Anti-PD-1 antitumor immunity is enhanced by local and abrogated by systemic chemotherapy in GBM

Trends in the immunotherapy for glioblastoma: A two-decade bibliometric analysis

Glioblastoma is a life-threatening primary malignant brain tumor with an unfavorable prognosis. Contributing factors to its poor outcome include tumor heterogeneity, low mutational burden, and immunosuppression within the tumor microenvironment. Recognizing these challenges, immunotherapeutic strategies have emerged as a promising avenue for glioblastoma treatment. Although several dynamic research and scientific trend have increasingly taken pace in the immunotherapeutic approaches to glioblastoma, systematic bibliometric studies on such trends are few. On this note, this study explores a bibliometric analysis of the research hotspots and trends in glioblastoma immunotherapy. We conducted a search in the Web of Science Core Collection database for articles on glioblastoma immunotherapy published between 2004 and 2024. Using VOSviewer and CiteSpace software, we analyzed collected articles to explore aspects such as country of origin, journal of publication, affiliated institute, authorship, keywords, and citation patterns. As of May 1, 2024, we retrieved 3,729 papers on Glioblastoma Immunotherapy. In the field of glioblastoma immunotherapy, the United States stands out as the leading contributor, with 1,708 publications and a substantial 90,590 citations. Following closely, China has made significant contributions through 926 publications, earning 17,533 citations, while Germany adds to the body of knowledge with 349 publications and 16,355 citations. Furthermore, Authoritative journals in this field include Clinical Cancer Research and Neuro-Oncology. The top five keywords during this period were temozolomide, radiotherapy, dendritic cell, cytotoxic T lymphocyte, and vaccination. Moreover, Hotspots in the field include immune checkpoint inhibitors and chimeric antigen receptor T cell therapy.

Targeting the glioblastoma resection margin with locoregional nanotechnologies

Surgical resection is the first stage of treatment for patients diagnosed with resectable glioblastoma and is followed by a combination of adjuvant radiotherapy and systemic single-agent chemotherapy, which is typically commenced 4-6 weeks after surgery. This delay creates an interval during which residual tumour cells residing in the resection margin can undergo uninhibited proliferation and further invasion, even immediately after surgery, thus limiting the effectiveness of adjuvant therapies. Recognition of the postsurgical resection margin and peri-marginal zones as important anatomical clinical targets and the need to rethink current strategies can galvanize opportunities for local, intraoperative approaches, while also generating a new landscape of innovative treatment modalities. In this Perspective, we discuss opportunities and challenges for developing locoregional therapeutic strategies to target the glioblastoma resection margin as well as emerging opportunities offered by nanotechnology in this clinically transformative setting. We also discuss how persistent barriers to clinical translation can be overcome to offer a potential path forward towards broader acceptability of such advanced technologies.

Homologous magnetic targeted immune vesicles for amplifying immunotherapy via ferroptosis activation augmented photodynamic therapy against glioblastoma

In spite of noteworthy breakthroughs in clinical treatments, immune checkpoint blockade (ICB) therapy is often hindered by T lymphocyte dysfunction in the immunosuppressive microenvironment of glioblastoma (GBM). Herein, GBM-derived exosomes (GBM-Exos) co-encapsulate ferroptosis inducer arsenic trioxide (ATO) and NIR photosensitizer IR780, modified with superparamagnetic iron oxide nanoparticle (SPION), to construct homologous magnetic targeted immune vesicles (Sp-Exo/AI) for reinvigorating anti-tumor immunity. SPION modified GBM-Exos display capacities of tumor accumulation and blood-brain barrier penetration. Notably, reactive oxygen species metabolism is disturbed by ferroptosis activation augmented photodynamic therapy (PDT), hence triggering tumor cell lysis and mitochondrial damage to reshape tumor microenvironment (TME) and transform GBM from immune "cold" to "hot". Accordingly, the tumor specific T lymphocytes function and phenotype transformation of macrophages were promoted to stimulate robust innate and adaptive immunities. Significantly, the remarkable ferroptosis activation augmented PDT combining with programmed death-1 antibody actives long-term immune memory and inhibits distal tumor metastasis. Superior anti-tumor effect of Sp-Exo/AI in the recurrence model, breast cancer model and patient-derived model were observed as well. Altogether, the presented homologous magnetic targeted immune vesicles exhibit substantial potential for amplifying immune response in "cold" tumors like GBM through revising immunosuppressive TME.

BRAF/MEK Inhibition Induces Cell State Transitions Boosting Immune Checkpoint Sensitivity in BRAFV600E -mutant Glioma

Resistance to BRAF plus MEK inhibition (BRAFi+MEKi) in BRAFV600E-mutant gliomas drives rebound, progression, and high mortality, yet it remains poorly understood. This study addresses the urgent need to develop treatments for BRAFi+MEKi-resistant glioma in novel mouse models and patient-derived materials. BRAFi+MEKi reveals glioma plasticity by heightening cell state transitions along glial differentiation trajectories, giving rise to astrocyte- and immunomodulatory oligodendrocyte (OL)-like states. PD-L1 upregulation in OL-like cells links cell state transitions to tumor evasion, possibly orchestrated by Galectin-3. BRAFi+MEKi induces interferon response signatures, tumor infiltration, and suppression of T cells. Combining BRAFi+MEKi with immune checkpoint inhibition enhances survival in a T cell-dependent manner, reinvigorates T cells, and outperforms individual or sequential therapies in mice. Elevated PD-L1 expression in BRAF-mutant versus BRAF-wildtype glioblastoma supports the rationale for PD-1 inhibition in patients. These findings underscore the potential of targeting glioma plasticity and highlight combination strategies to overcome therapy resistance in BRAFV600E-mutant HGG.

Efficacy and safety of arterial FOLFOX chemotherapy plus anti-PD-(L)1 immunotherapy as a first-line treatment for unresectable intrahepatic cholangiocarcinoma: a propensity score matching analysis

Background

Given the limited efficacy of current first-line therapies, there is an urgent need to develop novel treatment strategies to improve the prognosis of patients with unresectable intrahepatic cholangiocarcinoma (uICC). This study aimed to evaluate the efficacy and safety of hepatic arterial infusion chemotherapy (HAIC) with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) regimens (HAIC-FO) plus anti-programmed death-(ligand) 1 immunotherapy [αPD-(L)1] antibody [HAIC+αPD-(L)1] compared to systemic chemotherapy (SYS) plus αPD-(L)1 antibody [SYS+αPD-(L)1] as a first-line treatment for patients with uICC.

Methods

In this retrospective study, treatment-naive uICC patients who were treated with HAIC+αPD-(L)1 or SYS+αPD-(L)1 were included. The clinical characteristics, therapeutic outcomes, and adverse events (AEs) of the patients in the two groups were compared. Propensity score matching (PSM) was performed to minimize biases between groups.

Results

From January 2019 to January 2023, a total of 182 patients were enrolled; 147 patients were included in the HAIC+αPD-(L)1 group and 35 patients were included in the SYS+αPD-(L)1 group. After PSM, 61 and 26 patients were included in the HAIC+αPD-(L)1 and SYS+αPD-(L)1 groups, respectively. The HAIC+αPD-(L)1 group had longer median overall survival (mOS), median progression-free survival (mPFS), and median intrahepatic PFS (mIPFS) than did the SYS+αPD-(L)1 group (mOS: 14.5 vs. 10.5 months, P=0.02; mPFS: 10.4 vs. 6.4 months, P=0.02; mIPFS: 11.4 vs. 6.5 months, P<0.001). The overall incidence of AEs was comparable between the two groups, but the HAIC+αPD-(L)1 group had a lower incidence of grade 3-4 AEs related to anemia, leukopenia, weight loss, and fatigue.

Conclusions

HAIC+αPD-(L)1 had acceptable toxic effects and might improve outcomes compared to SYS+αPD-(L)1 as a first-line treatment for patients with uICC.

