Effects of Apatinib combined with Temozolomide on levels of sPD-1 and sPD-L1 in patients with drug-resistant recurrent glioblastoma

Abstract Objective This study aimed to explore the effects of Apatinib combined with Temozolomide (TMZ) on the levels of Soluble PD-1 (sPD-1) and Soluble Programmed Death-1 Ligand (sPD-L1) in patients with drug-resistant recurrent Glioblastoma (GB). Study design A total of 69 patients with recurrent GB from September 2020 to March 2022 were recruited and assigned to the control group (n = 34) and observation group (n = 35) according to different treatment options after tumor recurrence. The control group was treated with TMZ, and the observation group was treated with Apatinib combined with TMZ. Levels of sPD-1 and spd-l1, clinical efficacy, survival time and adverse reactions were observed and compared between the two groups. Results General data including gender, age, body mass index, and combined diseases indicated no statistical significance between groups (p > 0.05). Before the intervention, sPD-1 and sPD-L1 levels were not significantly different in the two groups (p > 0.05). After interventions, levels of PD-1 and sPD-L1 levels decreased significantly (p < 0.05). The objective remission rate and clinical benefit rate of the observation group were higher and overall survival and progression-free survival were longer than those of the control group (p < 0.05). No significant difference was observed in major adverse reactions among patients (p > 0.05). Conclusions Apatinib combined with TMZ is safe and effective in the treatment of recurrent GB. The combined application of the two can reduce the levels of sPD-1 and sPD-L1, which has important clinical application value.

nteraction between FAK/αB-crystalline is important for viability of the glioblastoma cells

Abstract Glioblastoma multiforme is a tumor of the central nervous system. Focal Adhesion Kinase (FAK) and αB-crystalline are two proteins involved in glioblastoma development. In this study, we investigated whether the FAK/αB-crystalline interaction is important for glioblastoma cells, we aimed to investigate the interaction of these two proteins in the glioblastoma multiforme cell line U87-MG. Two peptides named FP01 peptide (derived from αB-crystalline) and FP02 peptide (derived from FAK) were synthesized for this study. Treatment of U87-MG with the peptides FP01 and FP02 in the concentration at 50 µM reduced the viability cellular to around 41% and 51%, respectively. Morphological alterations in the cells treated with the peptides when compared to the control were observed. This study suggests that the interaction between FAK and αB-crystalline is important for the viability of glioblastoma cells

The 2021 World Health Organization classification of gliomas: an imaging approach / Nova classificação das neoplasias gliais segundo a Organização Mundial da Saúde 2021, com enfoque radiológico

Abstract The purpose of this pictorial essay is to describe the recommendations of the 2021 World Health Organization classification for adult-type and pediatric-type gliomas and to discuss the main modifications in relation to the previous (2016) classification, exemplified by imaging, histological, and molecular findings in nine patients followed at our institutions. In recent years, molecular biomarkers have gained importance in the diagnosis and classification of gliomas, mainly because they have been shown to correlate with the biological behavior and prognosis of such tumors. It is important for neuroradiologists to familiarize themselves with this new classification of central nervous system tumors, so that they can use this knowledge in evaluating and reporting the imaging examinations of patients with glioma.

Resumo O propósito deste ensaio iconográfico é descrever e discutir as novas recomendações da Organização Mundial da Saúde de 2021, referente aos gliomas dos tipos adulto e infantil, e suas principais diferenças com a classificação anterior (2016), exemplificadas com imagens de nove casos de pacientes atendidos nas nossas instituições. Recentemente, há uma crescente significância dos marcadores moleculares no diagnóstico e classificação dos gliomas e tumores do sistema nervoso central, principalmente pela correlação com o comportamento biológico e o prognóstico. É importante que os neurorradiologistas estejam familiarizados com a nova classificação dos tumores do sistema nervoso central para a prática clínica, na avaliação e emissão de laudos e opiniões nas imagens dos pacientes com gliomas.

