Radiotherapy, as a vital means of esophageal cancer treatment, has benefited countless cancer patients, but owing to the occurrence of radio-resistance, its therapeutic efficiency has been dramatically mitigated. Discovering key biomarkers governing radio-tolerance in esophageal cancer and revealing their inherent molecular mechanisms will be of great significance for clinical cancer treatment. Here, we have found roundabout guidance receptor 1 (ROBO1) was significantly upregulated in esophageal cancerous tissues and showed enhanced expression with the development of cancer staging. Cellular experiments demonstrated ROBO1 directly interacted with eukaryotic translation initiation factor 3A (eIF3A) and accelerated its degradation in esophageal cancer cells after irradiation treatment. Mass spectrum analysis further revealed that in response to irradiation, ROBO1, eIF3A and G3BP2 (Ras GTPase-activating protein-binding protein 2) formed a hetero-complex and triggered lysosomes-mediated protein degradation. Knocking down of G3BP2 abrogated the influence of ROBO1 on eIF3A instability. Besides, ROBO1-mediated eIF3A degradation interrupted P53 translation process which in turn provoked downstream mTOR signaling and increased DNA repair associated genes expressions, resulting in radio-resistance enhancement in cancer cells. In conclusion, our findings revealed a novel role of eIF3A in modulating P53/mTOR signaling activity and provided a drug candidate (ROBO1) for overcoming radio-resistance in esophageal cancer.

Oligodendrocyte maturation arrest in hypoxia-induced white matter injury (WMI) results in long-term neurofunctional disabilities of preterm infants. Although neurons are closely linked to myelination regulation, how neurons respond to the above process remains elusive. Here, we identify a compensatory role of neuronal Slit1-dependent signaling in protecting against hypoxia-induced hypomyelination and ameliorating motor and cognitive disabilities. Conditional ablation of Slit1 in neurons exacerbates hypoxia-induced hypomyelination but is negligible for developmental myelination. Secreted Slit1 from hypoxic neurons directly targets oligodendrocyte, acting through Robo2-srGAP1-RhoA signaling. Pharmacological inhibition of RhoA restores myelination and promotes neurofunctional recovery in adolescent mice. Notably, natural selection analysis and functional validation indicate an adaptive variant with higher Slit1 gene expression in the Tibetan population, which has low oxygen availability. Collectively, these findings show a neuronal Slit1-dependent program of OL differentiation and suggest that targeting the Slit1-Robo2 signaling axis may have therapeutic potential for treatment of preterm infants with hypoxic WMI.

The highly nuanced transition from an inflammatory process to tumorigenesis is of great scientific interest. While it is well known that environmental stimuli can cause inflammation, less is known about the oncogenic modifications that chronic inflammation in the tissue microenvironment can bring about, as well as how these modifications can set off pro-tumorigenic processes. It is clear that no matter where the environmental factors come from, maintaining an inflammatory microenvironment encourages carcinogenesis. In addition to encouraging angiogenesis and metastatic processes, sustaining the survival and proliferation of malignant transformed cells, and possibly altering the efficacy of therapeutic agents, inflammation can negatively regulate the antitumoral adaptive and innate immune responses. Because chronic inflammation has multiple pathways involved in tumorigenesis and metastasis, it has gained recognition as a marker of cancer and a desirable target for cancer therapy. Recent advances in our knowledge of the molecular mechanisms that drive cancer's progression demonstrate that inflammation promotes tumorigenesis and metastasis while suppressing anti-tumor immunity. In many solid tumor types, including breast, lung, and liver cancer, inflammation stimulates the activation of oncogenes and impairs the body's defenses against the tumor. Additionally, it alters the microenvironment of the tumor. As a tactical approach to cancer treatment, these findings have underscored the importance of targeting inflammatory pathways. This review highlights the role of inflammation in cancer development and metastasis, focusing on its impact on tumor progression, immune suppression, and therapy resistance. It examines current anti-inflammatory strategies, including NSAIDs, cytokine modulators, and STAT3 inhibitors, while addressing their potential and limitations. The review emphasizes the need for further research to unravel the complex mechanisms linking inflammation to cancer progression and identify molecular targets for specific cancer subtypes.

Cancer remains a leading cause of mortality worldwide. Despite significant advancements in cancer research, our understanding of its complex developmental pathways remains inadequate. Recent research has clarified the intricate relationship between the central nervous system (CNS) and cancer, particularly how the CNS influences tumor growth and metastasis via regulating immune cell activity. The interactions between the central nervous system and immune cells regulate the tumor microenvironment via various signaling pathways, cytokines, neuropeptides, and neurotransmitters, while also incorporating processes that alter the tumor immunological landscape. Furthermore, therapeutic strategies targeting neuro-immune cell interactions, such as immune checkpoint inhibitors, alongside advanced technologies like brain-computer interfaces and nanodelivery systems, exhibit promise in improving treatment efficacy. This complex bidirectional regulatory network significantly affects tumor development, metastasis, patient immune status, and therapy responses. Therefore, understanding the mechanisms regulating CNS-immune cell interactions is crucial for developing innovative therapeutic strategies. This work consolidates advancements in CNS-immune cell interactions, evaluates their potential in cancer treatment strategies, and provides innovative insights for future research and therapeutic approaches.

