Dormant cancer stem cells (CSCs) are the root cause of the drug resistance and metastatic processes of malignant tumors, but an in-depth analysis of their biological mechanisms is needed. Dormant CSCs are in the G0 phase of the cell cycle and are characterized by enhanced autophagic activity, a stable genomic structure and strong plasticity. Recently, several new specific markers of dormant CSCs, such as p27, CD13, QSOX1, Survivin, GPD1 and BEX2, have been identified, which offer hope for targeted therapy. In addition, epigenetic modifications such as DNA methylation and histone modifications have been reported to regulate the transition between the quiescent and proliferative states of dormant CSCs. From a clinical perspective, keeping cancer stem cells in a dormant state is helpful for preventing tumor recurrence and metastasis. To this end, clarifying the potential mechanisms and molecular regulation of cancer stem cell dormancy is vital. Here, in this review, we examine recent significant findings regarding tumor stem cell dormancy in both experimental and human disease models, emphasizing the underlying molecular mechanisms, regulatory processes, experimental models, and prospective research directions aimed at advancing this field and enhancing clinical translation.

Homologous recombination (HR) is crucial for maintaining genomic integrity and is tightly regulated, yet the role of ubiquitin-dependent degradation in HR proteins remains poorly understood. Through high-throughput screening for compounds that modulate the DNA replication stress response, we identify ML367 and its derivative, UNI418. Kinase profiling and detail molecular analyses reveal that UNI418 inhibits PIKfyve and PIP5K1C, reducing inositol hexaphosphate (IP6) levels and triggering Cul4A-dependent degradation of RAD51, CtIP, and CHK1. Further analysis identifies WDR5 as a DCAF protein that facilitates Cul4A-mediated proteolysis of RAD51 and CHK1. Functionally, UNI418 suppresses HR, enhances tumor sensitivity to PARP inhibitors (PARPis), and re-sensitizes PARPi-resistant tumor cells in both in vitro and in vivo xenograft models. These findings reveal a Cul4A-WDR5-dependent proteolysis pathway regulating HR protein stability via phosphatidyl inositol signaling. This mechanism offers a promising therapeutic strategy for overcoming PARPi resistance and improving combinatorial cancer treatment strategies.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of T-cell precursors. Although the survival rates have improved with the use of intensive chemotherapy, the emergence of relapse as well as treatment-related morbidity and mortality remain major challenges. Novel treatment approaches include the inhibition of anti-apoptotic regulators or cellular immunotherapies. Here, we analyzed the sensitivity of T-ALL to inhibitors of BCL-2 (venetoclax), BCL-XL (A1331852), MCL-1 (AZD5991) and dual inhibition of BCL-2/BCL-XL (AZD4320) and evaluated their combination effects with natural killer (NK) cells. While only early T-cell precursor (ETP) ALL was sensitive to BCL-2 inhibition, MCL-1 inhibition alone was not effective in most cell lines and patient-derived xenograft (PDX) samples. For BCL-XL and dual BCL-2/BCL-XL inhibition, we observed heterogeneous sensitivities, which were associated with anti-apoptotic dependencies on the respective BCL-2 family members as assessed by BH3-profiling. Moreover, we identified functional shifts in anti-apoptotic dependencies upon exposure to AZD4320 or AZD5991 alone and synergistic effects when both inhibitors were combined with each other, allowing cell death induction in resistant samples. We then explored the potential use of apoptosis-inducing drugs as sensitizers for immunotherapy. Therefore, we investigated the potential of NK cell-mediated killing in T-ALL and found heterogeneous sensitivity, with some cell lines showing responses even at low effector-to-target (E:T) ratios. Importantly, NK cell-mediated killing could be further enhanced by combining NK cells with AZD4320, proposing this combination as a potential effective treatment. Taken together, we demonstrated promising potential of BH3-mimetics and NK cells for the treatment of T-ALL alone and in combination, warranting further preclinical and potential clinical evaluation.