Role of cyclin D1 in glial tumors—A retrospective and observational study

Aim: High-grade glial tumors remain as one of the most lethal malignancies. Cyclin D1 is expressed in some human malignancies and is the potential target of intervention. The present study aims to determine the relationship of cyclin D1 expression with other clinicopathological parameters. Materials and Methods: A cross-sectional study was carried out in a tertiary care center. Biopsy proven 66 cases of glial tumor patients were included in the study. The patients with incomplete clinical details were excluded from the study. Immunohistochemistry using antibodies for IDH 1 and cyclin d1 was done in all the cases. Glial tumors were reclassified according to WHO 2016 classification. Data analysis was performed using SPSS 26.0 for the windows. Result: Among 66 patients, 49 (74.3%) were males and 17 (25.7%) were females. The age of the patients ranged from 20 years to 70 years. Overall, 6.02% were of grade I Glial tumors, 22.7% were of grade II Glial tumors, 19.6% patients were of grade III Glial tumors, and 51.6% patients were of grade IV Glial tumors. Of 66 samples tested cyclin D1 was positive in 25 (37.87%) as high expressers and 7 (10.60%) were low expressers. Our study showed a significant correlation between the expression of cyclin D1 with grade and IDH mutation status, No significant correlation of cyclin D1 was noted with age or sex of the patient. Conclusion: Cyclin D1 was associated with a higher grade of the glial tumor. It can be a potential marker both for prognosis and treatment of glial tumors.

WHO CNS5 2021 incluye mutaciones específicas en gliomas que pueden ser identificadas con biomarcadores cuantitativos de resonancia magnética / WHO CNS5 2021 includes specific mutations in gliomas that can be identified with MRI quantitative biomarkers

Resumen En 2021 se publicó la última versión de la clasificación de tumores del sistema nervioso central de la Organización Mundial de la Salud (WHO CNS5 por sus siglas en inglés), considerada un estándar internacional. Las primeras ediciones se basaron en características histológicas y posteriormente se incorporaron aspectos relacionados con nuevos conocimientos. En la revisión de 2016 se implementaron características moleculares para la clasificación y estadificación de los gliomas, como la presencia de mutaciones en IDH1 y IDH2. Actualmente, las técnicas de resonancia magnética avanzada permiten valorar la presencia de 2-HG (oncometabolito incrementado ante mutaciones en IDH), de forma que indirectamente y sin procedimientos invasivos pueden identificarse las mutaciones en IDH. La resonancia magnética avanzada es un procedimiento aún en desarrollo, de gran utilidad para el diagnóstico y manejo de distintas patologías. En el presente documento se abordan las implicaciones de la WHO CNS5 en la evaluación de gliomas, así como aspectos históricos, las bases de la resonancia magnética convencional y secuencias de resonancia magnética avanzada útiles en la clasificación actual.

Abstract In 2021, the latest version of the World Health Organization classification of central nervous system tumors (WHO CNS5) was published, which is considered an international standard. The first editions of this classification were based on histological characteristics and, subsequently, aspects related to new knowledge were incorporated. In the 2016 revision, molecular characteristics were implemented for the classification and staging of gliomas, such as the presence of mutations in IDH1 or IDH2. Currently, advanced magnetic resonance imaging (MRI) techniques allow assessing for the presence of 2-HG (increased oncometabolite that precedes IDH mutations), whereby IDH mutations can be indirectly identified, without invasive procedures being required. Advanced MRI is a growing field, highly useful for diagnosis and management of different pathologies. This document addresses the implications of WHO CNS5 classification in the evaluation of gliomas, as well as historical aspects, the bases of conventional MRI, and advanced MRI sequences useful in current classification.

Effects of RNA demethylase FTO inhibitor on function ofglioblastoma stem cells / 中国药理学通报

Aim To investigate the effect of m6A demethylase FTO inhibitor(FB23-2)on human glioblastoma stem cell activity. Methods The effects of FB23-2 and Temozolomide on GSC were detected by CCK-8 assay and neurosphere formation assay. The effect of FB23-2 on self-renewal of GSC was detected by limited dilution assay in vitro. The effect of FB23-2 on the proliferation of GSC was detected by EdU method. The effect of FB23-2 on apoptosis of glioblastoma stem cells was detected by flow cytometry. Results CCK-8 assay showed that FB23-2 could effectively inhibit the cell viability of GSC with IC50 values of 7.11 μmol·L-1 and 4.63 μmol·L-1,respectively. The size and number of GSC neural sphere in FB23-2 treatment group were significantly reduced compared with control group. In vitro limited dilution experiment showed that FB23-2 effectively inhibited the self-renewal ability of GSC. EdU incorporation experiment showed that compared with the control group,the treatment group decreased to(70.59±13.74)% and(50.33±4.53)%,respectively. The apoptotic rates of the treated group were(12.16±1.90)% and(16.77±1.17)% by flow cytometry. Conclusions FTO inhibitor FB23-2 can effectively inhibit GSC growth,self-renewal and the formation of neural sphere. In addition,FB23-2 can inhibit the proliferation of GSC and induce its apoptosis.