T-cell lymphoblastic lymphoma (T-LBL) has a poor response to traditional chemotherapy regimens, and is prone to relapse after treatment. Effective drugs are lacking for relapsed and refractory (RR) T-LBL patients, highlighting the need for novel treatments. Selinexor and decitabine have good effects on a variety of hematolymphatic diseases and solid tumors, but how effective they are in treating T-LBL has not been reported. In this study, we first investigated the efficacy and mechanism of selinexor combined with decitabine in the treatment of T- LBL.

The proliferation, apoptosis, and cell cycle progression of T-LBL cells were detected via CCK-8 and flow cytometry. Changes in mRNA expression and protein levels were assessed via mRNA sequencing, quantitative real-time PCR, and Western blotting. SLIT2 expression was detected by immunohistochemistry and Western blotting. Tumor xenograft models were established to evaluate the efficacy of drugs in vivo.

Selinexor or decitabine alone inhibited T-LBL cell proliferation in a dose-dependent manner. Cotreatment with both drugs had obvious synergistic effects, promoted cell apoptosis, and induced G0/G1-phase cell cycle arrest in T-LBL cells, and the RNA sequencing results indicated that the tumor suppressor gene SLIT2 might be involved in the synergistic effect of the two drugs. In vivo, this combination showed synergistic antitumor effects in xenograft mouse models.

In summary, selinexor in combination with decitabine has significant synergistic effects both in vitro and in vivo and represents a new treatment option for RR T-LBL.

Cellular plasticity and the ability to avoid terminal differentiation are hallmarks of cancer. Here, we review the evidence that tumor cells themselves can take on properties of neurons of the central nervous system, which can regulate tumor growth and metastasis. We discuss recent evidence that axon guidance molecules and regulators of electrical activity and synaptic transmission, such as ion channels and neurotransmitters, can drive the oncogenic and invasive properties of tumor cells from a range of cancers. We also review how FDA-approved treatments for neurological disorders are being tested in pre-clinical models and clinical trials for repurposing as anti-cancer agents, offering the potential for new therapies for cancer patients that can be accessed more quickly.

The blood-brain barrier is often altered in glioblastoma (GBM) creating a blood-brain-tumor barrier (BBTB) composed of pericytes. The BBTB affects chemotherapy efficacy. However, the expression signatures of BBTB-associated pericytes remain unclear. We aimed to identify BBTB-associated pericytes in single-cell RNA sequencing data of GBM using pericyte markers, a normal brain pericyte expression signature, and functional enrichment. We identified parathyroid hormone receptor-1 (PTH1R) as a potential marker of pericytes associated with BBTB function. These pericytes interact with other cells in GBM mainly through extracellular matrix-integrin signaling pathways. Compared with normal pericytes, pericytes in GBM exhibited upregulation of several ECM genes (including collagen IV and FN1), and high expression levels of these genes were associated with a poor prognosis. Cell line experiments showed that PTH1R knockdown in pericytes increased collagen IV and FN1 expression levels. In mice models, the expression levels of PTH1R, collagen IV, and FN1 were consistent with these trends. Evans Blue leakage and IgG detection in the brain tissue suggested a negative correlation between PTH1R expression levels and blood-brain barrier function. Further, a risk model based on differentially expressed genes in PTH1R+ pericytes had predictive value for GBM, as validated using independent and in-house cohorts.

Neuroinflammation hallmarks the pathology of depression although the etiological complexity has not yet been resolved. Previous studies demonstrate that bacterial lipopolysaccharide induces depressive-like behaviors by activating RagA-mTOR-p70S6K signaling pathway. The current project aims to investigate whether and how brain-specific RagA overexpression triggers depressive-like behaviors in mice. Full-length RagA cDNA is cloned into the mammalian expression vector under the control of brain specific promoter, and subsequently overexpressed in the brain of mouse embryos. Indeed, RagA transgenic mice exhibit depressive-like behaviors and memory impairments. RNA-seq profiling of the prefrontal cortex (PFC) transcriptome highlights adenosine A2a receptor (ADORA2A) as a key differentially expressed gene (DEG). Western blotting confirms that ADORA2A and phospho-p70S6K are markedly elevated in RagA transgenic mice. Behavioral assessments demonstrate that ADORA2A inhibitor istradefylline markedly attenuates depressive-like behaviors. Further metabolomics reveals that N-acetylserotonin and several depression-related metabolites are downregulated while proteomic profiling showed that OLIG1 and other proteins are significantly regulated in RagA transgenic mice. Collectively, RagA overexpression alters the expression patterns of signaling proteins and the metabolism of depression-associated metabolites. RagA may cause depressive-like behaviors in mice via activating p70S6K/ADORA2A signaling pathway. Thus, RagA-p70S6K-ADORA2A signaling pathway may be a target for the development of new antidepressant therapies.

Ovarian cancer is the most lethal gynecological cancer and presents significant therapeutic challenges. The discovery of synthetic lethality between PARP inhibitors (PARPi) and homologous recombination deficiency marked a new era in treating BRCA1/2-mutated tumors. However, PARPi resistance remains a major clinical challenge.

RNA sequencing was used to identify genes altered by PARPi treatment and LC-MS was used to detect proteins interacting with CYP1B1. Resistance mechanisms were explored through ATAC-seq and gene expression manipulation. Additional techniques, including micrococcal nuclease digestion assays, DAPI staining, and fluorescence microscopy, were used to assess changes in nuclear morphology and chromatin accessibility.

