Search Results (1,480)

Background/Objectives: While traditional transcriptomics and single-cell RNA sequencing can reveal differences in cell type and gene expression, they cannot provide spatial information within tissues. Spatial transcriptomics (ST), as an emerging technology in recent years, has achieved significant progress in resolving gene expression along the spatial dimension. This technology quantifies gene expression at defined spatial coordinates and describes the spatial distribution of transcripts and the co-localization patterns between cells within intact tissue, allowing for an integrated analysis of molecular and spatial information. This review aims to systematically trace the development of ST and highlight its application value in breast cancer research. Methods: We systematically reviewed the recent literature on ST platforms, on combined analyses of single-cell RNA sequencing (scRNA-seq) and ST, and on integrated spatial multi-omics in breast cancer. Key topics include tumor microenvironment organization, intra-tumor heterogeneity, the spatial distribution of immune cells, cancer-associated fibroblast function, treatment-response prediction, and personalized-treatment strategy development. Results: ST can characterize the spatial organization of interactions between breast cancer cells and the tumor microenvironment, describe the spatial dimensions of tumor heterogeneity, and provide multi-dimensional information that may support refined subtype classification and prognostic assessment. Existing studies indicate that ST shows significant potential to inform personalized treatment strategies, but the technology also faces bottlenecks in data integration, spatial resolution, standardization, and the need for functional validation. Conclusions: ST provides an important tool for an in-depth description of the complex spatial organization within breast cancer tumors. When integrated with functional perturbation, longitudinal cohorts, and orthogonal omics, it has the potential to ultimately improve clinical outcomes for breast cancer patients. Full article

Introduction: Cutaneous T cell lymphoma (CTCL), most commonly known as mycosis fungoides (MF), is characterized by an increasingly immunosuppressive tumor microenvironment (TME) as the disease progresses. Cancer-associated fibroblasts (CAFs) are key stromal components that support a permissive niche, in part through the secretion of small extracellular vesicles (sEVs), predominantly exosomes, that mediate intercellular communication. We investigated the immunomodulatory role of exosome-enriched sEVs derived from MF fibroblasts (MF-Fs) compared to normal fibroblasts (N-Fs). Materials and Methods: Primary MF-Fs from early-stage MF biopsies and N-Fs from healthy skin were cultured in vitro. sEVs enriched with exosomes were isolated by ultracentrifugation and characterized by flow cytometry (CD81), electron microscopy, Nanosight analysis, and protein quantification, and their uptake by normal peripheral blood mononuclear cells (nPBMCs) was confirmed using PKH26-labeled sEVs. nPBMCs, monocytes, CD4⁺ and CD8⁺ T cells from healthy donors were exposed to MF-F or N-F sEVs. Cell viability was assessed using MTT and trypan blue exclusion assays. Mass cytometry (CyTOF) profiled immune subsets and regulatory proteins for preliminary observation. Monocyte polarization was evaluated by flow cytometry for M1 (CD80, CD86) and M2 (CD163, CD206) markers and PD-L1 expression; M1/M2-associated cytokines and sEV-microRNAs were quantified by qRT-PCR. Results: Both MF-F and N-F sEVs were internalized by nPBMCs and reduced their viability, with a more pronounced effect observed for MF-F sEVs. In nPBMCs, MF-F sEVs also increased the frequency of M2-like macrophages, decreased M1 polarization, and enhanced PD-L1 expression. In primary monocytes, MF-F- compared with N-F-derived sEVs upregulated M2-associated cytokines (IL-10, TGF-β), increased PD-L1 expression, and generated M2-like cells that suppressed CD4⁺ and CD8⁺ T cell viability. Conclusions: MF-F sEVs promote an immunosuppressive TME and represent potential therapeutic or biomarker targets in MF. Full article

