Search Results (53)

The modulation of the tumour microenvironment represents a pivotal step in tumorigenesis and metastasis and results from direct and paracrine cellular interactions. The innate immune Toll-like receptor 4 (TLR4) controls immune and inflammatory signalling in the tumour microenvironment. A growing body of evidence shows that TLR4 activation in cancer, immune and stromal cells upregulate gelatinase expression and activity, linking innate immune responses to extracellular matrix (ECM) remodelling. Gelatinases, or matrix metalloproteinases (MMP2) and (MMP9) play a pivotal role in tumour matrix degradation, thereby facilitating invasion, angiogenesis and metastasis. Interestingly, although TLR4 signalling in cancer cells and tumour-associated macrophages leads to different activation outputs, they can both induce gelatinases through NF-κB, MAPK, and Akt pathways. Evidence from clinical tumour tissues, co-culture models, in vivo and in vitro studies supports the crucial interplay between TLR4 signalling and gelatinases production in tumour growth and metastasis. An in-depth understanding of this crosstalk may reveal new therapeutic opportunities in targeted strategies. Full article

Background/Objective: This systematic review aims to evaluate ex vivo brain slice models in glioblastoma (GBM) research, with a specific focus on tumour invasion, tumour–microenvironment interactions, and therapeutic response. Methods: A systematic search looking for studies employing ex vivo organotypic brain slice models in GBM research was conducted across multiple databases (January 2010–July 2025) in accordance with PRISMA guidelines. The study was registered in PROSPERO database (CRD420251138341). Inclusion criteria encompassed patient-derived brain slices, hybrid rodent–human slice co-cultures, and microfluidic-integrated ex vivo platforms designed to assess tumour invasion, microenvironmental interactions and therapeutic responses. Exclusion criteria included reviews, abstracts, conference proceedings, in vivo-only studies, purely in vitro models without organotypic integration, and studies not focused on GBM. Results: Twenty-six studies met the inclusion criteria. Among these, 18/26 (69%) investigated GBM invasion, 18/26 (69%) evaluated therapeutic responses, and 5/26 (19%) examined tumour–microenvironment interactions, with several studies spanning multiple domains. Across platforms, organotypic slices consistently recapitulated key features of GBM biology—including perivascular and white-matter-aligned invasion, stromal–immune interactions, and patient-specific drug sensitivity—while engineered systems enhanced perfusion and exposure control. Methodological variability, particularly regarding slice preparation, oxygenation and viability assessment, limits direct comparability between studies. Conclusions: Organotypic brain slice models represent an extremely relevant tool for translational investigations of GBM biology and treatment response. However, substantial methodological heterogeneity together with limited standardisation hamper reproducibility and cross-study validation. Future work should focus on enhancing reproducibility and harmonising protocols to support the development of clinically meaningful precision oncology strategies. Full article

Background: Malignant ovarian tumours are most often detected at an advanced stage, when peritoneal dissemination across abdominal organs is already present. Metastasis in ovarian cancer arises from complex interactions between cancer cells and diverse components of the tumour microenvironment (TME), including extracellular matrix elements, fibroblasts, adipocytes, mesenchymal cells and leukocytes. This dynamic niche drives tumour progression, invasiveness and immunosuppression through cytokine- and chemokine-mediated signalling. A deeper understanding of these interactions may enable targeted modulation of the TME and help limit metastatic spread. Methods: In this study, using immunoenzymatic assays and a computational digital twin—a mechanistic, ODE-based in silico model that replicates key cellular and microenvironmental processes—we investigated whether and how caffeic acid phenethyl ester (CAPE) influences TME activation, cytokine and growth factor levels, and extracellular matrix remodelling. Results: Our findings show that CAPE modulates both pro- and antitumourigenic signalling pathways across immune, stromal and hypoxia-related axes, suggesting its potential to reshape the ovarian cancer microenvironment and improve therapeutic outcomes in this challenging malignancy. Conclusions: Taken together, these results indicate that CAPE may serve as a multifaceted modulator capable of simultaneously targeting tumour cells and their microenvironment, offering a promising avenue for enhancing therapeutic strategies in ovarian cancer. Full article