The gradual exposure of Olaparib has developed a PARPi-resistant cell line, A2780-OlaR, which exhibits significant upregulation of CYP1B1 at both RNA and protein levels. Down-regulating CYP1B1 expression or using specific inhibitors decreased the cellular response to Olaparib. Linker histone H1.4 was identified as associated with CYP1B1. ATAC-seq showed differential chromatin accessibility between A2780-OlaR and parental cells, indicating that the downregulation of H1.4 was associated with increased chromatin accessibility and higher cell viability after Olaparib treatment.

Our findings reveal a novel role for CYP1B1 in driving PARPi resistance through distinct molecular mechanisms in A2780-OlaR. This study highlights the importance of chromatin accessibility in PARPi efficacy and suggests the CYP1B1/H1.4 axis as a promising therapeutic target for overcoming drug resistance in ovarian cancer, offering potentially therapeutic benefits.

Oxidative stress reflected by elevated reactive oxygen species (ROS) in the tumor ecosystem, is a hallmark of human cancers. The mechanisms by which oxidative stress regulate the metastatic ecosystem and resistance remain elusive. This study aimed to dissect the oxidative stress-sensing machinery during the evolvement of early dissemination and acquired drug resistance in breast cancer.

Here, we constructed single-cell landscape of primary breast tumors and metastatic lymph nodes, and focused on RGS5+ endothelial cell subpopulation in breast cancer metastasis and resistance.

We reported on RGS5 as a master in endothelial cells sensing oxidative stress. RGS5+ endothelial cells facilitated tumor-endothelial adhesion and transendothelial migration of breast cancer cells. Antioxidant suppressed oxidative stress-induced RGS5 expression in endothelial cells, and prevented adhesion and transendothelial migration of cancer cells. RGS5-overexpressed HLECs displayed attenuated glycolysis and oxidative phosphorylation. Drug-resistant HLECs with RGS5 overexpression conferred acquired drug resistance of breast cancer cells. Importantly, genetic knockdown of RGS5 prevented tumor growth and lymph node metastasis.

Our work demonstrates that RGS5 in lymphatic endothelial cells senses oxidative stress to promote breast cancer lymph node metastasis and resistance, providing a novel insight into a potentially targetable oxidative stress-sensing machinery in breast cancer treatment.

Cancers hijack the nervous system for growth and spread. Thus, disrupting neuron-cancer crosstalk holds promise for blocking metastasis. Recently, Padmanaban et al. reported new therapeutic targets and showed that breast cancer cells activate sensory neurons to secrete the neuropeptide substance P (SP), leading to single-strand (ss)RNA release and noncanonical Toll-like receptor (TLR)7 signaling that drives metastasis.

Tumor cells remodel the phenotype and function of tumor microenvironment (TME) cells to favor tumor progression. Previous studies have shown that neutrophils in TME are polarized to N2 tumor-associated neutrophils (TANs) by tumor derived factors, thus promoting tumor growth and metastasis, angiogenesis, therapy resistance, and immunosuppression. Exosomes act as critical intercellular messengers in human health and diseases including cancer. So far, the biological roles of exosomes from N2 TANs in gastric cancer have not been well characterized. Herein, we represented the first report that exosomes from N2 TANs promoted gastric cancer metastasis in vitro and in vivo. We found that exosomes from N2 TANs transferred miR-4745-5p/3911 to gastric cancer cells to downregulate SLIT2 (slit guidance ligand 2) gene expression. Adenovirus-mediated overexpression of SLIT2 reversed the promotion of gastric cancer metastasis by N2 TANs derived exosomes. We further revealed that gastric cancer cells induced glucose metabolic reprogramming in neutrophils through exosomal HMGB1 (high mobility group protein B1)/NF-κB pathway, which mediated neutrophil N2 polarization and miR-4745-5p/3911 upregulation. We further employed ddPCR (droplet digital PCR) to detect the expression of miR-4745-5p/3911 in N2 TANs exosomes from human serum samples and found their increased levels in gastric cancer patients compared to healthy controls and benign gastric disease patients. Conclusively, our results indicate that N2 TANs facilitate cancer metastasis via regulation of SLIT2 in gastric cancer cells by exosomal miR-4745-5p/3911, which provides a new insight into the roles of TME cells derived exosomes in gastric cancer metastasis and offers a potential biomarker for gastric cancer diagnosis.

The dysfunction of blood-vessel-lining endothelial cells is a major cause of mortality. Although endothelial cells, being present in all organs as a single-cell layer, are often conceived as a rather inert cell population, the vascular endothelium as a whole should be considered a highly dynamic and interactive systemically disseminated organ. We present here a holistic view of the field of vascular research and review the diverse functions of blood-vessel-lining endothelial cells during the life cycle of the vasculature, namely responsive and relaying functions of the vascular endothelium and the responsive roles as instructive gatekeepers of organ function. Emerging translational perspectives in regenerative medicine, preventive medicine, and aging research are developed. Collectively, this review is aimed at promoting disciplinary coherence in the field of angioscience for a broader appreciation of the importance of the vasculature for organ function, systemic health, and healthy aging.