The promise of mitochondria in the treatment of glioblastoma: a brief review

Glioblastoma (GBM) is a prevalent and refractory type of brain tumor. Over the past two decades, there have been minimal advancements in GBM therapy. The current standard treatment involves surgical excision followed by radiation and chemotherapy. Compared to other tumors, GBM is more challenging to treat due to the presence of glioma stem-like cells (GSCs) and the blood-brain barrier, resulting in an extremely low survival rate. Mitochondria play a critical role in tumor respiration, metabolism, and multiple signaling pathways involved in tumor formation, progression, and cell apoptosis. Consequently, mitochondria represent promising targets for developing novel anticancer agents, including those targeting oxidative phosphorylation, reactive oxygen species (ROS), mitochondrial transfer, and mitophagy. This review outlines the mitochondrial-related therapeutic targets in GBM, highlighting the potential of mitochondria as a target for GBM treatment.

Injectable supramolecular hydrogel co-loading abemaciclib/NLG919 for neoadjuvant immunotherapy of triple-negative breast cancer

The efficacy of cancer immunotherapy relies on a sufficient amount of functional immune cells. Triple-negative breast cancer lacks enough immune cell infiltration, and adjuvant therapy is necessary to prime anti-tumor immunity. However, the improvement in efficacy is unsatisfactory with concern about inducing systemic immunotoxicity. Herein, we create an abemaciclib-loaded supramolecular peptide hydrogel formed by peptide-drug amphiphiles for neoadjuvant immunotherapy of triple-negative breast cancer, where the amphiphile is a conjugate of a β-sheet-forming peptide with 1-cyclohexyl-2-(5H-imidazo[5,1-a]isoindol-5-yl)ethanol (NLG919), an inhibitor of indoleamine 2,3-dioxygenase 1. The hydrogel can be injected into the tumor site and retained for at least one week for the sustained release of both abemaciclib and NLG919. The abemaciclib is able to induce immunogenic cell death of cancer cells and increase interleukin-2 secretion by cytotoxic T lymphocytes. Abemaciclib adversely upregulates indoleamine 2,3-dioxygenase 1, whose kynurenine production activity is inhibited by NLG919. The neoadjuvant immunotherapy reduces tumor recurrence and pulmonary metastasis and prolongs the survival of animals. This hydrogel provides a potential platform for neoadjuvant immunotherapy of triple-negative breast cancer with reduced toxicity compared with free abemaciclib.

ATRX mutation modifies the DNA damage response in glioblastoma multiforme tumor cells and enhances patient prognosis

The presence of specific genetic mutations in patients with glioblastoma multiforme (GBM) is associated with improved survival outcomes. Disruption of the DNA damage response (DDR) pathway in tumor cells enhances the effectiveness of radiotherapy drugs, while increased mutational burden following tumor cell damage also facilitates the efficacy of immunotherapy. The ATRX gene, located on chromosome X, plays a crucial role in DDR. The aim of this research is to elucidate the correlation between ATRX mutations and GBM. Dataset obtained from TCGA-GBM were conducted an analysis on the genomic features, biological characteristics, immunopathological markers, and clinical prognosis of patients carrying ATRX mutations. Our findings revealed a significantly elevated level of microsatellite instability in individuals with ATRX mutants, along with significant alterations in the receptor-tyrosine kinase (RTK)-ras pathway among patients exhibiting combined ATRX mutations. TCGA-GBM patients with concurrent ATRX mutations exhibited sensitivity to 26 chemotherapeutic and anticancer drugs, which exerted their effects by modulating the DDR of tumor cells through highly correlated mechanisms involving the RTK-ras pathway. Additionally, we observed an enrichment of ATRX mutations in specific pathways associated with DDR among TCGA-GBM patients. Our model also demonstrated prolonged overall survival in patients carrying ATRX mutations, particularly showing strong predictive value for 3- and 5-year survival rates. Furthermore, additional protective factors such as younger age, female gender, combined IDH mutations, and TP53 mutations were identified. The results underscore the protective role and prognostic significance of ATRX mutations in GBM as a potential therapeutic target and biomarker for patient survival.

Interleukin 15-Presenting Nanovesicles with Doxorubicin-Loaded Ferritin Cores for Cancer Immunochemotherapy

Interleukin 15 (IL15) is crucial for fostering the survival and proliferation of nature killer (NK) cells and cytotoxic T lymphocytes (CTLs), playing a pivotal role in tumor control. However, IL15 supplementary therapy encounters challenges such as systemic inflammation and non-specific stimulation of cancer cells. Herein, a nanovesicle termed DoxFILN, comprising a membrane presenting IL15/IL15 receptor α complexes (IL15c) and a core of doxorubicin-loaded ferritin (Dox-Fn) are reported. The DoxFILN significantly enhances the densities and activities of intratumoral CTLs and NK cells. Mechanistically, DoxFILN undergoes deshelling in the acidic tumor microenvironment, releasing Dox-Fn and membrane-bound IL15c. Dox-Fn selectively target transferrin receptors on cancerous cells, facilitating intracellular Dox release and inducing immunogenic cell death. Concurrently, membrane-bound IL15c recognizes and activates IL15 receptor β/γc heterodimers, leading to a remarkable increase in the proliferation and activation of CTLs (16-fold and 28-fold) and NK cells (37-fold and 50-fold). The IL15-displaying nanovesicle introduced here holds promise as a potential platform for immunochemotherapy in the treatment of cancer.

Autogene cevumeran with or without atezolizumab in advanced solid tumors: a phase 1 trial

Effective targeting of somatic cancer mutations to enhance the efficacy of cancer immunotherapy requires an individualized approach. Autogene cevumeran is a uridine messenger RNA lipoplex-based individualized neoantigen-specific immunotherapy designed from tumor-specific somatic mutation data obtained from tumor tissue of each individual patient to stimulate T cell responses against up to 20 neoantigens. This ongoing phase 1 study evaluated autogene cevumeran as monotherapy (n = 30) and in combination with atezolizumab (n = 183) in pretreated patients with advanced solid tumors. The primary objective was safety and tolerability; exploratory objectives included evaluation of pharmacokinetics, pharmacodynamics, preliminary antitumor activity and immunogenicity. Non-prespecified interim analysis showed that autogene cevumeran was well tolerated and elicited poly-epitopic neoantigen-specific responses, encompassing CD4+ and/or CD8+ T cells, in 71% of patients, most of them undetectable at baseline. Responses were detectable up to 23 months after treatment initiation. CD8+ T cells specific for several neoantigens constituted a median of 7.3% of circulating CD8+ T cells, reaching up to 23% in some patients. Autogene cevumeran-induced T cells were found within tumor lesions constituting up to 7.2% of tumor-infiltrating T cells. Clinical activity was observed, including one objective response in monotherapy dose escalation and in two patients with disease characteristics unfavorable for response to immunotherapy treated in combination with atezolizumab. These findings support the continued development of autogene cevumeran in earlier treatment lines. ClinicalTrials.gov registration: NCT03289962 .

Rural Households' Vulnerability to Climate Variability and Adaptation Strategies in the Case of Begemdir District, Amhara Region, Ethiopia

Climate change vulnerability is the biggest threat to ecosystems and economies of the world. Hence, this study aims to assess the vulnerability to climate variability adaptation strategies of rural households in Begemdir District, Northwest Ethiopia. In this study, the cross-sectional research design was used to gain a wider and better understanding of vulnerability to climate variability. Both primary and secondary data were used to triangulate the study to maintain validity. A multi-stage random sampling technique was used to select 120 sample households from the study area. Moreover, climatic data, such as rainfall and temperature data were collected from meteorological stations. The data gathered from primary data sources analyzed by using descriptive statistics. Finally, a logistic regression model was employed to identify the factors that affecting households' decisions to climate adaptation strategies in the study area. The results of the study reveal that the overall IPCC-LVI score is 0.49, and the perceived rainfall has decreased over the last decade. This implies livelihoods of the households are vulnerable to climate variability and low adaptive capacity. The age, sex, education level, extension services, land size, credit access, access to climatic information, access to credit, and extension services affected significantly (p < 0.05) households' vulnerability to climate variability in the study area. Thus, the local governments, policymakers, non-governmental organizations, and farming communities need to consider these variables to realize climate change adaptation strategies in the study area. Moreover, higher focus should be given to enhancing education, expanding access to credit, increasing land management support, as well as strengthening extension services to build long-term sustainable climate-resilient practices and mitigate the impacts of climate change vulnerability to households in the study area.

