Search Results (788)

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

Neuroblastoma is characterized by frequent involvement of bone marrow (BM) as a site of cell dissemination and spread. In this study, single-cell RNA sequencing (scRNA-seq) was used to analyze the cellular heterogeneity of a subset of metastatic BM samples collected at initial diagnosis. Comparison of the single-cell data with bulk RNA sequencing further refined the analysis. An enrichment of regulatory T cells relative to a healthy control and activation of the CD24, CD47, and CD200 “don’t eat me” signals were documented. Computational analyses highlighted communication between neuroblastoma and myeloid cells via the amyloid precursor protein (APP) and midkine (MK) signaling networks. Within neuroblastoma cells, mutually exclusive adrenergic and transitory cell states were identified, and ten sub-clusters were denoted. In addition, common and unique tumor cell antigens were investigated. CNTFR and CHRNA3, as high-ranking candidates, were validated, confirming their strong selectivity for neuroblastoma cells. Taken together, these findings support the existence of a significant tumor-dependent modulation of the BM ecosystem, which should be considered when introducing immunotherapy. Furthermore, they highlight the potential to investigate new antigens at the single-cell resolution. Full article

Background: The metastatic dissemination of melanoma involves adhesion of circulating tumor cells within organ-specific vascular beds; however, the relative contribution of the endothelial environment versus that of the melanoma-intrinsic molecular state remains unclear. Materials and Methods: We quantified the in vitro adhesion of primary (n = 5) and metastatic (n = 3) melanoma cell lines to human hepatic, brain, and pulmonary endothelial cells under co-culture conditions, and we profiled the expression of 86 adhesion- and extracellular-matrix-related genes in melanoma and endothelial cells. Results: Adhesion was highest for the hepatic endothelium, intermediate for the pulmonary endothelium, and lowest for the brain endothelium. This endothelial preference was conserved in both primary and metastatic melanoma cells, though metastatic cells exhibited higher absolute adhesion. The linear mixed-effect models revealed that the effects of adhesion state on melanoma gene expression were modest and varied by endothelial type, whereas melanoma origin had more widespread and larger effects (mean absolute standardized coefficients of 0.32–0.47 versus 0.60–0.87, respectively). The expression of three genes (SPP1, ITGA11, and MMP2) was associated with melanoma origin in all endothelial types. Spearman’s co-expression analysis revealed endothelial-type-specific gene networks, and within-sample permutation confirmed the non-random coordination in all three endothelial types. Conclusions: Our findings support a model in which endothelial organ specificity contributes to melanoma cell adhesion behavior and associated transcriptional patterns, highlighting the importance of the vascular interface as a biologically active mediator of early metastatic cell–endothelium interactions. Full article

Appendiceal mucinous neoplasms (AMNs) are a rare but clinically significant category of gastrointestinal tumors, ranging from low-grade appendiceal mucinous neoplasm (LAMN), the main precursor of pseudomyxoma peritonei (PMP), to high-grade appendiceal mucinous neoplasm (HAMN), poorly differentiated and signet-ring-cell adenocarcinomas, and goblet cell adenocarcinoma. Although current WHO and PSOGI classifications provide well established diagnostic criteria, controversies persist regarding the biological behavior and prognostic significance of the most aggressive subtypes and the relationship between HAMN and mucinous adenocarcinoma. While appendectomy is sufficient for localized LAMN, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is the treatment of choice for peritoneal dissemination This review integrates the histopathological and molecular classification of AMN and PMP with the evolution of intraperitoneal chemotherapy. Key findings indicate that KRAS and GNAS mutations are central drivers of mucin overproduction and peritoneal spread, that tumor grade and mucin cellularity remain the strongest prognostic determinants, and that the evidence supporting HIPEC and PIPAC derives largely from observational rather than randomized data. As a novel insight, we highlight the emerging role of patient-derived organoids as translational models for functional drug testing. Progress will depend on integrating molecular characterization, critical appraisal of intraperitoneal therapies, and organoid-based testing to advance individualized treatment for peritoneal surface malignancies. Full article