Microplastics (MPs) are emerging pollutants that are associated with many diseases including atherosclerosis, inflammatory bowel disease (IBD), and Alzheimer's. The oral cavity is the primary point for the uptake of MPs by human, where MPs could pose risks to oral and even system health. Various polymer-based materials have been used as dental materials in oral treatment, however, the assessment of MPs in dental treatments remains limited and the processes and mechanisms by which MPs affect human health through the oral route are elusive. Here, we report the assessment of the risks and sources of MPs in dental clinics, the establishment of the relationship between MPs and oral inflammatory disorders, and also the elucidation of underlying mechanisms. Our results showed that commonly used therapeutic dental materials could generate MPs in dental clinics with proportions significantly higher than those in office areas and outdoors. As a representative, polymethyl methacrylate (PMMA) MPs showed significant toxicity to human oral keratinocytes (HOK), human periodontal ligament stem cells (hPDLCs), and THP-1-derived macrophages. Mechanistic investigations of apoptosis and inflammation processes revealed that MPs could lead to mitochondrial stress and autophagy and trigger the Notch signaling pathway and the JAK-STAT signaling pathway. Mice experiments showed that prolonged high-dose MPs exposure induced periodontal inflammatory reactions and even led to inflammatory bone resorption. This study provides a scientific basis for the oral health risks by MPs in dental practice and addresses the need for the development of dental materials with higher biocompatibility and environmentally sustainability.

This study investigates the therapeutic effects of ultrasound-guided transplantation of human umbilical cord mesenchymal stem cells (HUC-MSCs) on nerve injury and neuronal recovery in chronic constriction injury (CCI) rats. Behavioral analysis showed that HUC-MSCs treatment significantly improved Paw Mechanical Withdrawal Threshold (PMWT) and Thermal Paw Withdrawal Latency (TWL), with faster recovery in the HUC-MSCs groups. Histological analysis revealed enhanced repair and regeneration, reduced inflammation, and improved results in the dual-treatment group (CCI + U2). Ultrasound and histological examination demonstrated significant nerve fiber repair, reduced inflammation, and enhanced myelin recovery, especially in the CCI + U2 group. TMT-based proteomics identified differential protein expression in the spinal dorsal horn (SDH), confirming molecular changes associated with neuronal recovery. Analysis of microglial polarization in the SDH, and macrophage polarization in the dorsal root ganglion (DRG) and sciatic nerve (SN), showed that HUC-MSCs promoted the M2 phenotype, reducing inflammation and enhancing repair. HUC-MSCs also modulated the NLRP3 inflammasome, lowering NLRP3, ASC, caspase-1, and IL-1β levels. The study further explored HUC-MSCs-derived exosomes' effects on microglial polarization and NLRP3 activity, regulated by miR-223-3p to promote anti-inflammatory and neuroprotective effects, suggesting the potential of HUC-MSCs and exosomes in nerve regeneration and neuroinflammation reduction after SN injury.

Ameloblastoma is a benign odontogenic tumor with an aggressive growth phenotype orchestrated by a complex and heterogeneous tumor microenvironment. This review addresses how tumor cells, cancer-associated fibroblasts, mesenchymal stem cells, endothelial cells, and immune cells interact with non-cellular elements especially the extracellular matrix and hypoxic niches to drive invasive growth and recurrence. Several genetic changes associated with ameloblastoma activate mitogen-activated protein kinase (MAPK), Hedgehog (HH), Wnt/β-catenin, and less commonly PI3K/AKT signaling pathways. These pathways increase matrix-degrading enzymes such as matrix metalloproteinases and heparanase and reorganize collagen to create paths for local spread of ameloblastoma cells. Hypoxic niches in ameloblastoma stabilize hypoxia-inducible factor (HIF-1)α and activate vascular endothelial growth factor (VEGF) thereby linking low oxygen tension to new blood vessel growth within the microenvironment. Crosstalk between ameloblastoma epithelium and stroma through interleukin-6, transforming growth factor (TGF)-β, and connective tissue growth factor (CTGF) activates a positive feedback loops that stiffen the extracellular matrix and promote collective invasion. Within the encompassing jaw bone, a higher receptor activator of nuclear factor kappa-Β ligand/osteoprotegerin (RANKL/OPG) ratio and parathyroid hormone-related protein (PTHrP) level stimulate osteoclastogenesis, which accounts for the characteristic osteolysis displayed by ameloblastoma. Additionally, PD-L1 expression in ameloblastoma weakens T-cell activity in spite of the high population of M1 macrophages at the tumor leading edge. Collectively, coordinated interplay of these molecular processes define the invasive and aggressive growth phenotypes of ameloblastoma. Opportunities abound for development of targeted therapies for management of ameloblastoma. Potential candidates are inhibitors of BRAF/MEK and smoothened (SMO) gene/HH pathways, interruption of the TGF-β-Cancer-associated fibroblast axis, anti-angiogenic strategies, immune checkpoint blockade, and RANKL-directed therapy.