Polymeric Nanoparticles Revolutionizing Brain Cancer Therapy: A Comprehensive Review of Strategies and Advances

Brain cancer continues to be one of the most formidable malignancies to manage, mainly attributable to the presence of the blood-brain barrier (BBB) limiting the permeability of drugs and the diverse characteristics of brain tumors complicating treatment. The management of brain tumors has been hampered by many different factors, including the impermeability of the BBB, which restricts the delivery of chemotherapeutic agents to the tumor site, as well as intertumoral heterogeneity and the influence of brain tumor stem cells. In addition, small molecular weight drugs cannot specifically accumulate in malignant cells and have a limited circulation half-life. Nanoparticles (NPs) can be engineered to traverse the BBB and transport therapeutic medications directly into the brain, enhancing their efficacy compared with the conventional delivery of unbound drugs. Surface modifications of NPs can boost their efficiency by increasing their selectivity towards tumor receptors. This review covers treatment methods for malignant gliomas, associated risk factors, and improvements in brain drug administration, emphasizing the future potential of polymeric NPs and their mechanism for crossing the BBB. To surmount these obstacles, the newly formulated drug-delivery approach utilizing NPs, particularly those coated with cell membranes, has demonstrated potential in treating brain cancer. These NPs provide targeted tumor specificity, biocompatibility, extended circulation, enhanced BBB penetration, and immune evasion. This review focuses on coating strategies for PLGA NPs, particularly dual-targeting methods, to enhance BBB permeability and tumor-targeted delivery of drugs in brain cancer.

Local delivery of doxorubicin prodrug via lipid nanocapsule-based hydrogel for the treatment of glioblastoma

Glioblastoma (GBM) recurrences appear in most cases around the resection cavity borders and arise from residual GBM cells that cannot be removed by surgery. Here, we propose a novel treatment that combines the advantages of nanomedicine and local drug delivery to target these infiltrating GBM cells. We developed an injectable lipid nanocapsule (LNC)-based formulation loaded with lauroyl-doxorubicin prodrug (DOXC12). Firstly, we demonstrated the efficacy of intratumoral administration of DOXC12 in GL261 GBM-bearing mice, which extended mouse survival. Then, we formulated an injectable hydrogel by mixing the appropriate amount of prodrug with the lipophilic components of LNC. We optimized the hydrogel by incorporating cytidine-C16 (CytC16) to achieve a mechanical stiffness adapted for an application in the brain post-surgery (DOXC12-LNCCL). DOXC12-LNCCL exhibited high DOXC12 encapsulation efficiency (95%) and a size of approximately 60 nm with sustained drug release for over 1 month in vitro. DOXC12-LNCCL exhibited enhanced cytotoxicity compared to free DOXC12 (IC50 of 349 and 86 nM, respectively) on GL261 GBM cells and prevented the growth of GL261 spheroids cultured on organotypic brain slices. In vivo, post-surgical treatment with DOXC12-LNCCL significantly improved the survival of GL261-bearing mice. The combination of this local treatment with the systemic administration of anti-inflammatory drug ibuprofen further delayed the onset of recurrences. In conclusion, our study presents a promising therapeutic approach for the treatment of GBM. By targeting residual GBM cells and reducing the inflammation post-surgery, we present a new strategy to delay the onset of recurrences in the gap period between surgery and standard of care therapy.

Seasonal influences on the efficacy of anti-programmed cell death (ligand) 1 inhibitors in lung cancer

BACKGROUND

Seasonal variations in systemic immunity have been reported. This study aimed to evaluate whether seasonality affects the efficacy of anticancer immunotherapy.

METHODS

A total of 604 patients with lung cancer receiving single anti-programmed cell death (ligand) 1 (anti-PD-[L]1) inhibitors from two prospective observational cohorts were screened. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Patients were classified into two groups according to the season when the treatment started: winter (November-February) and other seasons (March-October). Kaplan-Meier analysis and Cox proportional hazards models were fitted to evaluate the impact of seasonality on survival. For validation, propensity score matching was performed.

RESULTS

A total of 484 patients with advanced non-small cell lung cancer were included. In an unmatched population, multivariable analysis demonstrated that the winter group (n = 173) had a significantly lower risk of progression or death from immunotherapy than the other group (n = 311) (PFS: hazard ratio [HR], 0.77 [95% confidence interval (CI), 0.62-0.96]; p = .018; OS: HR, 0.77 [95% CI, 0.1-0.98]; p = .032). In a propensity score-matched population, the winter group (n = 162) showed significantly longer median PFS (2.8 months [95% CI, 1.9-4.1 months] vs. 2.0 months [95% CI, 1.4-2.7 months]; p = .009) than the other group (n = 162). The winter group's median OS was also significantly longer than that of the other group (13.4 months [95% CI, 10.2-18.0 months] vs. 8.0 months [95% CI, 3.6-8.7 months]; p = .012). The trend toward longer survival in the winter group continued in subgroup analyses.

CONCLUSIONS

Starting an anti-PD-(L)1 inhibitor in winter was associated with better treatment outcomes in patients with lung cancer compared to other seasons.

Snake venom bioprospecting as an approach to finding potential anti-glioblastoma molecules

Glioblastoma (GB) is the most common type of malignant tumor of the central nervous system, responsible for significant morbidity and with a 5-year overall relative survival of only 6.8%. Without advances in treatment in the last twenty years, the standard of care continues to be maximum safe resection, Temozolomide (TMZ), and radiotherapy. Many new trials are ongoing, and despite showing increased progression-free survival, these trials did not improve overall survival. They did not consider the adverse effects of these therapies. Therefore, an increasing number of bioprospecting studies have used snake venom molecules to search for new strategies to attack GB selectively without producing side effects. The present review aims to describe GB characteristics and current and new approaches for treatment considering their side effects. Besides, we focused on the antitumoral activity of snake venom proteins from the Viperidae family against GB, exploring the potential for drug design based on in vitro and in vivo studies. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. In January 2024, a systematic search was performed in the PubMed, EMBASE, and Web of Science databases from January 2000 to December 2023. Search terms were selected based on the population/exposure/outcome (PEO) framework and combined using Boolean operators ("AND", "OR"). The search strategy used these terms: glioblastoma, glioma, high-grade glioma, WHO IV glioma, brain cancer, snake venom, Viperidae, and bioprospection. We identified 10 in vivo and in vitro studies with whole and isolated proteins from Viperidae venom that could have antitumor activity against glioblastoma. Studies in bioprospecting exploring the advantage of snake venom proteins against GB deserve to be investigated due to their high specificity, small size, inherent bioactivity, and few side effects to cross the blood-brain barrier (BBB) to reach the tumor microenvironment.

The Role of Systemic Therapies in the Treatment of Grades 1-4 Gliomas

The primary treatment for gliomas typically involves tumor resection followed by adjuvant radiotherapy, with increasing emphasis on chemotherapy and molecularly targeted drugs. This study aimed to review and summarize the literature on the systemic therapy of malignant gliomas. Chemotherapy may be considered in grades 2 and 3 gliomas, especially when mutations in 1p19q-codeletion are detected. The beneficial impact of adding chemotherapy to radiotherapy (PCV: procarbazine, lomustine, vincristine) has also been demonstrated. In grade 4 glioblastoma multiforme (GBM), wild-type isocitrate dehydrogenase (IDH) status showed the best treatment outcomes with temozolomide (TMZ) in patients with O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. Prolonging adjuvant TMZ therapy improves treatment outcomes compared to the standard 6-cycle adjuvant therapy. Bevacizumab (BEV) monotherapy can improve progression-free survival and maintain the initial quality of life. Despite advancements in GBM treatment, outcomes remain unsatisfactory, with a median survival of 14-16 months. Further research is still needed regarding the systemic treatment of central nervous system gliomas.

Nanomedicine-induced programmed cell death in cancer therapy: mechanisms and perspectives

The balance of programmed cell death (PCD) mechanisms, including apoptosis, autophagy, necroptosis and others, is pivotal in cancer progression and treatment. Dysregulation of these pathways results in uncontrolled cell growth and resistance to conventional therapies. Nanomedicine offers a promising solution in oncology through targeted drug delivery enabling precise targeting of cancer cells while preserving healthy tissues. This approach reduces the side effects of traditional chemotherapy and enhances treatment efficacy by engaging PCD pathways. We details each PCD pathway, their mechanisms, and innovative nanomedicine strategies to activate these pathways, thereby enhancing therapeutic specificity and minimizing harm to healthy tissues. The precision of nanotechnology in targeting PCD pathways promises significant improvements in cancer treatment outcomes. This synergy between nanotechnology and targeted PCD activation could lead to more effective and less toxic cancer therapies, heralding a new era in cancer treatment.

