The Journal of Pathology最新文献

Osteoid osteoma and osteoblastoma are non-malignant bone-forming tumours of the skeleton, characterised by the presence of irregular trabeculae of woven bone. Rearrangements in FOS, and less frequently FOSB, have recently been identified in osteoid osteoma and osteoblastoma. Identical rearrangements in FOS were previously detected in epithelioid haemangioma, where these led to truncation of the FOS protein in the C-terminal domain, causing increased protein stability due to impaired degradation. Since FOS plays a role in osteogenic differentiation, the effect of FOS truncation on osteogenic differentiation and proliferation was investigated in an in vitro model for osteoid osteoma and osteoblastoma. In this model, truncated FOS (FOSΔ) was overexpressed in human foetal mesenchymal stem cells through a lentiviral vector. Osteogenic differentiation — assessed by measuring mineralisation, ALPL expression, and ALP activity — and proliferation rate were reduced in cells overexpressing FOSΔ compared to mesenchymal stem cells with an empty lentiviral vector (pLV). Transcriptome-sequencing and differential gene expression analysis revealed decreased gene expression of genes in pathways involving cell cycling and mitosis and osteogenic differentiation, including WNT signalling, extracellular matrix organisation, and matrix metalloproteinases (MMPs), in FOSΔ as compared to empty vector cells, indicating decreased proliferation and osteogenesis. Instead, FOSΔ cells showed upregulation of genes involved in prostaglandin signalling and NF-kB inflammatory pathways. These findings highlight that FOSΔ compromises cellular growth and osteogenesis, which is in line with the morphological features of osteoid osteoma and osteoblastoma with woven bone formation instead of mature lamellar bone, as well as the indolent clinical behaviour. Additionally, FOSΔ promotes inflammatory signalling instead, which correlates with clinically exquisite response to non-steroid anti-inflammatory drugs. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

High-grade neuroendocrine tumors of the small intestine are separated into two groups: well-differentiated neuroendocrine tumors (NETs, high-grade) and poorly differentiated neuroendocrine carcinomas (NECs). They represent very rare entities, with few molecular data available, and are very challenging to treat. In this study we aimed to describe the molecular profile of these tumors and their spatial and temporal heterogeneity. We collected a national multicenter cohort of high-grade NETs (14 patients) and NECs (11 patients). DNA and RNA were extracted and somatic point mutations, copy number variations, and gene expression levels were studied using high-throughput sequencing of a panel of 571 genes and RNA sequencing, respectively. Additional samples to study spatial or temporal heterogeneity were available for 12 patients, leading to a total of 42 samples analyzed. Differential diagnostic markers were confirmed by immunohistochemistry. NECs resemble their counterparts in other organs, with a relatively high tumor mutational burden (TMB) and frequent alteration of TP53 and RB1, together with organ-specific alterations such as APC. In contrast, high-grade NETs resemble low-grade NETs, with a low TMB but frequent chromosomic alterations. Transcriptomic analysis confirmed that high-grade NETs and NECs are two distinct entities, with specific drivers. Serotonin pathway markers were the most efficient to discriminate high-grade ileal NETs from NECs. Despite variations in the proliferation index, NETs showed little spatial and temporal heterogeneity, suggesting that epigenetic mechanisms play a crucial role in tumor progression. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cervical cancer remains the fourth most common cancer affecting women worldwide, and incidences of other HPV-related cancers continue to rise. For the development of effective prevention strategies in high-risk patients, we aimed to better understand the roles of inflammatory pathways and the tumour microenvironment as the main driver of progression to malignancy in HPV-infected tissues. We analysed the spatial organisation of seven samples of HPV+ high-grade squamous intraepithelial lesion (HSIL) and cervical intraepithelial neoplasia 3 (CIN3), comparing tumour heterogeneity and immune microenvironments between premalignant (neoplastic) and adjacent cervical tissues. We observed evidence of immune suppression within the neoplastic regions across all samples and identified distinct immune clusters for each dysplastic lesion. Previous single-cell data analyses in an HPV16 E7 oncoprotein-driven transgenic mouse model suggested a potential role for IL34-CSF1R signalling in immune modulation, where low IL34 expression was associated with Langerhans cell dysfunction, and, in cervical cancer, with poor patient outcome. Here we observed that IL34-CSF1R coexpression was absent within HPV-associated neoplastic regions, but present in adjacent normal tissue regions. Additionally, we identified enrichment of an M2 gene signature in neoplastic regions, while adjacent tissue was enriched with a proinflammatory M1 gene signature. Our findings provide biopathological insights into the spatial cellular and molecular mechanisms underlying HPV-associated cervical cancer immune regulation and suggest a strategy to modulate the immune system in HPV-positive neoplastic cervical and other tissues. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Type B1 and B2 thymomas are lymphocyte-rich malignant tumours with few somatic mutations in protein-coding regions of the nuclear genome; nonetheless, noncoding regions remain uncharacterized. Here, we developed a method to isolate pure thymoma cells from lymphocyte-rich tissues, and then performed genome-wide deep sequencing. The total number of somatic mutations was ~80 times higher in noncoding regions than in coding regions in type B12 thymomas (1,671.3 versus 21.1 per case). Coding mutations were identified in epigenetic regulators, DNA repair genes, and some other genes. Nevertheless, 40% of the cases exhibited fewer than four nonsynonymous mutations in coding regions. A systematic noncoding analysis identified 405.0 mutations per case in cis-regulatory elements and detected six recurrent mutations: one interferon regulatory factor (IRF8), two E3 ubiquitin ligases (UBR2 and RNF213), and three intergenic regions. Tumour-specific/enriched mitochondrial heteroplasmic shift was observed in 90% of cases, with a significant proportion of mutations located in the D-loop region. When tracing the evolutionary lineage of mtDNA mutation, the majority of cases can be explained by a linear evolutionary model. This suggests that positive selection may be operating on the mitochondrial genome during thymoma development. In summary, numerous noncoding mutations and mitochondrial heteroplasmic shift were detected in type B1 and B2 thymomas, some of which may be functional. Given the paucity of coding mutations observed in this disease entity, other factors such as disruption of the noncoding landscape and tumour-specific/enriched mitochondrial heteroplasmic shift, may contribute to the development of thymoma. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Small cell neuroendocrine carcinoma of the cervix (SCNECC) is a rare and highly aggressive malignancy with poor prognosis that predominantly affects premenopausal women. Histopathological evaluation is central to diagnosis and clinical management; however, distinguishing SCNECC from other ‘small blue round cell’ malignancies often requires a multimodal approach that integrates morphology, immunohistochemistry, and advanced molecular testing. In the absence of specific and sensitive biomarkers, SCNECC largely remains a diagnosis of exclusion, underscoring the need for comprehensive diagnostic algorithms. A study by Pan, Yan, Yuan et al employed whole transcriptome profiling and identified three molecular subgroups within SCNECC. Importantly, one subgroup displayed an inflamed phenotype, characterized by high expression of MHC-II complex and IFN-α/β–related genes, suggesting potential susceptibility to immunotherapy, a finding that mirrors observations in small cell lung cancer. These findings highlight the biological heterogeneity of SCNECC and reinforce the importance of integrating molecular data to refine diagnostic accuracy and guide therapeutic decision-making. This commentary emphasizes the pressing need for comprehensive diagnostics and further research to advance treatment strategies for this rare and challenging malignancy. © 2025 The Pathological Society of Great Britain and Ireland.

