Neuronal CaMKK2 promotes immunosuppression and checkpoint blockade resistance in glioblastoma

Therapeutic approaches for targeting the pediatric brain tumor microenvironment

Central nervous system (CNS) tumors are the most frequent solid malignant tumors in pediatric patients and are the leading cause of tumor-related death in children. Treatment for this heterogeneous group of tumors consists of various combinations of safe maximal surgical resection, chemotherapy, and radiation therapy which offer a cure for some children but often cause debilitating adverse late effects in others. While therapies targeting the tumor microenvironment (TME) like immune checkpoint inhibition (ICI) have been successful in treating some cancers, these therapies failed to exhibit treatment efficacy in the majority of pediatric brain tumors in the clinic. Importantly, the pediatric TME is unique and distinct from adult brain tumors and designing therapies to effectively target these tumors requires understanding the unique biology of pediatric brain tumors and the use of translational models that recapitulate the TME. Here we describe the TME of medulloblastoma (MB) and diffuse midline glioma (DMG), specifically diffuse intrinsic pontine glioma (DIPG), and further present the current drug delivery approaches and clinical administration routes targeting the TME in these tumors, including preclinical and clinical studies.

Orchestrating Intracellular Calcium Signaling Cascades by Phosphosite-Centric Regulatory Network: A Comprehensive Analysis on Kinases CAMKK1 and CAMKK2

Intracellular calcium signaling is a cornerstone in cell biology and a key molecular target for human health and disease. Calcium/calmodulin dependent protein kinase kinases, CAMKK1 and CAMKK2 are serine/threonine kinases that contribute to the regulation of intracellular calcium signals in response to diverse stimuli. CAMKK1 generally has stable dynamics, whereas CAMKK2 dysregulation triggers oncogenicity and neurological disorders. To differentiate the phosphosignaling hierarchy associated with predominant phosphosites of CAMKK1 and CAMKK2, we assembled and analyzed the global cellular phosphoproteome datasets. We found that predominant phosphosites in CAMKK1 and CAMKK2 are located outside the kinase domain, and their phosphomotifs are highly homologous. Further, we employed a coregulation analysis approach to these predominant phosphosites, to infer the co-occurrence patterns of phosphorylations within CAMKKs and the coregulation patterns of other protein phosphosites with CAMKK sites. We report herein that independent phosphorylations at CAMKK2 S100 and S511 increase their enzymatic activity in the presence of calcium/calmodulin. In addition, the study unveils kinase-substrate associations such as RPS6KB1 as a novel high-confidence upstream kinase of both CAMKK1 S74 and CAMKK2 S100. Further, CAMKK2 was identified as a primary orchestrator in mediating intracellular calcium signaling cascades compared to CAMKK1 based on coregulation patterns of phosphosites from proteins involved in the calcium signaling pathway. These molecular details shed promising insights into the pathophysiology of several diseases such as cancers and psychiatric disorders associated with kinase activity dysregulations of CAMKK2 and further open the avenue for novel PTM-directed therapeutic strategies to regulate CAMKK2.

CaMKK2 Regulates Macrophage Polarization Induced by Matrix Stiffness: Implications for Shaping the Immune Response in Stiffened Tissues

Macrophages are essential for immune responses and maintaining tissue homeostasis, exhibiting a wide range of phenotypes depending on their microenvironment. The extracellular matrix (ECM) is a vital component that provides structural support and organization to tissues, with matrix stiffness acting as a key regulator of macrophage behavior. Using physiologically relevant 3D stiffening hydrogel models, it is found that increased matrix stiffness alone promoted macrophage polarization toward a pro-regenerative phenotype, mimicking the effect of interleukin-4(IL-4) in softer matrices. Blocking Calcium/calmodulin-dependent kinase kinase 2 (CaMKK2) selectively inhibited stiffness-induced macrophage polarization without affecting IL-4-driven pro-regenerative pathways. In functional studies, CaMKK2 deletion prevented M2-like/pro-tumoral polarization caused by matrix stiffening, which in turn hindered tumor growth. In a murine wound healing model, loss of CaMKK2 impaired matrix stiffness-mediated macrophage accumulation, ultimately disrupting vascularization. These findings highlight the critical role of CaMKK2 in the macrophage mechanosensitive fate determination and gene expression program, positioning this kinase as a promising therapeutic target to selectively modulate macrophage responses in pathologically stiff tissues.