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract and a key example for targeted therapy with tyrosine kinase inhibitors (TKIs), which have significantly improved survival rates. However, no effective treatments exist for TKI-resistant or mutation-negative tumours. Until now, research on the effects of TKIs has mainly used 2D cultures or mouse models, lacking patient-specific 3D GIST models. We investigated various 3D GIST models, including spheroids, organoids, patient-derived microtumours (PDMs), and precision-cut tumour slices (PCTSs), to assess their feasibility as alternatives for 2D cell culture or in vivo mouse models. Moreover, 2D monolayer and 3D spheroid GIST cell lines showed mutation-dependent responses to TKI treatment, but differences between 2D and 3D cultures were minimal. Thus, patient-derived 3D models, incorporating tumour microenvironment cells, were developed for more accurate in vivo representation. PDMs and PCTSs were successfully isolated from primary tumours and cultivated for up to two weeks. Three-dimensional models were immunohistochemically characterised, and the response to TKI therapies was tested and compared with expected clinical outcomes. In addition to already established 2D cell cultures and mouse models, PDMs and PCTSs are novel patient-derived 3D models that can be used to study tumour cell interactions within the microenvironment. Moreover, they could be used to investigate TKI resistance, and novel treatment options such as immunotherapies and combination therapies. Full article

Breast cancer is the most common cancer in women, depending on the sub-type of breast cancer treatment options are different. After completing adjuvant therapy, there are patients who may relapse even many years later. This review examines minimal residual disease, defined as small, microscopic foci of cancer cells that have survived curative treatment, have disseminated to distant tissues, and implanted there. However, the cancer cells do not exist alone but are a small part of the tumour microenvironment, described as an ecosystem. This includes stromal cells, immunosuppressive regulatory T-cells, myeloid derived suppression cells, cancer associated fibroblasts, tumour associated macrophages. The balance of the immunosuppressive tumour microenvironment and the anti-tumour immune response will determine if there is a future relapse. The interactions between the cancer cells and the tumour microenvironment are dynamic and change with time. Most therapeutic options involve therapies directed against tumour cells, only in the last few years has there been attention on the dynamic effects of the tumour microenvironment and the cancer cells on disease progression and the possibility of decreasing the risk of metastatic disease. This article reviews the latest development in preventing metastatic disease by influencing the tumour microenvironment; at best eliminating cancer cells or at least prolonging the latent period of cancer cell dormancy. Full article

Triple-negative breast cancer (TNBC) remains one of the most aggressive and treatment-resistant forms. TNBC is an aggressive and therapeutically resistant subtype of breast cancer, marked by the absence of estrogen, progesterone, and HER2 receptors. The lack of defined molecular targets significantly limits treatment options and contributes to high recurrence rates. Among the key pathways involved in TNBC progression and resistance, the CXCR4/CXCL12 chemokine axis has emerged as a critical player. CXCR4, a G-protein-coupled receptor, binds specifically to its ligand CXCL12, promoting tumour cell proliferation, metastasis, immune evasion, and stromal remodelling. Its overexpression is frequently associated with poor prognosis, disease progression, and resistance to conventional therapies in TNBC. This review explores how the chemokine receptor type 4 (CXCR4/CXCL12) axis facilitates drug resistance through mechanisms such as epithelial–mesenchymal transition (EMT), cancer stemness, and microenvironmental interactions. Notably, CXCR4 antagonists like plerixafor, balixafortide, and POL5551 have shown encouraging preclinical and clinical results, particularly when combined with chemotherapy or immunotherapy. Additionally, innovative strategies, including radiopharmaceuticals, peptide inhibitors, and nanotechnology-based delivery platforms, offer expanded therapeutic avenues. Despite persistent challenges such as tumour heterogeneity and potential toxicity, growing clinical evidence supports the translational relevance of this axis. This manuscript provides an in-depth analysis of CXCR4/CXCL12-mediated drug resistance in TNBC and evaluates current and emerging therapeutic interventions. Full article

