Search Results (897)

Metastatic triple-negative breast cancer (mTNBC) remains one of the most challenging therapeutic settings in oncology. Although it has traditionally been defined by the absence of hormone receptor expression—estrogen receptor (ER) and progesterone receptor (PR)—and HER2 amplification or overexpression, this simplified definition fails to capture the biological complexity that drives its marked clinical heterogeneity, therapeutic resistance, and prognostic variability. Over the past decade, multiple studies have challenged the notion of TNBC as a single disease entity, identifying distinct molecular subtypes, including Basal-like 1 (BL1), Basal-like 2 (BL2), Mesenchymal (M), Mesenchymal Stem-like (MSL), Immunomodulatory (IM), and Luminal Androgen Receptor (LAR), each characterized by specific biological programs and therapeutic vulnerabilities. In parallel, clinically oriented systems such as the Fudan classification have enabled the prospective evaluation of subtype-guided therapeutic strategies in metastatic disease, as illustrated by the FUTURE and FUTURE-SUPER trials. In this review, we examine the molecular classification and clinical behavior of mTNBC subtypes, integrating genomic, transcriptomic, epigenetic, immunologic, stromal, and biomechanical dimensions of tumor heterogeneity. We also discuss emerging tools, including single-cell RNA sequencing, spatial transcriptomics, circulating tumor DNA analysis, long non-coding RNA profiling, and surrogate immunohistochemistry-based classifiers, as well as their potential role in refining patient stratification. From a therapeutic perspective, we review subtype-guided strategies involving chemotherapy, platinum agents, PARP inhibitors, immunotherapy, antiandrogen therapy, PI3K/AKT/mTOR pathway inhibition, antiangiogenic approaches, and antibody–drug conjugates. Redefining mTNBC through biologically driven stratification represents a rational strategy to optimize treatment selection, support clinical trial design, and accelerate the development of precision oncology approaches. However, clinical implementation requires greater methodological standardization, validated predictive biomarkers, accessible diagnostic platforms, and dynamic monitoring strategies capable of capturing subtype evolution under therapeutic pressure. TNBC should therefore not be regarded as a single disease, but as a spectrum of biologically distinct and clinically evolving entities whose integrated characterization may be essential to improving outcomes in this historically poor-prognosis population. 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

The heterogenous mesenchymal stem/stromal cells (MSCs) express the surface antigens associated with distinct cell subpopulations. CD271, characteristic of stem cells derived from the neural crest, could indicate cells with a unique phenotype. The study examined whether the CD271+ subpopulation characterized by better stem and neural properties than the heterogeneous MSC population. The initial Wharton jelly-derived MSCs (WJ-MSCs) population was divided into two subpopulation: CD271-positive (WJ-MSC-CD271+) and CD271-negative (WJ-MSC-CD271−) with Fluorescence-Activated Cell Sorting (FACS). We compared the clonogenic potential and neural marker expression under standard culture conditions and in the presence of nerve tissue components—cerebrospinal fluid (CSF) or nerve tissue fragments (hippocampus). FACS allowed the enrichment of CD271+ cells from 1% to approximately 50%. WJ-MSC-CD271+ is characterized by significantly more self-renewal cells and increased expression of neuronal genes than WJ-MSC-CD271−. Under co-culture with CSF or hippocampal fragments, WJ-MSC-CD271+ contained more cells expressing Β-III-tubulin as well. Finally, we reported that stimulation with epithelial growth factor (EGF) and basal fibroblast growth factor (bFGF) enhanced CD271+ numbers in the initial population and stabilized them in further cell culture. WJ-MSC-CD271+ cells showed improved potential for differentiation into neural progenitors, although further research is needed for their potential use in neurological diseases. Full article