Intratumoral gene delivery of 4-1BBL boosts IL-12-triggered anti-glioblastoma immunity

The standard of care in high-grade gliomas has remained unchanged in the past 20 years. Efforts to replicate effective immunotherapies in non-cranial tumors have led to only modest therapeutical improvements in glioblastoma (GB). Here, we demonstrate that intratumoral administration of recombinant interleukin-12 (rIL-12) promotes local cytotoxic CD8 POS T cell accumulation and conversion into an effector-like state, resulting in a dose-dependent survival benefit in preclinical GB mouse models. This tumor-reactive CD8 T cell response is further supported by intratumoral rIL-12-sensing dendritic cells (DCs) and is accompanied by the co-stimulatory receptor 4-1BB expression on both cell types. Given that DCs and CD8 POS T cells are functionally suppressed in the tumor microenvironments of de novo and recurrent glioma patients, we tested whether anti-tumor response at the rIL-12-inflamed tumor site could be enhanced with 4-1BBL, the ligand of 4-1BB. 4-1BBL was delivered using an adeno-associated virus (AAV) vector targeting GFAP-expressing cells and resulted in prolonged survival of rIL-12 treated GB-bearing mice. This study establishes that tumor antigen-specific CD8 T cell activity can be directed using an AAV-vector-mediated gene therapy approach, effectively enhancing anti-GB immunity.

Antigen presentation by tumor-associated macrophages drives T cells from a progenitor exhaustion state to terminal exhaustion

Whereas terminally exhausted T (Tex_term) cells retain anti-tumor cytotoxic functions, the frequencies of stem-like progenitor-exhausted T (Tex_prog) cells better reflect immunotherapeutic responsivity. Here, we examined the intratumoral cellular interactions that govern the transition to terminal T cell exhaustion. We defined a metric reflecting the intratumoral progenitor exhaustion-to-terminal exhaustion ratio (PETER), which decreased with tumor progression in solid cancers. Single-cell analyses of Tex_prog cells and Tex_term cells in glioblastoma (GBM), a setting of severe T cell exhaustion, revealed disproportionate loss of Tex_prog cells over time. Exhaustion concentrated within tumor-specific T cell subsets, with cognate antigen exposure requisite for acquisition of the Tex_term phenotype. Tumor-associated macrophages (TAMs)-not tumor cells-were the primary source of antigenic exposure governing the Tex_prog to Tex_term transition. TAM depletion increased frequencies of Tex_prog cells in multiple tumor models, increased PETER, and promoted responsiveness to αPD1 immunotherapy. Thus, targeting TAM-T cell interactions may further license checkpoint blockade responses.

β-Hydroxybutyrate Protects Against Cisplatin-Induced Renal Damage via Regulating Ferroptosis

Cisplatin is a particularly potent antineoplastic drug. However, its usefulness is restricted due to the induction of nephrotoxicity. More recent research has indicated that β-hydroxybutyrate (β-HB) protects against acute or chronic organ damage as an efficient healing agent. Nonetheless, the therapeutic mechanisms of β-HB in acute kidney damage caused by chemotherapeutic drugs remain unclear. Our study developed a model of cisplatin-induced acute kidney injury (AKI), which involved the administration of a ketogenic diet or β-HB. We analyzed blood urea nitrogen (BUN) and creatinine (Cr) levels in serum, and used western blotting and immunohistochemical staining to assess ferroptosis and the calcium/calmodulin-dependent kinase kinase 2 (Camkk2)/AMPK pathway. The mitochondrial morphology and function were examined. Additionally, we conducted in vivo and in vitro experiments using selective Camkk2 inhibitor or activator to investigate the protective mechanism of β-HB on cisplatin-induced AKI. Exogenous or endogenous β-HB effectively alleviated cisplatin-induced abnormally elevated levels of BUN and Cr and renal tubular necrosis in vivo. Additionally, β-HB reduced ferroptosis biomarkers and increased the levels of anti-ferroptosis biomarkers in the kidney. β-HB also improved mitochondrial morphology and function. Moreover, β-HB significantly attenuated cisplatin-induced cell ferroptosis and damage in vitro. Furthermore, western blotting and immunohistochemical staining indicated that β-HB may prevent kidney injury by regulating the Camkk2-AMPK pathway. The use of the Camkk2 inhibitor or activator verified the involvement of Camkk2 in the renal protection by β-HB. This study provided evidence of the protective effects of β-HB against cisplatin-induced nephrotoxicity and identified inhibited ferroptosis and Camkk2 as potential molecular mechanisms.

