The Journal of Pathology

Introduction Conjunctival melanoma (CM) is a rare cancer with a potentially high recurrence rate. The mechanics of its progression, its relationship with neighboring tissues, and its molecular characteristics are largely unknown. Diagnosis currently requires a biopsy and the time and expertise of a pathologist. Methods Archived human biopsies containing CM were submitted to Xenium spatial transcriptomic analysis. Regions were graded by disease progression through histopathology. Differential expression (DE) and composition analysis were performed across disease states. Results From three patients, 12 formalin-fixed paraffin-embedded (FFPE) tissue specimens were recovered. Composition analysis showed that melanoma depletes fibroblast and epithelial cells while melanocytes proliferate. DE signatures specific to each state show a clear pattern of progression from inflammation, to cellular restructuring, and then to tumor progression and malignancy. Conclusion Spatial transcriptomics allows single-cell transcriptomics techniques to compare spatially relevant annotations that are difficult to separate by library. This study proposes disease progression biomarker candidates that may elucidate the mechanics of CM progression and function as objective diagnostic and prognostic tools in the future.

PurposeOvarian clear cell carcinoma (OCCC) is strongly associated with endometriosis and shows geographic variation in incidence. We investigated whether OCCC and adjacent endometriosis exhibit distinct transcriptional states and whether these patterns differ between United Kingdom (UK) and Japanese cohorts. Experimental DesignWe performed whole-transcriptome spatial profiling on specimens from 16 OCCC cases (8 UK, 8 Japan) in which tumor and endometriosis were both present. Gene expression was analyzed in tumor, endometriosis and stroma. ARID1A status was assessed by immunohistochemistry. ResultsMedian age was 59 years (range 26-82). 13/16 cases (81.3%) had early-stage disease. Tissue compartment rather than cohort of origin was the dominant source of variation across endometriosis and tumor regions. Endometriosis was enriched for inflammatory and immune-related pathways compared to tumor, whilst there was greater representation of chromatin and protein-DNA complex assembly pathways in tumor regions. These patterns were conserved across both cohorts and after stratification by ARID1A status. Mesenchymal-associated gene expression scores also significantly differed across stroma, endometriosis and tumor with clear compartmental separation. Cell type deconvolution analyses showed clear compositional differences between stromal and epithelial disease compartments. ConclusionsOCCC and coexisting endometriosis are transcriptionally distinct, with the dominant contrast being compartmental rather than geographic. ARID1A alone is unlikely to account for the principal spatial transcriptional states identified here. Further analyses will be required to ascertain whether these differences reflect genuine biological differences between OCCC and coexisting endometriosis or represent different stages of endometriosis-associated tumorigenesis. Translational RelevanceOvarian clear cell carcinoma often arises in association with endometriosis, yet the biological transition between these lesions remains poorly understood. Using spatial transcriptomics in matched tumor and adjacent endometriosis from Japanese and UK cohorts, we showed that endometriosis is characterized by inflammatory and antigen-presentation features, whereas tumor regions showed chromatin-organization and oncogenic transcriptional states. These patterns were largely maintained irrespective of ARID1A status and geographic background. In addition, spatial deconvolution suggested differences in local immune composition, with tumor regions showing relatively greater neutrophil- and T cell-associated signals. Together, our data suggest that OCCC and coexisting endometriosis share a spatially linked tissue context, but that tumor regions have distinct transcriptional profile and microenvironment that may be involved in the malignant transformation and inform interpretation of molecular classification in endometriosis-associated OCCC.