Mesenchymal stromal cells derived from adipose tissue (ASCs) are widely used in regenerative medicine, requiring scalable expansion strategies that preserve both cellular function and biological quality. However, current bioprocess optimization approaches are primarily guided by proliferation and phenotypic stability, often overlooking genomic integrity as a critical attribute. In this study, we developed a stirred-tank bioreactor system for ASC expansion on microcarriers and applied a genotoxicity-informed optimization strategy by integrating growth kinetics, metabolic profiling, and DNA damage assessment across multiple operational conditions (B₁–B₅), including variations in dissolved oxygen, agitation, inoculum density, and medium renewal. Optimized culture conditions (B5) enabled high cell productivity within a reduced cultivation period (9 days), while maintaining high viability (>90%), mesenchymal immunophenotype, and differentiation capacity. Distinct metabolic profiles were associated with enhanced proliferation, with increased glycolytic activity observed under optimized conditions. Despite these favorable outcomes, genotoxic analyses revealed a progressive, time-dependent accumulation of DNA damage and increased micronucleus frequency during expansion. Notably, these alterations did not impair cell proliferation, phenotype, or differentiation potential, indicating that conventional optimization metrics may not fully capture underlying genomic changes. Collectively, our findings demonstrate that bioprocess optimization based solely on classical performance parameters may overlook relevant biological alterations. By incorporating genotoxic endpoints into the evaluation framework, this study provides a refined approach for assessing large-scale stem cell expansion and contributes to improving the robustness and reliability of biomanufacturing strategies for therapeutic applications. Full article

Mesenchymal stem/stromal cells (MSCs) hold promise for treating different equine conditions but enter senescence during culture. Using induced pluripotent stem cells (iPSCs) to derive MSC-like cells (iMSCs) can increase cell availability and diminish the need for invasive and repeated tissue harvesting. While human iMSCs are intensively studied, research on equine iMSCs (eqiMSCs) is very limited and has focused on strategies for spontaneous differentiation to obtain these cells. The aim of this study was to obtain MSC-like cells from equine iPSCs (eqiPSCs) by directing their differentiation via the neural crest pathway. The resulting eqiMSCs downregulated pluripotent gene expression compared to originating eqiPSCs, and the majority of lines met most of the standard criteria for tissue-derived MSCs (immunophenotype and tri-lineage differentiation potential). Nevertheless, eqiMSCs showed some differences from primary equine MSCs, possibly due to their different developmental origin, and displayed certain inter-line variability, which might be related to the different kinetics of independent eqiPSC lines. This study demonstrates for the first time that equine MSC-like cells (eqiMSCs) can be derived from eqiPSCs by directing their differentiation through the neural crest pathway. This constitutes an important advancement towards more sustainable sources of therapeutic cells in veterinary medicine and warrants further exploration of the functional characteristics of these novel cells. Full article

Background: Tumor–stroma interactions play a critical role in renal cell carcinoma (RCC) progression. Cancer-associated fibroblasts (CAFs) are considered key components of the tumor microenvironment; however, their origin remains controversial. This study aimed to determine whether bone marrow-derived mesenchymal stem cells (MSCs) contribute to CAF-like stromal changes and RCC progression. Methods: An orthotopic xenograft mouse model was established using luciferase- and GFP-labeled Caki-1 cells. MSCs labeled with PKH26 were administered intravenously. Tumor growth was evaluated using an in vivo imaging system and tumor volume measurements. Immunohistochemical analyses were performed to assess MSC localization and α-smooth muscle actin (α-SMA) expression. In vitro proliferation and migration assays were conducted using direct and indirect co-culture systems. Results: The intravenous administration of MSCs significantly increased tumor growth and bioluminescence intensity in an orthotopic model. The tumor volumes were significantly larger in the MSC-treated versus control group. An immunofluorescence analysis demonstrated partial co-localization of PKH26-labeled MSCs with α-SMA-positive fibroblast-like cells, suggesting acquisition of CAF-like features. Direct co-culture with MSCs significantly enhanced RCC cell proliferation and migration in vitro, whereas culturing in conditioned medium alone did not produce similar effects. Conclusions: Exogenously administered bone marrow-derived MSCs may be recruited into RCC tissues and acquire CAF-like features through interactions with tumor cells. These findings suggest that stromal–tumor cell interactions within the tumor microenvironment may contribute to RCC progression and represent a potential therapeutic target. Full article