Background: Phosphaturic mesenchymal tumours secreting fibroblast growth factor 23 (hereinafter referred to as FGF23+ PMT) are rare neoplasms that can cause hypophosphataemic osteomalacia, owing to excessive FGF23 production. Mast cells (MCs) play a key role in tumour biology by modulating proliferative activity of atypical cells, resistance to innate and acquired immunity, angiogenesis, and metastatic behaviour. However, MCs associated with FGF23+ PMT have not previously been investigated. This study, to our knowledge, is the first to characterise features of the tumour microenvironment through spatial phenotyping of the immune and stromal landscape, together with histotopographic mapping of intercellular MC interactions with other subcellular populations in FGF23+ PMT. Methods: Histochemical staining (haematoxylin and eosin, toluidine blue, Giemsa solution, picro-Mallory protocol, silver impregnation), as well as monoplex and multiplex immunohistochemical staining with spatial phenotyping, were performed to detect atypical FGF23-secreting cells, immune cells (CD3, CD4, CD8, CD14, CD20, CD38, CD68, or CD163), stromal components (CD31, α-SMA, or vimentin), and specific MC proteases (tryptase, chymase, or carboxypeptidase A3). Bioinformatics analysis using artificial intelligence technologies was applied for spatial profiling of MC interactions with tumour, immunocompetent, and stromal cells in the tumour microenvironment. Results: Bioinformatic analysis of the entire tumour histological section, comprising over 70,000 cells stained using monoplex and multiplex immunohistochemical protocols, enabled identification of more than half of the cell population. The most abundant were CD14+ (30.7%), CD163+ (23.2%), and CD31+ (17.9%) cells. Tumour-associated MCs accounted for 0.7% of the total pool of immunopositive cells and included both mucosal and connective tissue subpopulations, predominantly of the tryptase + chymase-CPA3-specific protease phenotype. This pattern reflected combined multidirectional morphogenetic processes in the patient’s FGF23+ PMT. More than 50% of MCs were colocalized with neighbouring cells of the tumour microenvironment within 20 μm, most frequently with monocytes (CD14+CD68+), M2 macrophages (CD68+CD163+), and endothelial cells (CD31+). In contrast, colocalization with atypical FGF23-secreting cells was rare, indicating minimal direct effects on tumour cell activity. Interaction with T lymphocytes, including CD8+, was also infrequent, excluding their activation and the development of antitumour effects. Mapping of MC histotopography validated the hypothesis of their inductive role in monocyte differentiation into M2 macrophages and probable polarisation of macrophages from M1 into M2, thereby contributing to slow tumour growth. MCs were further involved in extracellular matrix remodelling and participated in the formation of pro-osteogenic niches within the FGF23+ PMT microenvironment, leading to pathological osteoid development. Conclusions: This study demonstrated active MC participation in the evolution of the FGF23+ PMT microenvironment. The findings may be applied in translational medicine to develop novel algorithms for personalised therapy in patients with FGF23-secreting tumours, offering an alternative when surgical removal of the tumour is not feasible. Full article

Chemoresistance is a major challenge in the treatment of triple-negative breast cancer (TNBC). Multicellular spheroids are an attractive platform for investigating chemoresistance in TNBC, as they replicate the cues of the tumour microenvironment in vivo. We conducted a comprehensive literature search to summarise the multifactorial and interlinked mechanisms driving chemoresistance in TNBC spheroids. These mechanisms include spatial heterogeneity, hypoxia, extracellular matrix remodelling, tumour–stroma crosstalk, drug efflux, apoptotic resistance, and cancer stem cell signalling. Strategies for overcoming chemoresistance in TNBC spheroids include nanocarrier systems to overcome spatial diffusion limitations, pathway inhibition, and targeting tumour–microenvironment interactions. Despite their advantages, some spheroid models face challenges such as low reproducibility, a lack of heterogeneity, variability in size and shape, limited vascularisation, and constraints in long-term culture. Advanced culturing platforms such as clinostat bioreactors allow for extended culture periods, enabling mature spheroid drug testing. Furthermore, advanced analytical techniques provide spatially resolved spheroid data. These multifactorial and interlinked mechanisms reflect the tumour microenvironment in vivo that spheroids recapitulate, rendering them valuable models for studying chemoresistance. The incorporation of stromal components and advanced analytical workflows will enhance the utility and translational relevance of spheroids as reliable preclinical models for drug discovery in TNBC. Full article