Tumour innervation is associated with worse patient outcomes in multiple cancers1,2, which suggests that it may regulate metastasis. Here we observed that highly metastatic mouse mammary tumours acquired more innervation than did less-metastatic tumours. This enhanced innervation was driven by expression of the axon-guidance molecule SLIT2 in tumour vasculature. Breast cancer cells induced spontaneous calcium activity in sensory neurons and elicited release of the neuropeptide substance P (SP). Using three-dimensional co-cultures and in vivo models, we found that neuronal SP promoted breast tumour growth, invasion and metastasis. Moreover, patient tumours with elevated SP exhibited enhanced lymph node metastatic spread. SP acted on tumoral tachykinin receptors (TACR1) to drive death of a small population of TACR1high cancer cells. Single-stranded RNAs (ssRNAs) released from dying cells acted on neighbouring tumoural Toll-like receptor 7 (TLR7) to non-canonically activate a prometastatic gene expression program. This SP- and ssRNA-induced Tlr7 gene expression signature was associated with reduced breast cancer survival outcomes. Therapeutic targeting of this neuro-cancer axis with the TACR1 antagonist aprepitant, an approved anti-nausea drug, suppressed breast cancer growth and metastasis in multiple models. Our findings reveal that tumour-induced hyperactivation of sensory neurons regulates multiple aspects of metastatic progression in breast cancer through a therapeutically targetable neuropeptide/extracellular ssRNA sensing axis.

Breast cancer (BC) represents a paradigm of heterogeneity, manifesting as a spectrum of molecular subtypes with divergent clinical trajectories. It is fundamentally characterized by the aberrant proliferation of malignant cells within breast tissue, a process modulated by a myriad of factors that govern its progression. Recent endeavors outline the interplay between BC and the nervous system, illuminate the complex symbiosis between neural structures and neoplastic cells, and elucidate nerve dependence as a cornerstone of BC progression. This includes the neural modulations on immune response, neurovascular formation, and multisystem interactions. Such insights have unveiled the critical impact of neural elements on tumor dynamics and patient prognosis. This revelation beckons a deeper exploration into the neuro-oncological interface, potentially unlocking novel therapeutic vistas. This review endeavors to delineate the intricate mechanisms between the nervous system and BC, aiming to accentuate the implications and therapeutic strategies of this intersection for tumor evolution and the formulation of innovative therapeutic approaches.

Venous thromboembolism is associated with endothelial cell activation that contributes to the inflammation-dependent activation of the coagulation system. Cellular damage is associated with the release of different species of extracellular RNA (eRNA) involved in inflammation and coagulation. TLR3 (toll-like receptor 3), which recognizes (viral) single-stranded or double-stranded RNAs and self-RNA fragments, might be the receptor of these species of eRNA during venous thromboembolism. Here, we investigate how the TLR3/eRNA axis contributes to venous thromboembolism.

Thrombus formation and size in wild-type and TLR3 deficient (-/-) mice were monitored by ultrasonography after venous thrombosis induction using the ferric chloride and stasis models. Mice were treated with RNase I, with polyinosinic-polycytidylic acid, a TLR3 agonist, or with RNA extracted from murine endothelial cells. Gene expression and signaling pathway activation were analyzed in HEK293T cells overexpressing TLR3 in response to eRNA or in human umbilical vein endothelial cells transfected with a small interference RNA against TLR3. Plasma clot formation on treated human umbilical vein endothelial cells was analyzed. Thrombosis exacerbated eRNA release in vivo and increased eRNA content within the thrombus. RNase I treatment reduced thrombus size compared with vehicle-treated mice (P<0.05). Polyinosinic-polycytidylic acid and eRNA treatments increased thrombus size in wild-type mice (P<0.01 and P<0.05), but not in TLR3-/- mice, by reinforcing neutrophil recruitment (P<0.05). Mechanistically, TLR3 activation in endothelial cells promotes CXCL5 (C-X-C motif chemokine 5) secretion (P<0.001) and NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation (P<0.05). Finally, eRNA triggered plasma clot formation in vitro (P<0.01).

We show that eRNA and TLR3 activation enhance venous thromboembolism through neutrophil recruitment possibly through secretion of CXCL5, a potent neutrophil chemoattractant.

It is estimated that only 0.02% of disseminated tumour cells are able to seed overt metastases1. While this suggests the presence of environmental constraints to metastatic seeding, the landscape of host factors controlling this process remains largely unclear. Here, combining transposon technology2 and fluorescence niche labelling3, we developed an in vivo CRISPR activation screen to systematically investigate the interactions between hepatocytes and metastatic cells. We identify plexin B2 as a critical host-derived regulator of liver colonization in colorectal and pancreatic cancer and melanoma syngeneic mouse models. We dissect a mechanism through which plexin B2 interacts with class IV semaphorins on tumour cells, leading to KLF4 upregulation and thereby promoting the acquisition of epithelial traits. Our results highlight the essential role of signals from the liver parenchyma for the seeding of disseminated tumour cells before the establishment of a growth-promoting niche. Our findings further suggest that epithelialization is required for the adaptation of CRC metastases to their new tissue environment. Blocking the plexin-B2-semaphorin axis abolishes metastatic colonization of the liver and therefore represents a therapeutic strategy for the prevention of hepatic metastases. Finally, our screening approach, which evaluates host-derived extrinsic signals rather than tumour-intrinsic factors for their ability to promote metastatic seeding, is broadly applicable and lays a framework for the screening of environmental constraints to metastasis in other organs and cancer types.