BackgroundFibrosis and tumor innervation are two features of the tumor microenvironment (TME) that contribute directly to the lethality of pancreatic ductal adenocarcinoma (PDAC), but their potential interactions have not been explored. Moreover, although it is known that activated Schwann cells (SCs) stimulate cancer cell invasion, it remains unclear how SCs are activated. ObjectiveWe determined how SCs are activated in the pancreatic fibrotic microenvironment. DesignThe correlation between physical features of the microenvironment and SC activation was assessed in human patient samples and in mice by SC c-Jun phosphorylation monitoring, atomic force microscopy and multiphoton live imaging. Several in vitro models in which forces were applied to SCs expressing a reporter for c-Jun phosphorylation and RNA-Seq analysis were used to decipher the cellular and molecular mechanisms of SC activation. ResultsNerves surrounded by stiff stroma present higher SC activation. Intravital imaging shows a matrix dependent SC activation. Mechanical forces on SCs induce c-Jun phosphorylation in SCs in a non-canonical manner that involves a nuclear sensing machinery with the proinflammatory enzyme Phospholipase A2. ConclusionFibrosis enhances the protumorigenic impact of innervation by activating SCs via a mechanism in which nuclear compression triggers non-canonical activation of the AP-1 transcription factor complex. Pancreatic fibrosis alone, without cancer cells, is sufficient to activate SCs, suggesting this mechanism may be common across non-malignant pancreatic diseases. Notably, SCs are more sensitive to mechanical activation than PDAC cells. These findings reveal TME interactions that may guide future microenvironment-targeted PDAC therapies. What is already known on this topicThe pancreatic cancer tumor microenvironment is highly innervated and fibrotic, two components of the tumor microenvironment that regulate tumorigenesis. How they impact each other is unknown. Schwann cells have emerged as a significant protumorigenic player, but the triggers of Schwann cell activation remain undefined. What this study addsWe establish that fibrosis induces Schwann cell activation and characterize the mechanism by which it occurs. We uncovered a mechanical mode of action that deforms nuclear membrane and activates c-Jun in Schwann cells, which contradicts the traditional view of c-Jun activation through a stimulus detected at the plasma membrane. How this study might affect research, practice or policyThis study provides a better understanding of the biology of pancreatic ductal adenocarcinoma and supports the development of novel precision therapies that target the fibrotic microenvironment to impact the protumorigenic effect of tumor innervation.

Collagen organisation within the tumour microenvironment plays a critical role in tumour progression and has emerged as an important structural biomarker in cancer. Second Harmonic Generation (SHG) microscopy enables label-free visualisation and quantitative assessment of fibrillar collagen architecture; however, its high cost, specialised instrumentation, and limited field-of-view restrict routine clinical application. In this study, we evaluated whether collagen features quantified from digitally scanned Masson-Goldners Trichrome-stained histopathological sections can approximate measurements obtained from SHG microscopy. Formalin-fixed paraffin-embedded breast tumour tissues, including benign and invasive ductal carcinoma (IDC) samples with varying collagen content, were analysed using SHG microscopy and whole-slide brightfield imaging. Matched regions of interest were analysed using two independent digital image analysis approaches: a conventional ImageJ-based workflow (TWOMBLI) and a machine learning-based computational pipeline. Collagen structural parameters including collagen deposition area, fibre number, and alignment metrics were quantified and compared across imaging modalities using correlation analysis. SHG signals were consistently detected from trichrome-stained sections, confirming compatibility of SHG imaging. Quantitative comparison demonstrated significant concordance between SHG-derived collagen metrics and those obtained from digital image analysis pipelines, particularly for collagen area and fibre alignment. These findings demonstrate that computational analysis of routine histopathological images can capture key spatial features of collagen organisation comparable to SHG microscopy. Digital pathology-based collagen quantification therefore, represents a scalable and clinically accessible approach for assessing extracellular matrix architecture in tumour tissues.

Uveal melanoma is an aggressive intraocular tumour characterised by a limited number of genetic alterations. However, the evolution of this malignancy remains enigmatic. In this study, we performed a deep quantitative analysis of 80 primary uveal melanomas by novel digital PCR-based approaches. Mutations were quantified by targeted and drop-off mutation assays, copy number alterations were precisely measured by quantifying the allelic imbalance of heterozygous single-nucleotide polymorphisms. By comparing the absolute abundances of genetic alterations present in a bulk tumour, the heterogeneity and early evolution could be inferred. Tumour progression was further studied by analysing matched primary and metastatic lesions from five patients. Gq signalling mutations were generically and always clonally present, suggesting to be acquired in the earliest stage of uveal melanoma development ( primary driver). Next, three main evolutionary subtypes could be identified based on having an EIF1AX mutation, SF3B1 mutation or monosomy 3p. These alterations were usually mutually-exclusive and (near-) clonally abundant, suggesting to represent distinct secondary drivers. This contrasts with gains and amplifications of chromosome 8q, which were not restricted to one of the main subtypes and showed subclonality in 31% of the affected tumours. These tertiary alterations were not required for metastatic dissemination. Using high-resolution analyses, we identified systematic differences in the evolutionary timing of genetic events in uveal melanoma. The observed intratumour heterogeneity suggests a more complex model of gradual tumour evolution and argues for a comprehensive genetic analysis in clinical practice, which may be facilitated by the sensitive digital PCR assays developed in this study.