Dysregulated cell movement is a hallmark of cancer progression and metastasis, the leading cause of cancer-related mortality. The metastatic cascade involves tumour cell migration, invasion, intravasation, dissemination, and colonisation of distant organs. These processes are influenced by reciprocal interactions between cancer cells and the tumour microenvironment (TME), including immune cells, stromal components, and extracellular matrix proteins. The epithelial–mesenchymal transition (EMT) plays a crucial role in providing cancer cells with invasive and stem-like properties, promoting dissemination and resistance to apoptosis. Conversely, the mesenchymal–epithelial transition (MET) facilitates metastatic colonisation and tumour re-initiation. Immune cells within the TME contribute to either anti-tumour response or immune evasion. These cells secrete cytokines, chemokines, and growth factors that shape the immune landscape and influence responses to immunotherapy. Notably, immune checkpoint blockade (ICB) has transformed cancer treatment, yet its efficacy is often dictated by the immune composition of the tumour site. Elucidating the molecular cross-talk between immune and cancer cells, identifying predictive biomarkers for ICB response, and developing strategies to convert cold tumours into immune-active environments is critical to overcoming resistance to immunotherapy and improving patient survival. Full article

Background/Objectives: BRCA1 pathogenic variant (PV)-associated breast cancers are most commonly seen in hereditary genetic conditions such as the autosomal-dominant Hereditary Breast and Ovarian Cancer (HBOC) syndrome, and rarely in sporadic breast cancer. Such breast cancers tend to exhibit greater aggressiveness and poorer prognoses due to the influence of BRCA1 pathogenic variants (PVs) on the tumour microenvironment. Additionally, while the genetic basis of BRCA1 PV breast cancer is well-studied, the role of epigenetic mediators in the tumourigenesis of these hereditary breast cancers is also worth exploring. Results: PVs in the BRCA1 gene interact with stromal cells and immune cells, promoting epithelial–mesenchymal transition, angiogenesis, and affecting oestrogen levels. Additionally, BRCA1 PVs contribute to breast cancer development through epigenetic effects on cells, including DNA methylation and histone acetylation, leading to the suppression of proto-oncogenes and dysregulation of cytokines. In terms of epigenetics, lysine-specific demethylase 1 (LSD-1) is considered a master epigenetic regulator, governing both transcriptional repression and activation. It exerts epigenetic control over BRCA1 and, to a lesser extent, BRCA2 genes. The upregulation of LSD-1 is generally associated with a poorer prognosis in cancer patients. In the context of breast cancer in BRCA1/2 PV carriers, LSD-1 contributes to tumour development through various mechanisms. These include the maintenance of a hypoxic environment and direct suppression of BRCA1 gene expression. Conclusions: While LSD-1 itself does not directly cause mutations in BRCA1 or BRCA2 genes, its epigenetic influence sheds light on the potential role of LSD-1 inhibitors as a therapeutic approach in managing breast cancer, particularly in individuals with BRCA1/2 PVs. Targeting LSD-1 may help counteract its detrimental effects and provide a promising avenue for therapy in this specific subgroup of breast cancer. Full article

Cancer-associated fibroblast (CAF)s in the tumour microenvironment (TME) modulate the extracellular matrix, interact with cancer cells, and facilitate communication with infiltrating leukocytes, significantly contributing to cancer progression and therapeutic response. In prostate cancer (PCa), CAFs promote malignancy through metabolic rewiring, cancer stem cell regulation, and therapy resistance. Pre-clinical studies indicate that targeting amino acid metabolism, particularly glutamine (Gln) metabolism, reduces cancer proliferation and stemness. However, most studies lack the context of CAF–cancer interaction, focusing on monocultures. This study assesses the influence of CAFs on PCa growth by manipulating Gln metabolism using colour-labelled PCa cell lines (red) and fibroblast (green) in a co-culture system to evaluate CAFs’ effects on PCa cell proliferation and clonogenic potential. CAFs increased the proliferation of hormone-sensitive LNCaP cells, whereas the castration-resistant C4-2 cells were unaffected. However, clonogenic growth increased in both cell lines. Gln deprivation and GLS1 inhibition experiments revealed that the increased growth rate of LNCAP cells was associated with increased dependence on Gln, which was confirmed by proteomic analyses. Tissue analysis of PCa patients revealed elevated GLS1 levels in both the PCa epithelium and stroma, suggesting that GLS1 is a therapeutic target. Moreover, the median overall survival analysis of GLS1 expression in the PCa epithelium and stroma identified a “high-risk” patient group that may benefit from GLS1-targeted therapies. Therefore, GLS1 targeting appears promising in castration-resistant PCa patients with high GLS1 epithelium and low GLS1 stromal expression. Full article