Our previous studies have highlighted the pivotal role of gastric cancer mesenchymal stem cells (GCMSCs) in tumor initiation, progression, and metastasis. In parallel, it is well-documented that endothelial cells (ECs) undergo functional alterations in response to challenging tumor microenvironment. This study aims to elucidate whether functional changes in ECs might be induced by GCMSCs and thus influence cancer progression. Cell proliferation was assessed through CCK-8 and colony formation assays, while cell migration and invasion capabilities were evaluated by wound-healing and Transwell assays. Immunohistochemistry was employed to examine protein distribution and expression levels. Additionally, quantitative analysis of protein and mRNA expression was carried out through Western blotting and qRT-PCR respectively, with gene knockdown achieved using siRNA. Our findings revealed that GCMSCs effectively stimulate cell proliferation, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs), both in vitro and in vivo. GCMSCs promote the migration and invasion of gastric cancer cells by inducing the expression of Slit2 in HUVECs. Notably, the inhibition of phosphorylated AKT partially mitigates the aforementioned effects. In conclusion, GCMSCs may exert regulatory control over Slit2 expression in ECs via the AKT signaling pathway, thereby inducing functional changes in ECs that promote tumor progression.

Toll-like receptors (TLRs) are a key family of pattern recognition receptors (PRRs) in the innate immune system. The activation of TLRs will not only prevent pathogen infection but also respond to damage-induced danger signaling. Increasing evidence suggests that TLRs play a critical role in breast cancer development and treatment. However, the activation of TLRs is a double-edged sword that can induce either pro-tumor activity or anti-tumor effect. The underlying mechanisms of these opposite effects of TLR signaling in cancer are not fully understood. Targeting TLRs is a promising strategy for improving breast cancer treatment, either as monotherapies or by improving other current therapies. Here we provide an update on the role of TLRs in breast cancer immunity and immunotherapy.

Vascular endothelial cells (VECs) are key players in the formation of neovessels and tumor metastasis, the ultimate cause of the majority of cancer-related human death. However, the crosstalk between VECs and metastasis remain greatly elusive. Based on our finding that tumor-associated VECs present significant decrease of Nrdp1 protein which is closely correlated with higher metastatic probability, herein we show that the conditional medium from hypoxia-incubated cancer cells induces extensive Nrdp1 downregulation in human and mouse VECs by vascular endothelial growth factor (VEGF), which activates CHIP, followed by Nrdp1 degradation in ubiquitin-proteasome-dependent way. More importantly, lung metastases of cancer cells significantly increase in conditional VECs Nrdp1 knockout mice. Mechanically, Nrdp1 promotes degradation of Fam20C, a secretory kinase involved in phosphorylating numerous secreted proteins. Reciprocally, deficiency of Nrdp1 in VECs (ecNrdp1) results in increased secretion of Fam20C, which induces degradation of extracellular matrix and disrupts integrity of vascular basement membrane, thus driving tumor metastatic dissemination. In addition, specific overexpression of ecNrdp1 by Nrdp1-carrying adeno-associated virus or chemical Nrdp1 activator ABPN efficiently mitigates tumor metastasis in mice. Collectively, we explore a new mechanism for VEGF to enhance metastasis and role of Nrdp1 in maintaining the integrity of vascular endothelium, suggesting that ecNrdp1-mediated signaling pathways might become potential target for anti-metastatic therapies.

Crosstalk between cancer cells and the immune microenvironment is determinant for liver cancer progression. A tumor subpopulation called liver cancer stem cells (CSCs) significantly accounts for the initiation, metastasis, therapeutic resistance, and recurrence of liver cancer. Emerging evidence demonstrates that the interaction between liver CSCs and immune cells plays a crucial role in shaping an immunosuppressive microenvironment and determining immunotherapy responses. This review sheds light on the bidirectional crosstalk between liver CSCs and immune cells for liver cancer progression, as well as the underlying molecular mechanisms after presenting an overview of liver CSCs characteristic and their microenvironment. Finally, we discuss the potential application of liver CSCs-targeted immunotherapy for liver cancer treatment.

Toll-like receptors (TLRs) are inflammatory triggers and belong to a family of pattern recognition receptors (PRRs) that are central to the regulation of host protective adaptive immune responses. Activation of TLRs in innate immune myeloid cells directs lymphocytes to produce the most appropriate effector responses to eliminate infection and maintain homeostasis of the body's internal environment. Inappropriate TLR stimulation can lead to the development of general autoimmune diseases as well as chronic and acute inflammation, and even cancer. Therefore, TLRs are expected to be targets for therapeutic treatment of inflammation-related diseases, autoimmune diseases, microbial infections, and human cancers. This review summarizes the recent discoveries in the molecular and structural biology of TLRs. The role of different TLR signaling pathways in inflammatory diseases, autoimmune diseases such as diabetes, cardiovascular diseases, respiratory diseases, digestive diseases, and even cancers (oral, gastric, breast, colorectal) is highlighted and summarizes new drugs and related clinical treatments in clinical trials, providing an overview of the potential and prospects of TLRs for the treatment of TLR-related diseases.