Necroptosis-based glioblastoma prognostic subtypes: implications for TME remodeling and therapy response

BACKGROUND

Glioblastoma (GBM) is an aggressive primary brain tumor with a high recurrence rate and poor prognosis. Necroptosis, a pathological hallmark of GBM, is poorly understood in terms of its role in prognosis, tumor microenvironment (TME) alteration, and immunotherapy.

METHODS & RESULTS

We assessed the expression of 55 necroptosis-related genes in GBM and normal brain tissues. We identified necroptosis-stratified clusters using Uni-Cox and Least Absolute Shrinkage and Selection Operator (LASSO) regression to establish the 10-gene Glioblastoma Necroptosis Index (GNI). GNI demonstrated significant prognostic efficacy in the TCGA dataset (n = 160) and internal validation dataset (n = 345) and in external validation cohorts (n = 591). The GNI-high subgroup displayed a mesenchymal phenotype, lacking the IDH1 mutation, and MGMT methylation. This subgroup was characterized by significant enrichment in inflammatory and humoral immune pathways with prominent cell adhesion molecules (CD44 and ICAM1), inflammatory cytokines (TGFB1, IL1B, and IL10), and chemokines (CX3CL1, CXCL9, and CCL5). The TME in this subgroup showed elevated infiltration of M0 macrophages, neutrophils, mast cells, and regulatory T cells. GNI-related genes appeared to limit macrophage polarization, as confirmed by immunohistochemistry and flow cytometry. The top 30% high-risk score subset exhibited increased CD8 T cell infiltration and enhanced cytolytic activity. GNI showed promise in predicting responses to immunotherapy and targeted treatment.

CONCLUSIONS

Our study highlights the role of necroptosis-related genes in glioblastoma (GBM) and their effects on the tumor microenvironment and patient prognosis. TheGNI demonstrates potential as a prognostic marker and provides insights into immune characteristics and treatment responsiveness.

The prognostic value and immunological role of calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) in pan-cancer study

A thorough assessment of calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) in pan-cancer studies is currently absent. We integrate multi-omics and clinical data to conduct a molecular landscape of CAMKK2. Gene variation results revealed abnormal high frequency mutations of CAMKK2 in uterine corpus endometrial carcinoma, while expression level analysis demonstrated relatively high expression of CAMKK2 in prostate adenocarcinoma. The aberrant expression of CAMKK2 was found to be predictive of survival outcomes in several cancer types. Additionally, we identified potential regulators of CAMKK2 expression, including miRNAs such as miR.129.1.3p, as well as small-molecule drugs such as EPZ004777, which significantly correlated with CAMKK2 expression. Single-cell transcriptome analysis of kidney renal clear cell carcinoma further revealed a significantly higher expression of CAMKK2 in and monocyte and macrophage M1. Furthermore, in the kidney renal clear cell carcinoma IMvigor210 cohort, patients ongoing immunotherapy with higher CAMKK2 expression experienced a significantly longer median overall survival, but it was observed that in bladder urothelial carcinoma GSE176307 and skin cutaneous melanoma GSE78220 cohorts, CAMKK2 might significantly prolong overall survival. Briefly, CAMKK2 emerges as a promising molecular biomarker that holds potential implications for prognostic evaluation and predicting the effectiveness of immunotherapy across cancers.