Background and AimsIn clinical trials for reducing fibrosis in NASH patients, therapeutics that target macrophages have had variable results. We evaluated intrahepatic macrophages in patients with non-alcoholic steatohepatitis to determine if fibrosis influenced phenotypes and expression of CCR2 and Galectin-3. Approach & ResultsWe used nCounter to analyze liver biopsies from well-matched patients with minimal (n=12) or advanced (n=12) fibrosis to determine which macrophage-related genes would be significantly different. Known therapy targets (e.g., CCR2 and Galectin-3) were significantly increased in patients with cirrhosis. However, several genes (e.g., CD68, CD16, and CD14) did not show significant differences, and CD163, a marker of pro-fibrotic macrophages was significantly decreased with cirrhosis. Next, we analyzed patients with minimal (n=6) or advanced fibrosis (n=5) using approaches that preserved hepatic architecture by multiplex-staining with anti-CD68, Mac387, CD163, CD14, and CD16. Spectral data were analyzed using deep learning/artificial intelligence to determine percentages and spatial relationships. This approach showed patients with advanced fibrosis had increased CD68+, CD16+, Mac387+, CD163+, and CD16+CD163+ populations. Interaction of CD68+ and Mac387+ populations was significantly increased in patients with cirrhosis and enrichment of these same phenotypes in individuals with minimal fibrosis correlated with poor outcomes. Evaluation of a final set of patients (n=4) also showed heterogenous expression of CD163, CCR2, Galectin-3, and Mac387, and significant differences were not dependent on fibrosis stage or NAFLD activity. ConclusionsApproaches that leave hepatic architecture intact, like multispectral imaging, may be paramount to developing effective treatments for NASH. In addition, understanding individual differences in patients may be required for optimal responses to macrophage-targeting therapies.

Histological assessment is foundational to multi-omics studies of liver disease, yet conventional fibrosis staging lacks resolution, and quantitative metrics like collagen proportionate area (CPA) fail to capture tissue architecture. While recent AI-driven approaches offer improved precision, they are proprietary and not accessible to academic research. Here, we present a novel, interpretable AI-based framework for characterising liver fibrosis from picrosirius red (PSR)-stained slides. By identifying distinct data-driven collagen deposition phenotypes (CDPs) which capture distinct morphologies, our method substantially improves the sensitivity and specificity of downstream transcriptomic and proteomic analyses compared to CPA and traditional fibrosis scores. Pathway analysis reveals that CDPs 4 and 5 are associated with active extracellular matrix remodelling, while phenotype correlates highlight links to liver functional status. Importantly, we demonstrate that selected CDPs can predict clinical outcomes with similar accuracy to established fibrosis metrics. All models and tools are made freely available to support transparent and reproducible multi-omics pathology research. HighlightsO_LIWe present a set of data-driven collagen deposition phenotypes for analysing PSR-stained liver biopsies, offering a spatially informed alternative to conventional fibrosis staging and CPA available as open-source code. C_LIO_LIThe identified collagen deposition phenotypes enhance transcriptomic and proteomic signal detection, revealing active ECM remodelling and distinct functional tissue states. C_LIO_LISelected phenotypes predict clinical outcomes with performance comparable to fibrosis stage and CPA, highlighting their potential as candidate quantitative indicators of fibrosis severity. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=98 SRC="FIGDIR/small/25334719v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@2d80aeorg.highwire.dtl.DTLVardef@15b5c1forg.highwire.dtl.DTLVardef@fd0a62org.highwire.dtl.DTLVardef@b4b0a4_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundPenile squamous cell carcinoma (PSCC) remains a relatively rare but formidable malignancy, especially in regions with limited access to preventive measures. The tumor microenvironment (TME) -specifically, the balance between CD8+ cytotoxic T cells (CTLs) and FOXP3+ regulatory T cells (Tregs)- has emerged as a pivotal determinant of tumor progression and immune evasion. This study aimed to evaluate CD8+/FOXP3+ ratios in both tumor and stromal compartments across different PSCC subtypes and grades. MethodsThis retrospective study analyzed tissue microarray (TMA) samples from 108 patients with invasive PSCC. Immunohistochemical staining for CD8+ and FOXP3+ was performed. Tumor and stromal compartments were assessed separately. Ratios of CD8+/FOXP3+ were categorized as CD8 > FOXP3 or CD8 [≤] FOXP3. Associations with histologic subtype and grade were examined using Chi-Square or Fishers Exact tests, with Cramers V indicating effect size. ResultsEighty TMA spots (15.2% of the total) had quantifiable data for both markers. We observed a significant association between CD8+/FOXP3+ ratio and histologic grade in both tumor (P=0.03) and stromal compartments (P=0.02), with moderate effect sizes (Cramers V ~ 0.3). Although no statistically significant associations emerged for histologic subtype, effect size measures suggested potential immune-infiltration differences across subtypes. Descriptive analyses indicated that tumor compartments often contained fewer T cells overall, while stromal areas demonstrated robust infiltration patterns. ConclusionsTumor grade appears to influence the relative infiltration of cytotoxic and regulatory T cells in PSCC, underscoring the need for compartment-specific immune profiling. These observations highlight the potential utility of CD8+/FOXP3+ ratios as prognostic markers and in guiding future immunotherapeutic strategies. Prospective studies incorporating larger cohorts and HPV stratification could further clarify the immunobiology of PSCC and inform personalized treatment approaches.