Head and neck squamous cell carcinoma (HNSCC) remains one of the most aggressive and heterogeneous malignancies worldwide, characterized by high rates of locoregional recurrence, metastatic dissemination, and therapeutic resistance. Angiogenesis plays a central role in tumor progression by supporting vascular remodeling, hypoxia adaptation, invasion, immune evasion, and metastatic spread. In HNSCC, angiogenic activation is regulated through complex interactions involving hypoxia-inducible factors, vascular endothelial growth factor (VEGF) signaling, stromal remodeling, inflammatory pathways, and epigenetic mechanisms within the tumor microenvironment. Recent evidence has also highlighted the role of non-coding RNAs, particularly microRNAs, and exosome-mediated communication in modulating angiogenic and immune-related signaling pathways. Although antiangiogenic therapies, including monoclonal antibodies and tyrosine kinase inhibitors, have demonstrated biological activity in HNSCC, their clinical efficacy remains limited by tumor heterogeneity, adaptive resistance mechanisms, toxicity, and the lack of validated predictive biomarkers. Several emerging therapeutic strategies are under preclinical or early clinical investigation in HNSCC, including miRNA-based approaches, nanoparticle-assisted delivery systems, vascular normalization concepts, and combinations with immune checkpoint inhibitors; however, robust clinical evidence for most of these strategies remains limited, and their translation to routine practice requires further validation. This review provides a comprehensive overview of the molecular mechanisms regulating angiogenesis in HNSCC and critically discusses current and emerging pharmacological strategies targeting these pathways. Particular emphasis is placed on VEGF/VEGFR signaling, the integration of miRNA and exosome biology, resistance mechanisms, and translational perspectives for biomarker-guided personalized therapy. The novelty of this review lies in the systematic integration of miRNA- and exosome-mediated angiogenic regulation, therapeutic resistance pathways, and precision medicine strategies into a unified pharmacological framework, addressing gaps not fully covered by prior reviews focused primarily on VEGF-targeted agents. Full article

Background: Brain metastasis is associated with poor prognosis in lung adenocarcinoma (LUAD). Anoikis resistance may contribute to tumor cell survival during metastatic dissemination and brain colonization; however, robust biomarkers for prognostic stratification and brain metastasis-associated classification remain limited. This study aimed to investigate anoikis-related molecular features in LUAD brain metastasis and develop a machine learning-based signature for prognostic assessment and exploratory classification of primary and brain-metastatic LUAD samples. Methods: We integrated single-cell and multi-cohort bulk transcriptomic data. Single-cell analysis was performed to characterize anoikis-related cellular states and intercellular communication in primary and brain-metastatic LUAD samples. In the bulk transcriptomic analysis, TCGA-LUAD was used for prognostic feature selection and risk-model construction, and GSE26939 was used for external prognostic validation. The classification performance of the fixed signature for distinguishing primary LUAD from brain-metastatic LUAD samples was further evaluated in GSE161116 and GSE271259. Immune microenvironment features were assessed, and an LLM-assisted exploratory drug-screening strategy combined with molecular docking was used to prioritize candidate compounds. Results: Single-cell analysis suggested that metastatic epithelial cells exhibited enhanced anoikis-related activity, accompanied by macrophage-associated SPP1-CD44 and MIF-(CD74+CXCR4) communication patterns. Machine learning-based feature selection identified an eight-gene signature consisting of BIRC3, CCL20, CLEC7A, CTSL, GOLM1, ICAM3, MTUS1, and SERPINH1. The signature showed prognostic value in TCGA-LUAD and GSE26939 and demonstrated exploratory classification performance in distinguishing primary LUAD from brain-metastatic LUAD samples. High-risk patients exhibited immune microenvironment alterations and enrichment of tumor progression-related pathways. LLM-assisted compound prioritization and molecular docking highlighted resveratrol and SB431542 as hypothesis-generating candidates with predicted interactions with core targets. Conclusions: This study identified an anoikis-related eight-gene signature for LUAD prognostic stratification and exploratory brain metastasis-associated classification. The findings suggest the potential involvement of anoikis-related tumor–microenvironment interactions in LUAD brain metastasis and provide candidate genes and compounds for further experimental validation. Full article