Astrocytes and the tumor microenvironment inflammatory state dictate the killing of glioblastoma cells by Smac mimetic compounds

Smac mimetic compounds (SMCs) are small molecule drugs that sensitize cancer cells to TNF-α-induced cell death and have multiple immunostimulatory effects through alterations in NF-κB signaling. The combination of SMCs with immunotherapies has been reported to result in durable cures of up to 40% in syngeneic, orthotopic murine glioblastoma (GBM) models. Herein, we find that SMC resistance is not due to a cell-intrinsic mechanism of resistance. We thus evaluated the contribution of GBM and brain stromal components to identify parameters leading to SMC efficacy and resistance. The common physiological features of GBM tumors, such as hypoxia, hyaluronic acid, and glucose deprivation were found not to play a significant role in SMC efficacy. SMCs induced the death of microglia and macrophages, which are the major immune infiltrates in the tumor microenvironment. This death of microglia and macrophages then enhances the ability of SMCs to induce GBM cell death. Conversely, astrocytes promoted GBM cell growth and abrogated the ability of SMCs to induce death of GBM cells. The astrocyte-mediated resistance can be overcome in the presence of exogenous TNF-α. Overall, our results highlight that SMCs can induce death of microglia and macrophages, which then provides a source of death ligands for GBM cells, and that the targeting of astrocytes is a potential mechanism for overcoming SMC resistance for the treatment of GBM.

Fractalkine in Health and Disease

CX3CL1 is one of the 50 up-to-date identified and characterized chemokines. While other chemokines are produced as small, secreted proteins, CX3CL1 (fractalkine) is synthetized as a transmembrane protein which also leads to a soluble form produced as a result of proteolytic cleavage. The membrane-bound protein and the soluble forms exhibit different biological functions. While the role of the fractalkine/CX3CR1 signaling axis was described in the nervous system and was also related to the migration of leukocytes to sites of inflammation, its actions are controversial in cancer progression and anti-tumor immunity. In the present review, we first describe the known biology of fractalkine concerning its action through its cognate receptor, but also its role in the activation of different integrins. The second part of this review is dedicated to its role in cancer where we discuss its role in anti-cancer or procarcinogenic activities.

Chemical conjugation mitigates immunotoxicity of chemotherapy via reducing receptor-mediated drug leakage from lipid nanoparticles

Immunotoxicity remains a major hindrance to chemotherapy in cancer therapy. Nanocarriers may alleviate the immunotoxicity, but the optimal design remains unclear. Here, we created two variants of maytansine (DM1)-loaded synthetic high-density lipoproteins (D-sHDL) with either physically entrapped (ED-sHDL) or chemically conjugated (CD-sHDL) DM1. We found that CD-sHDL showed less accumulation in the tumor draining lymph nodes (DLNs) and femur, resulting in a lower toxicity against myeloid cells than ED-sHDL via avoiding scavenger receptor class B type 1 (SR-B1)-mediated DM1 transportation into the granulocyte-monocyte progenitors and dendritic cells. Therefore, higher densities of lymphocytes in the tumors, DLNs, and blood were recorded in mice receiving CD-sHDL, leading to a better efficacy and immune memory of CD-sHDL against colon cancer. Furthermore, liposomes with conjugated DM1 (CD-Lipo) showed lower immunotoxicity than those with entrapped drug (ED-Lipo) through the same mechanism after apolipoprotein opsonization. Our findings highlight the critical role of drug loading patterns in dictating the biological fate and activity of nanomedicine.

In situ chemoimmunotherapy hydrogel elicits immunogenic cell death and evokes efficient antitumor immune response

BACKGROUND

Chemoimmunotherapy has shown promising advantages of eliciting immunogenic cell death and activating anti-tumor immune responses. However, the systemic toxicity of chemotherapy and tumor immunosuppressive microenvironment limit the clinical application.

METHODS

Here, an injectable sodium alginate hydrogel (ALG) loaded with nanoparticle albumin-bound-paclitaxel (Nab-PTX) and an immunostimulating agent R837 was developed for local administration. Two murine hepatocellular carcinoma and breast cancer models were established. The tumor-bearing mice received the peritumoral injection of R837/Nab-PTX/ALG once a week for two weeks. The antitumor efficacy, the immune response, and the tumor microenvironment were investigated.

RESULTS

This chemoimmunotherapy hydrogel with sustained-release character was proven to have significant effects on killing tumor cells and inhibiting tumor growth. Peritumoral injection of our hydrogel caused little harm to normal organs and triggered a potent antitumor immune response against both hepatocellular carcinoma and breast cancer. In the tumor microenvironment, enhanced immunogenic cell death induced by the combination of Nab-PTX and R837 resulted in 3.30-fold infiltration of effector memory T cells and upregulation of 20 biological processes related to immune responses.

CONCLUSIONS

Our strategy provides a novel insight into the combination of chemotherapy and immunotherapy and has the potential for clinical translation.

Induction of therapeutic immunity and cancer eradication through biofunctionalized liposome-like nanovesicles derived from irradiated-cancer cells

Immunotherapy has revolutionized the treatment of cancer. However, its efficacy remains to be optimized. There are at least two major challenges in effectively eradicating cancer cells by immunotherapy. Firstly, cancer cells evade immune cell killing by down-regulating cell surface immune sensors. Secondly, immune cell dysfunction impairs their ability to execute anti-cancer functions. Radiotherapy, one of the cornerstones of cancer treatment, has the potential to enhance the immunogenicity of cancer cells and trigger an anti-tumor immune response. Inspired by this, we fabricate biofunctionalized liposome-like nanovesicles (BLNs) by exposing irradiated-cancer cells to ethanol, of which ethanol serves as a surfactant, inducing cancer cells pyroptosis-like cell death and facilitating nanovesicles shedding from cancer cell membrane. These BLNs are meticulously designed to disrupt both of the aforementioned mechanisms. On one hand, BLNs up-regulate the expression of calreticulin, an "eat me" signal on the surface of cancer cells, thus promoting macrophage phagocytosis of cancer cells. Additionally, BLNs are able to reprogram M2-like macrophages into an anti-cancer M1-like phenotype. Using a mouse model of malignant pleural effusion (MPE), an advanced-stage and immunotherapy-resistant cancer model, we demonstrate that BLNs significantly increase T cell infiltration and exhibit an ablative effect against MPE. When combined with PD-1 inhibitor (α-PD-1), we achieve a remarkable 63.6% cure rate (7 out of 11) among mice with MPE, while also inducing immunological memory effects. This work therefore introduces a unique strategy for overcoming immunotherapy resistance.

The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

Engineering Hyaluronic Acid Microneedles Loaded with Mn2+ and Temozolomide for Topical Precision Therapy of Melanoma

Topical therapy has received worldwide attention for in situ tumors owing to its higher efficacy of drug delivery. Herein, this work reports a dissolvable multifunctional hyaluronic acid microneedles (HMNs) patch coloaded with temozolomide (TMZ) and MnCl2 (TMZ/MnCl2@HMN) for chemoimmunotherapy of melanoma. HMNs can ensure the stability of TMZ over time, and exhibit fewer side effects with a localized release way. In particular, TMZ not only promotes dendritic cell maturation by triggering immunogenic cell death in tumor cells, but also induces DNA damage that can further enhance the Mn2+-activated cGAS-STING (stimulator of interferon genes pathway). As a result, the TMZ/MnCl2@HMN multifunctional platform significantly inhibits lung metastases for melanoma, providing a practical strategy for precision therapy of melanoma.

Progressive, multi-organ, and multi-layered nature of cancer cachexia

Cancer cachexia is a complex, multifaceted condition that negatively impacts the health, treatment efficacy, and economic status of cancer patients. The management of cancer cachexia is an essential clinical need. Cancer cachexia is currently defined mainly according to the severity of weight loss and sarcopenia (i.e., macrosymptoms). However, such macrosymptoms may be insufficient to give clinicians clues on how to manage this condition as these symptoms appear at the late stage of cancer. We need to understand earlier events during the progression of cancer cachexia so as not to miss a clinical opportunity to control this complex syndrome. Recent research indicates that cancer-induced changes in the host are much wider than previously recognized, including disruption of liver function and the immune system. Furthermore, such changes are observed before the occurrence of visible distant metastases (i.e., in early, localized cancers). In light of these findings, we propose to expand the definition of cancer cachexia to include all cancer-induced changes to host physiology, including changes caused by early, localized cancers. This new definition of cancer cachexia can provide a new perspective on this topic, which can stimulate the research and development of novel cancer cachexia therapies.