Intraductal papillary mucinous neoplasms (IPMN) are one of the main precursor lesions of Pancreatic Ductal Adenocarcinoma (PDAC). The number of patients diagnosed with IPMN is constantly increasing. While in most of the cases IPMN present as indolent and nonmalignant entities, some degenerate into PDAC. The main mechanisms behind the IPMN progression to malignancy is still not fully understood. This is mainly due to the technological limit of the analyzes and to cysts heterogeneity whose malignant transformation potential is estimated based on size and degree of dysplasia without take in consideration the transformation time and therefore the real malignancy potential. Moreover, there is a general lack of consensus diagnostic markers to discern the Low-grade nonmalignant from High-grade malignant IPMN. In this study, we used two different Spatial Transcriptomic technologies (Visium, and GeoMx) to investigate the transcriptome of Low-grade dysplasia nonmalignant IPMN, Borderline IPMN, and High-grade dysplasia malignant IPMN to dissect the main mechanism that drives carcingenesis and to find specific markers associated to risk of tumor progression. We performed Visium spatial transcriptomics on two TMAs containing three Low-grade dysplasia nonmalignant IPMN, one Borderline IPMN, two High-grade dysplasia malignant IPMN, and two PDAC. We identified three specific epithelial cell clusters that characterize Low-grade dysplasia IPMN, Borderline IPMN, and High-grade dysplasia malignant IPMN and three transcription factors whose expression is associated with each grade. High-grade malignant IPMN were characterized by high expression levels of NKX6-2 and other markers of gastric isthmus cell lineage such as MUC5AC, PSCA, FERIL6. The SPDEF high IPMN cluster was found in Borderline IPMN and spotted in some regions of High-grade malignant IPMN. This cluster was characterized by high expression levels of SPDEF and other goblet cell lineage markers such as TFF2, AQP5, and MUC6. Low-grade nonmalignant IPMN were characterized by high expression levels of HOXB3, HOXB5, ZNF117. The association of these markers with the different grades was validated by GeoMx spatial transcriptomics on 43 additional IPMN samples divided according to their grade of dysplasia and malignancy. To better understand the transcriptomic changes along IPMN progression we performed spatial trajectory inference and we found that SPDEF high IPMN cluster cells are likely to evolve into NKX6-2 high malignant IPMN, and we found that this switch is characterized by the expression of NKX6-2 and other gastric markers. Taken together, the results presented here not only shed more light in to IPMN and PDAC oncogenesis, but also provided a plethora of novel malignancy-associated markers to be tested in diagnostic routine, to better delineate IPMN progression in patients and improve clinical management.

Fibroblasts display complex functions associated with distinct gene expression profiles that influence matrix production and cell communications and the autonomy of tissue development and repair. Thrombospondin-2 (TSP-2), produced by fibroblasts, is a potent angiogenesis inhibitor and negatively associated with tissue repair. Single-cell (sc) sequencing analysis on WT and TSP2KO skin fibroblasts demonstrate distinct cell heterogeneity. Specifically, we found an enrichment of Sox10+ multipotent progenitor cells, identified as Schwann precursor cells, in TSP2KO fibroblasts, while fibrosis-related subpopulations decreased. Immunostaining of tissue and cells validated the increase of this Sox10+ population in KO fibroblasts. Furthermore, in silico analysis suggested enhanced pro-survival signaling, including WNT, TGF-{beta}, and PDGF-{beta}, alongside a reduced BMP4 response. Additionally, the creation of two TSP2KO NIH3T3 cell lines using the CRISPR/Cas9 technique allowed functional and signaling validation in a less complex system. Moreover, KO 3T3 cells exhibited enhanced migration and proliferation, with elevated levels of pro-regenerative molecules including TGF-{beta}3 and Wnt4, and enrichment of nuclear {beta}-catenin. These functional and molecular alterations likely contribute to improved healing and increased neurogenesis in TSP2-deficient wounds. Overall, our findings describe the heterogeneity of dermal fibroblasts and identify pro-regenerative features of TSP2KO fibroblasts.

