�����ƽ��

INTRODUCTION: Glioma stem cells (GSCs) are pivotal drivers of tumor progression and therapeutic resistance; however, the underlying regulatory mechanisms have not been fully elucidated. This study aimed to identify novel oncogenic drivers in glioma via a comprehensive multiomics analysis. METHODS: We integrated three datasets to screen potential oncogenic drivers. Functional experiments were performed to examine the effects of C1orf226 on glioma cell proliferation, cell cycle, epithelial-mesenchymal transition (EMT), and apoptosis. Additionally, tumor sphere formation assays, ALDH+/CD133+ cell detection, and stemness marker analysis were used to evaluate the role of C1orf226 in GSC stemness. Mechanistic studies involving immunoprecipitation (IP) and ubiquitination assays were applied to characterize the interaction between C1orf226 and PLK1, as well as their regulation on β-catenin stability and Wnt/β-catenin signaling. Rescue assays further verified the functional crosstalk between C1orf226 and PLK1. Xenograft mouse models were used in vivo to assess the impacts of C1orf226 knockdown on tumor growth and stemness markers. RESULTS: C1orf226 was significantly upregulated in glioma tissues compared with normal brain tissues. Its high expression correlated with shorter patient survival and served as an independent prognostic factor in the CGGA cohort. In vitro, C1orf226 exerted oncogenic function by facilitating cell proliferation, cell cycle progression, EMT-like processes, and stemness, and suppressing apoptosis. Mechanistically, C1orf226 interacts with PLK1 to block its degradation, thereby activating PLK1 and downstream Wnt/β-catenin signaling. Rescue experiments verified that PLK1 overexpression restored β-catenin stability, Wnt/β-catenin target gene expression, and GSC properties impaired by C1orf226 knockdown. In vivo, C1orf226 knockdown restrained xenograft growth and reduced stemness marker levels, and PLK1 co-expression abrogated these effects. CONCLUSIONS: Our findings reveal that C1orf226 is a PLK1-dependent regulator of Wnt/β-catenin signaling and GSC plasticity, highlighting its potential as a promising therapeutic target in glioma.

Glioblastoma multiforme (GBM) is defined by rapid progression, high invasiveness, and a poor prognosis, with a median survival of only ≅13 months despite current treatments. Its marked genetic heterogeneity, high mutational burden, and cancer stem cell population make GBM exceptionally difficult to treat, highlighting the urgent need for more effective, multitargeted therapies. Non-coding RNAs, particularly tumor suppressor microRNAs (miRNAs), have gained attention for suppressing key oncogenic processes that drive tumorigenesis, metastasis, and drug resistance, positioning them as promising tools for targeting multiple oncogenic pathways. We recently found that FOXM1/AXL-eEF2K collaboratively drive GBM cell proliferation, survival, and invasion through the formation of a signaling hub complex. In this study, we employed miRNA prediction algorithms to identify a specific miRNA, in vitro functional assays and in vivo GBM flank model to target GBM tumorigenesis by distrupting the FOXM1/AXL-eEF2K signaling hub. Our results indicated that FOXM1, AXL, and eEF2K are overexpressed in GBM patient tumors. To target the FOXM1/AXL-eEF2K signaling hub, we identified miR-449b-5p, miR-329-3p, and miR-518c as potential co-inhibitors of FOXM1/AXL-eEF2K and suppressors of cell proliferation, migration-invasion, and spheroid formation. Furthermore, the combination of miR-449b-5p, miR-329-3p, and miR-518c treatments with temozolomide led to synergistic enhancements in cell proliferation suppression and the induction of apoptosis and ferroptosis. More importantly, in vivo miR-329-3p treatment led to remarkable suppression of GBM tumor xenografts. These findings indicate that miR-329-3p-based tumor suppressor therapy may offer a multitargeted approach for GBM treatment.

Elevated levels of platelet-derived growth factor (PDGF) isoforms in fibrosis are implicated in driving a dysfunctional profibrotic fibroblast phenotype. This study investigated the differential effects of the five PDGF isoforms (AA, AB, BB, CC, and DD) in inducing neonatal dermal and fetal lung fibroblast contraction, proliferation, cytokine production, myofibroblast differentiation, and extracellular matrix (ECM) deposition. All PDGF isoforms, except PDGF-AA, increased contraction of 3-dimensional collagen I gels by dermal (p < 0.01) and lung fibroblasts (p < 0.05) compared to media control. PDGF-AB, BB, and CC enhanced proliferation only in dermal fibroblasts (p < 0.05). PDGF-BB induced profibrotic IL-11 cytokine release in dermal and lung fibroblasts (p < 0.0001) and IL-6 cytokine release in dermal fibroblasts (p < 0.05) compared to media control. None of the PDGF isoforms affected ECM synthesis or myofibroblast differentiation. Dermal fibroblasts exhibited elevated PDGF Receptor-β (PDGFRβ) expression (p < 0.01) and increased basal ERK1/2 phosphorylation (p < 0.05) compared to lung fibroblasts. In summary, PDGF modulates fibroblast functions in a tissue-specific manner, with PDGF-BB driving profibrotic processes in dermal fibroblasts through high PDGFRβ expression and ERK1/2 signalling. Further research is needed to explore the benefit of tissue and isoform-specific PDGF inhibition strategies in skin and lung fibrosis.