Enhancer of zeste homolog 2 (EZH2), the catalytic component of the polycomb repressive complex 2, is frequently overexpressed in lung adenocarcinoma and contributes to transcriptional programs that support tumor proliferation and cellular plasticity. However, its role in regulating senescence-associated signaling and tumor–stromal interactions in lung cancer remains incompletely understood. In this study, we combined transcriptomic analysis of The Cancer Genome Atlas lung adenocarcinoma cohort with functional characterization of EZH2 targeting in A549 cells using the catalytic inhibitor EPZ6438 and the EZH2 degrader MS1943. Elevated EZH2 expression was associated with enrichment of cell cycle-related transcriptional pathways. Pharmacological targeting of EZH2 reduced proliferation, migration, stemness-associated features, and sphere-forming capacity, with more pronounced effects observed following EZH2 degradation. Both compounds promoted features consistent with senescence-associated phenotypic remodeling characterized by increased expression of p16 and p21, enhanced β-galactosidase activity, G0/G1 cell cycle arrest, and increased expression of cytokines commonly associated with senescence-related secretory signaling, including IL-6, CCL2, and CXCL8. Conditioned medium from treated tumor cells promoted activation of primary lung fibroblasts, indicating functional paracrine microenvironmental remodeling. Importantly, EZH2 targeting elicited cytostatic responses without induction of apoptosis. Collectively, these findings suggest that EZH2 contributes to regulation of proliferation-associated and senescence-associated phenotypic programs together with stromal signaling in lung adenocarcinoma. Full article

The fibroblast activation protein (FAP) has emerged as a compelling theranostic target because it is highly expressed in the tumour microenvironment of many solid malignancies, predominantly on cancer-associated fibroblasts and, in selected tumour types, also on tumour cells. Following the rapid clinical expansion of FAP-targeted PET imaging, FAP-targeted radionuclide therapy (FAP-TRT) is now being explored as a predominantly stromal-directed therapeutic strategy across a broad range of solid malignancies. However, unlike established theranostic paradigms, such as prostate-specific membrane antigen- and somatostatin receptor-directed radioligand therapies, FAP-TRT faces distinct biological and translational challenges, including stromal heterogeneity, variable patterns of FAP expression, and limited tumour retention of many early radioligands. This review outlines the biological rationale, mechanistic basis, radiopharmaceutical development, and emerging clinical evidence for FAP-TRT. We highlight the recent ligand-engineering strategies aimed to improve tumour residence time and absorbed dose, and to summarise the current clinical data with particular focus on dosimetry, safety, and early efficacy signals. We also discuss key future directions, including disease-focused clinical development and rational combination strategies with immune checkpoint inhibitors, DNA damage response inhibitors, and chemotherapy. Overall, the available data support the feasibility of FAP-TRT but also underscore the need for improved ligand design and biologically informed clinical development to define its role within the evolving theranostic landscape. Full article

For decades, peritoneal metastases (PM) have been regarded as a terminal manifestation of advanced malignancies and managed primarily with palliative intent because of limited sensitivity to systemic therapies. Accumulating clinical, molecular, and immunological evidence now supports the view that PM is not merely an anatomic pattern of spread but a distinct metastatic niche with characteristic biological, microenvironmental, and therapeutic features. This review summarizes the major routes of PM development—transcoelomic, lymphatic, and hematologic dissemination—and emphasizes how these pathways converge through shared biological programs. Core mechanisms include epithelial–mesenchymal transition (EMT), adhesion signaling, extracellular matrix remodeling, and tumor–immune cell interactions. A central focus is the peritoneal tumor microenvironment: mesothelial-to-mesenchymal transition, cancer-associated fibroblast activity, adipocyte-derived metabolic support, macrophage polarization, and regulatory T-cell enrichment collectively shape an immunotolerant and treatment-resistant niche on the peritoneal surface. In addition, evidence from pre-metastatic niche biology suggests that primary tumor-derived exosomes and epitranscriptomic regulation can prime the peritoneal environment before overt implantation. These features provide a biological rationale for locoregional strategies such as cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, as well as emerging intraperitoneal modalities and microenvironment-targeted approaches. Finally, organoid platforms, liquid biopsy-based minimal residual disease monitoring, and theranostic technologies may enable more personalized, biology-driven management of PM. Full article