Background and objectives Atherosclerosis is a chronic disease marked by the build up of lipids and inflammatory cells in arterial walls, leading to vessel narrowing and increasing the risk of serious complications like heart attack and stroke. Recent findings suggest that microRNAs (miRNAs) serve as key regulators in the mechanisms driving atherosclerotic disease. However, the expression levels and functional roles of miRNA-133a-3p and miRNA-124-3p in atherosclerosis remain incompletely understood. The aim of this study was to determine the relationship between the expression levels of miR-124-3p and miR-133a-3p, and the phenotypic changes of S100A4-positive vascular smooth muscle cells in atherosclerosis. Methods We collected tissue samples from 25 patients with atherosclerosis who underwent coronary artery bypass graft surgery. IMA tissues were used as controls; atherosclerotic aortic tissues as cases. Expression levels of miRNAs were assessed using reverse transcription polymerase chain reaction (RT-PCR). Tissue samples underwent immunohistochemical staining with S100A4 protein to evaluate cellular and structural characteristics. Results A marked decrease in the expression of miR-133a-3p and miR-124-3p was observed in the atherosclerosis group compared to the control group, and both differences were statistically significant (P=0). Additionally, an increase in S100A4 protein immunoreactivity was detected in the atherosclerosis group. Interpretations and conclusions The downregulation of miRNA-133a-3p and miRNA-124-3p in atherosclerotic tissues, along with the observed increase in S100A4 protein immunoreactivity, suggests that these two miRNAs may play a role in the regulation of inflammatory endothelial phenotypes. Therefore, the interaction between miRNA-133a-3p, miRNA-124-3p, and S100A4 protein may help elucidate a potential mechanism underlying the prevention of atherosclerosis.

Kidney size is sex-dimorphic and regulated by androgens in adult humans and mice. However, the effects of developmental androgen deficiency on kidneys remain elusive. We hypothesized that androgens program future kidney growth during fetal development. Male mice lacking the main testosterone-producing enzyme HSD17B3 had reduced testosterone at embryonic day 15.5, but the concentrations increased by E18.5, creating a short time window of androgen deficiency resulting in reduced kidney size in adult males. In male Hsd17b3-/- kidneys, nephron development was qualitatively normal, but the number of glomeruli and proliferation of proximal tubules were reduced, as was proximal tubule size in adults. Testosterone supplementation at E14.5-17.5 normalized the renal size in adult Hsd17b3-/- males. Our data suggest that androgen receptor and HNF4A jointly regulate IGFBP5, putatively influencing FOXO1 and mTOR signaling to promote male-specific kidney growth in the fetal period. In conclusion, we have identified a novel developmental programming effect on male kidneys, where fetal androgen deficiency reduces kidney growth and androgen responsiveness in adult males.

Mesenchymal stem cells (MSC) represent the main stromal component of the bone marrow (BM) niche and are crucial to maintain hematopoietic tissue homeostasis. MSC exhibits extraordinary and multiple properties. In terms of expanding potential and differentiation capacity, Wharton jelly MSC (WJ-MSC), derived from the umbilical cord, was described as being greater and more performing than MSC from BM or other sources. WJ-MSC mimics the hematopoietic niche and supports hematopoietic stem cells (HSC) expansion ex vivo. This study aimed to evaluate the effects of human WJ-MSC cocultured with HSC in a B-cell differentiation protocol. Remarkably, results highlight WJ-MSC use as a preferable feeder layer to efficiently support HSC commitment toward the B-lineage. Over 11 days of HSC coculture with WJ-MSC, B-cell genes (E2A, RAG1, RAG2, etc.) expression patterns and B-cell markers (CD19, immunoglobulin chain, etc.) acquisition were evidenced. WJ-MSc were also able to unlock the B-lineage differentiation blockade of the acute lymphoblastic leukemia cell line Nalm16. This model might provide a new strategy to support ex vivo B-cell differentiation using the powerful properties of WJ-MSC. This study implements a new approach to improve understanding of B-leukemogenesis and B-cell acute lymphoblastic leukemia (B-ALL) pathophysiology.

