Sacrococcygeal teratomas (SCTs) are the most common neonatal tumors, yet their cellular origins, clinical stratification, and sex bias-occurring three times more in XX than XY individuals-remain poorly understood. To address these gaps, we examined six postnatal (one male and five female) and two prenatal (both female) SCTs by single nuclei RNA-seq and spatial transcriptomics. We identified five broad cellular lineages in SCTs: stroma, epithelia, endothelia, neuroectoderm, and immune. The transcriptomes and lineage compositions showed significant heterogeneity, which offer a framework for future molecular stratification. SCTs are thought to originate from and be propagated by pluripotent cells, notably however, we did not detect these populations. Among female tumors, a subset of cells exhibited biallelic expression of X-linked genes, consistent with X-inactivation failure or reactivation of the once inactivated X-chromosome. These biallelic cells were enriched for developmental and neuronal programs, whereas cells with single-allelic X-chromosome preferentially expressed immune-related genes. Biallelic X-chromosome activation, which can occur only in female cells, may result in transcriptomic features that favor survival of tumor cells, contributing to the sex bias of SCTs. Our findings reveal a link between X-chromosome inactivation and SCT cell identity, suggesting that X-dosage dysregulation may influence SCT heterogeneity and immune landscape.

Abstract Prostate cancer (PCa) is the most frequently diagnosed cancer in men and metastasizes predominantly to bone, lymph node, liver, and lung. Liver metastasis has been shown to associate with the worst patient outcomes with a median overall survival of 13.5 months and treatment options for metastatic castration resistant PCa are limited to chemotherapy. Retrospective analysis of liver metastatic biopsies identified an enrichment of genetic alterations in p53, Rb1, and PTEN tumor suppressor genes. Current pre-clinical models have limited capability to assess the effect of these genomic alterations on tumor progression in the liver tumor microenvironment (TME). Thus, there is a critical need to develop new models of liver metastatic PCa for discovery to identify transcriptomic profiles that associate with high-risk disease and assess potential therapeutic vulnerabilities. We report the development of a novel, fully humanized ‘tumor on a chip” model of the liver metastatic niche that incorporate human liver stroma and PCa organoids. We utilize a microfluidic platform, LumeNEXT, which allows 3D culture of multicellular TME networks in the context of an endothelial lined lumen. We have optimized media conditions to co-culture HepG2 hepatocytes, LNCaP tumor organoids and HUVEC endothelial cells in hydrogel matrix. Confocal microscopy is performed for live cell, multi-parameter analysis of spatio-temporal investigation of the liver TME. Direct, in-chip, live cell analysis of cell viability is performed with Hoechst nuclear labeling, Calcein AM and Ethidium homodimer staining. Culture conditions have been optimized to maintain >85% viability for each cell type after 3 days of co-culture. We demonstrated that HUVEC cells were able to form endothelial lined vessels that maintained 3D structure within this multi-cellular TME. This platform enables future testing of different cellular compositions of liver TME, including different immune cell and stromal populations. We are currently incorporating CRISPR engineered LNCaP cell lines with p53 and Rb1 loss to evaluate the functional impact of the liver TME in the context of high-risk genomic mutations. This novel model system may expedite discovery of the molecular drivers behind this aggressive form of disease and allow identification of targetable mechanisms to develop more effective treatment strategies to improve outcomes for patients with PCa liver metastasis. More recent iterations implement a normal hepatocyte model of THLE-2, SV40 immortalized normal hepatocytes, to replace HepG2, liver carcinoma cells. Future model development will include incorporating primary patient-derived liver cells such as hepatocytes, Kupffer cells and stellate cells, matched with prostate tumor cells for a personalized medicine approach to treatment strategies. Citation Format: Katherine Vietor, Erika Heninger, Gabriel Eades, Adeline B. Ding, Cristina Sanchez de Diego, David A. Quigley, Sheena C. Kerr, Joshua M. Lang. Development of a fully humanized vascularized "tumor on a chip" model for prostate cancer liver metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Innovations in Prostate Cancer Research and Treatment; 2026 Jan 20-22; Philadelphia PA. Philadelphia (PA): AACR; Cancer Res 2026;86(2_Suppl):Abstract nr PR023.