Caspase-4 in glioma indicates deterioration and unfavorable prognosis by affecting tumor cell proliferation and immune cell recruitment

Gliomas are the most common malignant tumors of the central nervous system, accounting for approximately 80% of all malignant brain tumors. Accumulating evidence suggest that pyroptosis plays an essential role in the progression of cancer. Unfortunately, the effect of the pyroptosis-related factor caspase-4 (CASP4) on immunotherapy and drug therapy for tumors has not been comprehensively investigated. In this study, we systematically screened six hub genes by pooling differential pyroptosis-related genes in The Cancer Genome Atlas (TCGA) glioma data and the degree of centrality of index-related genes in the protein-protein interaction network. We performed functional and pathway enrichment analyses of the six hub genes to explore their biological functions and potential molecular mechanisms. We then investigated the importance of CASP4 using Kaplan-Meier survival analysis of glioma patients. TCGA and the Chinese Glioma Genome Atlas (CGGA) databases showed that reduced CASP4 expression leads to the potent clinical deterioration of glioma patients. Computational analysis of the effect of CASP4 on the infiltration level and recruitment of glioma immune cells revealed that CASP4 expression was closely associated with a series of tumor-suppressive immune checkpoint molecules, chemokines, and chemokine receptors. We also found that aberrant CASP4 expression correlated with chemotherapeutic drug sensitivity. Finally, analysis at the cellular and tissue levels indicated an increase in CASP4 expression in glioma, and that CASP4 inhibition significantly inhibited the proliferation of glioma cells. Thus, CASP4 is implicated as a new prognostic biomarker for gliomas with the potential to further guide immunotherapy and chemotherapy strategies for glioma patients.

A Manganese-Based Nanodriver Coordinates Tumor Prevention and Suppression through STING Activation in Glioblastoma

Glioblastoma (GBM), the most prevalent and aggressive primary malignant brain tumor, exhibits profound immunosuppression and demonstrates a low response rate to current immunotherapy strategies. Manganese cations (Mn2+) directly activate the cGAS/STING pathway and induce the unique catalytic synthesis of 2'3'-cGAMP to facilitate type I IFN production, thereby enhancing innate immunity. Here, a telodendrimer and Mn2+-based nanodriver (PLHM) with a small size is developed, which effectively target lymph nodes through the blood circulation and exhibit tumor-preventive effects at low doses of Mn2+ (3.7 mg kg-1). On the other hand, the PLHM nanodriver also exhibits apparent antitumor effects in GBM-bearing mice via inducing in vivo innate immune responses. The combination of PLHM with doxorubicin nanoparticles (PLHM-DOX NPs) results in superior inhibition of tumor growth in GBM-bearing mice due to the synergistic potentiation of STING pathway functionality by Mn2+ and the presence of cytoplasmic DNA. These findings demonstrate that PLHM-DOX NPs effectively stimulate innate immunity, promote dendritic cell maturation, and orchestrate cascaded infiltration of CD8 cytotoxic T lymphocytes within glioblastomas characterized by low immunogenicity. These nanodivers chelated with Mn2+ show promising potential for tumor prevention and antitumor effects on glioblastoma by activating the STING pathway.

γδ T cells as a potential therapeutic agent for glioblastoma

Although γδ T cells comprise a small population of T cells, they perform important roles in protecting against infection and suppressing tumors. With their distinct tissue-localizing properties, combined with their various target recognition mechanisms, γδ T cells have the potential to become an effective solution for tumors that do not respond to current therapeutic procedures. One such tumor, glioblastoma (GBM), is a malignant brain tumor with the highest World Health Organization grade and therefore the worst prognosis. The immune-suppressive tumor microenvironment (TME) and immune-evasive glioma stem cells are major factors in GBM immunotherapy failure. Currently, encouraged by the strong anti-tumoral function of γδ T cells revealed at the preclinical and clinical levels, several research groups have shown progression of γδ T cell-based GBM treatment. However, several limitations still exist that block effective GBM treatment using γδ T cells. Therefore, understanding the distinct roles of γδ T cells in anti-tumor immune responses and the suppression mechanism of the GBM TME are critical for successful γδ T cell-mediated GBM therapy. In this review, we summarize the effector functions of γδ T cells in tumor immunity and discuss current advances and limitations of γδ T cell-based GBM immunotherapy. Additionally, we suggest future directions to overcome the limitations of γδ T cell-based GBM immunotherapy to achieve successful treatment of GBM.