BackgroundB cells and tertiary lymphoid structures (TLS) are reported to be important in the improvement of survival of cancer patients. These secondary lymphoid organs have been associated with the generation of an anti-tumor response. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types and the stromal architecture shapes the intratumoral heterogeneity. The stroma of PDAC is a complex system in which crosstalk takes place between cancer-associated fibroblasts, immune cells, endothelial cells and the cancer cells. Besides immune cells and fibroblasts, there is some limited data about the influence of nerve fibers on cancer progression. Patients and methodsNerve Fiber Density (NFD) was analysed in our cohort of 188 patients with Pancreatic Ductal Adenocarcinoma who underwent pancreatic surgery. We used immunohistochemistry and multiplex imaging to phenotype the immune cell infiltrate. The cell detection classifier measured distance from immune cell to cancer gland and with a heat map we could count TLS. By using Machine learning we were able to define the spatial distribution and counting Tertiary Lymphoid Structures. ResultsHigh NFD is significantly associated with prolonged overall survival (HR 1.676 (95%CI 1.126,2.495) for low vs. high NFD, p-value 0.0109). The immune cells surrounding the nerve fibers were phenotyped in B cells, T cells and dendritic follicular cells, matching a TLS. Here we show that small nerve fibers are located at the TLS in Pancreatic Cancer and a high Nerve Fiber Density combined with more than 5 TLS is associated with a better survival (HR 0.388 (95%CI 0.218, 0.689). ConclusionThe co-localization of small nerve fibers with TLS is a new finding which has not been described before. However the precise roles of these TLS and nerve fibers remains unknown. These findings unravel future pathways and has the potential to reach new directions into already existing targeted therapy.

Dystrophinopathies are caused by pathogenic variants in the DMD gene resulting in partial (Becker) or complete loss (Duchenne) of dystrophin. Becker (BMD) and Duchenne muscular dystrophy (DMD), are characterized by progressive muscle wasting, fatty replacement, fibrosis, and loss of function. To study histopathological changes, we used spatial transcriptomics to profile skeletal muscle biopsies of BMD, DMD patients and healthy controls (N = 4 per group). We estimated the proportion of cell types and their spatial localization across samples applying a deconvolution strategy using single-nuclei RNA-sequencing data. We identified genes enriched in fat patches and cell types such as fibroadipogenic progenitor cells (FAPs) in areas of active pathology. Using expression data of ligand receptor pairs, we highlight cell-cell communications leading to fibrotic and adipogenic lesions. Finally, analysis of gene expression gradients in areas of adjacent muscle and fat, allowed the identification of genes associated with muscle areas committed to become fat. Significance statementThis study investigates the cellular and molecular changes that occur in muscles affected by Becker and Duchenne muscular dystrophy (BMD and DMD). These diseases are caused by mutations in the DMD gene, leading to muscle degeneration and the replacement of muscle tissue with fibrotic and fatty tissue causative for an early death. By using spatial transcriptomics, the researchers analyzed muscle biopsies from BMD, DMD patients, and healthy controls. They identified specific genes and cell types, such as fibroadipogenic progenitor cells, that are involved in disease progression. The study also revealed how different cells communicate with each other to drive muscle degeneration and fat accumulation. These findings provide new insights into the mechanisms of disease and potential targets for future therapies.

BackgroundIntraductal papillary mucinous neoplasms (IPMNs) are preinvasive pancreatic lesions with a spectrum of histologic phenotypes and variable risk in progressing to invasive cancer. Aberrant repetitive element expression has been shown to be functionally linked to cell state changes in pancreatic cancer. ObjectiveThis study utilized spatial transcriptomics with customized repeat element probes to better understand the relationship of histologic subtypes, repeat element dysregulation, and molecular profiles of different cell populations in IPMN. DesignA total of 52 lesions from 18 patients with resected IPMNs of different histologies and degrees of dysplasia were analyzed with whole transcriptome spatial analysis (GeoMx). Of these, 50 lesions from 17 patients were also processed for single-cell spatial molecular imaging (CosMx). Repeat element probes for LINE1, HSATII, HERVK, and HERVH were used for GeoMx and CosMx. ResultsPancreaticobiliary-type IPMN was enriched for basal-like epithelium and infiltration of Treg cells. Intestinal-type IPMN was enriched for classical epithelium and macrophage infiltrates. Gastric-type IPMN was found to have equal basal-like and classical epithelium with a diverse immune infiltrate. Repeat RNAs were expressed at high levels across IPMN phenotypes and enriched in high-grade dysplasia. Single-cell transcriptional trajectory analysis revealed a phylogeny starting from gastric toward intestinal and pancreaticobiliary branches associated with higher-grade dysplasia and repeat RNA expression. ConclusionSpatial transcriptomics of IPMN identified a molecular continuum between histological subtypes supporting a common gastric-type origin that transitions to intestinal and pancreatobiliary phenotypes. This cell state plasticity is linked with repeat element expression that can be a potential biomarker for IPMN progression. What is already known on this topicO_LIMolecular characterization of IPMN subtypes using regional spatial transcriptomics has described the differences between histologies C_LIO_LIRepeat element expression is associated with cell state changes in pancreatic ductal neoplasm C_LI What this study addsO_LISingle cell spatial molecular imaging of IPMN subtypes reveals a cellular and molecular continuum starting from gastric histology with distinct branches to Intestinal and pancreatobiliary subtypes C_LIO_LIRepeat element expression is associated with higher grade IPMN histology C_LIO_LIRepeat element expression is elevated in the histologic and molecular continuum from gastric to intestinal and pancreatobiliary-type IPMN C_LI How this study might affect research, practice, or policyO_LIThese results support a common gastric histology origin of IPMN subtypes with different molecular trajectories towards higher grade disease C_LIO_LIOur findings suggest that repeat RNA expression can be used in conjunction with other transcriptional markers of cell state as a biomarker for IPMN progression C_LI