Congenital Pulmonary Airway malformations (CPAM) may lead to malignant degeneration, and therefore many surgeons opt to resect CPAM even in asymptomatic patients. Previously, we identified Kirsten rat sarcoma virus (KRAS) mutations in a subset of CPAM patients, possibly indicating a pre-malignant state. In order to unify treatment strategy in (asymptomatic) patients we focused on KRAS mutations as a potential risk factor for developing malignancy in CPAM. Resected lung tissue of CPAM patients was separated in affected region ("cyst") and non-affected region ("control") to subsequently initiate airway organoids. Cyst and control organoids from the same patients with and without KRAS mutations (KRASPOS vs. KRASNEG) (n = 3) where processed for single cell RNA sequencing (scRNA-Seq), and the cellular composition of the organoids was validated by immunofluorescent staining. The role of KRAS was identified by manipulating the expression in the organoids. ScRNA-Seq data revealed differences in cell proportions between KRASPOS and KRASNEG cyst, and control organoids. The significant differentially expressed genes in the KRASPOS cyst are comparable to those identified in lung cancer patients with KRAS mutations. Manipulation of KRAS expression showed that KRASPOS cyst organoids grew larger due to more proliferative cells and that KRAS directly affected the cell cycle. KRASPOS cyst organoids show transcriptomic similarities with KRAS mutated lung cancers, show changes in cellular composition and have increased growth and proliferation. These findings support the hypothesis that KRAS mutated CPAM cysts belong to a group of CPAM patients at higher risk of developing a malignancy.

The identification of Daphne taxa is difficult because of the lack of available morphological characteristics. Here, we aimed to describe leaf and wood micromorpho‐anatomical characteristics of native Turkish Daphne taxa ( D. glomerata , D. gnidioides , D. mezereum , D. mucronata , D. oleoides subsp. kurdica , D. pontica and D. sericea ) from three phytogeographical regions (Europeo‐Siberian, Irano‐Turanian and Mediterranean) from Türkiye to contribute to the systematic position of taxa. Totally, 41 leaf and wood characters were investigated. Most of the features were characterised in detail for the first time in these taxa, and statistical analyses were used to evaluate the diagnostic characters. SEM analysis was carried out to determine the surface structures of leaves and tracheal elements of wood. We encountered the following distinct anatomical differences: 1) differences in wax depositions in leaves, 2) in pubescens details, 3) in cell wall patterns, 4) in mesophyll types, 5) in midrib structures, 6) in stomatal number and stomatal length in hypostomatic leaves with anomocytic stomata and 7) in vessel arragement in growth rings, with different ray frequency and cellular ray composition, and the presence of tori in intervessel pits in wood. An identification key based on these micromorpho‐anatomical characters is presented, some ecological interpretations are made, and the study's results are compared to existing data in the literature. Our results demonstrate that the micromorpho‐anatomical data across taxa are partly congruent with the classification in the Turkish Flora, but new sectional arrangements may be recommended for the systematic positions of taxa based on their phytogeographical origins.

Fibrosis is one of the major causes of cardiac allograft malfunction and is mainly driven by fibroblasts. However, the role of recipient-derived cells in generating allograft fibroblasts and the underlying mechanisms remain to be explored. We analyzed human heart allograft samples and used murine transplant models (C57BL/6J, Cd34-CreERT2; R26-tdTomato, mRFP mice, Rosa26-iDTR, Postn-CreERT2; R26-tdTomato, double-tdTomato, and immunodeficient mice with BALB/c donors). Human progenitor cells were cultivated from blood. Single-cell RNA sequencing, Western blotting, quantitative polymerase chain reaction, and immunohistochemistry, whole-mount staining with 3-dimensional reconstruction, and in vivo/in vitro experiments were applied to characterize allograft cellular composition and communication. Single-cell RNA sequencing was introduced to delineate the allograft cell atlas of patients and mice. Y chromosome analysis identified that recipient-derived cells contributed to allograft fibroblasts in both patients and murine models. Combining the genetic cell lineage tracing technique, we found that recipient-derived CD34+ cells could give rise to activated fibroblasts. Bone marrow transplantation and parabiosis models revealed that the recipient's circulating non-bone marrow Cd34+ cells could generate allograft fibroblasts. Human CD34+ cells could differentiate into fibroblasts both in vivo and in vitro. CD34+ fibroblast progenitors were recruited by CXCL12-ACKR3 and MIF-ACKR3 interactions and differentiated via the TGFβ (transforming growth factor beta)/GFPT2 (glutamine-fructose-6-phosphate transaminase 2)/SMAD2/4 axis. Ablation of recipient Cd34+ cells reduced activated fibroblasts and alleviated allograft fibrosis. We identify circulating CD34+ cells as a novel source of fibroblast progenitors that contribute to cardiac allograft fibrosis, suggesting that targeting recipient CD34+ cells could be a novel therapeutic potential for treating cardiac fibrosis after heart transplantation.