Targeting the dendritic cell-T cell axis to develop effective immunotherapies for glioblastoma

Glioblastoma is an aggressive primary brain tumor that has seen few advances in treatments for over 20 years. In response to this desperate clinical need, multiple immunotherapy strategies are under development, including CAR-T cells, immune checkpoint inhibitors, oncolytic viruses and dendritic cell vaccines, although these approaches are yet to yield significant clinical benefit. Potential reasons for the lack of success so far include the immunosuppressive tumor microenvironment, the blood-brain barrier, and systemic changes to the immune system driven by both the tumor and its treatment. Furthermore, while T cells are essential effector cells for tumor control, dendritic cells play an equally important role in T cell activation, and emerging evidence suggests the dendritic cell compartment may be deeply compromised in glioblastoma patients. In this review, we describe the immunotherapy approaches currently under development for glioblastoma and the challenges faced, with a particular emphasis on the critical role of the dendritic cell-T cell axis. We suggest a number of strategies that could be used to boost dendritic cell number and function and propose that the use of these in combination with T cell-targeting strategies could lead to successful tumor control.

Drug resistance in glioblastoma: from chemo- to immunotherapy

As the most common and aggressive type of primary brain tumor in adults, glioblastoma is estimated to end over 10,000 lives each year in the United States alone. Stand treatment for glioblastoma, including surgery followed by radiotherapy and chemotherapy (i.e., Temozolomide), has been largely unchanged since early 2000. Cancer immunotherapy has significantly shifted the paradigm of cancer management in the past decade with various degrees of success in treating many hematopoietic cancers and some solid tumors, such as melanoma and non-small cell lung cancer (NSCLC). However, little progress has been made in the field of neuro-oncology, especially in the application of immunotherapy to glioblastoma treatment. In this review, we attempted to summarize the common drug resistance mechanisms in glioblastoma from Temozolomide to immunotherapy. Our intent is not to repeat the well-known difficulty in the area of neuro-oncology, such as the blood-brain barrier, but to provide some fresh insights into the molecular mechanisms responsible for resistance by summarizing some of the most recent literature. Through this review, we also hope to share some new ideas for improving the immunotherapy outcome of glioblastoma treatment.

Interactions between microglia and glioma in tumor microenvironment

Gliomas, the most prevalent primary tumors in the central nervous system, are marked by their immunosuppressive properties and consequent poor patient prognosis. Current evidence emphasizes the pivotal role of the tumor microenvironment in the progression of gliomas, largely attributed to tumor-associated macrophages (brain-resident microglia and bone marrow-derived macrophages) that create a tumor microenvironment conducive to the growth and invasion of tumor cells. Yet, distinguishing between these two cell subgroups remains a challenge. Thus, our review starts by analyzing the heterogeneity between these two cell subsets, then places emphasis on elucidating the complex interactions between microglia and glioma cells. Finally, we conclude with a summary of current attempts at immunotherapy that target microglia. However, given that independent research on microglia is still in its initial stages and has many shortcomings at the present time, we express our related concerns and hope that further research will be carried out to address these issues in the future.

Genome sequencing of 2000 canids by the Dog10K consortium advances the understanding of demography, genome function and architecture

BACKGROUND

The international Dog10K project aims to sequence and analyze several thousand canine genomes. Incorporating 20 × data from 1987 individuals, including 1611 dogs (321 breeds), 309 village dogs, 63 wolves, and four coyotes, we identify genomic variation across the canid family, setting the stage for detailed studies of domestication, behavior, morphology, disease susceptibility, and genome architecture and function.