BackgroundIntraductal papillary mucinous neoplasms (IPMNs) are clinically detectable precursors of pancreatic adenocarcinoma, yet the mechanisms initiating their development remain poorly defined. Although KRAS mutations are highly frequent in human IPMNs, KRAS activation in pancreatic ductal cells alone fails to recapitulate IPMN development in murine models, indicating that additional tumor-suppressive mechanisms must be overcome. ObjectiveThe objective was to determine whether loss of the transcription factor HNF1B predisposes to initiation of IPMN. DesignWe assessed HNF1B nuclear expression and promoter methylation in resected human IPMN specimens. To model IPMN initiation, we generated mice with ductal-specific inactivation of Hnf1b, alone or combined with KRASG12D. Ductal organoids and RNA-sequencing were used to investigate molecular mechanisms. Transcriptomic analyses were also performed on human IPMN surgical specimens. MRI from germline HNF1B mutation/deletion carriers was re-evaluated for IPMN prevalence. ResultsHuman IPMNs showed loss of HNF1B by immunochemistry, with enrichment to promoter methylation that increased with dysplasia grade. The KHC model recapitulated the key features of IPMN development including ductal dilation, high proliferation, papillary architecture and mucin production. Loss of Hnf1b together with Kras activation induced loss of primary cilia, cellular reprogramming and engaged oncogenic YAP and Wnt/{beta}-catenin signaling, similar to human IPMNs. Moreover, germline HNF1B carriers exhibited a markedly increased prevalence of branch-duct IPMN. ConclusionHNF1B functions as a tumor-suppressive gatekeeper of pancreatic ductal cells. These findings highlight HNF1B inactivation as a potential biomarker and therapeutic entry point for early interception of IPMN-driven pancreatic cancer. They also have implications for the surveillance of HNF1B-syndrome.

IntroductionThe extracellular matrix (ECM) supports tumor progression by influencing tumor cell migration and invasion. This study examines the link between peritumoral ECM morphology and five-year recurrence risk in TNM Stage II colon cancer, using quantitative whole-slide ECM imaging. We hypothesize that loose ECM regions are associated with increased recurrence risk due to enhanced tumor budding (TB) or poorly differentiated clusters (PDC). MethodsIn a case-control study of 100 TNM Stage II colon cancer patients (25 with recurrence and 75 controls matched by lymph node sampling and tumor extent), Picrosirius red-stained sections were imaged to quantify ten ECM parameters across 798 regions of interest (ROIs). Conditional logistic regression assessed associations between ECM morphologies, TB, PDCs, and recurrence. ResultsUnsupervised clustering identified three ECM morphologies: dense fibrous, loose sparse, and complex tortuous. Dense fibrous ECM correlated strongly with recurrence (aOR 9.43, 95% CI 3.29-29.30, p < 0.001), while loose sparse and complex tortuous ECMs were associated with reduced recurrence risk (aOR 0.33, 95% CI 0.11-0.91, p = 0.040, and aOR 0.14, 95% CI 0.02-0.53, p = 0.012, respectively). TB was highest in loose sparse ECM (mean 9.3), and PDCs were highest in dense fibrous ECM (mean 5.5). DiscussionOur findings suggest that ECM morphology, particularly dense fibrous ECM, predicts recurrence in Stage II colon cancer, highlighting ECM profiling as a promising tool for patient stratification beyond traditional staging.