Multimodal neuro-nanotechnology: Challenging the existing paradigm in glioblastoma therapy

Integrating multimodal neuro- and nanotechnology-enabled precision immunotherapies with extant systemic immunotherapies may finally provide a significant breakthrough for combatting glioblastoma (GBM). The potency of this approach lies in its ability to train the immune system to efficiently identify and eradicate cancer cells, thereby creating anti-tumor immune memory while minimizing multi-mechanistic immune suppression. A critical aspect of these therapies is the controlled, spatiotemporal delivery of structurally defined nanotherapeutics into the GBM tumor microenvironment (TME). Architectures such as spherical nucleic acids or poly(beta-amino ester)/dendrimer-based nanoparticles have shown promising results in preclinical models due to their multivalency and abilities to activate antigen-presenting cells and prime antigen-specific T cells. These nanostructures also permit systematic variation to optimize their distribution, TME accumulation, cellular uptake, and overall immunostimulatory effects. Delving deeper into the relationships between nanotherapeutic structures and their performance will accelerate nano-drug development and pave the way for the rapid clinical translation of advanced nanomedicines. In addition, the efficacy of nanotechnology-based immunotherapies may be enhanced when integrated with emerging precision surgical techniques, such as laser interstitial thermal therapy, and when combined with systemic immunotherapies, particularly inhibitors of immune-mediated checkpoints and immunosuppressive adenosine signaling. In this perspective, we highlight the potential of emerging treatment modalities, combining advances in biomedical engineering and neurotechnology development with existing immunotherapies to overcome treatment resistance and transform the management of GBM. We conclude with a call to action for researchers to leverage these technologies and accelerate their translation into the clinic.

The need for paradigm shift: prognostic significance and implications of standard therapy-related systemic immunosuppression in glioblastoma for immunotherapy and oncolytic virotherapy

Despite significant advances in our knowledge regarding the genetics and molecular biology of gliomas over the past two decades and hundreds of clinical trials, no effective therapeutic approach has been identified for adult patients with newly diagnosed glioblastoma, and overall survival remains dismal. Great hopes are now placed on combination immunotherapy. In clinical trials, immunotherapeutics are generally tested after standard therapy (radiation, temozolomide, and steroid dexamethasone) or concurrently with temozolomide and/or steroids. Only a minor subset of patients with progressive/recurrent glioblastoma have benefited from immunotherapies. In this review, we comprehensively discuss standard therapy-related systemic immunosuppression and lymphopenia, their prognostic significance, and the implications for immunotherapy/oncolytic virotherapy. The effectiveness of immunotherapy and oncolytic virotherapy (viro-immunotherapy) critically depends on the activity of the host immune cells. The absolute counts, ratios, and functional states of different circulating and tumor-infiltrating immune cell subsets determine the net immune fitness of patients with cancer and may have various effects on tumor progression, therapeutic response, and survival outcomes. Although different immunosuppressive mechanisms operate in patients with glioblastoma/gliomas at presentation, the immunological competence of patients may be significantly compromised by standard therapy, exacerbating tumor-related systemic immunosuppression. Standard therapy affects diverse immune cell subsets, including dendritic, CD4+, CD8+, natural killer (NK), NKT, macrophage, neutrophil, and myeloid-derived suppressor cell (MDSC). Systemic immunosuppression and lymphopenia limit the immune system's ability to target glioblastoma. Changes in the standard therapy are required to increase the success of immunotherapies. Steroid use, high neutrophil-to-lymphocyte ratio (NLR), and low post-treatment total lymphocyte count (TLC) are significant prognostic factors for shorter survival in patients with glioblastoma in retrospective studies; however, these clinically relevant variables are rarely reported and correlated with response and survival in immunotherapy studies (e.g., immune checkpoint inhibitors, vaccines, and oncolytic viruses). Our analysis should help in the development of a more rational clinical trial design and decision-making regarding the treatment to potentially improve the efficacy of immunotherapy or oncolytic virotherapy.

Redox-responsive polymer micelles co-encapsulating immune checkpoint inhibitors and chemotherapeutic agents for glioblastoma therapy

Immunotherapy with immune checkpoint blockade (ICB) for glioblastoma (GBM) is promising but its clinical efficacy is seriously challenged by the blood-tumor barrier (BTB) and immunosuppressive tumor microenvironment. Here, anti-programmed death-ligand 1 antibodies (aPD-L1) are loaded into a redox-responsive micelle and the ICB efficacy is further amplified by paclitaxel (PTX)-induced immunogenic cell death (ICD) via a co-encapsulation approach for the reinvigoration of local anti-GBM immune responses. Consequently, the micelles cross the BTB and are retained in the reductive tumor microenvironment without altering the bioactivity of aPD-L1. The ICB efficacy is enhanced by the aPD-L1 and PTX combination with suppression of primary and recurrent GBM, accumulation of cytotoxic T lymphocytes, and induction of long-lasting immunological memory in the orthotopic GBM-bearing mice. The co-encapsulation approach facilitating efficient antibody delivery and combining with chemotherapeutic agent-induced ICD demonstrate that the chemo-immunotherapy might reprogram local immunity to empower immunotherapy against GBM.

Glioma stem cells remodel immunotolerant microenvironment in GBM and are associated with therapeutic advancements

Glioma is the most common primary tumor of the central nervous system (CNS). Glioblastoma (GBM) is incurable with current treatment strategies. Additionally, the treatment of recurrent GBM (rGBM) is often referred to as terminal treatment, necessitating hospice-level care and management. The presence of the blood-brain barrier (BBB) gives GBM a more challenging or "cold" tumor microenvironment (TME) than that of other cancers and gloma stem cells (GSCs) play an important role in the TME remodeling, occurrence, development and recurrence of giloma. In this review, our primary focus will be on discussing the following topics: niche-associated GSCs and macrophages, new theories regarding GSC and TME involving pyroptosis and ferroptosis in GBM, metabolic adaptations of GSCs, the influence of the cold environment in GBM on immunotherapy, potential strategies to transform the cold GBM TME into a hot one, and the advancement of GBM immunotherapy and GBM models.

Nanomedicine - Immune System Interactions: Limitations and Opportunities for the Treatment of Cancer

Nanoparticles interact with immune cells in many different ways. These interactions are crucially important for determining nanoparticles' ability to be used for cancer therapy. Traditionally, strategies such as PEGylation have been employed to reduce (the kinetics of) nanoparticle uptake by immune cells, to endow them with long circulation properties, and to enable them to exploit the Enhanced Permeability and Retention (EPR) effect to accumulate in tumors. More recently, with immunotherapy becoming an increasingly important cornerstone in the clinical management of cancer, ever more research efforts in academia and industry are focusing on specifically targeting immune cells with nanoparticles. In this chapter, we describe the barriers and opportunities of immune cell targeting with nanoparticles, and we discuss how nanoparticle-based drug delivery to specific immune cell populations in tumors as well as in secondary myeloid and lymphoid organs (such as bone marrow, lymph nodes, and spleen) can be leveraged to boost the efficacy of cancer immunotherapy.

Therapeutic Supramolecular Polymers: Designs and Applications

The self-assembly of low-molecular-weight building motifs into supramolecular polymers has unlocked a new realm of materials with distinct properties and tremendous potential for advancing medical practices. Leveraging the reversible and dynamic nature of non-covalent interactions, these supramolecular polymers exhibit inherent responsiveness to their microenvironment, physiological cues, and biomolecular signals, making them uniquely suited for diverse biomedical applications. In this review, we intend to explore the principles of design, synthesis methodologies, and strategic developments that underlie the creation of supramolecular polymers as carriers for therapeutics, contributing to the treatment and prevention of a spectrum of human diseases. We delve into the principles underlying monomer design, emphasizing the pivotal role of non-covalent interactions, directionality, and reversibility. Moreover, we explore the intricate balance between thermodynamics and kinetics in supramolecular polymerization, illuminating strategies for achieving controlled sizes and distributions. Categorically, we examine their exciting biomedical applications: individual polymers as discrete carriers for therapeutics, delving into their interactions with cells, and in vivo dynamics; and supramolecular polymeric hydrogels as injectable depots, with a focus on their roles in cancer immunotherapy, sustained drug release, and regenerative medicine. As the field continues to burgeon, harnessing the unique attributes of therapeutic supramolecular polymers holds the promise of transformative impacts across the biomedical landscape.