RESULTS

We report the analysis of > 48 M single-nucleotide, indel, and structural variants spanning the autosomes, X chromosome, and mitochondria. We discover more than 75% of variation for 239 sampled breeds. Allele sharing analysis indicates that 94.9% of breeds form monophyletic clusters and 25 major clades. German Shepherd Dogs and related breeds show the highest allele sharing with independent breeds from multiple clades. On average, each breed dog differs from the UU_Cfam_GSD_1.0 reference at 26,960 deletions and 14,034 insertions greater than 50 bp, with wolves having 14% more variants. Discovered variants include retrogene insertions from 926 parent genes. To aid functional prioritization, single-nucleotide variants were annotated with SnpEff and Zoonomia phyloP constraint scores. Constrained positions were negatively correlated with allele frequency. Finally, the utility of the Dog10K data as an imputation reference panel is assessed, generating high-confidence calls across varied genotyping platform densities including for breeds not included in the Dog10K collection.

CONCLUSIONS

We have developed a dense dataset of 1987 sequenced canids that reveals patterns of allele sharing, identifies likely functional variants, informs breed structure, and enables accurate imputation. Dog10K data are publicly available.

Enhancing Immunogenicity in Metastatic Melanoma: Adjuvant Therapies to Promote the Anti-Tumor Immune Response

Advanced melanoma is an aggressive form of skin cancer characterized by low survival rates. Less than 50% of advanced melanoma patients respond to current therapies, and of those patients that do respond, many present with tumor recurrence due to resistance. The immunosuppressive tumor-immune microenvironment (TIME) remains a major obstacle in melanoma therapy. Adjuvant treatment modalities that enhance anti-tumor immune cell function are associated with improved patient response. One potential mechanism to stimulate the anti-tumor immune response is by inducing immunogenic cell death (ICD) in tumors. ICD leads to the release of damage-associated molecular patterns within the TIME, subsequently promoting antigen presentation and anti-tumor immunity. This review summarizes relevant concepts and mechanisms underlying ICD and introduces the potential of non-ablative low-intensity focused ultrasound (LOFU) as an immune-priming therapy that can be combined with ICD-inducing focal ablative therapies to promote an anti-melanoma immune response.

Analysis and validation of aging-related genes in prognosis and immune function of glioblastoma

BACKGROUND

Glioblastoma (GBM) is a common malignant brain tumor with poor prognosis and high mortality. Numerous reports have identified the correlation between aging and the prognosis of patients with GBM. The purpose of this study was to establish a prognostic model for GBM patients based on aging-related gene (ARG) to help determine the prognosis of GBM patients.

METHODS

143 patients with GBM from The Cancer Genomic Atlas (TCGA), 218 patients with GBM from the Chinese Glioma Genomic Atlas (CGGA) of China and 50 patients from Gene Expression Omnibus (GEO) were included in the study. R software (V4.2.1) and bioinformatics statistical methods were used to develop prognostic models and study immune infiltration and mutation characteristics.

RESULTS

Thirteen genes were screened out and used to establish the prognostic model finally, and the risk scores of the prognostic model was an independent factor (P < 0.001), which indicated a good prediction ability. In addition, there are significant differences in immune infiltration and mutation characteristics between the two groups with high and low risk scores.

CONCLUSION

The prognostic model of GBM patients based on ARGs can predict the prognosis of GBM patients. However, this signature requires further investigation and validation in larger cohort studies.

The role of CaMKK2 in Golgi-associated vesicle trafficking

Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a serine/threonine-protein kinase, that is involved in maintaining various physiological and cellular processes within the cell that regulate energy homeostasis and cell growth. CaMKK2 regulates glucose metabolism by the activation of downstream kinases, AMP-activated protein kinase (AMPK) and other calcium/calmodulin-dependent protein kinases. Consequently, its deregulation has a role in multiple human metabolic diseases including obesity and cancer. Despite the importance of CaMKK2, its signalling pathways and pathological mechanisms are not completely understood. Recent work has been aimed at broadening our understanding of the biological functions of CaMKK2. These studies have uncovered new interaction partners that have led to the description of new functions that include lipogenesis and Golgi vesicle trafficking. Here, we review recent insights into the role of CaMKK2 in membrane trafficking mechanisms and discuss the functional implications in a cellular context and for disease.