Background: Spread through air spaces (STAS) is a recognized histologic pattern of invasion associated with poor prognosis in non-small-cell lung cancer (NSCLC), particularly adenocarcinoma. However, its presence in pulmonary squamous cell carcinoma (SCC), whether primary or metastatic, remains largely unexplored. Given the limited available evidence, this study was designed as an exploratory analysis to evaluate the prevalence and potential prognostic significance of STAS in pulmonary SCC. Material and Methods: In this exploratory retrospective study, we analyzed 57 patients who underwent surgical resection for pulmonary squamous cell carcinoma (P-SCC) at the Department of Thoracic Surgery at the University Hospital Erlangen between 2008 and 2020. The cohort included both primary lung SCC and metastatic SCC to the lung from extrapulmonary sites, primarily from ear, nose, and throat (ENT) tumors. Histological slides were reviewed to assess the presence of STAS, as defined by established morphological criteria. The Chi-square test was used to investigate the presence of STAS. Disease-free survival (DFS) and overall survival (OS) was evaluated using Kaplan–Meier analysis, and the prognostic impact of STAS along other variables were assessed using Cox proportional hazards regression. Results: A total of 57 patients with squamous cell carcinoma (SCC), 22 (39%) had primary lung SCC and 35 (61%) had metastatic SCC from head and neck tumours (ENT). Spread through air spaces (STAS) was detected in 20 patients (35%). Disease-free survival (DFS) differed according to primary tumour location (p-value of 0.009), with higher 1-, 3-, and 5-year DFS in patients with primary lung SCC (86.4%, 77.3%, 63.3%) than in those with head and neck SCC (54.3%, 31.4%, 22.2%). DFS was also significantly higher in patients undergoing solitary resections compared with multiple resections (78.6%, 64.3%, 49.5% vs. 33.3%, 6.7%, not estimable; p-value < 0.001). DFS was slightly longer in STAS-negative patients compared with STAS-positive patients (1-, 3-, 5-year DFS: 64.9%, 51.4%, 40.5% vs. 70%, 45%, not estimable), (median DFS 36 vs. 25 months; p-value of 0.776). Overall survival (OS) was significantly longer in patients with primary lung SCC (median OS 125 months) than in those with head and neck SCC (27 months; p-value of 0.039). STAS-negative patients had also a longer OS than STAS-positive patients (median OS 46 vs. 38 months; HR = 1.11, 95% CI 0.56–2.20; p-value of 0.771). Conclusions: STAS was identified in metastatic pulmonary SCC lesions as well as in primary lung SCC, occurring in approximately one-third of cases. However, due to the limited cohort size and the exploratory univariate design of the study, the prognostic significance of STAS could not be definitively established and requires further investigation in larger, adequately powered studies. Full article

Metastatic hormone-naïve prostate cancer (mHNPC) is a clinically aggressive form of prostate cancer characterized by early systemic dissemination and poor long-term outcomes; however, the intrinsic epithelial cell states present at diagnosis remain poorly defined. In this study, we performed single-cell transcriptomic profiling of diagnostic prostate biopsy specimens from five patients with treatment-naïve mHNPC using Fixed RNA Profiling. Integrated and case-specific analyses characterized epithelial heterogeneity and lineage-associated transcriptional programs. Across 17,825 high-quality single cells, epithelial heterogeneity was identified in all cases. In addition to luminal androgen receptor (AR)-dependent epithelial cells, reproducible basal-associated epithelial populations with reduced AR signaling and stem-like transcriptional features were observed across tumors. Epithelial–mesenchymal transition (EMT)-related transcriptional programs were detected across multiple epithelial states with inter-case variability without forming a distinct EMT cluster, whereas no transcriptionally discrete neuroendocrine epithelial cluster was identified at baseline. These findings demonstrate that treatment-naïve mHNPC harbors pre-existing basal-associated epithelial states that contribute to intrinsic tumor heterogeneity at diagnosis. The presence of AR-low and stem-like epithelial populations prior to systemic therapy suggests a potential role for lineage plasticity in the aggressive biological behavior of metastatic prostate cancer. Full article

Tumor metastasis constitutes a frequent contributor to high mortality rates, with EMT intimately implicated in this disseminative process. Accumulating evidence in recent years indicates that neoplastic cells undergoing EMT frequently exhibit concurrent metabolic reprogramming. Multiple modalities—including glycolysis, mitochondrial oxidative phosphorylation, lipid metabolism, as well as amino acid metabolism—cooperatively supply energy, facilitate membrane remodeling, and sustain redox homeostasis. Specifically, glycolytic flux, oxidative phosphorylation, lipid turnover, and amino acid catabolism/anabolism function in a concerted manner to meet the bioenergetic demands, support biogenesis of cellular membranes, and preserve the intracellular redox equilibrium during phenotypic conversion. Notably, intermediate metabolites can in turn modulate the trajectory of EMT through signal transduction cascades or epigenetic modifications. This review systematically delineates the bidirectional regulatory circuitry interconnecting EMT and metabolic reprogramming; furthermore, it examines the implications of this crosstalk for neoplastic disease progression. Finally, therapeutic strategies targeting the nexus of metabolic reprogramming and EMT are summarized. Full article