Medulloblastoma (MB) is one of the most common pediatric brain tumors and it is estimated that one-third of patients will not achieve long-term survival. Conventional prognostic parameters have limited and unreliable correlations with MB outcome, presenting a major challenge for patients' clinical improvement. Acknowledging this issue, our aim was to build a gene signature and evaluate its potential as a new prognostic model for patients with the disease. In this study, we used six datasets totaling 1679 samples including RNA gene expression and DNA methylation data from primary MB as well as control samples from healthy cerebellum. We identified methylation-driven genes (MDGs) in MB, genes whose expression is correlated with their methylation. We employed LASSO regression, incorporating the MDGs as a parameter to develop the prognostic model. Through this approach, we derived a two-gene signature (GS-2) of candidate prognostic biomarkers for MB (CEMIP and NCBP3). Using a risk score model, we confirmed the GS-2 impact on overall survival (OS) with Kaplan-Meier analysis. We evaluated its robustness and accuracy with receiver operating characteristic curves predicting OS at 1, 3, and 5 years in multiple independent datasets. The GS-2 showed highly significant results as an independent prognostic biomarker compared to traditional MB markers. The methylation-regulated GS-2 risk score model can effectively classify patients with MB into high and low-risk, reinforcing the importance of this epigenetic modification in the disease. Such genes stand out as promising prognostic biomarkers with potential application for MB treatment.

The innate immune pathway is receiving increasing attention in cancer therapy. This pathway is ubiquitous across various cell types, not only in innate immune cells but also in adaptive immune cells, tumor cells, and stromal cells. Agonists targeting the innate immune pathway have shown profound changes in the tumor microenvironment (TME) and improved tumor prognosis in preclinical studies. However, to date, the clinical success of drugs targeting the innate immune pathway remains limited. Interestingly, recent studies have shown that activation of the innate immune pathway can paradoxically promote tumor progression. The uncertainty surrounding the therapeutic effectiveness of targeted drugs for the innate immune pathway is a critical issue that needs immediate investigation. In this review, we observe that the role of the innate immune pathway demonstrates heterogeneity, linked to the tumor development stage, pathway status, and specific cell types. We propose that within the TME, the innate immune pathway exhibits multidimensional diversity. This diversity is fundamentally rooted in cellular heterogeneity and is manifested as a variety of signaling networks. The pro-tumor effect of innate immune pathway activation essentially reflects the suppression of classical pathways and the activation of potential pro-tumor alternative pathways. Refining our understanding of the tumor's innate immune pathway network and employing appropriate targeting strategies can enhance our ability to harness the anti-tumor potential of the innate immune pathway and ultimately bridge the gap from preclinical to clinical application.

Human satellite II (HSATII), composed of tandem repeats in pericentromeric regions, is aberrantly transcribed in epithelial cancers, particularly pancreatic cancer. Dysregulation of repetitive elements in cancer tissues can facilitate incidental dsRNA formation; however, it remains controversial whether dsRNAs play tumor-promoting or tumor-suppressing roles during cancer progression. Therefore, we focused on the double-stranded formation of HSATII RNA and explored its molecular function. The overexpression of double-stranded HSATII (dsHSATII) RNA promoted mesenchymal-like morphological changes and enhanced the invasiveness of pancreatic cancer cells. We identified an RNA-binding protein, spermatid perinuclear RNA-binding protein (STRBP), which preferentially binds to dsHSATII RNA rather than single-stranded HSATII RNA. The mesenchymal transition of dsHSATII-expressing cells was rescued by STRBP overexpression. Mechanistically, STRBP is involved in the alternative splicing of genes associated with epithelial-mesenchymal transition (EMT). We also confirmed that isoform switching of CLSTN1, driven by dsHSATII overexpression or STRBP depletion, induced EMT-like morphological changes. These findings reveal a novel tumor-promoting function of dsHSATII RNA, inducing EMT-like changes and cell invasiveness, thus enhancing our understanding of the biological significance of aberrant expression of satellite arrays in malignant tumors.

Distant metastasis is responsible for high mortality in most cancer cases and the lung is one of the most common target organs, severely affecting the quality of daily life and overall survival of cancer patients. With relevant research breakthroughs accumulating, scientists have developed a deeper understanding of lung metastasis (LM) from the rudimentary "seed and soil" theory to a more vivid concept of the pre-metastatic niche (PMN). Thus, the mechanisms of PMN formation become considerably complicated, involving various types of cells, chemokines, cytokines, and proteins, providing potential biomarkers for improved LM diagnosis and treatment techniques. Here we summarized the latest findings (in 3 years) of lung PMN and systematically collated it from basic research to clinical application, which clearly exhibited the influences of the primary tumor, stromal, and bone marrow-derived cells (BMDCs) and associated molecules in the formation of lung PMN.