Cholangiocarcinoma (CCA) is a highly malignant tumor originating from the epithelium of the bile ducts. It has an insidious onset, is difficult to diagnose in its early stages, has a low rate of curative resection, and carries an extremely poor prognosis. Among these, intrahepatic cholangiocarcinoma (iCCA), as the most representative subtype, is a classic “immunologically cold tumor.” The response rate to single-agent immunotherapy is only 5–10%, and the mechanisms of immune resistance are complex and not yet fully elucidated. The tumor microenvironment, serving as the core site of immune resistance, forms a highly immunosuppressive network composed of cancer-associated fibroblasts, hypoxia, metabolic reprogramming, and epigenetic abnormalities; a population of immunosuppressive cells centered on tumor-associated macrophages further amplifies tolerance signals; and the gut–biliary microbiome exerts systemic immune regulation via the gut–liver axis. Based on mutant mouse models generated via tail vein injection and in-depth studies of mutations in key signaling pathways, our understanding of the mechanisms underlying iCCA’s immune resistance is deepening at both the molecular and systems levels. This article reviews the local and systemic regulatory mechanisms of immune resistance in primary iCCA, summarizes the research value of experimental and preclinical models, and reviews novel strategies such as tumor microenvironment remodeling, activation of immune cell networks, microbiome interventions, and multidimensional combination therapies. It analyzes current research bottlenecks and clinical challenges and outlines the future direction of precision immunotherapy, aiming to provide a theoretical basis and new insights for overcoming iCCA immunotherapy resistance and advancing clinical translation. Full article

Background/Objectives: Accurate preoperative assessment of peritoneal dissemination is essential in ovarian cancer because it influences surgical strategy and the achievement of complete gross resection. However, [¹⁸F]FDG-PET may be limited in detecting lesions with low glycolytic activity and in differentiating malignancy from inflammatory changes. This case series evaluated the clinical relevance of [¹⁸F]FAPI-74 PET/CT for preoperative assessment of peritoneal dissemination in ovarian cancer. Methods: Four patients underwent [¹⁸F]FAPI-74 PET/CT as part of preoperative evaluation, with comparison to [¹⁸F]FDG-PET/CT when available. Imaging findings were correlated with intraoperative observations and histopathological results, including immunohistochemical assessment of fibroblast activation protein and α-smooth muscle actin. Results: FAPI-PET detected peritoneal dissemination not identified by FDG-PET in several cases, including occult metastasis confirmed histologically and additional lesions after neoadjuvant chemotherapy. FAPI-avid lesions showed stromal activation on immunohistochemistry, supporting the biological basis of FAPI uptake. In one case, additional FAPI uptake may have been partly influenced by inflammatory changes associated with bloody ascites. Conclusions: FAPI-PET may provide complementary information by visualizing stromal components of ovarian cancer and may support preoperative mapping of peritoneal dissemination, although interpretation should consider inflammatory conditions. Full article

Background: Metastasis and poor chemotherapy response have stagnated therapeutic progress in osteosarcoma (OS) for the past three decades. Defining the transition from localized to metastatic OS before overt dissemination is fundamental for improving survival. However, effective early diagnostic tools remain scarce, largely due to limited exploitation of the metastasis-associated tumor microenvironment’s own record of prior environmental and stress exposures encoded in cell-intrinsic transcriptional states. Here, we employed a supervised machine learning framework with iterative resampling and multi-stage model selection to identify molecular markers associated with metastasis in osteosarcoma and to develop a computational signature, Auto-RS. Methods: Transcriptomic and clinical data from 139 OS patients with ≥5 years of follow-up were analyzed. A LASSO–Cox framework was applied to derive a gene expression-based risk score, Auto-RS, from which a nomogram integrating age and sex was generated for individualized prognosis. Model interpretability was assessed across six independent single-cell OS patient datasets, and drug sensitivity predictions were inferred by integrating Auto-RS with the Precily algorithm to uncover actionable therapeutic vulnerabilities. Results: Auto-RS, constructed from the expression of four autophagy genes (BNIP3, MYC, PEA15, and SAR1A), served as an independent prognostic factor for overall survival (HR = 1.091; 95% CI, 1.047–1.136; p < 0.001). Time-dependent ROC analysis showed that Auto-RS was the most accurate single predictor (AUC = 0.88), exceeding metastasis (0.83), sex (0.45), and age (0.39). A basic prognostic model (BpM) incorporating metastasis status yielded a C-index of 0.741 (95% CI, 0.679–0.803). The addition of Auto-RS (CpM) improved discrimination (C-index = 0.788; 95% CI, 0.731–0.845), whereas a model without metastasis information (ApM) retained predictive ability (C-index = 0.709; 95% CI, 0.640–0.778). Single-cell analysis confirmed that Auto-RS features aligned with known metastatic trajectories, reflecting the transition from proliferative to invasive tumor states and highlighting coordinated programs among cancer-associated fibroblasts and immune cells. Drug sensitivity integration through Precily identified gemcitabine and cytarabine as FDA-approved agents predicted in silico to show greater sensitivity in the high-risk subgroup. Conclusions: We identified autophagy-mediated transcriptional ‘stress fingerprints’ that are tightly associated with OS metastasis. The Auto-RS signature, composed of BNIP3, MYC, PEA15, and SAR1A, enables early therapeutic stratification of patients independent of overt metastatic status. Moreover, Auto-RS delineates key molecular underpinnings of OS metastasis at single-cell resolution. As a practical laboratory tool, Auto-RS may represent a step toward improved risk stratification, where advances in metastasis prediction and therapeutic guidance converge to improve outcomes in OS. Full article