Lectin staining of benign and malignant cartilage proliferations indicates restricted glycoprofiles and significant differences. In general terms benign lesions show less cellular binding and more matrical binding than malignant lesions. This suggests that in the benign category cells are less metabolically active and the matrix more structurally stable. Chondrosarcoma cells stain with the lectin lPHA indicating increased {beta}1-6 branching linkages in complex N-linked glycans which is also a known feature of carcinoma cells. Increased angiogenesis and increased mast cell numbers are present in the connective tissue septa separating lobules of chondrosarcoma. The blood vessels stain with the lectins PTL-II and lPHA. Mast cells stain with lPHA. {beta} 1-6 linkage is initiated by the Golgi-bound glycosyltransferase GnTase V. Increased {beta}1-6 linkages are believed to enhance the metastatic potential of a malignant cell by angiogenesis. LPHA ligand is present not only in chondrosarcoma cells but also in endothelial cells and mast cells of the septa. The ligand for the lectin PTL-II is a core 1 O-linked glycans produced under the auspices of the galactosyltransferase T synthase. Production of this glycans by endothelial cells is believed to be obligatory for the formation of these cells into tubes as part of the construction of functioning blood vessels. There are, therefore, two candidate genes in chondrosarcoma worthy of further study viz those for GnTase V and T synthase. Targeted disruption of the activities of these genes has therapeutic possibilities.

Overactive bladder (OAB) is a urological symptom complex defined by urinary urgency. It can have a devastating impact on an individuals quality of life and leads to significant financial cost. Insulin-like growth factor 1 (IGF-1) is a protein hormone involved in a broad range of processes including cell proliferation and differentiation. IGF-1 is also regulated through alternative splicing. While the primary IGF-1Ea transcript is highly expressed in liver, the alternative IGF-1Ec transcript encodes the proteolytically-derived MGF peptide and has been primarily studied in skeletal muscle. MGF has been shown to stimulate satellite cell proliferation following tissue mechanical stretch or injury, but the role of MGF in smooth muscle, such as the detrusor muscle of the bladder, has been little explored. The aim of this study was to explore the expression of MGF in bladder biopsies from patients with OAB and age-matched controls. We show using immunohistochemistry that MGF is widely expressed in bladder tissue. Quantification of MGF expression by western blot showed that average MGF expression is more than doubled in OAB biopsies compared to controls (mean MGF in OAB=0.51{+/-}0.1, n=23; mean MGF in controls=0.22{+/-}0.07, n=9; p=0.05). Furthermore, there is an inverse correlation between MGF protein levels and symptom severity, as determined by the urodynamic parameter maximum cystometric capacity (correlation=0.53, p=0.03 n=16). MGF expression was highest in OAB biopsies with strong expression of the muscle cell marker DES. Combined with our observation that MGF induces cell proliferation in primary bladder cultures, our data suggests that high MGF expression in OAB patients may represent an attempted protective response in the bladder.

To date, characterization of the Barretts esophagus (BE) immune microenvironment in patients with known progression status to determine how the microenvironment may influence BE progression to esophageal adenocarcinoma (EAC) has been understudied, hindering both the biological understanding of progression and the development of novel diagnostics and therapies. Therefore, this studys aim was to determine if highly multiplex interrogation of the immune microenvironment can be performed on endoscopic formalin-fixed, paraffin-embedded (FFPE) samples utilizing the Nanostring GeoMx digital spatial profiling (GeoMx DSP) platform. We performed spatial proteomic analysis of 49 proteins expressed in the microenvironment and epithelial cells of histologically identical FFPE endoscopic biopsies from patients with non-dysplastic BE (NDBE) who later progressed to high-grade dysplasia (HGD) or EAC (N=7) or from patients who after at least 5 years follow up did not (N=8). In addition, we performed RNA analysis of 1,812 cancer related transcripts on a series of three endoscopic mucosal resections containing regions of normal tissue, BE, dysplasia (DYS), and EAC. Our primary goal was to determine feasibility of this approach and begin to identify the types of specific immune cell populations that may mediate the progression of pre-neoplastic BE to EAC. Spatial proteomic and transcriptomic profiling with GeoMx DSP showed reasonable quality metrics and detected expected differences between epithelium and stroma. Several proteins were found to have increased expression within non-dysplastic BE biopsies from progressors compared to non-progressors, suggesting further studies on the BE microenvironment are warranted. SummaryNew biological insights into the stepwise development and progression of esophageal adenocarcinoma (EAC) from Barretts esophagus (BE) are imperative to develop tailored approaches for early detection and optimal clinical management of the disease. This study aimed to determine the feasibility to spatially profile stromal and immunologic properties that accompany malignant transformation of BE to EAC in formalin-fixed, paraffin-embedded (FFPE) tissues. NanoStrings Digital Spatial Profiling (DSP) technology can detect and quantify protein and RNA transcripts in a highly multiplexed manner with spatial resolution, within specific regions of interest on FFPE tissue. Here, we performed a pilot study using the Nanostring GeoMx DSP, for measurement of protein and ribonucleic acid (RNA) expression on a series of FFPE slides from endoscopic biopsies and endoscopic mucosal resections (EMR) of BE. We compare a small series of biopsies of non-dysplastic BE (NDBE) from patients who progressed to more advanced disease to patients with NBDE who did not progress and then perform RNA profiling on EMRs with a range of histologic diagnoses.