Background: Knee osteoarthritis (KOA) is a major cause of disability worldwide, and adipose-derived stromal vascular fraction (SVF) has emerged as a potential regenerative treatment to modify disease progression. Objective: This study aimed to assess the effectiveness of autologous adipose-derived stromal vascular fraction (SVF) through intra-articular injection to treat early-stage knee osteoarthritis (KOA). Materials and Methods: This multicenter observational study (2019–2023) included adults aged 18–65 years with radiographically confirmed knee osteoarthritis. Patients were assigned to one of two groups through a retrospective, non-randomized process based on the actual treatment received during their clinical follow-up. Group T received intra-articular adipose-derived stromal vascular fraction (SVF) injections, while Group C received conservative treatment with non-steroidal anti-inflammatory drugs (NSAIDs) only. SVF was obtained from abdominal adipose tissue using a standardized closed-system device and injected intra-articularly. Pain and functional outcomes were assessed using the Visual Analog Scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and at 1, 3, 6, 9, and 12 months. Results: Sixty-seven patients (41 SVF, 26 controls) were included, with comparable baseline characteristics (all p > 0.05). Preoperative VAS was lower in the SVF group (7.44 ± 1.44 vs. 8.31 ± 1.09; p = 0.029). At 12 months, VAS significantly decreased to 3.77 ± 1.49 in the SVF group, whereas it increased to 8.85 ± 0.67 in controls (p < 0.001). Similarly, baseline WOMAC scores were lower in the SVF group (62.6 ± 21.7 vs. 76.8 ± 8.76; p = 0.004). At 12 months, WOMAC improved to 29.4 ± 15 in the SVF group but worsened to 87.6 ± 3.21 in controls (p < 0.001). Within-group improvements were significant only in the SVF group (p < 0.001). No procedure-related complications were observed. Conclusions: The autologous adipose-derived stromal vascular fraction is an effective treatment option for early-stage KOA patients. However, a prospective, randomized, controlled study is warranted. Full article

Mesenchymal stromal/stem cells (MSCs) are increasingly investigated as intra-articular therapies for equine osteoarthritis (OA), although most studies have focused on allogeneic or combination-based approaches. Evidence supporting the use of autologous MSCs as a stand-alone treatment remains limited. The present study evaluated the safety and clinical evolution following intra-articular administration of autologous muscle-derived MSCs (mdMSCs) in horses with naturally occurring chronic OA. Thirteen horses with confirmed clinical disease were included. Each affected joint received a single injection, with the administered cell dose adapted to joint size (1 × 10⁷ or 2 × 10⁷ cells). Clinical assessments were conducted at baseline and at 6 and 12 weeks post-treatment using the American Association of Equine Practitioners (AAEP) lameness scale, together with a joint inflammation score and a composite total clinical score (TCS). Clinical scores decreased over time, with statistically significant improvements observed at both follow-up time points. Seven of thirteen horses met the predefined responder criteria based on AAEP improvement, including complete resolution of lameness in several cases. The treatment was well tolerated, with only mild and transient local reactions that resolved without intervention. These results indicate that intra-articular administration of autologous mdMSCs is associated with clinically relevant improvement in horses with chronic OA. Full article

Background/Objectives: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition characterized by pelvic pain, urinary symptoms, and reduced quality of life, with limited effective treatment options. Regenerative approaches using adipose-derived mesenchymal stromal cells (MSCs) have shown promising preclinical results. This study aimed to evaluate the feasibility, safety, and preliminary efficacy of transurethral implantation of autologous micronized adipose tissue (MAT) in patients with refractory IC/BPS. Methods: We conducted a single-center retrospective observational pilot study including 20 patients with refractory IC/BPS treated between April and October 2024. Adipose tissue was harvested via liposuction and mechanically processed using a closed system (Matrigen device) to obtain minimally manipulated micronized adipose tissue. The product was injected transurethrally into the bladder submucosa. Patients were evaluated at baseline and at 1, 3, and 6 months using validated questionnaires (ICSI/ICPI, SF-36, MOS Sexual Function), verbal rating scale (VRS) for pain and urgency, urodynamic parameters, and cystoscopic findings. Changes over time were assessed using paired non-parametric tests. Results: At 6 months, 65% of patients met responder criteria, defined as ≥50% improvement in pain and/or urgency or a positive global response. Significant improvements were observed in IC Problem Index, SF-36, MOS scores, and VRS urgency, while VRS pain improved significantly at 6 months. Urodynamic parameters showed increased bladder capacity (median 275 to 325 mL, p < 0.001) and reduced post-void residual volume (80 to 40 mL, p < 0.001). Cystoscopic findings demonstrated improvement in bladder mucosal appearance. The procedure was well tolerated, with no serious adverse events or immunological complications observed. Conclusions: In this exploratory pilot study, transurethral implantation of autologous micronized adipose tissue was associated with improvements in symptoms, bladder function, and cystoscopic findings in patients with refractory IC/BPS. These results support the feasibility and potential role of minimally manipulated adipose-derived therapies in this setting. Given the small sample size and absence of a control group, findings should be considered exploratory. Larger controlled studies are warranted to confirm efficacy and evaluate long-term outcomes. Full article