Enhancing Cancer Chemo-Immunotherapy: Innovative Approaches for Overcoming Immunosuppression by Functional Nanomaterials

Chemotherapy is a critical modality in cancer therapy to combat malignant cell proliferation by directly attacking cancer cells and inducing immunogenic cell death, serving as a vital component of multi-modal treatment strategies for enhanced therapeutic outcomes. However, chemotherapy may inadvertently contribute to the immunosuppression of the tumor microenvironment (TME), inducing the suppression of antitumor immune responses, which can ultimately affect therapeutic efficacy. Chemo-immunotherapy, combining chemotherapy and immunotherapy in cancer treatment, has emerged as a ground-breaking approach to target and eliminate malignant tumors and revolutionize the treatment landscape, offering promising, durable responses for various malignancies. Notably, functional nanomaterials have substantially contributed to chemo-immunotherapy by co-delivering chemo-immunotherapeutic agents and modulating TME. In this review, recent advancements in chemo-immunotherapy are thus summarized to enhance treatment effectiveness, achieved by reversing the immunosuppressive TME (ITME) through the exploitation of immunotherapeutic drugs, or immunoregulatory nanomaterials. The effects of two-way immunomodulation and the causes of immunoaugmentation and suppression during chemotherapy are illustrated. The current strategies of chemo-immunotherapy to surmount the ITME and the functional materials to target and regulate the ITME are discussed and compared. The perspective on tumor immunosuppression reversal strategy is finally proposed.

An In Situ Chemotherapy Drug Combined with Immune Checkpoint Inhibitor for Chemoimmunotherapy

Clinically, cancer chemotherapy still faces unsatisfactory efficacy due to drug resistance and severe side effects, including tiredness, hair loss, feeling sick, etc. The clinical benefits of checkpoint inhibitors have revived hope for cancer immunotherapy, but the objective response rate of immune checkpoint inhibitors remains around 10-40%. Herein, two types of copper-doped mesoporous silica nanoparticles (MS-Cu-1 with a diameter of about 30 nm and MS-Cu-2 with a diameter of about 200 nm) were synthesized using a one-pot method. Both MS-Cu-1 and MS-Cu-2 nanoparticles showed excellent tumor microenvironment regulation properties with elevated extracellular and intracellular ROS generation, extracellular and intracellular oxygenation, and intracellular GSH depletion. In particular, MS-Cu-2 nanoparticles demonstrated a better microenvironment modulation effect than MS-Cu-1 nanoparticles. The DSF/MS-Cu composites with disulfiram (DSF) and copper co-delivery characteristics were prepared by a straightforward method using chloroform as the solvent. Cell survival rate and live/dead staining results showed that DSF and MS-Cu alone were not toxic to LLC cells, while a low dose of DSF/MS-Cu (1-10 μg/mL) showed a strong cell-killing effect. In addition, MS-Cu-2 nanoparticles released more Cu2+ in a weakly acidic environment (pH = 5) than in a physiological environment (pH = 7.4), and the Cu2+ released was 41.72 ± 0.96 mg/L in 1 h under weakly acidic conditions. UV-visible absorption spectrometry confirmed the production of tumor-killing drugs (CuETs). The intratumoral injection of DSF/MS-Cu significantly inhibited tumor growth in vivo by converting nontoxic DSF/MS-Cu into toxic CuETs. The combination of DSF/MS-Cu and anti-CTLA-4 antibody further inhibited tumor growth, showing the synergistic effect of DSF/MS-Cu and immune checkpoint inhibitors.

Immune Escape in Glioblastoma: Mechanisms of Action and Implications for Immune Checkpoint Inhibitors and CAR T-Cell Therapy

Glioblastoma, the most common primary brain cancer in adults, is characterized by a poor prognosis and resistance to standard treatments. The advent of immunotherapy has revolutionized the treatment of several cancers in recent years but has failed to demonstrate benefit in patients with glioblastoma. Understanding the mechanisms by which glioblastoma exerts tumor-mediated immune suppression in both the tumor microenvironment and the systemic immune landscape is a critical step towards developing effective immunotherapeutic strategies. In this review, we discuss the current understanding of immune escape mechanisms in glioblastoma that compromise the efficacy of immunotherapies, with an emphasis on immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy. In parallel, we review data from preclinical studies that have identified additional therapeutic targets that may enhance overall treatment efficacy in glioblastoma when administered alongside existing immunotherapies.

Self-Cross-Linked Chitosan/Albumin-Bound Nanoparticle Hydrogel for Inhibition of Postsurgery Malignant Glioma Recurrence

The development of chemoimmunotherapy with reduced systemic toxicity using local formulations is an effective strategy for combating tumor recurrence. Herein, we reported a localized hydrogel system for antitumor chemoimmunotherapy, formed by doxorubicin (DXR)-loaded bovine serum albumin (BSA) nanoparticles self-cross-linked with natural polysaccharide chitosan (CS). The drug-loaded hydrogel (DXR-CBGel) with antiswelling performance and prolonged drug-release profile was combined with antiprogrammed cell death protein 1 (aPD-1) as an in situ vaccine for treating glioblastoma multiforme (GBM) lesions. The antiswelling hydrogel system shows excellent biosafety for volume-sensitive GBM lesions. Both the albumin-bound formulation and the in situ gelation design facilitate the local retention and sustained release of DXR to generate long-term chemoimmunotherapy with reduced systemic toxicity. The chemotherapy-induced immunogenic cell death of DXR with the assistance of immunotherapeutic CS can trigger tumor-specific immune responses, which are further amplified by an immune checkpoint blockade to effectively inhibit cancer recurrence. The strategy of combining albumin-bound drug formulation and biocompatible polymer-based hydrogel for localized chemoimmunotherapy shows great potential against postsurgery glioblastoma recurrence.

The need of radiotherapy optimization for glioblastomas considering immune responses

Glioblastoma is the most common of malignant primary brain tumors and one of the tumors with the poorest prognosis for which the overall survival rate has not significantly improved despite recent advances in treatment techniques and therapeutic drugs. Since the emergence of immune checkpoint inhibitors, the immune response to tumors has attracted increasing attention. Treatments affecting the immune system have been attempted for various tumors, including glioblastomas, but little has been shown to be effective. It has been found that the reason for this is that glioblastomas have a high ability to evade attacks from the immune system, and that the lymphocyte depletion associated with treatment can reduce its immune function. Currently, research to elucidate the resistance of glioblastomas to the immune system and development of new immunotherapies are being vigorously carried out. Targeting of radiation therapy for glioblastomas varies among guidelines and clinical trials. Based on early reports, target definitions with wide margins are common, but there are also reports that narrowing the margins does not make a significant difference in treatment outcome. It has also been suggested that a large number of lymphocytes in the blood are irradiated by the irradiation treatment to a wide area in a large number of fractionations, which may reduce the immune function, and the blood is being recognized as an organ at risk. Recently, a randomized phase II trial comparing two types of target definition in radiotherapy for glioblastomas was conducted, and it was reported that the overall survival and progression-free survival were significantly better in a small irradiation field group. We review recent findings on the immune response and the immunotherapy to glioblastomas and the novel role of radiotherapy and propose the need to develop an optimal radiotherapy that takes radiation effects on the immune function into account.