In animals, low-dose-rate radiation induces cancer at a reduced rate compared with a high-dose-rate at an identical cumulative dose, although the underlying mechanism is not well understood. The immediate responses of cells to irradiation are well established, including DNA double-strand break repair, cell-cycle arrest and cell death; conversely, the changes in tissues weeks after irradiation are not well understood. We therefore analysed cellular dynamics in rat mammary tissue weeks after high- or low-dose-rate irradiation. We irradiated 5-week-old rats with 2Gy (30Gy/h) or 3- to 5-week-old rats with continuous 2Gy (6mGy/h). For histological analysis, luminal cells were identified with anti-cytokeratin (CK) 8 + 18; CK8 + 18Low cells are luminal progenitor cells, and CK8 + 18High cells are luminal mature cells. To evaluate cell composition by flow cytometry, epithelial cells were isolated from mammary tissue. The proliferative potential of luminal progenitor cells-as measured by Ki-67 on paraffin sections-decreased 2weeks after irradiation at either the high- or low-dose rate but recovered to the control level by 4weeks. No significant difference was observed in the S phase and total cell-cycle length identified by 5-ethynyl-2'-deoxyuridine and 5-bromo-2'-deoxyuridine or cell death marked by cleaved caspase-3 among the dose-rates. Furthermore, the composition of luminal mature cells changed 2-6weeks after completing the high- and, to a lesser extent, low-dose-rate radiation exposure, indicating potential proliferative stimulation of luminal progenitor cells related to susceptibility to carcinogenesis. These findings suggest that the altered cell composition and dynamics of luminal cells for several weeks contribute to carcinogenesis.

Enhancing forensic casework interpretation through DNA methylation-based analysis: A case study of pooled blood samples.

Molecular and cellular composition changes after neoadjuvant letrozole and palbociclib in early luminal breast cancer.

Yak is a unique bovinespecies that adapts to the extreme climate of the Qinghai-Tibet Plateau in part owing to its dense skin coat. Despite its essential role in cold adaptation, the genetic basis of hair follicle structure and growth has not been extensively studied in this iconic animal. In the present study, we construct a single-cell atlas of hair follicle (HF) cells from yak and taurine cattle and examine differences in their cellular composition and gene expression. Among the 14 cell types identified in HFs, the dermal papilla (DP) displays the most dramatic differences between cattle and yak. Detailed analysis reveals that the genes in the WNT signaling pathway are differentially expressed in the dermal papilla (DP) cells of yak. Using primary cultures of DP cells, we reveal that the inhibition or activation of WNT/β-Catenin dramatically alters cell cycle progression and autophagy. In complimentary with the ATAC-seq data, we show that SOX4 is directly associated with the promoters of WNT1 and WNT3A. Interestingly, increased autophagy regulates the expression of SOX4/WNT/β-Catenin to promote the proliferation of DP cells in yak. Together, these results reveal the molecular signature of coat adaptation at the single-cell transcription level and provide a new understanding of animal adaptation to extreme environments.

Abstract Introduction and aims Keloids are a type of fibroproliferative scar that progressively grow beyond the original wound site. Currently, there are no treatments to halt or revert keloid scarring, emphasizing an unmet clinical need. Fibroblasts are presumed to be one of the main cells involved in keloid, due to their role in depositing and remodelling extracellular matrix. In normal tissue repair fibroblasts enter a resolution phase, which we hypothesize fails in keloid. Therefore, this study investigates the chromatin and transcriptional landscape of keloid fibroblasts, questioning whether manipulation of the epigenome can reverse their locked profibrotic state. Methods We performed ATAC sequencing (ATACseq) and RNA sequencing on a patient-matched pair of keloid and nonlesional fibroblasts. Bioinformatic analysis revealed differential accessible regions with multiple transcription factors and regulatory elements which we correlated to gene expression changes. Identified key candidates were manipulated in two-dimensional cell culture models and validated in keloid scar tissue. Results ATACseq analysis revealed a more accessible chromatin structure in keloid fibroblasts in areas regulating developmental, growth factor signalling and profibrotic gene signatures. This was confirmed in vitro with increased histone acetylation and methylation marks, associated with open chromatin and higher transcriptional activation. The most accessible chromatin regions in keloid fibroblasts were around the FGFR2 and TGFβR3 gene loci. Stimulation of cells with these growth factors increased signalling responsiveness in proliferation in keloid fibroblasts. Additionally, keloid cells had shown a more reticular-like cellular membrane lipid composition which can be altered in response to fibroblast growth factor 2 and transforming growth factor β stimulation. Treatment with chromatin-modifying drugs such as trichostatin A actively modulated the fibrotic morphology of keloid fibroblasts. Conclusions Keloids have a more open chromatin that is anticipated to play an active role in maintaining profibrotic signalling pathways and cell behaviours. We are currently exploring the therapeutic potential of manipulating the chromatin in keloid fibroblasts to reduce scarring.