Breast cancer, a multifaceted and heterogeneous disease, poses significant challenges in terms of understanding its intricate resistance mechanisms and devising effective therapeutic strategies. This review provides a comprehensive overview of the intricate landscape of extracellular vesicles (EVs) in the context of breast cancer, highlighting their diverse subtypes, biogenesis, and roles in intercellular communication within the tumour microenvironment (TME). The discussion spans various aspects, from EVs and stromal cells in breast cancer to their influence on angiogenesis, immune response, and chemoresistance. The impact of EV production in different culture systems, including two dimensional (2D), three dimensional (3D), and organoid models, is explored. Furthermore, this review delves into the therapeutic potential of EVs in breast cancer, presenting emerging strategies such as engineered EVs for gene delivery, nanoplatforms for targeted chemotherapy, and disrupting tumour derived EVs as a treatment approach. Understanding these complex interactions of EV within the breast cancer milieu is crucial for identifying resistance mechanisms and developing new therapeutic targets. Full article

Tumour progression relies on interactions with untransformed cells in the tumour microenvironment (TME), including cancer-associated fibroblasts (CAFs), which promote blood supply, tumour progression, and immune evasion. Eph receptor tyrosine kinases are cell guidance receptors that are most active during development but re-emerge in cancer and are recognised drug targets. EphA3 is overexpressed in a wide range of tumour types, and we previously found expression particularly in stromal and vascular tissues of the TME. To investigate its role in the TME, we generated transgenic mice with inducible shRNA-mediated knockdown of EphA3 expression. EphA3 knockdown was confirmed in aortic mesenchymal stem cells (MSCs), which displayed reduced angiogenic capacity. In mice with syngeneic lung tumours, EphA3 knockdown reduced vasculature and CAF/MSC-like cells in tumours, and inhibited tumour growth, which was confirmed also in a melanoma model. Single cell RNA sequencing analysis of multiple human tumour types confirmed EphA3 expression in CAFs, including in breast cancer, where EphA3 was particularly prominent in perivascular- and myofibroblast-like CAFs. Our results thus indicate expression of the cell guidance receptor EphA3 in distinct CAF subpopulations is important in supporting tumour angiogenesis and tumour growth, highlighting its potential as a therapeutic target. Full article

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest solid malignancies, with a five-year survival of less than 10%. The resistance of the disease and the associated lack of therapeutic response is attributed primarily to its dense, fibrotic stroma, which acts as a barrier to drug perfusion and permits tumour survival and invasion. As clinical trials of chemotherapy (CT), radiotherapy (RT), and targeted agents have not been successful, improving the survival rate in unresectable PDAC remains an urgent clinical need. Photodynamic stromal depletion (PSD) is a recent approach that uses visible or near-infrared light to destroy the desmoplastic tissue. Preclinical evidence suggests this can resensitise tumour cells to subsequent therapies whilst averting the tumorigenic effects of tumour–stromal cell interactions. So far, the pre-clinical studies have suggested that PDT can successfully mediate the destruction of various stromal elements without increasing the aggressiveness of the tumour. However, the complexity of this interplay, including the combined tumour promoting and suppressing effects, poses unknowns for the clinical application of photodynamic stromal depletion in PDAC. Full article

Hepatocellular carcinoma (HCC) is a common and aggressive cancer with a high mortality rate. The incidence of HCC is increasing worldwide, and the lack of effective screening programs often results in delayed diagnosis, making it a challenging disease to manage. Immunotherapy has emerged as a promising treatment option for different kinds of cancers, with the potential to stimulate the immune system to target cancer cells. However, the current immunotherapeutic approaches for HCC have shown limited efficacy. Since HCC arises within a complex tumour microenvironment (TME) characterized by the presence of various immune and stromal cell types, the understanding of this interaction is crucial for the identification of effective therapy. In this review, we highlight recent advances in our understanding of the TME of HCC and the immune cells involved in anti-tumour responses, including the identification of new possible targets for immunotherapy. We illustrate a possible classification of HCC based on the tumour immune infiltration and give evidence about the role of SerpinB3, a serine protease inhibitor involved in the regulation of the immune response in different cancers. Full article