Background/Objectives: An ideal bone scaffold should promote bone cell growth and functional vascularization, hence the importance of imbuing biomaterials with pro-angiogenic cues. In this work, silica-based bioactive glasses, either pristine (SBA3) or doped with copper (SBA3_Cu), were embedded in poly(ε-caprolactone) (PCL), which was also used as a control. Methods: In vitro co-cultures of adipose-derived mesenchymal stem/stromal cells (ASCs) and human microvascular endothelial cells (HMEC-1s) were kept in α-MEM, MCDB131, and EndoGRO media to test the biomaterials. The co-cultures were visualized by immunofluorescence and SEM, while flow cytometry was performed to characterize cellular immunophenotype. The angiogenic potential was evaluated using conditioned media of co-cultures to perform a tubulogenesis assay and VEGF-A quantification. Results: Immunophenotypic analysis showed a significant decrease in the endothelial CD31+ cellular subset, whereas the OB-like cellular subset expressing CD105, CD73, CD90, and ALP increased in all culture media over time. In α-MEM, HMEC-1s were unable to form a capillary network independent of the substrates. A more organized network was visible when co-cultures were plated on PCL, in MCDB131 and EndoGRO, or if they were kept in EndoGRO on PCL/SBA3_Cu. The VEGF-A concentrations were similar in the conditioned media from co-cultures grown on PCL/SBA_Cu, in EndoGRO, and on PCL and PCL/SBA3, in MCDB131. Conclusions: The presence of copper did not promote the angiogenic potential of HMEC-1, likely due to the low concentration of released copper ions and the predominant osteoinductive effect of the other ions released by the bioglass. A re-evaluation of formulation and structure of bioglass scaffold could enhance the angiogenic potential. Full article

Mesenchymal stem/stromal cells (MSCs) are multipotent progenitor cells with potent immunomodulatory properties, making them attractive candidates for treating inflammatory and autoimmune diseases. A key mediator of MSC-induced immunosuppression is programmed death-ligand 1 (PD-L1), a checkpoint molecule that interacts with PD-1 on immune cells to regulate immune responses and promote tolerance. This review synthesizes current evidence on the role of PD-L1 expression in MSCs, emphasizing its effects on both the innate and adaptive immune systems, its therapeutic potential, and its utility as a biomarker for MSC potency and clinical efficacy. We examine how PD-L1 modulates T cell activation, dendritic cell maturation, macrophage polarization, and cytokine profiles, including its role in exosomal contexts. Additionally, we highlight its synergistic interactions with other immune checkpoints and discuss its dual function as both a therapeutic effector and a dynamic biomarker. Finally, we explore its relevance in clinical contexts such as autoimmune diseases, graft-versus-host disease, sepsis, and transplantation and conclude with a discussion of challenges and future directions in harnessing PD-L1 for MSC-based therapies. Full article

Most high-tech drugs and tissue engineering products based on human chondrocytes currently available on the market are aimed at restoring traumatic damage to cartilage tissue. However, in the presence of inflammation, their regenerative potential is significantly reduced, which limits their use in patients with osteoarthritis—one of the most common degenerative and inflammatory joint pathologies. The central element of the pathogenesis of osteoarthritis is inflammation—not classical acute inflammation, but rather chronic low-grade inflammation, primarily mediated by mechanisms of the innate immune response. Therefore, a key challenge is to enhance the anti-inflammatory effectiveness of cell-based drugs to broaden their indications to include degenerative diseases such as osteoarthritis and arthrosis. In recent years, cell-based drugs using stem cells, including mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), and stromal vascular fraction (SVF) cells, have been actively studied. Despite their confirmed safety in inflammatory processes, meta-analyses of clinical trials show limited effectiveness in improving symptoms and MRI data in the treatment of osteoarthritis. A promising direction appears to be the development of combined cell-based drugs that combine MSCs with M2-polarized macrophages; however, data on their clinical effectiveness are still insufficient. This review explores key cellular effectors of inflammation and its molecular mechanisms, potential strategies for creating tissue engineering products that possess not only regenerative but also pronounced anti-inflammatory effects. The development of such products will expand their application in the treatment of inflammatory-degenerative joint diseases. Full article