IntroductionInflammatory breast cancer (IBC) is a rare invasive tumor and characterized by the formation of tumor emboli within dermal lymphatic vessels. The tumor microenvironment (TME) is a key factor in IBC aggressiveness, but its heterogeneity and intercellular role remain incompletely understood.MethodsWeighted gene coexpression network analysis (WGCNA) was performed to identify immune infiltration-associated genes. We also depicted cellular communication networks and specific ligand-receptor signaling pathways using the single-cell transcriptomics analysis of IBC and non-IBC samples. Finally, we verified the expression of key proteins by immunohistochemistry.ResultsThrough the intersection of WGCNA module genes and differentially expressed genes between pathological complete response and residual disease samples, GZMB was identified as hub gene which is related to immune infiltration and efficacy of neoadjuvant therapy in IBC. In IBC cohort, patients with high expression of GZMB harbored more immunosuppressive cells thus showed unfavorable prognosis compared with GZMB-low expression group (p<0.05). Subsequent to dimension reduction and clustering, 12 clusters were identified to construct the single-cell atlas between IBC and non-IBC samples. Cellular communication analysis unveiled the heterogeneity of cell communication in IBC. The proportion of immune cells was significantly lower than that of malignant epithelial cells in the cellular composition of IBC. Moreover, it indicated that SPP1 and plasmacytoid dendritic cells were specific in IBC and associated with an immunosuppressive microenvironment in IBC. Immunohistochemical analysis suggested that protein levels of GZMB and SPP1 tended to be higher in the samples from patients with residual disease compared to the patient achieving pathological complete response, though this observation is based on an extremely small sample size.DiscussionThis study identifies GZMB and SPP1 as potential immunosuppressive-related prognostic biomarkers in IBC patients, reveals the key role of plasmacytoid dendritic cells in remodeling of immunosuppressive microenvironment in IBC.

Background/Objectives: Platelet-rich plasma (PRP) is increasingly used in musculoskeletal medicine. Variability in PRP composition, driven by preparation- and donor-related factors, is considered a major contributor to inconsistent clinical outcomes. This study investigated whether habitual dietary patterns are associated with the cellular and molecular composition of leukocyte-poor PRP (LP-PRP). Methods: In this cross-sectional study, 75 healthy adults (25 vegans, 25 vegetarians, and 25 omnivores) who adhered to their dietary patterns for ≥6 months were enrolled. LP-PRP was prepared by a standardized protocol. Cell profiles were quantified in whole blood and LP-PRP; LP-PRP proteins (IL-6, IGF-1, HGF, and PDGF-BB) were measured by ELISA. Group differences, correlations, and multivariable regressions were performed. Results: Whole blood differed by diet with respect to total leukocytes, lymphocytes, and basophils, while platelet and erythrocyte counts did not. In LP-PRP, platelet enrichment ratios and leukocyte counts were comparable across diets. IL-6 in LP-PRP was lower in vegans vs. omnivores (p = 0.017); the Animal-Based Diet Score correlated positively with LP-PRP IL-6 and remained independently associated in regression (β = 0.35, p = 0.004). While IGF-1, HGF, and PDGF-BB did not differ between dietary groups, intake-based analyses revealed associations between specific dietary components and LP-PRP proteins; notably, the fruit and vegetable intake correlated inversely with PDGF-BB, and platelet–growth factor coupling was most pronounced among omnivores. Conclusions: Dietary patterns were associated with selected molecular components of LP-PRP—most consistently IL-6—while cell counts remain largely unchanged. However, interventional studies are needed to establish causality and determine whether dietary modification can influence clinical outcomes.