Endoplasmic reticulum (ER) stress is a common state of cellular adversity experienced by tumor cells under unfavorable conditions such as hypoxia, nutrient deprivation, and oncogene activation. As the most conserved signaling branch of the unfolded protein response (UPR), the inositol-requiring enzyme 1α (IRE1α)- X-box-binding protein 1 (XBP1) pathway plays a central role in sustaining tumor cell survival, driving malignant progression, and remodeling the tumor microenvironment (TME). XBP1, the terminal transcription factor of this pathway, finely orchestrates tumor cell fate through both its canonical and non-canonical functions. This review systematically summarizes the dual mechanisms of XBP1 in cancer: within cancer cells, XBP1 promotes proliferation, metastasis, and chemoresistance via metabolic reprogramming, anti-apoptotic proteins, and DNA repair; within immune cells (macrophages, dendritic cells, T cells), XBP1 fosters an immunosuppressive microenvironment, while also modulating cancer-associated fibroblasts, endothelial cells, and osteoclasts. Despite its therapeutic promise, several major unresolved questions remain, including the precise molecular switch governing XBP1’s pro-tumorigenic versus anti-tumorigenic functions, the functional divergence between XBP1u and XBP1s isoforms in different cellular contexts, and the lack of reliable predictive biomarkers for patient stratification. Key translational challenges involve the on-target toxicity of systemic XBP1/IRE1α inhibition due to its essential roles in normal tissues, the cell-type-specific and context-dependent effects that complicate therapeutic outcomes, and the limited selectivity and off-target effects of current inhibitors, as well as compensatory activation of other UPR branches that may drive adaptive resistance. Finally, this review discusses XBP1-targeted therapeutic strategies, including small-molecule inhibitors, nucleic acid-based drugs, immunotherapeutic combination approaches, and XBP1-based tumor vaccines, and provides perspectives on future research directions, aiming to establish a theoretical foundation for the development of more effective and precise XBP1-targeted therapies for tumorigenesis and cancer progression. Full article

Pancreatic ductal adenocarcinoma (PDAC) remains among the most therapeutically intractable malignancies, with a 5-year survival rate of approximately 10% and near-universal resistance to immune checkpoint inhibitor (ICI) therapy. This refractoriness arises from the convergence of pronounced intratumoral heterogeneity (ITH) and a profoundly immunosuppressive tumor microenvironment (TME), which together configure PDAC as a prototypical immune-excluded tumor. Beyond low tumor mutational burden, PDAC exhibits layered genetic, epigenetic, transcriptional, and metabolic heterogeneity that enables rapid adaptation and immune evasion under selective pressure, while dense desmoplastic stroma, cancer-associated fibroblasts (CAFs), and immunosuppressive immune populations collectively impose formidable physical and immunologic barriers to antitumor immunity. In this review, we synthesize multi-omics, spatial transcriptomic, and immunologic evidence to elucidate how ITH and the TME dynamically interact to reinforce immune resistance. We examine reciprocal crosstalk mechanisms—including immune-driven clonal selection, interclonal cooperation, metabolic niche specialization, and metabolic–epigenetic coupling—and discuss emerging platforms such as single-cell spatial omics, patient-derived organoid immune co-culture systems, and longitudinal circulating tumor DNA monitoring that enable high-resolution mapping of ITH–TME dynamics. Finally, we evaluate ITH–TME-guided combination therapeutic strategies targeting oncogenic drivers, stromal architecture, myeloid suppression, and metabolic checkpoints, and propose a prioritized framework for near-term and speculative clinical translation in PDAC. Full article