Gastric cancer peritoneal metastasis is not simply an extension of the primary tumor into the abdominal cavity. It represents a biologically distinct disease context shaped by interactions between disseminated tumor cells, peritoneal fluid, mesothelial surfaces, submesothelial stroma, extracellular matrix, immune populations, and malignant ascites. In this narrative review, we examine peritoneal metastasis as a transition between three related but physiologically different states: the primary gastric tumor, free-floating tumor cells or spheroids in the peritoneal fluid, and established mesothelial or submesothelial metastatic implants. We discuss how tumor cells acquire dissemination competence in the primary tumor, survive detachment and fluid-phase stress, adhere to remodeled mesothelium, recruit stromal and immune support, and adapt to ascites-mediated signaling. We also review how the peritoneal niche may contribute to biomarker discordance, immune exclusion, therapeutic resistance, and limitations of conventional response assessment. Where relevant, we distinguish evidence derived directly from gastric cancer peritoneal metastasis from preclinical data, extrapolation from other peritoneal malignancies, and hypothesis-generating interpretation. Finally, we summarize practical implications for tissue sampling, ascites and lavage analysis, biomarker interpretation, translational modeling, and peritoneal-directed therapeutic strategies. A clearer understanding of the biological divergence between the primary tumor, the fluid-phase compartment, and peritoneal implants may improve the study and clinical management of gastric cancer peritoneal metastasis. Full article

Background: Epithelial ovarian cancer (EOC) is characterized by aggressive peritoneal dissemination and an immunosuppressive tumor microenvironment in which tumor-associated macrophages (TAMs) play a central role. Chemokine signaling pathways regulate macrophage recruitment and function; however, the contribution of the CX3CL1–CX3CR1 axis to ovarian cancer progression and TAM-mediated effector mechanisms remains unclarified. This study aimed to clarify the role of CX3CL1–CX3CR1 signaling in ovarian cancer progression, focusing on macrophage-derived pro-tumorigenic factors. Methods: CX3CL1 and CX3CR1 expression was examined in human EOC and healthy ovarian tissues by real-time polymerase chain reaction and immunohistochemistry. Functional effects of CX3CL1 on ovarian cancer cells were evaluated via migration and proliferation assays in the murine ID8 cell line. An intraperitoneal syngeneic ovarian cancer model was established by injecting ID8 cells into wild-type and Cx3cr1-deficient mice. Tumor burden, ascites formation, survival, macrophage infiltration, and expression levels of matrix metalloprotease-2 (MMP-2) and transforming growth factor-β (TGF-β) were assessed by histological, immunohistochemical, and molecular analyses. Results: CX3CL1 and CX3CR1 expression was significantly upregulated in human EOC tissues and associated with marked macrophage infiltration. CX3CL1 stimulation enhanced migration, but not proliferation, of ID8 cells. Cx3cr1 deficiency significantly suppressed intraperitoneal tumor growth, reduced ascitic fluid volume, and prolonged survival. This was accompanied by reduced CX3CR1⁺ TAM accumulation and decreased MMP-2 and TGF-β expression, which were predominantly produced by infiltrating macrophages. Conclusions: The CX3CL1–CX3CR1 axis promotes ovarian cancer progression by recruiting MMP-2- and TGF-β-producing macrophages. Targeting CX3CR1-dependent TAM functions may represent a therapeutic strategy for limiting peritoneal dissemination in ovarian cancer. Full article

Background: Pancreatic ductal adenocarcinoma (PDAC) exhibits high post-resection relapse and early systemic dissemination rates. The level of circulating tumor cells (CTCs) correlates with early metastatic failure, motivating CTC interception strategies. Methods: In this hypothesis-driven review, we synthesized the contemporary evidence on PDAC staging and therapy, CTC detection (including portal versus peripheral sampling), and circulating tumor DNA (ctDNA)-based minimal residual disease (MRD), and evaluated the translational rationale for CTC-targeted adoptive immunotherapy focusing on CEACAM6 and CAR-T cells. Results: Prospective studies report higher portal versus peripheral CTC yields and stronger associations with relapse; tumor-informed ctDNA positivity in peri-operative and surveillance windows predicts shorter disease-free survival. CEACAM6 is overexpressed in PDAC and linked to invasion and metastasis, supporting antigen selection. However, target overexpression alone does not establish clinical suitability for adoptive cell transfer. Consequently, its therapeutic implementation must contend with assay heterogeneity, on-target/off-tumor risks, and the lack of interventional outcome data in PDAC, all of which remain key hurdles. Conclusions: CTC-targeting is biologically plausible and operationally measurable in PDAC. Consequently, a CEACAM6-directed CAR-T approach is proposed as a potential strategy for the interception of minimal residual disease (MRD). Randomized and biomarker-selected trials with composite MRD-clearance endpoints (CTC < LOQ and ctDNA-negative) may be justified to validate this interventional hypothesis. Full article