Lower urinary tract symptoms (LUTS), associated with benign prostatic hyperplasia (BPH), are an aging-related disease, with more than 210 million cases worldwide. Estrogen exposure and estrogen regulation have been implicated in a variety of disease processes, with estrogen receptor (ER)-α pathways associated with disease progression and ERβ pathways considered to be disease-protective through enhanced apoptosis and reduced cellular proliferation. Preclinical models of LUTS/BPH have shown that ERα activation contributes to disease initiation and progression. Self-identified African American (AA) men have a high incidence of LUTS/BPH, with increased incidence of non-surgical treatment failure, larger prostates at time of surgery, and surgery occurring at a younger age compared with self-identified European American (EA) men. While circulating estrogen levels are higher in AA individuals, regulation of ERs, particularly ERβ, in normal and LUTS/BPH human prostate has not been well characterized. In this study, we examined differences in ER expression between peripheral zone (PZ) and transition zone (TZ) prostate tissues using multiplex, multispectral imaging. Additionally, we assessed changes in ERs and steroid metabolism genes involved in ERβ signaling between normal and LUTS/BPH prostate samples. Our study revealed underlying differences in steroid metabolism gene expression between normal AA and EA prostates, which were further altered with LUTS/BPH. Importantly, the contribution of ERα to LUTS/BPH was more pronounced in EA prostate samples, whereas AA prostate samples exhibited an overall increase in the expression of both ER and estrogen metabolism-related genes. Although estrogens have also been implicated in collagen deposition in the prostate of LUTS/BPH patients, we did not observe significant differences in collagen deposition between AA and EA samples. These results suggest that racial differences in steroid hormone signaling pathways within the benign prostate represent a promising area for the development of precision-based therapies to reduce LUTS in aging men. © 2025 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 use of immune checkpoint inhibitors is a promising therapeutic strategy for metastatic papillary renal cell carcinoma (PRCC); however, predictive biomarkers remain limited. PRCCs with high ABCC2 expression represent an aggressive subset frequently associated with metastasis. The tumor microenvironment (TME) profile of these tumors remains poorly defined. This study aims to characterize the TME of PRCC in relation to its ABCC2 status. A discovery cohort of 157 ABCC2-high PRCCs, 156 ABCC2-low PRCCs, and 72 normal kidneys was evaluated. Using RNA sequencing data, immune cell composition, immune checkpoint markers, and immune signature scores were assessed. Validation was performed in an independent cohort (31 ABCC2-high, 36 ABCC2-low, and 15 normal kidneys) using RNA in situ hybridization (RNA-ISH) and immunohistochemistry (IHC). ABCC2-high PRCCs demonstrated increased infiltration of cytotoxic T cells (p < 0.001), M2 macrophages (p = 0.021), and regulatory T cells (p < 0.001) compared to ABCC2-low tumors. ABCC2-high PRCCs also had higher expression of immune checkpoint biomarkers including programmed cell death ligand 1 (PD-L1) (p < 0.001). The validation cohort showed this similar TME profile. Additionally, ABCC2-high PRCCs had higher PD-L1 IHC positivity (combined positive score ≥ 1, p = 0.035; tumor proportion score ≥ 1%, p = 0.006) and immune predictive signature score (p = 0.029). NRF2–Antioxidant Response Element signaling pathway was enriched in ABCC2-high PRCCs as evidenced by overrepresentation in pathway analysis, higher gene signature score (p < 0.001), and elevated transcript signals (NFE2L2, p < 0.001; NQO1, p < 0.001), compared to ABCC2-low PRCCs. In conclusion, ABCC2-high PRCCs are immune-infiltrated tumors with a suppressive phenotype potentially responsive to immune checkpoint inhibitors. ABCC2 IHC may serve as a predictive biomarker to help identify patients likely to benefit from such therapy. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Lung adenocarcinoma (LUAD) is one of the most prevalent forms of cancer and continues to be associated with high mortality rates, despite recent advances in cancer therapy. Effective risk stratification is critical for guiding treatment decisions and improving our understanding of disease mechanisms. However, current prognostic approaches face considerable limitations. Growth pattern-based grading serves as a prognostic indicator of tumour aggressiveness, but is inherently subjective and prone to a high degree of variability among observers. Other well-established prognostic indicators, such as tumour infiltrating lymphocytes (TILs) and stromal TILs (sTILs) scores, provide valuable prognostic information but require labour-intensive assessment. The pronounced heterogeneity of LUAD further complicates prognosis and underscores the need for robust, integrative biomarkers that capture both the morphological and immunological characteristics of the tumour. To address this need, we propose an AI-based growth-pattern-specific TILs (GPS-TILs) marker that quantifies TILs and sTILs within each growth pattern separately. By integrating morphological information from the tumour growth patterns and immune microenvironment data from TILs, we demonstrate that the proposed GPS-TILs marker improves patient stratification. We evaluated the prognostic utility of GPS-TILs using survival analysis with Cox proportional hazards models in a cross-validation setting using The Cancer Genome Atlas LUAD (TCGA-LUAD) cohort. Our findings revealed that GPS-TILs offers strong prognostic value for overall survival (p < 0.0001, C-index = 0.59), outperforming conventional TIL-based measures and morphology-based stratification approaches. These results highlight the potential of GPS-TILs as a more objective and effective tool for improving patient risk stratification in LUAD. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Splicing dysregulation is a relevant mechanism of pathogenicity for variants in disease susceptibility genes. Variants affecting the critical intronic +1 and +2 GT nucleotides of the 5’ splice sites (5'ss) are generally strong indicators of pathogenicity. However, some +2 T variants create functional noncanonical 5'ss that generate wildtype transcripts, hampering accurate variant interpretation and genetic counseling. We previously showed that variants PALB2 c.108+2T > C and ATM c.1898+2T > G generated significant levels of full-length (FL) transcripts by creating functional atypical GC and GG donor sites, respectively. In this study, we aimed to investigate the splicing impact of +2T variants in the breast cancer susceptibility genes ATM, BRCA1, and PALB2. For this purpose, five minigenes encompassing 29 exons of ATM, BRCA1, and PALB2 were employed. A total of 30 +2T > C/G/A variants were introduced into these constructs by site-directed mutagenesis and analyzed in MCF-7 cells. Four +2T > C variants (ATM c.6347+2T > C, BRCA1 c.5193+2T > C and c.5277+2T > C, and PALB2 c.2748+2T > C) and ATM variants c.6347+2T > A/G produced FL-transcripts (4%–81% of the overall expression). All +2T > C leaky variants conserved a central core of 6 nucleotides (AGgcaa). Variants were assessed according to the ClinGen specifications of the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) interpretation guidelines. Two variants (ATM c.6347+2T > C and BRCA1 c.5193+2T > C) were classified as likely benign, consistent with predictions based on their respective ACMG/AMP-based gene specifications. Conversely, two variants (ATM c.6347+2T > G and BRCA1 c.4675+2T > C), initially predicted as likely pathogenic, were reclassified as variant of uncertain significance (VUS). In conclusion, a significant proportion of +2T variants can create functional noncanonical 5'ss, resulting in the production of FL-transcripts that may preserve gene function. Variant-splicing assays provide essential data for accurate clinical classification and for the development of effective clinical management strategies for patients and their families. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Exploiting vulnerabilities in switch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complexes for cancer therapy is a promising therapeutic strategy. The SWI/SNF chromatin remodeling complex acts as a regulatory component of transcription, and our previous study found an immune-active microenvironment and better response to immunotherapy of gastric cancer with ARID1A loss. However, little is known about the clinical significance of SMARCA4, which encodes for another subunit of the SWI/SNF complex, in gastric cancer (GC) patients. This study analyzed the association of SMARCA4 status with clinicopathological features, survival outcomes, therapeutic response, and immune microenvironment characteristics in three independent cohorts: Zhongshan Hospital (ZSHS) cohort (n = 442), Zhongshan Hospital immune checkpoint blockade (ZSHS-ICB) cohort (n = 41), and Samsung Medical Center cohort (SMC, n = 51). SMARCA4-deficient GC patients exhibit clinicopathological features associated with enhanced tumor aggressiveness, including a higher prevalence of poorly differentiated disease (p = 0.034), pN3 stage at diagnosis (p = 0.059), E-cadherin negative expression (p < 0.001), and genomically stable (GS) and microsatellite stable/epithelial–mesenchymal transition molecular subtype (MSS/EMT) (p < 0.001 and p < 0.001, respectively). Kaplan–Meier analysis revealed that SMARCA4 deficiency indicated poor prognosis in GC (p < 0.001). Moreover, SMARCA4 deficiency identified a subgroup of GC patients who exhibited poor outcomes despite receiving adjuvant chemotherapy in the GS subtype (p = 0.029). In contrast, these patients demonstrated increased sensitivity to anti-PD-1 therapy in both the ZSHS-ICB (p = 0.039) and SMC (p = 0.062) cohorts. Immunological analysis revealed a distinct immune profile characterized by abundant but exhausted CD8⁺ T cells in SMARCA4-deficient GC. In conclusion, patients with SMARCA4-deficient GC patients demonstrated poor prognosis but improved response to immunotherapy. These observed clinical outcomes may be attributed to the immunosuppressive microenvironment, highlighting the potential for developing novel therapeutic approaches. © 2025 The Pathological Society of Great Britain and Ireland.