Non-thermal millimeter-wave (MMW) irradiation represents a promising non-invasive strategy for cancer therapy, yet its effects in physiologically relevant 3D systems remain poorly defined. Here, we evaluated the biological impact of MMW exposure in 3D non-small-cell lung cancer (NSCLC) spheroids (NCI-H1299, A549) and normal WI-38 fibroblasts under active cooling to suppress bulk heating. We demonstrate that cellular responses are governed primarily by power density (PD), irradiation geometry, and genotype-dependent susceptibility. High-PD pyramidal horn (PH) irradiation (~4.9 mW/cm²) induced rapid apoptosis, metabolic collapse, and near-complete loss of clonogenic survival, whereas lower-PD waveguide (WG) irradiation (~0.6 mW/cm²) produced depth-limited, cumulative cytotoxicity. Surviving cancer cells exhibited robust senescence-associated growth arrest, particularly in p53-deficient NCI-H1299 cells, indicating a dual apoptotic–senescent anti-proliferative response. In contrast, WI-38 fibroblasts showed minimal apoptosis and only transient stress-associated senescence, confirming selective tumor vulnerability. Mechanistic modeling suggests that MMW energy couples to glycan-rich membrane domains, generating localized electromagnetic hotspots that trigger calcium influx, mitochondrial dysfunction, and depth-dependent apoptosis. These findings establish a mechanistic basis for selective, non-thermal MMW-induced cytotoxicity in 3D NSCLC models and support further preclinical development of MMW-based therapeutic strategies. Full article

Cancer remains one of the most formidable health challenges worldwide. Extensive research has shown that tumor progression is not driven solely by malignant cells but is profoundly shaped by the tumor microenvironment (TME), which influences cancer initiation, immune evasion, and metastatic spread. Consequently, the TME has become an increasingly compelling therapeutic target. Nanotechnology has transformed cancer diagnostics and therapy, with metallic nanoparticles (mNPs) gaining particular attention due to their distinctive physicochemical properties and broad therapeutic potential. However, their interactions within the TME remain insufficiently understood, particularly with the non-cancerous cellular components, such as Cancer-Associated Fibroblasts (CAFs), Tumor-Associated Macrophages (TAMs), Dendritic Cells (DCs), Natural Killer (NK) cells, and T cells. Most existing reviews emphasize nanoparticle interactions with non-cellular TME components, such as the extracellular matrix, while far less attention has been given to their effects on cellular constituents (a gap this work specifically addresses). Although several molecular pathways through which mNPs modulate TME-resident cells have been identified, these likely represent only a small portion of the underlying mechanisms explored in this review. Progress in the field is further hindered by the limited availability of physiologically relevant experimental models; current in vitro and in vivo systems often fail to capture the complexity and dynamic heterogeneity of the TME. These limitations highlight the urgent need for more comprehensive and mechanistically grounded studies to validate the TME as a viable therapeutic target for nanoparticle-based cancer interventions. In particular, deeper insights into how mNPs influence immune regulation, stromal remodeling, and metabolic reprogramming within the TME will be essential for unlocking their full therapeutic potential in oncology. Full article