Ovarian dysfunction resulting from metabolic or toxic injury is characterized by follicular depletion, stromal remodeling, oxidative stress, and endocrine dysregulation. Placenta-derived mesenchymal stem cells (PD-MSCs) have been proposed as a potential therapeutic approach due to their paracrine factors, including placental growth factor (PlGF). However, the pathways through which PD-MSCs exert protective effects on the ovary remain insufficiently defined. In this study, we examined whether PD-MSC transplantation ameliorates ovarian injury in a thioacetamide (TAA)-induced ovarian insufficiency model and explored the signaling events potentially associated with this response. Female rats were administered TAA for 12 weeks, and PD-MSCs were transplanted at week 8. We assessed ovarian morphology, fibrosis, oxidative stress markers, hormonal profiles, and follicle development. Complementary in vitro experiments using TAA-treated KGN granulosa-like cells were performed to investigate potential mechanistic associations. PD-MSC transplantation improved ovarian architecture, reduced collagen deposition, enhanced follicle growth, and mitigated oxidative stress. These changes were accompanied by increased PlGF expression and enhanced activation of fms-like tyrosine kinase-1 (Flt-1), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), and nuclear factor erythroid 2-related factor 2 (Nrf2)-related antioxidant pathways. In vitro, PD-MSCs coculture similarly attenuated oxidative stress and partially improved mitochondrial membrane potential in damaged KGN cells. Together, these findings suggest that PD-MSCs ameliorate ovarian structural damage and oxidative stress in TAA-induced injury, potentially through paracrine mechanisms partly involving PlGF/Flt-1-associated antioxidant signaling. This work supports the therapeutic potential of PD-MSCs for metabolic or toxicant-induced ovarian insufficiency while underscoring the need for further studies to fully delineate the specific contribution of PlGF and its interaction with downstream antioxidant pathways. Full article

Human endometrial mesenchymal stem/stromal cells (eMSCs) are widely used in laboratories and clinical applications to study various aspects of tissue engineering and regenerative medicine. Three-dimensional (3D) cultivated MSCs have a higher therapeutic efficacy compared to 2D culture. Ion channels are involved in maintaining many physiological cell functions, including proliferation, differentiation, apoptosis, and migration. This study describes the functional expression of voltage-gated sodium channels (NaV) in eMSCs and the role of these channels in cell migration. Using RT-PCR analysis and immunofluorescent microscopy, we identified the expression of almost all pore-forming alpha (NaV 1.1, 1.2, 1.4–1.9) and channel-modulating beta-NaV subunits (except beta2) in eMSCs. In the whole-cell patch-clamp configuration, channels activated by membrane depolarization of eMSC were detected. The channels were blocked by the selective NaV antagonist TTX in nanomolar concentrations. The NaV agonist veratridine at a concentration of less than 40 μM inhibited voltage-gated sodium currents, while 100 μM and above prevented channel inactivation. The wound healing assay showed that both TTX (10 μM) and veratridine (100 μM) reduced the migration properties (the wound healing rate) of eMSCs cultivated in 2D conditions compared to the control. An opposite effect by both agents was shown on the motility of eMSCs cultivated in 3D conditions, increasing the cell spreading rate from spheroids. Our data suggest that NaV channels are expressed in human eMSCs and play an important role in the regulation of stem cell migration; this regulatory mechanism significantly depends on the culture conditions of MSCs. Full article

Mesenchymal stromal cells (MSCs) have shown immunomodulatory effects and great promise in many inflammatory diseases such as acute respiratory distress syndrome (ARDS). However, several barriers to translation remain such as cell availability and potency. This study evaluates the therapeutic potentials of three types of MSCs, bone marrow-derived MSCs (BM-MSC), the human induced pluripotent stem cell-derived MSC wild type (iMSC WT) and β2 microglobulin-knockout iMSCs (iMSC B2M KO) with or without proinflammatory cytokine preconditioning. BM-MSC, iMSC WT and iMSC B2M KO were preconditioned with a proinflammatory cytokine cocktail (Cytomix: IL-1β, IFN-γ and TNF-α). Immunoregulatory biomarkers were analysed by flow cytometry and cytokines released by ELISA. MSC antimicrobial properties were analysed via CFU assays while the MSCs’ immunomodulatory effects were evaluated using macrophage activation and T cell proliferation assays. Proinflammatory cytokine preconditioning enhanced the therapeutic potency of all three types of MSCs by increasing immunomodulatory marker expression, enhancing the antimicrobial effects and improving MSC-mediated inhibition of T cell proliferation. These findings provided new insights into the therapeutic potencies of MSCs in inflammation. Further studies are required for in vitro characterisation of the MSCs and in vivo efficacy verification of these MSCs prior to their clinical application. Full article