Mechanism of M2 macrophage-derived exosomes in promoting the migration of glioblastoma via transferring miR-1260b / 中国药科大学学报

@#Tumor-associated macrophage promotes the progression of glioblastoma (GBM) by infiltrating into tumor tissue, yet its mechanism has not been fully elucidated.This paper aimed to investigate the mechanism of M2 macrophages in affecting the migratory capacity of GBM via secreting exosomes.Ultracentrifugation was used to extract exosomes; RNA sequencing was carried out to screen differentially expressed miRNAs; target prediction database was used to predict the possible target proteins of miRNA; Dual-luciferase reporter assay was performed to verify the interaction between miRNA and target genes; and the proliferation ability of tumor cells was detected by subcutaneous xenograft model in nude mice.Results showed that tumor-related macrophages were mainly M2 macrophages, and that exosomes secreted by M2 macrophages could promote the migration of glioma cells.Meanwhile, exosomes secreted by M2 macrophages transported miR-1260b and affected the migration of glioma cells through directly targeted AJAP1, suggesting that exosomes secreted by macrophages could affect the migration ability of GBM through transporting miR-1260b.

Effect of Morus alba extract sanggenon C on growth and proliferation of glioblastoma cells / 中国中药杂志

Glioblastoma is the most common primary cranial malignancy, and chemotherapy remains an important tool for its treatment. Sanggenon C(San C), a class of natural flavonoids extracted from Morus plants, is a potential antitumor herbal monomer. In this study, the effect of San C on the growth and proliferation of glioblastoma cells was examined by methyl thiazolyl tetrazolium(MTT) assay and 5-bromodeoxyuridinc(BrdU) labeling assay. The effect of San C on the tumor cell cycle was examined by flow cytometry, and the effect of San C on clone formation and self-renewal ability of tumor cells was examined by soft agar assay. Western blot and bioinformatics analysis were used to investigate the mechanism of the antitumor activity of San C. In the presence of San C, the MTT assay showed that San C significantly inhibited the growth and proliferation of tumor cells in a dose and time-dependent manner. BrdU labeling assay showed that San C significantly attenuated the DNA replication activity in the nucleus of tumor cells. Flow cytometry confirmed that San C blocked the cell cycle of tumor cells in G_0/G_1 phase. The soft agar clone formation assay revealed that San C significantly attenuated the clone formation and self-renewal ability of tumor cells. The gene set enrichment analysis(GSEA) implied that San C inhibited the tumor cell division cycle by affecting the myelocytomatosis viral oncogene(MYC) signaling pathway. Western blot assay revealed that San C inhibited the expression of cyclin through the regulation of the MYC signaling pathway by lysine demethylase 4B(KDM4B), which ultimately inhibited the growth and proliferation of glioblastoma cells and self-renewal. In conclusion, San C exhibits the potential antitumor activity by targeting the KDM4B-MYC axis to inhibit glioblastoma cell growth, proliferation, and self-renewal.

Endocannabinoids are potential inhibitors of glioblastoma multiforme proliferation / 中西医结合学报

Globally, it is evident that glioblastoma multiforme (GBM) is an aggressive malignant cancer with a high mortality rate and no effective treatment options. Glioblastoma is classified as the stage-four progression of a glioma tumor, and its diagnosis results in a shortened life expectancy. Treatment options for GBM include chemotherapy, immunotherapy, surgical intervention, and conventional pharmacotherapy; however, at best, they extend the patient's life by a maximum of 5 years. GBMs are considered incurable due to their high recurrence rate, despite various aggressive therapeutic approaches which can have many serious adverse effects. Ceramides, classified as endocannabinoids, offer a promising novel therapeutic approach for GBM. Endocannabinoids may enhance the apoptosis of GBM cells but have no effect on normal healthy neural cells. Cannabinoids promote atypical protein kinase C, deactivate fatty acid amide hydrolase enzymes, and activate transient receptor potential vanilloid 1 (TRPV1) and TRPV2 to induce pro-apoptotic signaling pathways without increasing endogenous cannabinoids. In previous in vivo studies, endocannabinoids, chemically classified as amide formations of oleic and palmitic acids, have been shown to increase the pro-apoptotic activity of human cancer cells and inhibit cell migration and angiogenesis. This review focuses on the biological synthesis and pharmacology of endogenous cannabinoids for the enhancement of cancer cell apoptosis, which have potential as a novel therapy for GBM. Please cite this article as: Duzan A, Reinken D, McGomery TL, Ferencz N, Plummer JM, Basti MM. Endocannabinoids are potential inhibitors of glioblastoma multiforme proliferation. J Integr Med. 2023; 21(2): 120-128.