Cellular senescence connects aging and cancer. Cellular senescence is a common program activated by cells in response to various types of stress. During this process, cells lose their proliferative capacity and undergo distinct morphological and metabolic changes. Senescence itself constitutes a tumor suppression mechanism and plays a significant role in organismal aging by promoting chronic inflammation. Additionally, age is one of the major risk factors for developing breast cancer. Therefore, while senescence can suppress tumor development early in life, it can also lead to an aging process that drives the development of age-related pathologies, suggesting an antagonistic pleiotropic effect. In this work, we identified Rian/MEG8 as a potential biomarker connecting aging and breast cancer for the first time. We found that Rian/MEG8 expression decreases with age; however, it is high in mice that age prematurely. We also observed decreased MEG8 expression in breast tumors compared to normal tissue. Furthermore, MEG8 overexpression reduced the proliferative and stemness properties of breast cancer cells both in vitro and in vivo by activating apoptosis. MEG8 could exemplify the antagonistic pleiotropic theory, where senescence is beneficial early in life as a tumor suppression mechanism due to increased MEG8, resulting in fewer breast tumors at an early age. Conversely, this effect could be detrimental later in life due to aging and cancer, when MEG8 is reduced and loses its tumor-suppressive role.

IFNγ-secreting T cells are central for the maintenance of immune surveillance within the central nervous system (CNS). It was previously reported in healthy donors that the T-cell environment in the CNS induces distinct signatures related to cytotoxic capacity, CNS trafficking, tissue adaptation, and lipid homeostasis. These findings suggested that the CNS milieu consisting predominantly of lipids mediated the metabolic conditions leading to IFNγ-secreting brain CD4 T cells. Here, we demonstrate that the supplementation of CD4+CD45RO+CXCR3+ cells with cholesterol modulates their function and increases IFNG expression. The heightened IFNG expression was mediated by the activation of the serum/glucocorticoid-regulated kinase (SGK1). Inhibition of SGK1 by a specific enzymatic inhibitor significantly reduces the expression of IFNG Our results confirm the crucial role of lipids in maintaining T-cell homeostasis and demonstrate a putative role of environmental factors to induce effector responses in CD4+ effector/memory cells. These findings offer potential avenues for further research targeting lipid pathways to modulate inflammatory conditions.

INTRODUCTION: NK cells are dysfunctional in myasthenia gravis (MG), but the mechanism is unclear. This study aims to measure associations and underlying mechanisms between the NK cells and the development of MG. METHODS: Twenty healthy controls (HCs) and 53 MG patients who did not receive glucocorticoids and immunosuppressants were collected. According to the Myasthenia Gravis Foundation of America (MGFA) classification, MG patients were categorized into MGFA I group (n = 18) and MGFA II-IV group (n = 35). Flow cytometry, cell sorting, ELISA, mRNA-sequencing, RT-qPCR, western blot, and cell culture experiments were performed to evaluate the regulatory mechanism of exhausted NK cells. RESULTS: Peripheral NK cells in MGFA II-IV patients exhibit exhausted phenotypes than HCs, marked by the dramatic loss of total NK cells, CD56dimCD16- NK cells, elevated PD1 expression, reduced NKG2D expression, impaired cytotoxic activity (perforin, granzyme B, CD107a) and cytokine secretion (IFN-γ). Plasma IL-6 and IL-21 are elevated in MG patients and mainly derived from the aberrant expansion of monocytes and Tfh cells, respectively. IL-6/IL-21 cooperatively induced NK-cell exhausted signature via upregulating SOCS2 and inhibiting the phosphorylation of STAT5. SOCS2 siRNA and IL-2 supplement attenuated the IL-6/IL-21-mediated alteration of NK-cell phenotypes and function. DISCUSSION: Inhibition of IL-6/IL-21/SOCS2/STAT5 pathway and recovery of NK-cell ability to inhibit autoimmunity may be a new direction in the treatment of MG.