Triply periodic minimal surface (TPMS) lattices are an emerging class of cellular materials with excellent potential for lightweight structural and energy‐absorbing applications. In this study, gyroid (G), diamond (D), and primitive (P) architectures were fabricated via fused filament fabrication (FFF) using three material configurations: (i) single‐phase polylactic acid (PLA) or polyethylene terephthalate glycol (PETG); (ii) layered PLA‐PETG composite structures (50/50), in which the lower half was printed with PLA and the upper half with PETG; and (iii) layered composites with PLA shells and PETG cores. Quasi‐static compression tests were combined with finite element simulations to elucidate stress distribution, deformation mechanisms, and collapse progression. The results demonstrate that homogeneous blends delay crack initiation and enhance specific energy absorption through progressive collapse, while layered composites improve stability by redirecting stresses via the PLA shell. Finite element analysis successfully captured shear banding, layer‐wise buckling, and localized fracture, confirming the predictive capability of the simulations. The findings highlight the strong interplay between lattice geometry and material configuration in tailoring mechanical performance and provide guidelines for the design of multifunctional polymer‐based cellular composites produced by additive manufacturing.

Oral mucosal wounds heal faster and with minimal scarring compared to skin injuries, yet the underlying mechanisms remain poorly understood. To explore the cellular and molecular basis of this difference, we performed single-cell RNA sequencing (scRNA-seq) on paired, uninjured human oral mucosa and skin tissues from the same donors. This approach enabled the construction of a comprehensive single-cell transcriptomic atlas, facilitating direct comparison of cellular composition, gene expression profiles, and intercellular communication between the two tissues. Our analysis revealed distinct tissue-specific heterogeneity among keratinocytes, fibroblasts, immune cells, and endothelial cells. Oral keratinocytes exhibited signatures associated with proliferation and metabolic activity, while oral fibroblasts and immune cells expressed gene profiles suggestive of pro-regenerative and anti-fibrotic functions. Cell-cell communication analysis indicated that endothelial cells in oral mucosa participate in interactions that may promote rapid tissue remodeling. Although our data were derived from uninjured tissues, the identified differentially expressed genes and enriched pathways suggest potential regulatory networks that may underlie the distinct wound-healing behaviors of oral mucosa and skin. A subset of these genes was validated by RT-PCR in both autologous and allogeneic samples across different age and sex groups, confirming the robustness and reproducibility of our findings. This study provides the first single-cell transcriptomic comparison of intact human oral mucosa and skin under steady-state conditions, establishing a foundational atlas that reveals intrinsic tissue-specific features and identifies candidate targets for promoting scarless healing.

Outer retinal tubulation associated with photoreceptor degeneration.

Sex-related variations in liver homeostasis and disease: From zonation dynamics to clinical implications.

Coronary atherosclerotic plaque composition and classification in hypercholesterolemic pigs.

Changes in haematology, metabolic rate, and cellular structure of spleen and head kidney of brown trout, Salmo trutta, after exposure to polystyrene microplastic particles.

Innervation Changes in Apical Periodontitis and its Correlation with Preoperative Symptoms.

BackgroundOsteoarthritis (OA) is a complex, progressive joint disease characterized by cartilage degradation and inflammation. Traditional bulk tissue analyses have limited our understanding of the cellular diversity within OA tissues.MethodsThis study employed scRNA‐seq and integrated bioinformatic analyses to investigate the cellular composition and molecular pathways involved in OA. Publicly available datasets were analyzed to identify differentially expressed genes (DEGs) and enriched pathways. The genes, such as NR4A2, BMP1, and AVPR1A, were selected for further analysis. Molecular docking studies were conducted to explore the interaction with two identified compounds. Additionally, immune infiltration characteristics were analyzed using gene set variation analysis (GSVA) and correlation with key OA‐associated genes.ResultsWe analyzed cartilage samples from OA and normal individuals (GSE220243) and identified eight distinct chondrocyte subpopulations, with significant pathway enrichment in TNF, TGF‐β, and PI3K–Akt signaling pathways. Further differential gene expression analysis of GSE114007 identified 2247 genes, including 26 key OA‐associated drug targets, such as NR4A2, BMP1, and AVPR1A, which demonstrated strong diagnostic potential (AUC > 0.70) across multiple cohorts. Immune infiltration analysis revealed significant correlations between these key genes and immune cell subsets, highlighting their roles in the inflammatory microenvironment of OA. Additionally, molecular docking studies suggested that bexarotene has a favorable binding affinity for NR4A2, BMP1, and AVPR1A, making it a promising therapeutic candidate.ConclusionOur findings provide new insights into the molecular landscape of OA, offering valuable biomarkers and therapeutic targets for future OA interventions.