Fibroblast activation protein (FAP) has emerged as a promising target for the development of cancer radiotheranostics due to its selective overexpression in cancer-associated fibroblasts (CAFs) within the tumor stroma. Affinity and selectivity refer to the binding affinities of FAP inhibitors toward FAP and related family members, whereas the accumulation of radiolabeled-FAP inhibitors varies by tumor type. Although monomeric FAP inhibitors (FAPIs) have shown extraordinary utility in diagnostic imaging, their clinical application in radiotherapy has been limited by short tumor retention times and heterogeneous uptake. To address these challenges, homomultimeric FAPI ligands—featuring two or more identical FAP-targeting motifs—have been developed with the aim of enhancing binding avidity and prolonging tumor residence. This review comprehensively examines the evolution of homomultimeric FAPI ligands, from molecular design and preclinical validation to early clinical implementation. We highlight how dimeric and higher-order multimeric constructs improve tumor retention and therapeutic efficacy compared to monomers, while also discussing the impact of linker chemistry, valency, and scaffold architecture on pharmacokinetics and targeting efficiency. Preclinical studies demonstrate that optimized dimers and trimers achieve superior tumor-to-background ratios and sustained tumor uptake, whereas excessive multimerization can lead to steric hindrance and reduced efficacy. Clinical data from pioneering studies using agents such as [¹⁷⁷Lu]Lu-DOTAGA.(SA.FAPi)₂ and [¹⁷⁷Lu]Lu-DOTAGA.Glu.(FAPi)₂ confirm prolonged tumor retention, encouraging therapeutic responses and a favorable safety profile in advanced cancers. However, translational challenges remain, including the need for better preclinical models that reflect stromal FAP heterogeneity, optimized radiometal–chelator pairs, and standardized dosing protocols for comparative clinical trials. Overall, homomultimeric FAPI ligands represent a significant advance in FAP-targeted theranostics, offering a robust platform for personalized cancer management. Full article

Metastasis remains the leading cause of mortality in breast cancer and is closely linked to epithelial–mesenchymal transition (EMT) and tumor microenvironment (TME)-associated processes. Diosmetin (DT), the active metabolite of diosmin, a widely used venoactive drug, has emerged as a potential anticancer agent. Building on our previous findings demonstrating that DT enhances doxorubicin efficacy, this study investigated its effects on tumor cell plasticity and stromal activation-associated responses. EMT was induced in MCF-7 cells, while a stromal model was established by TGF-β-mediated activation of BJ fibroblasts toward a cancer-associated fibroblast (CAF)-like phenotype. Additionally, doxorubicin-induced senescence was generated in fibroblasts. Migration assays and quantitative real-time PCR were used to assess functional and transcriptional changes. EMT induction resulted in decreased CDH1 expression and increased levels of VIM, MMP2, MMP9, IL-6, and HIF-1A, accompanied by enhanced migratory activity. DT attenuated TGF-β-induced CAF-like activation, as reflected by reduced expression of ACTA2, HGF, MMP2, MMP9, and IL6, and modulated hyaluronan turnover-related genes. Moreover, DT partially alleviated selected senescence-associated features in doxorubicin-treated fibroblasts. Collectively, these findings indicate that DT modulates EMT-associated plasticity and stromal activation-related responses in parallel in vitro models. Given its origin as a metabolite of a clinically used compound and its previously demonstrated chemosensitizing properties, DT may warrant further investigation as a potential adjunctive agent to modulate tumor- and stromal-associated processes in breast cancer. Full article

Background: The oral squamous cell carcinoma (OSCC) is a very aggressive cancer that is the product of tumor cell interactions with the microenvironment. The tumor microenvironment (TME) has a severe impact on OSCC progression, metastasis, and resistance to treatment by altering gene expression via various cellular and molecular signal transductions. Aim: This review systematizes the information on gene regulation in the OSCC TME (cellular components, signaling pathways that regulate tumor progression and resistance). Methods: We used PRISMA guidelines to search PubMed, Scopus, Web of Science, and Google Scholar (up to April 2025) with OSCC studies addressing the subject of gene regulation and tumor microenvironment. The quality of human or experimental models was evaluated using the Newcastle–Ottawa Scale and the qualitative synthesis was performed because of heterogeneity. Results: The significant regulatory functions of tumor-associated macrophages, cancer-associated fibroblasts, immune cells, and non-coding RNAs were found, especially in the pathways like JAK/STAT, EGFR, Wnt/ -β catenin, and PI3K/AKT/mTOR. Conclusions: The conceptualization of gene regulatory networks in the OSCC TME identifies the emerging biomarkers and targets of therapy. Merging multimodal omics and single-cell studies can further contribute to the precision strategies to enhance the outcomes of OSCC. Full article