The prognostic value of tumor-associated macrophages in glioma patients

Glioma is a complex tumor composed of both neoplastic and non-neoplastic cells, including tumor-infiltrating leukocytes (TILs), and each cell type contributes to tumor formation and malignant progression. Among TILs, tumor-associated macrophages (TAMs) are of great importance and play a key role in the immune response to cancer. In this study, 22 types of adaptive and innate TILs were evaluated in gliomas. TAMs, which account for 38.7% of all these cells, are the most abundant immune infiltrates in the tumor microenvironment. In addition, we observed different immune cell patterns in low-grade glioma and glioblastoma. Our research indicated that there was a connection between TILs, and 13 of 22 TILs were significantly associated with patient outcomes. Finally, the prognosis and diagnostic value of TAMs were revealed using Kaplan-Meier analysis. We identified the optimal cutoff point of TAMs at an infiltrating level of 0.47 to predict patient prognosis, with a median overall survival of 448 days in patients with higher TAM infiltration levels and 2660 days in patients with lower TAM infiltration levels. These findings provide a new idea for glioma to regulate tumor-specific immunity, clarify the potential effects of TAMs on disease pathology, and provide a theoretical basis for immune intervention treatment of gliomas.

A Nanobody-Bioorthogonal Catalyst Conjugate Triggers Spatially Confined Prodrug Activation for Combinational Chemo-immunotherapy

Checkpoint inhibitors have been used with chemotherapy to improve antitumor efficacy. However, overcoming the immunosuppressive effect of chemotherapeutics remains a challenge. We report a nanobody-catalyst conjugate Ru-PD-L1 by fusing a ruthenium catalyst to an anti-PD-L1 nanobody. After administration of Ru-PD-L1 and a doxorubicin (DOX) prodrug, Ru-PD-L1 disrupts the PD-L1/PD-1 interaction and catalyzes the uncaging of the DOX prodrug. The spatially confined release of DOX reduces its systemic toxicity and leads to immunogenic cell death (ICD). The induced ICD triggers antitumor immune responses, which are further amplified by PD-L1 blockade to elicit synergistic chemo-immunotherapy, substantially increasing the number of tumor-infiltrating T-cells by 49.7% compared with the controls, thereby exhibiting high antitumor activity and low cytotoxicity in murine models. The combinational treatment could inhibit the growth of mice tumors by 67.7% compared to the control group. This combinational approach circumvents the negative immunogenic effects of chemotherapeutics and provides a potential chemo-immunotherapy strategy for human cancer treatment.

Plasma fractalkine contributes to systemic myeloid diversity and PD-L1/PD-1 blockade in lung cancer

Recent studies highlight the importance of baseline functional immunity for immune checkpoint blockade therapies. High-dimensional systemic immune profiling is performed in a cohort of non-small-cell lung cancer patients undergoing PD-L1/PD-1 blockade immunotherapy. Responders show high baseline myeloid phenotypic diversity in peripheral blood. To quantify it, we define a diversity index as a potential biomarker of response. This parameter correlates with elevated activated monocytic cells and decreased granulocytic phenotypes. High-throughput profiling of soluble factors in plasma identifies fractalkine (FKN), a chemokine involved in immune chemotaxis and adhesion, as a biomarker of response to immunotherapy that also correlates with myeloid cell diversity in human patients and murine models. Secreted FKN inhibits lung adenocarcinoma growth in vivo through a prominent contribution of systemic effector NK cells and increased tumor immune infiltration. FKN sensitizes murine lung cancer models refractory to anti-PD-1 treatment to immune checkpoint blockade immunotherapy. Importantly, recombinant FKN and tumor-expressed FKN are efficacious in delaying tumor growth in vivo locally and systemically, indicating a potential therapeutic use of FKN in combination with immunotherapy.

Metastatic lymph node targeted CTLA4 blockade: a potent intervention for local and distant metastases with minimal ICI-induced pneumonia

BACKGROUND

Immune checkpoint blockade (ICB) elicits a strong and durable therapeutic response, but its application is limited by disparate responses and its associated immune-related adverse events (irAEs). Previously, in a murine model of lymph node (LN) metastasis, we showed that intranodal administration of chemotherapeutic agents using a lymphatic drug delivery system (LDDS) elicits stronger therapeutic responses in comparison to systemic drug delivery approaches, while minimizing systemic toxicity, due to its improved pharmacokinetic profile at the intended site. Importantly, the LN is a reservoir of immunotherapeutic targets. We therefore hypothesized that metastatic LN-targeted ICB can amplify anti-tumor response and uncouple it from ICB-induced irAEs.

METHODS

To test our hypothesis, models of LN and distant metastases were established with luciferase expressing LM8 cells in MXH10/Mo-lpr/lpr mice, a recombinant inbred strain of mice capable of recapitulating ICB-induced interstitial pneumonia. This model was used to interrogate ICB-associated therapeutic response and immune related adverse events (irAEs) by in vivo imaging, high-frequency ultrasound imaging and histopathology. qPCR and flowcytometry were utilized to uncover the mediators of anti-tumor immunity.

RESULTS

Tumor-bearing LN (tbLN)-directed CTLA4 blockade generated robust anti-tumor response against local and systemic metastases, thereby improving survival. The anti-tumor effects were accompanied by an upregulation of effector CD8T cells in the tumor-microenvironment and periphery. In comparison, non-specific CTLA4 blockade was found to elicit weaker anti-tumor effect and exacerbated ICI-induced irAEs, especially interstitial pneumonia. Together these data highlight the importance of tbLN-targeted checkpoint blockade for efficacious response.

CONCLUSIONS

Intranodal delivery of immune checkpoint inhibitors to metastatic LN can potentiate therapeutic response while minimizing irAEs stemming from systemic lowering of immune activation threshold.

Updates in Glioblastoma Immunotherapy: An Overview of the Current Clinical and Translational Scenario

Glioblastoma (GBM) is the most common and aggressive central nervous system tumor, requiring multimodal management. Due to its malignant behavior and infiltrative growth pattern, GBM is one of the most difficult tumors to treat and gross total resection is still considered to be the first crucial step. The deep understanding of GBM microenvironment and the possibility of manipulating the patient's innate and adaptive immune system to fight the neoplasm represent the base of immunotherapeutic strategies that currently express the future for the fight against GBM. Despite the immunotherapeutic approach having been successfully adopted in several solid and haematologic neoplasms, immune resistance and the immunosuppressive environment make the use of these strategies challenging in GBM treatment. We describe the most recent updates regarding new therapeutic strategies that target the immune system, immune checkpoint inhibitors, chimeric antigen receptor T cell therapy, peptide and oncolytic vaccines, and the relevant mechanism of immune resistance. However, no significant results have yet been obtained in studies targeting single molecules/pathways. The future direction of GBM therapy will include a combined approach that, in contrast to the inescapable current treatment modality of maximal resection followed by chemo- and radiotherapy, may combine a multifaceted immunotherapy treatment with the dual goals of directly killing tumor cells and activating the innate and adaptive immune response.

Long-Acting Therapeutic Delivery Systems for the Treatment of Gliomas

Despite the emergence of cutting-edge therapeutic strategies and tremendous progress in research, a complete cure of glioma remains elusive. The heterogenous nature of tumor, immunosuppressive state and presence of blood brain barrier are few of the major obstacles in this regard. Long-acting depot formulations such as injectables and implantables are gaining attention for drug delivery to brain owing to their ease in administration and ability to elute drug locally for extended durations in a controlled manner with minimal toxicity. Hybrid matrices fabricated by incorporating nanoparticulates within such systems help to enhance pharmaceutical advantages. Utilization of long-acting depots as monotherapy or in conjunction with existing strategies rendered significant survival benefits in many preclinical studies and some clinical trials. The discovery of novel targets, immunotherapeutic strategies and alternative drug administration routes are now coupled with several long-acting systems with an ultimate aim to enhance patient survival and prevent glioma recurrences.

Self-assembling paclitaxel-mediated stimulation of tumor-associated macrophages for postoperative treatment of glioblastoma

The unique cancer-associated immunosuppression in brain, combined with a paucity of infiltrating T cells, contributes to the low response rate and poor treatment outcomes of T cell-based immunotherapy for patients diagnosed with glioblastoma multiforme (GBM). Here, we report on a self-assembling paclitaxel (PTX) filament (PF) hydrogel that stimulates macrophage-mediated immune response for local treatment of recurrent glioblastoma. Our results suggest that aqueous PF solutions containing aCD47 can be directly deposited into the tumor resection cavity, enabling seamless hydrogel filling of the cavity and long-term release of both therapeutics. The PTX PFs elicit an immune-stimulating tumor microenvironment (TME) and thus sensitizes tumor to the aCD47-mediated blockade of the antiphagocytic "don't eat me" signal, which subsequently promotes tumor cell phagocytosis by macrophages and also triggers an antitumor T cell response. As adjuvant therapy after surgery, this aCD47/PF supramolecular hydrogel effectively suppresses primary brain tumor recurrence and prolongs overall survivals with minimal off-target side effects.