Metformin shows promise in breast cancer prevention, but its underlying mechanisms remain unclear. This study investigated the impact of metformin on the repopulation dynamics of mammary epithelial cells (MECs) and the signaling pathways in non-tumorigenic FVB/N mice. This study aimed to enhance our understanding of the role of metformin in reducing the susceptibility of MECs in premalignant tissues to oncogenic factors. In this study, female mice were administered 200 mg/kg/day of metformin via intraperitoneal (i.p.) injection from 8 to 18 weeks of age. After this treatment period, morphogenesis, flow cytometry, analyses of MEC stemness, and RNA sequencing were performed. The study findings indicated that metformin treatment in adult mice reduced mammary gland proliferation, as demonstrated by decreased Ki67+ cells and lateral bud formation. Additionally, metformin significantly reduced both basal and mammary repopulating unit subpopulations, indicating an impact on mammary epithelial cell repopulation. Mammosphere, colony-forming cell, and 3D culture assays revealed that metformin adversely affected mammary epithelial cell stemness. Furthermore, metformin downregulated signaling in key pathways including AMPK/mTOR, MAPK/Erk, PI3K/Akt, and ER, which contribute to its inhibitory effects on mammary proliferation and stemness. Transcriptome analysis with RNA sequencing indicated that metformin induced significant downregulation of genes involved in multiple critical pathways. KEGG-based pathway analysis indicated that genes in PI3K/Akt, focal adhesion, ECM-receptor, small cell lung cancer and immune-modulation pathways were among the top groups of differentially regulated genes. In summary, our research demonstrates that metformin inhibits MEC proliferation and stemness, accompanied by the downregulation of intrinsic signaling. These insights suggest that the regulatory effects of metformin on premalignant mammary tissues could potentially delay or prevent the onset of breast cancer, offering a promising avenue for developing new preventive strategies.

PURPOSE: Spontaneously occurring glioma in pet dogs is increasingly recognized as a valuable translational model for human glioblastoma. Canine high-grade glioma and human glioblastomas share many molecular similarities, including the accumulation of immunosuppressive regulatory T cells (Tregs) that inhibit anti-tumor immune responses. Identifying in dog mechanisms responsible for Treg recruitment may afford to target the cellular population driving immunosuppression, the results providing a rationale for translational clinical studies in human patients. Our group has previously identified C-C motif chemokine 2 (CCL2) as a glioma-derived T-reg chemoattractant acting on chemokine receptor 4 (CCR4) in a murine orthotopic glioma model. Recently, we demonstrated a robust increase of CCL2 in the brain tissue of canine patients bearing high-grade glioma. METHODS: We performed a series of in vitro experiments using canine Tregs and patient-derived canine glioma cell lines (GSC 1110, GSC 0514, J3T-Bg, G06A) to interrogate the CCL2-CCR4 signaling axis in the canine. RESULTS: We established a flow cytometry gating strategy for identifying and isolating FOXP3+ Tregs in dogs. The canine CD4 + CD25high T-cell population was highly enriched in FOXP3 and CCR4 expression, indicating they are bona fide Tregs. Canine Treg migration was enhanced by CCL2 or by glioma cell line-derived supernatant. Blockade of the CCL2-CCR4 axis significantly reduced migration of canine Tregs. CCL2 mRNA was expressed in all glioma cell lines, and expression increased when exposed to Tregs but not CD4 + helper T-cells. CONCLUSION: Our study validates CCL2-CCR4 as a bi-directional Treg-glioma immunosuppressive and tumor-promoting axis in canine high-grade glioma.

BACKGROUND: CD72 is a highly required regulatory molecule in B cells. Its sufficient expression is crucial for maintaining self-tolerance. In contrast, soluble CD72 (sCD72) is reported to be increased in the serum of autoimmune diseases such as systemic lupus erythematosus and primary Sjogren's syndrome (pSS). OBJECTIVE: We wanted to assess the biological effect of sCD72 on CD4+T cells. METHODS: We performed mass spectrometry and co-immunoprecipitation experiments to look for a sCD72 receptor on activated CD4+T cells. Afterward, to explore the biological functions of sCD72, we used flow cytometry for the cytokine secretion profile, a phosphorylation assay for the signaling pathway, and a CFSE dye-based assay for cell proliferation. RESULTS: We found and validated the sCD72 and CD6 interaction as a possible ligand-receptor interaction. We also demonstrated that sCD72 significantly increases the expression of pro-inflammatory cytokines, namely IL-17A and IFN-γ, in activated CD4+T cells and increases the proliferation of CD4+T cells, possibly through its activation of the SLP-76-AKT-mTOR pathway. CONCLUSION: The sCD72-CD6 axis on activated CD4+T cells is probably a new signaling pathway in the induction of immune-mediated diseases. Therefore, targeting sCD72 may become a valuable therapeutic tool in some autoimmune disorders.