The objective of the study was to compare the role of Cryopreserved human amniotic membrane (cHAM) for early pulp biomineralisation in comparison to Biodentine using the tooth culture model. This study was conducted in two stages. The first stage aimed to establish the tooth culture model and assess the viability of pulp cells at 28 and 50 days. In the second stage, pulp capping was performed in the tooth culture model using cHAM and Biodentine. A total of 20 freshly extracted teeth (for orthodontic reasons) were used for pulp capping with either cHAM or Biodentine. The samples were evaluated for biomineralisation at 14 and 28 days using micro-computed tomography (micro-CT) and histological analysis. Morphometric data from micro-CT scans were analysed using the Chi-square test. The viability of pulp cells in the tooth culture model was 66.1% at 28 days and 38.4% at 50 days. Pulp capping with cHAM resulted in a thicker and larger volume of mineralisation at 28 days (720 μm, 0.7 mm3) compared to Biodentine (630 μm, 0.46 mm3). Histological analysis revealed that the dentine formed in the HAM group was homogeneous and continuous, while the Biodentine group showed discontinuous foci of mineralisation in the newly formed hard tissue. Within the study's limitations, it is observed that cHAM induces enhanced early pulpal mineralisation compared to Biodentine.

Human embryonic stem cell (hESC) can be differentiated into definitive endoderm (DE) through multiple branching lineage choices. Although different DE differentiation methods have been established, there are still several limitations, such as the yield of heterogeneous cell populations containing undifferentiated or non-DE cells. Therefore, this study aimed to suppress the alternate fates at branch points and establish a robust and highly efficient differentiation protocol for hESC-derived hepatocytes (hESC-Heps). We developed a two-step DE induction protocol. First, hESCs were treated with a GSK-3α/β inhibitor and an mTOR inhibitor combined with TGF-β activation to generate an anterior primitive streak (progenitor to endoderm). Subsequently, a BMP inhibitor combined with TGF-β activation was used to abolish the mesoderm lineage. The resulting DE cells were further differentiated into hESC-Heps to evaluate their functionality. By regulating the branching lineage choices, we established an efficient two-step method that yielded up to 96% DE cells with minimal expression of pluripotency and mesodermal markers. Notably, this method reduced the dosage of Activin A, which makes it cost-effective for future applications. The derived hESC-Heps exhibited mature hepatocyte characteristics, including glycogen storage, indocyanine green uptake, and cytochrome P450 activity. Additionally, these cells demonstrated robust liver-specific functions such as sensitive innate immune responses and permissiveness to hepatitis B virus infection. In summary, we developed a novel and cost-effective method that achieves high-purity DE by precisely modulating cell fate decisions in the early stages. The derived hESC-Heps can serve as a model for further studies, such as host-virus interaction and hepatotoxicity testing.

Overcoming remyelination failure is one of the main targets in therapeutic strategies for multiple sclerosis. This process requires the differentiation of oligodendrocyte precursor cells (OPCs) to mature myelinating oligodendrocytes (OLs), a process known to be controlled by thyroid hormone, nuclear receptors, and sonic hedgehog (SHH). Retinoid X receptor gamma (RXRg) is one of the nuclear receptors acting as a positive regulator of remyelination, but little is known about its mechanisms of function. Using transcriptomic and pharmacological analysis of primary neural stem cell-derived OPCs, we show that RXRg is involved in the induction of the thyroid hormone-driven differentiation process and in refining it toward an oligodendrogenic cell fate. RXRg also emerged as an important negative modulator of SHH expression and signaling, as Shh and additional genes from this pathway were found to be strongly upregulated in Rxrg-/- OPCs. An inhibition of SHH signaling by cyclopamine or GANT61 entirely normalized the differentiation deficit of Rxrg-/- OPCs, but also myelination of newly generated Rxrg-/- OLs. Such data indicate a key role of SHH hyperactivity in the oligodendrogenesis block associated with the absence of RXRg. Importantly, hyperactivation of the SHH pathway by purmorphamine or SAG inhibited the oligodendrogenesis and myelination potential of wild-type OPCs, indicating that SHH hyperactivity can also be a sufficient factor to block OPC differentiation. These results point to RXRg as an important regulator of SHH pathway signaling and underline the need of an optimal, fine-tuning of SHH signaling to assure successful oligodendrogenesis.