Intrahepatic macrophages influence the composition of the microenvironment, host immune response to liver injury, and development of fibrosis. Compared to stellate cells, the role of intrahepatic macrophages in the development of fibrosis remains ill defined. Multispectral imaging allows detection of multiple markers in situ in human formalin-fixed, paraffin-embedded tissue. This cutting-edge technology is ideal for analyzing human liver tissues since it allows spectral unmixing of fluorophore signals, subtraction of auto-fluorescence, and preserves architecture and the in vivo hepatic milieu. We analyzed resident Kupffer cells (CD68+), monocyte-derived macrophages (Mac387+), pro-fibrogenic macrophages (CD163+), and co-expression of pro-inflammatory (CD14) and anti-inflammatory (CD16) markers in liver biopsies from patients with hepatitis C virus (HCV) and different stages of fibrosis. Liver biopsies with advanced fibrosis showed increased accumulation of CD163+, MAC387+ and CD68+ macrophages in the portal tracts when compared to those with minimal fibrosis. Imaging software generated t-distributed stochastic neighbor embedding (t-SNE) plots and phenotype matrices that facilitated comparison of macrophage profiles. These included monocyte-derived (CD68+/Mac387+) and pro-fibrotic/anti-inflammatory (CD163+/CD16+) phenotypes. We established that the utility of this platform could be extended to liver biopsies from patients with other chronic liver diseases including nonalcoholic steatohepatitis and autoimmune hepatitis. Each disease exhibited a unique profile after spectral imaging analysis and this platform holds the potential to identify patients predisposed to progressive liver disease based on the macrophage composition. In summary, spectral imaging is a powerful tool that enables analysis of macrophage profiles in different types of chronic liver diseases and has potential to change the manner in which we evaluate liver biopsies leading to more personalized treatment strategies.

Benign prostatic hyperplasia (BPH) is a prevalent age-related condition often characterized by debilitating urinary symptoms. Its etiology is believed to stem from hormonal imbalance, particularly an elevated estradiol-to-testosterone ratio and chronic inflammation. Our previous studies using a mouse steroid hormone imbalance model identified a specific increase in macrophages that migrate and accumulate in the prostate lumen where they differentiate into lipid-laden foam cells in mice implanted with testosterone and estradiol pellets, but not in sham animals. The current study focused on further characterizing the cellular heterogeneity of the prostate in this model as well as identifying the specific transcriptomic signature of the recruited foam cells. Moreover, we aimed to identify the epithelia-derived signals that drive macrophage infiltration and luminal translocation. Male C57BL/6J mice were implanted with slow-release testosterone and estradiol pellets (T+E2) and harvested the ventral prostates two weeks later for scRNA-seq analysis, or performed sham surgery. We identified Ear2+ and Cd72+ macrophages that were elevated in response to steroid hormone imbalance, whereas a Mrc1+ resident macrophage population did not change. In addition, an Spp1+ foam cell cluster was almost exclusively found in T+E2 mice. Further markers of foam cells were also identified, including Gpnmb and Trem2, and GPNMB was confirmed as a novel histological marker with immunohistochemistry. Foam cells were also shown to express known pathological factors Vegf, Tgfb1, Ccl6, Cxcl16 and Mmp12. Intriguingly, a screen for chemokines identified the upregulation of epithelial-derived Cxcl17, a known monocyte attractant, in T+E2 prostates suggesting that it might be responsible for the elevated macrophage number as well as their translocation to the lumen. Our study identified macrophage subsets that respond to steroid hormone imbalance as well as further confirmed a potential pathological role of luminal foam cells in the prostate. These results underscore a pathological role of the identified prostate foam cells and suggests CXCL17-mediated macrophage migration as a critical initiating event.