Type 1 diabetes (T1D) arises from autoimmune-mediated destruction of insulin-producing pancreatic beta cells. Recent advancements in the technology of generating pancreatic beta cells from human pluripotent stem cells (SC-beta cells) have facilitated the exploration of cell replacement therapies for treating T1D. However, the persistent threat of autoimmunity poses a significant challenge to the survival of transplanted SC-beta cells. Genetic engineering is a promising approach to enhance immune resistance of beta cells as we previously showed by inactivating the Renalase (Rnls) gene. Here, we demonstrate that Rnls loss of function in beta cells shapes autoimmunity by mediating a regulatory natural killer (NK) cell phenotype important for the induction of tolerogenic antigen-presenting cells. Rnls-deficient beta cells mediate cell-cell contact-independent induction of hallmark anti-inflammatory cytokine Tgfβ1 in NK cells. In addition, surface expression of regulatory NK immune checkpoints CD47 and Ceacam1 is markedly elevated on beta cells deficient for Rnls. Altered glucose metabolism in Rnls mutant beta cells is involved in the upregulation of CD47 surface expression. These findings are crucial to better understand how genetically engineered beta cells shape autoimmunity, giving valuable insights for future therapeutic advancements to treat and cure T1D.

Image-based lineage tracing enables tissue turnover kinetics and lineage potentials of different adult cell populations to be investigated. Previously, we reported a genetic mouse model system, Red2Onco, which ectopically expressed mutated oncogenes together with red fluorescent proteins (RFP). This system enabled the expansion kinetics and neighboring effects of oncogenic clones to be dissected. We now report Red2Flpe-SCON: a mosaic knockout system that uses multicolor reporters to label both mutant and wild-type cells. We develop the Red2Flpe mouse line for red clone-specific Flpe expression, as well as the FRT-based SCON (Short Conditional IntrON) method to facilitate tunable conditional mosaic knockouts in mice. We use the Red2Flpe-SCON method to study Sox2 mutant clonal analysis in the esophageal epithelium of adult mice which reveal that the stem cell gene, Sox2, is less essential for adult stem cell maintenance itself, but rather for stem cell proliferation and differentiation.

BACKGROUND: Ovarian cancer has a high mortality rate mainly due to its resistance to currently used therapies. This resistance has been associated with the presence of cancer stem cells (CSCs), interactions with the microenvironment, and intratumoral heterogeneity. Therefore, the search for new therapeutic targets, particularly those targeting CSCs, is important for improving patient prognosis. HOOK1 has been found to be transcriptionally altered in a substantial percentage of ovarian tumors, but its role in tumor initiation and development is still not fully understood. METHODS: The downregulation of HOOK1 was performed in ovarian cancer cell lines using CRISPR/Cas9 technology, followed by growth in vitro and in vivo assays. Subsequently, migration (Boyden chamber), cell death (Western-Blot and flow cytometry) and stemness properties (clonal heterogeneity analysis, tumorspheres assay and flow cytometry) of the downregulated cell lines were analysed. To gain insights into the specific mechanisms of action of HOOK1 in ovarian cancer, a proteomic analysis was performed, followed by Western-blot and cytotoxicity assays to confirm the results found within the mass spectrometry. Immunofluorescence staining, Western-blotting and flow cytometry were also employed to finish uncovering the role of HOOK1 in ovarian cancer. RESULTS: In this study, we observed that reducing the levels of HOOK1 in ovarian cancer cells reduced in vitro growth and migration and prevented tumor formation in vivo. Furthermore, HOOK1 reduction led to a decrease in stem-like capabilities in these cells, which, however, did not seem related to the expression of genes traditionally associated with this phenotype. A proteome study, along with other analysis, showed that the downregulation of HOOK1 also induced an increase in endoplasmic reticulum stress levels in these cells. Finally, the decrease in stem-like properties observed in cells with downregulated HOOK1 could be explained by an increase in cell death in the CSC population within the culture due to endoplasmic reticulum stress by the unfolded protein response. CONCLUSION: HOOK1 contributes to maintaining the tumorigenic and stemness properties of ovarian cancer cells by preserving protein homeostasis and could be considered an alternative therapeutic target, especially in combination with inducers of endoplasmic reticulum or proteotoxic stress such as proteasome inhibitors.