In tumor treatment, the highly disordered vascular system and lack of accumulation of chemotherapeutic drugs in tumors severely limit the therapeutic role of nanocarriers. Smaller drug-containing nanoparticles (NPs) can better penetrate the tumor but are easily removed, which severely limits the tumor-killing properties of the drug. The chemotherapeutic medication doxorubicin (DOX) is highly toxic to the heart, but this toxicity can be effectively mitigated and the combined anticancer effect can be enhanced by clinically incorporating curcumin (CUR) as part of the dual therapy. We designed a small-molecule peptide, Pep1, containing a targeting peptide (CREKA) and a pH-responsive moiety. These NPs can target the blood vessels in tumor microthrombi and undergo a morphological shift in the tumor microenvironment. This process enhances the penetration and accumulation of drugs, ultimately improving the effectiveness of cancer treatment. In vitro and in vivo experiments demonstrated that this morphological transformation allowed rapid and effective drug release into tumors, the effective inhibition of tumor angiogenesis, and the promotion of tumor cell apoptosis, thus effectively killing tumor cells. Our findings provide a novel and simple approach to nhibit the growth and metastasis of hepatocellular carcinoma.

Growth of new blood vessels is considered requisite to cancer progression. Recent findings revealed that in addition to inducing angiogenesis, tumor-derived factors alter endothelial cell gene transcription within the tumor mass but also systemically throughout the body. This subsequently contributes to immunosuppression, altered metabolism, therapy resistance and metastasis. Clinical studies demonstrated that targeting the endothelium can increase the success rate of immunotherapy. Single-cell technologies revealed remarkable organ-specific endothelial heterogeneity that becomes altered by the presence of a tumor. In metastases, endothelial transcription differs remarkably between newly formed and co-opted vessels which may provide a basis for developing new therapies to target endothelial cells and overcome therapy resistance more effectively. This review addresses how cancers impact the endothelium to facilitate tumor progression.

DNA methylation is a fundamental mechanism of epigenetic control in cells and its dysregulation is strongly implicated in cancer development. Cancers possess an extensively hypomethylated genome with focal regions of hypermethylation at CPG islands. Due to the highly conserved nature of cancer-specific methylation, its detection in cell-free DNA in plasma using liquid biopsies constitutes an area of interest in biomarker research. The advent of next-generation sequencing and newer computational technologies have allowed for the development of diagnostic and prognostic biomarkers that utilize methylation profiling to diagnose disease and stratify risk. Methylome-based predictive biomarkers can determine the response to anti-cancer therapy. An additional emerging application of these biomarkers is in minimal residual disease monitoring. Several key challenges need to be addressed before cfDNA-based methylation biomarkers become fully integrated into practice. The first relates to the biology and stability of cfDNA. The second concerns the clinical validity and generalizability of methylation-based assays, many of which are cancer type-specific. The third involves their practicability, which is a stumbling block for translating technologies from bench to clinic. Future work on developing pan-cancer assays with their respective validities confirmed using well-designed, prospective clinical trials is crucial in pushing for the greater use of these tools in oncology.

Glioblastoma is the most lethal primary brain tumor with glioblastoma stem cells (GSCs) atop a cellular hierarchy. GSCs often reside in a perivascular niche, where they receive maintenance cues from endothelial cells, but the role of heterogeneous endothelial cell populations remains unresolved. Here, we show that lymphatic endothelial-like cells (LECs), while previously unrecognized in brain parenchyma, are present in glioblastomas and promote growth of CCR7-positive GSCs through CCL21 secretion. Disruption of CCL21-CCR7 paracrine communication between LECs and GSCs inhibited GSC proliferation and growth. LEC-derived CCL21 induced KAT5-mediated acetylation of HMGCS1 on K273 in GSCs to enhance HMGCS1 protein stability. HMGCS1 promoted cholesterol synthesis in GSCs, favorable for tumor growth. Expression of the CCL21-CCR7 axis correlated with KAT5 expression and HMGCS1K273 acetylation in glioblastoma specimens, informing patient outcome. Collectively, glioblastomas contain previously unrecognized LECs that promote the molecular crosstalk between endothelial and tumor cells, offering potentially alternative therapeutic strategies.

Immunotherapy is a promising and safer alternative to conventional cancer therapies. It involves adaptive T-cell therapy, cancer vaccines, monoclonal antibodies, immune checkpoint blockade (ICB), and chimeric antigen receptor (CAR) based therapies. However, most of these modalities encounter restrictions in solid tumours owing to a dense, highly hypoxic and immune-suppressive microenvironment as well as the heterogeneity of tumour antigens. The elevated intra-tumoural pressure and mutational rates within fastgrowing solid tumours present challenges in efficient drug targeting and delivery. The tumour microenvironment is a dynamic niche infiltrated by a variety of immune cells, most of which are macrophages. Since they form a part of the innate immune system, targeting macrophages has become a plausible immunotherapeutic approach. In this review, we discuss several versatile approaches (both at pre-clinical and clinical stages) such as the direct killing of tumour-associated macrophages, reprogramming pro-tumour macrophages to anti-tumour phenotypes, inhibition of macrophage recruitment into the tumour microenvironment, novel CAR macrophages, and genetically engineered macrophages that have been devised thus far. These strategies comprise a strong and adaptable macrophage-toolkit in the ongoing fight against cancer and by understanding their significance, we may unlock the full potential of these immune cells in cancer therapy.