Chronic non-healing wounds pose a significant clinical challenge, driven by dysregulation of the "inflammation-immune-microbiome" triad. Traditional "debridement-anti-infection-coverage" approaches fail to break the vicious cycle of dysbiosis and immune dysfunction. Leveraging structural diversity and bioactivity, natural polysaccharides provide a versatile platform for multi-targeted intervention. This review systematically explores the mechanisms through which polysaccharides modulate the wound immune microenvironment, restructure microbial communities, and facilitate barrier repair. This interaction enables precise regulation of macrophage polarization, particularly the promotion of the M2 phenotype, as well as neutrophil function and adaptive immunity, thereby alleviating chronic inflammation. Moreover, polysaccharides utilize a variety of mechanisms to impact the microbiome, including direct antimicrobial effects through electrostatic interactions and prebiotic support that promotes the colonization and metabolism of beneficial bacteria. This review also explores advancements in intelligent delivery systems, such as microenvironment-responsive hydrogels, discusses challenges in clinical translation, and considers future directions that incorporate single-cell multi-omics, microbiota-based personalization, organ-on-a-chip models, and phage-polysaccharide synergistic therapies. This work offers a theoretical foundation and translational perspective for the development of next-generation polysaccharide-based strategies for chronic wound management.

Polysaccharides have attracted increasing attention due to their potential protective effects against oxidative stress-related ovarian dysfunction. Panax ginseng (P. ginseng) stem-leaf contains abundant polysaccharides. However, their protective effects on ovarian granulosa cells remain underexplored. An acidic polysaccharide (PGPW-a2, 9535 Da) was isolated from P. ginseng stem-leaf. Its backbone consists of 4-α-GalAp, 2-α-Rhap, 2,4-α-Rhap, 3,4-α-Glcp, and 3,6-β-Galp residues, with three side chain (R1, R2 and R3). PGPW-a2 significantly boosted the functionality of antioxidant enzymes and reduced ROS levels by activating the Keap1/Nrf2/HO-1 signaling axis, and protected H2O2-damaged KGN cells by inhibiting the mitochondrial apoptosis pathway. Critically, these protective effects were substantially reversed by the Nrf2 inhibitor ML385. Furthermore, at equivalent concentrations, the main chain core unit of PGPW-a2 (PGPW-a2-a6) exhibited significantly attenuated antioxidant and anti-apoptotic effects compared to PGPW-a2, suggesting synergistic action between the main and branched chains is essential for full bioactivity. These findings indicate that PGPW-a2 protects KGN cells against oxidative stress, highlighting its potential relevance to ovarian health.

CAR T cell therapy has demonstrated remarkable efficacy in treating haematological malignancies, including B-cell lymphomas, B-cell leukaemias, and multiple myeloma. CAR T cell therapy for acute myeloid leukaemia (AML) is also urgently needed. One of the major challenges is identifying AML-specific antigens, since many potential candidates (e.g. CD33, CD123, CLL-1, CD70, TIM-3 and FLT3) are also expressed on normal haematopoietic progenitors. This can lead to 'on-target/off-tumour' toxicity and bone marrow aplasia. CAR NK cell therapy for AML shows promise as a lower-toxicity, off-the-shelf alternative. NK cells have a lower inherent risk of GVHD and may cause milder CRS/ICANS. In this review, we will describe the current status of CAR T/NK cell development for AML. We will also introduce a new CAR T-cell or NK-cell therapy that targets mismatched HLA-DRB1 in patients with AML who have relapsed following an allogeneic haematopoietic stem cell transplant.

