistry confirmed uniform CLDN18 expression in IMAs and its absence in nonmucinous adenocarcinomas. These findings provide spatial transcriptomic evidence supporting a club cell-associated mucinous pathway in lung tumorigenesis and identify CLDN18 as a defining molecular feature of IMA. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.