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancer types with a dismal prognosis, where early metastatic dissemination and rich desmoplastic stroma limit the therapeutic efficacy. Nischarin (NISCH)/Imidazoline-1 receptor (IR-1) is a potential tumor suppressor that is involved in the regulation of cell migration, invasion, and cytoskeletal organization. Importantly, several clinically approved agonists have been shown to target this receptor. This study aimed to examine NISCH expression in PDAC and the effects of its agonists with the intent of drug repurposing. NISCH was expressed in PDAC tumor tissue, in both the epithelial and stromal compartments of tumors, and higher NISCH expression was associated with longer patient survival. Out of the three tested NISCH agonists, moxonidine, clonidine and rilmenidine, rilmenidine was the only one affecting cancer cell viability and at high doses induced cancer cell apoptosis. Transcriptome analysis of rilmenidine-treated PDAC cells revealed changes associated with cytoskeletal organization, translating into decreased adhesion and migration in vitro. In cancer-associated fibroblasts (CAFs), rilmenidine treatment decreased the expression of activation markers and limited cancer cell-CAF cytokine communication in the co-culture. Ultimately, in the in vivo tumor xenograft zebrafish model, rilmenidine reduced the metastatic spread of pancreatic cancer cells. Our results suggest that the NISCH agonist rilmenidine is a promising candidate for drug repurposing as an antimetastatic agent in PDAC, and that NISCH can be a potential target for the development of new PDAC therapeutics. Full article

Cancer stem cells (CSCs) are a highly influential population of tumor cells involved in tumor initiation, progression, metastasis, recurrence, and resistance to therapy. Although CSCs have been widely investigated, their behavior cannot be understood solely through intrinsic cellular features, as these cells strongly depend on a specialized supportive microenvironment known as the CSC niche. In this review, we discuss the CSC niche as a dynamic and therapeutically relevant ecosystem that is distinct from, but closely connected with, the broader tumor microenvironment. Particular attention is given to stromal cells, immune cells, endothelial cells, extracellular matrix components, hypoxia, cytokines, chemokines, and metabolic stress as regulators of CSC self-renewal, plasticity, dormancy, immune escape, epithelial–mesenchymal transition, metastatic dissemination, and survival under therapeutic pressure. We further consider how CSC–niche interactions contribute to pre-metastatic niche formation and tumor relapse. Finally, we outline emerging therapeutic strategies aimed at disrupting CSC-supportive signals, including approaches targeting developmental pathways, angiogenesis, hypoxia, extracellular matrix remodeling, immunosuppressive networks, and cytokine-mediated communication. Overall, this review emphasizes that targeting the CSC-supportive microenvironment is essential for limiting metastasis, recurrence, and long-term treatment failure. Full article

Background: Remodeling of epithelial junctional architecture contributes to colorectal cancer (CRC) progression; however, the spatial organization linking tight-junction components to early dissemination remains incompletely characterized. Claudin-2 (CLDN-2) is frequently upregulated in CRC, yet whether it is associated with compartment-specific epithelial remodeling has not been systematically examined. Methods: In a retrospective single-center cohort of 54 surgically resected CRCs, we integrated clinicopathological variables, quantitative tumor budding counts, compartment-specific membranous E-cadherin expression, lymphovascular invasion, lymphoid follicles, and immune-cell densities. Analyses focused on spatial structural relationships within the tumor. Results: Higher CLDN-2 expression was enriched among node-positive tumors and advanced TNM stages. CLDN-2–higher tumors exhibited increased tumor budding and spatially selective adhesion remodeling, characterized by reduced membranous E–cadherin at the invasive front and budding sites, with more preserved membranous epithelial organization within metastatic lymph-node deposits. Descriptive co-occurrence and correlation analyses demonstrated concordant spatial relationships among CLDN-2 expression, tumor budding, nodal involvement, lymphovascular invasion, and compartment-specific E-cadherin patterns. In contrast, immune-related parameters showed weaker differentiation across CLDN-2 strata. Conclusions: CLDN-2 expression is associated with spatial epithelial remodeling in colorectal cancer, characterized by compartment-specific adhesion changes and increased microinvasive activity. The findings support a model in which CLDN-2 expression aligns with an invasion-associated epithelial configuration linked to tumor budding and nodal dissemination. These observations warrant validation in independent cohorts with outcome data. Full article