The complex interplay between tumour cells and the tumour microenvironment (TME) underscores the necessity for gaining comprehensive insights into disease progression. This study centres on elucidating the elusive the elusive role of endothelial cells within the TME of head and neck squamous cell carcinoma (HNSCC). Despite their crucial involvement in angiogenesis and vascular function, the mechanistic diversity of endothelial cells among HNSCC patients remains largely uncharted. Leveraging advanced single-cell RNA sequencing (scRNA-Seq) technology and the Scissor algorithm, we aimed to bridge this knowledge gap and illuminate the intricate interplay between endothelial cells and patient prognosis within the context of HNSCC. Here, endothelial cells were categorized into Scissorhigh and Scissorlow subtypes. We identified Scissor+ endothelial cells exhibiting pro-tumorigenic profiles and constructed a prognostic risk model for HNSCC. Additionally, four biomarkers also were identified by analysing the gene expression profiles of patients with HNSCC and a prognostic risk prediction model was constructed based on these genes. Furthermore, the correlations between endothelial cells and prognosis of patients with HNSCC were analysed by integrating bulk and single-cell sequencing data, revealing a close association between SHSS and the overall survival (OS) of HNSCC patients with malignant endothelial cells. Finally, we validated the prognostic model by RT-qPCR and IHC analysis. These findings enhance our comprehension of TME heterogeneity at the single-cell level and provide a prognostic model for HNSCC.

Uveitis is a devastating intraocular inflammatory disease. The secreted leucine-rich repeat protein slit homologue 2 (Slit2) has been found to be an essential regulator of inflammation. This study aimed to analyse the anti-inflammatory effects and the underlying mechanisms of Slit2 in an endotoxin-induced uveitis (EIU) rat model. In this study, rats with EIU pretreated recombinant human Slit2 (rhSlit2) or a control vehicle by intravitreal injection. The clinical scores were graded under a slit lamp. The protein concentrations and total number of cells in the aqueous humour (AqH) were examined, and the retinal expression of various inflammatory mediators was detected. The levels of nuclear factor-kappa B (NF-κB), phosphorylated NF-κB, IkappaB-a (IκB-a), phosphorylated IκB-a, IKK, phosphorylated IKK, PI3Kp85, phosphorylated PI3Kp85, Akt and phosphorylated Akt were evaluated by western blotting. Treatment with rhSlit2 dramatically diminished the clinical scores of EIU, with significant decreases in inflammatory cell infiltration, protein concentrations, cellulose-like exudates, the production of ICAM-1, MCP-1, TNF-α and IL-6 in the AqH; and adhesion of leucocytes. The PI3K/Akt/IKK/NF-κB pathway was found to be activated in EIU. However, the pre-treatment of rhSlit2 significantly inhibited the production of ICAM-1, MCP-1, TNF-α, and IL-6, and inhibited leucocyte adhesion by modulating the PI3K/Akt/IKK/NF-κB pathway. In conclusion, the intravitreal injection of rhSlit2 alleviated EIU-related inflammation in Sprague-Dawley rats by reducing the proinflammatory cytokines and leucocyte adhesion; in particular, rhSlit2 may inhibit LPS-induced inflammation by inhibiting the activation of PI3K/Akt/IKK/NF-κB signalling pathway. Therefore, rhSlit2 shows significant potential for effectively alleviating immune inflammatory responses in vivo.

Neutrophils are essential for host defense against Staphylococcus aureus (S. aureus). The neuro-repellent, SLIT2, potently inhibits neutrophil chemotaxis, and might, therefore, be expected to impair antibacterial responses. We report here that, unexpectedly, neutrophils exposed to the N-terminal SLIT2 (N-SLIT2) fragment kill extracellular S. aureus more efficiently. N-SLIT2 amplifies reactive oxygen species production in response to the bacteria by activating p38 mitogen-activated protein kinase that in turn phosphorylates NCF1, an essential subunit of the NADPH oxidase complex. N-SLIT2 also enhances the exocytosis of neutrophil secondary granules. In a murine model of S. aureus skin and soft tissue infection (SSTI), local SLIT2 levels fall initially but increase subsequently, peaking at 3 days after infection. Of note, the neutralization of endogenous SLIT2 worsens SSTI. Temporal fluctuations in local SLIT2 levels may promote neutrophil recruitment and retention at the infection site and hasten bacterial clearance by augmenting neutrophil oxidative burst and degranulation. Collectively, these actions of SLIT2 coordinate innate immune responses to limit susceptibility to S. aureus.

SLIT/ROBO signaling impacts many aspects of tissue development and homeostasis, in part, through the regulation of cell growth and proliferation. Recent studies have also linked SLIT/ROBO signaling to the regulation of diverse phagocyte functions. However, the mechanisms by which SLIT/ROBO signaling acts at the nexus of cellular growth control and innate immunity remain enigmatic. Here, we show that SLIT2-mediated activation of ROBO1 leads to inhibition of mTORC1 kinase activity in macrophages, leading to dephosphorylation of its downstream targets, including transcription factor EB and ULK1. Consequently, SLIT2 augments lysosome biogenesis, potently induces autophagy, and robustly promotes the killing of bacteria within phagosomes. Concordant with these results, we demonstrate decreased lysosomal content and accumulated peroxisomes in the spinal cords of embryos from Robo1 -/- , Robo2 -/- double knockout mice. We also show that impediment of auto/paracrine SLIT-ROBO signaling axis in cancer cells leads to hyperactivation of mTORC1 and inhibition of autophagy. Together, these findings elucidate a central role of chemorepellent SLIT2 in the regulation of mTORC1 activity with important implications for innate immunity and cancer cell survival.