The mechanistic role of trisomy 8 in the development of myelodysplastic syndrome (MDS) remains poorly defined. Here, we generated a trisomy 8 mouse model by transferring a human chromosome 8 into murine embryonic stem cells and prospectively examined the effects on hematopoietic stem cells (HSC) by trisomy 8. The expression of inflammatory genes was enhanced, and hematopoietic programs mediated by transcription factors and polycomb repressive complex 2 (PRC2) were dysregulated in trisomy 8 HSC, which impaired their self-renewal and balanced differentiation. Trisomy 8 HSC altered the chromatin accessibility and conformations and activated Y chromosome genes, such as Uty/Kdm6c epigenetic modifier, which is known to demethylate histone H3K27me3 modification. The Uty gene facilitated the activation of PRC2-target and Runx1-target genes in leukemogenesis and drove the proliferation of human trisomy 8 leukemic cells. Since the RUNX1 gene is frequently mutated in patients with trisomy 8 MDS, its deletion attenuated the enhanced expression of inflammatory genes and mitigated the impaired self-renewal of trisomy 8 HSC in mice. Our findings reveal that trisomy 8 altered the transcriptional programs and chromatin conformations in HSC and drove a pre-malignant state through activating the expression of Uty, suggesting a route for the development of trisomy 8 MDS.

Transendothelial migration (TEM), is a complex, multistep process impacted by diseases like autoimmune disorders and cancer. Deciphering aspects of the process enhances our understanding and possibilities for disease treatments. The extent to which this potential can be leveraged is often limited due to conventional assays neither accurately mimicking specific in vivo conditions like sheer stress nor visualizing the whole transmigration cascade, hence missing distinct mechanisms. Flow-based adhesion assays overcome these limitations and allow the use of various endothelial cells from different tissues with distinct properties. So far, a broader and translational assay application is hampered by potential operator-based bias/lack of standardization, as well as poor scalability due to time-consuming manual analysis. In this study, we successfully combined this assay with AI-based analysis including subsequent classification of cell-transmigration phases by a Keras/TensorFlow-based deep learning model. Trained on healthy-donor and pancreatic cancer patient-derived T cells, the model achieved a high accuracy of 91.6 % in identifying/categorizing cell transmigration, surpassing the currently accepted 80 %-threshold, therefore qualifying as a fast, standardized AI-based live-cell imaging tool. Additionally, its architecture grants highly convenient reconfiguration for various disease-model investigations. Hence, by combining an affordable and simplistic, yet potent live-cell-imaging technique with a comprehensive AI-approach, we have established a powerful tool which allows for integrating TEM-assays into various disease models.

CD34 has long been defined as a canonical marker for endothelial progenitors as well as hematopoietic stem cells, implicating its role in vascular development and hematopoiesis. However, the precise developmental hierarchy and lineage potential of CD34+ cells remain controversial. In this study, we integrated inducible genetic lineage tracing techniques, proteomics and single-cell RNA-seq (scRNA-seq) analyses to elucidate the dynamic developmental trajectory of CD34+ cells during various embryonic periods in both humans and mice. Remarkably, our analyses indicated that the progeny of CD34+ cells marked distinct, spatiotemporally restricted progenitor waves with divergent fates, at which point cells adopted endothelial, hematopoietic and fibroblastic fates, respectively. During gastrulation (E6.5-E8.5), an initial wave of CD34+ progenitors predominantly orchestrates vasculogenesis via a Kdr-dependent mechanism. Subsequently, from E9.5 to E14.5, cell cycle activation serves as a molecular switch, facilitating the endothelial-to-hematopoietic transition (EHT) of CD34+ progenitors. Unexpectedly, we identify a wave of CD34+ progenitors in late embryogenesis that gives rise to fibroblasts, distinct from earlier endothelial or hematopoietic lineages. Furthermore, because umbilical cord blood is a valuable source of different circulating stem/progenitor cells, we distinguish circulating endothelial progenitors from fibroblast progenitors in human cord blood by unique molecular signatures, with GFPT2 specifically marking the fibroblast progenitors. Collectively, our study provides a high-resolution spatiotemporal atlas of CD34+ cells during embryogenesis, redefining the temporal shifts of CD34+ cells in cell states and offering a precise framework for manipulating CD34+ cells in regenerative medicine.

Melanocyte stem cells (McSCs) are a crucial melanocyte reservoir within the hair follicle niche. This review provides an overview of the processes for McSC quiescence and activation. Because McSCs closely interact with hair follicle stem cells, we have focused on this interaction. Given the high prevalence of hair graying, the McSC system serves as a model for cellular aging. Here, we highlight current research on the mechanisms of hair graying.