Combination of local immunogenic cell death-inducing chemotherapy and DNA vaccine increases the survival of glioblastoma-bearing mice

Immunotherapy efficacy as monotherapy is negligible for glioblastoma (GBM). We hypothesized that combining therapeutic vaccination using a plasmid encoding an epitope derived from GBM-associated antigen (pTOP) with local delivery of immunogenic chemotherapy using mitoxantrone-loaded PEGylated PLGA-based nanoparticles (NP-MTX) would improve the survival of GBM-bearing mice by stimulating an antitumor immune response. We first proved that MTX retained its ability to induce cytotoxicity and immunogenic cell death of GBM cells after encapsulation. Intratumoral delivery of MTX or NP-MTX increased the frequency of IFN-γ-secreting CD8 T cells. NP-MTX mixed with free MTX in combination with pTOP DNA vaccine increased the median survival of GL261-bearing mice and increased M1-like macrophages in the brain. The addition of CpG to this combination abolished the survival benefit but led to increased M1 to M2 macrophage ratio and IFN-γ-secreting CD4 T cell frequency. These results highlight the benefits of combination strategies to potentiate immunotherapy and improve GBM outcome.

cRGD-modified nanoparticles of multi-bioactive agent conjugate with pH-sensitive linkers and PD-L1 antagonist for integrative collaborative treatment of breast cancer

Targeted co-delivery and co-release of multi-drugs is essential to have an integrative collaborative effect on treating cancer. It is valuable to use few drug carriers for multi-drug delivery. Herein, we develop cRGD-modified nanoparticles (cRGD-TDA) of a conjugate of doxorubicin as cytotoxic agent, adjudin as an anti-metastasis agent and D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) as a reactive oxygen species inducer linked with pH-sensitive bonds, and then combine the nanoparticles with PD-L1 antagonist to treat 4T1 triple-negative breast cancer. cRGD-TDA NPs present tumor-targeted co-delivery and pH-sensitive co-release of triple agents. cRGD-TDA NPs combined with PD-L1 antagonist much more significantly inhibit tumor growth and metastasis than single-drug treatment, which is due to their integrative collaborative effect. It is found that TPGS elicits a powerful immunogenic cell death effect. Meanwhile, PD-L1 antagonist mitigates the immunosuppressive environment and has a synergistic effect with the cRGD-TDA NPs. The study provides a new strategy to treat refractory cancer integratively and collaboratively.

Penetrative and Sustained Drug Delivery Using Injectable Hydrogel Nanocomposites for Postsurgical Brain Tumor Treatment

Postsurgical treatment of glioblastoma multiforme (GBM) by systemic chemotherapy and radiotherapy is often inefficient. Tumor cells infiltrating deeply into the brain parenchyma are significant obstacles to the eradication of GBM. Here, we present a potential solution to this challenge by introducing an injectable thermoresponsive hydrogel nanocomposite. As a liquid solution that contains drug-loaded micelles and water-dispersible ferrimagnetic iron oxide nanocubes (wFIONs), the hydrogel nanocomposite is injected into the resected tumor site after surgery. It promptly gelates at body temperature to serve as a soft, deep intracortical drug reservoir. The drug-loaded micelles target residual GBM cells and deliver drugs with a minimum premature release. Alternating magnetic fields accelerate diffusion through heat generation from wFIONs, enabling penetrative drug delivery. Significantly suppressed tumor growth and improved survival rates are demonstrated in an orthotopic mouse GBM model. Our system proves the potential of the hydrogel nanocomposite platform for postsurgical GBM treatment.

Mismatch between Bioluminescence Imaging (BLI) and MRI When Evaluating Glioblastoma Growth: Lessons from a Study Where BLI Suggested "Regression" while MRI Showed "Progression"

Orthotopic glioblastoma xenografts are paramount for evaluating the effect of innovative anti-cancer treatments. In longitudinal studies, tumor growth (or regression) of glioblastoma can only be monitored by noninvasive imaging. For this purpose, bioluminescence imaging (BLI) has gained popularity because of its low cost and easy access. In the context of the development of new nanomedicines for treating glioblastoma, we were using luciferase-expressing GL261 cell lines. Incidentally, using BLI in a specific GL261 glioblastoma model with cells expressing both luciferase and the green fluorescent protein (GL261-luc-GFP), we observed an apparent spontaneous regression. By contrast, the magnetic resonance imaging (MRI) analysis revealed that the tumors were actually growing over time. For other models (GL261 expressing only luciferase and U87 expressing both luciferase and GFP), data from BLI and MRI correlated well. We found that the divergence in results coming from different imaging modalities was not due to the tumor localization nor the penetration depth of light but was rather linked to the instability in luciferase expression in the viral construct used for the GL261-luc-GFP model. In conclusion, the use of multi-modality imaging prevents possible errors in tumor growth evaluation, and checking the stability of luciferase expression is mandatory when using BLI as the sole imaging modality.

Combination of hyaluronic acid conjugates with immunogenic cell death inducer and CpG for glioblastoma local chemo-immunotherapy elicits an immune response and induces long-term survival

The efficacy of standard glioblastoma (GBM) treatments has been limited due to the highly immunosuppressive tumor immune microenvironment, interpatient tumor heterogenicity and anatomical barriers, such as the blood brain barrier. In the present work, we hypothesized that a new local therapy based on the combination of doxorubicin (DOX) as an immunogenic cell death (ICD) inducer and CpG, a Toll-like receptor (TLR)-9 agonist, would act synergistically to eradicate GBM. DOX and CpG were first tested in an orthotopic GL261 GBM model showing enhanced survival. To improve the outcome with a reduced dose, we designed bioresponsive hyaluronic acid (HA)-drug conjugates for effective in situ chemoimmunotherapy. HA was derivatized with CpG. The new HA-CpG conjugate showed high efficacy in re-educating protumoral M2-like microglia into an antitumoral M1-like phenotype, inducing the expression of immune-stimulatory cytokines. DOX was also conjugated to HA. DOX conjugation increased ICD induction in GL261 cells. Finally, a combination of the conjugates was explored in an orthotopic GL261 GBM model. The local delivery of combined HA-DOX + HA-CpG into the tumor mass elicited antitumor CD8⁺ T cell responses in the brain tumor microenvironment and reduced the infiltration of M2-like tumor-associated macrophages and myeloid-derived suppressor cells. Importantly, the combination of HA-DOX and HA-CpG induced long-term survival in >66% of GBM-bearing animals than other treatments (no long-term survivor observed), demonstrating the benefits of conjugating synergistic drugs to HA nanocarrier. These results emphasize that HA-drug conjugates constitute an effective drug delivery platform for local chemoimmunotherapy against GBM and open new perspectives for the treatment of other brain cancers and brain metastasis.

Recent Developments in Glioblastoma Therapy: Oncolytic Viruses and Emerging Future Strategies

Glioblastoma is the most aggressive form of malignant brain tumor. Standard treatment protocols and traditional immunotherapy are poorly effective as they do not significantly increase the long-term survival of glioblastoma patients. Oncolytic viruses (OVs) may be an effective alternative approach. Combining OVs with some modern treatment options may also provide significant benefits for glioblastoma patients. Here we review virotherapy for glioblastomas and describe several OVs and their combination with other therapies. The personalized use of OVs and their combination with other treatment options would become a significant area of research aiming to develop the most effective treatment regimens for glioblastomas.

The Tumor Immune Microenvironment in Primary CNS Neoplasms: A Review of Current Knowledge and Therapeutic Approaches

Primary CNS neoplasms are responsible for considerable mortality and morbidity, and many therapies directed at primary brain tumors have proven unsuccessful despite their success in preclinical studies. Recently, the tumor immune microenvironment has emerged as a critical aspect of primary CNS neoplasms that may affect their malignancy, prognosis, and response to therapy across patients and tumor grades. This review covers the tumor microenvironment of various primary CNS neoplasms, with a focus on glioblastoma and meningioma. Additionally, current therapeutic strategies based on elements of the tumor microenvironment, including checkpoint inhibitor therapy and immunotherapeutic vaccines, are discussed.