Resolving the lineage relationship between malignant cells and vascular cells in glioblastomas

Glioblastoma multiforme (GBM), a highly malignant and heterogeneous brain tumor, contains various types of tumor and non-tumor cells. Whether GBM cells can trans-differentiate into non-neural cell types, including mural cells or endothelial cells (ECs), to support tumor growth and invasion remains controversial. Here we generated two genetic GBM models de novo in immunocompetent mouse brains, mimicking essential pathological and molecular features of human GBMs. Lineage-tracing and transplantation studies demonstrated that, although blood vessels in GBM brains underwent drastic remodeling, evidence of trans-differentiation of GBM cells into vascular cells was barely detected. Intriguingly, GBM cells could promiscuously express markers for mural cells during gliomagenesis. Furthermore, single-cell RNA sequencing showed that patterns of copy number variations (CNVs) of mural cells and ECs were distinct from those of GBM cells, indicating discrete origins of GBM cells and vascular components. Importantly, single-cell CNV analysis of human GBM specimens also suggested that GBM cells and vascular cells are likely separate lineages. Rather than expansion owing to trans-differentiation, vascular cell expanded by proliferation during tumorigenesis. Therefore, cross-lineage trans-differentiation of GBM cells is very unlikely to occur during gliomagenesis. Our findings advance understanding of cell lineage dynamics during gliomagenesis, and have implications for targeted treatment of GBMs.

Hypoxia-induced ROS aggravate tumor progression through HIF-1α-SERPINE1 signaling in glioblastoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Hypoxia, as an important hallmark of the tumor microenvironment, is a major cause of oxidative stress and plays a central role in various malignant tumors, including glioblastoma. Elevated reactive oxygen species (ROS) in a hypoxic microenvironment promote glioblastoma progression; however, the underlying mechanism has not been clarified. Herein, we found that hypoxia promoted ROS production, and the proliferation, migration, and invasion of glioblastoma cells, while this promotion was restrained by ROS scavengers N-acetyl-L-cysteine (NAC) and diphenyleneiodonium chloride (DPI). Hypoxia-induced ROS activated hypoxia-inducible factor-1α (HIF-1α) signaling, which enhanced cell migration and invasion by epithelial-mesenchymal transition (EMT). Furthermore, the induction of serine protease inhibitor family E member 1 (SERPINE1) was ROS-dependent under hypoxia, and HIF-1α mediated SERPINE1 increase induced by ROS via binding to the SERPINE1 promoter region, thereby facilitating glioblastoma migration and invasion. Taken together, our data revealed that hypoxia-induced ROS reinforce the hypoxic adaptation of glioblastoma by driving the HIF-1α-SERPINE1 signaling pathway, and that targeting ROS may be a promising therapeutic strategy for glioblastoma.

The action mechanism of glioblastoma cell-derived exosome: a review / 生物工程学报

Patients with glioblastoma (GBM) generally have a bad prognosis and short overall survival after being treated with surgery, chemotherapy or radiotherapy due to the histological heterogeneity, strong invasive ability and rapid postoperative recurrence of GBM. The components of GBM cell-derived exosome (GBM-exo) can regulate the proliferation and migration of GBM cell via cytokines, miRNAs, DNA molecules and proteins, promote the angiogenesis via angiogenic proteins and non-coding RNAs, mediate tumor immune evasion by targeting immune checkpoints with regulatory factors, proteins and drugs, and reduce drug resistance of GBM cells through non-coding RNAs. GBM-exo is expected to be an important target for the personalized treatment of GBM and a marker for diagnosis and prognosis of this kind of disease. This review summarizes the preparation methods, biological characteristics, functions and molecular mechanisms of GBM-exo on cell proliferation, angiogenesis, immune evasion and drug resistance of GBM to facilitate developing new strategies for the diagnosis and treatment of GBM.

Ferroptosis-related Recurrence Risk Model Predicts Clinical Outcomes and Immune Infiltration in Glioblastoma / 肿瘤防治研究

Objective To construct a ferroptosis-related glioblastoma (GBM) recurrence risk model and evaluate the prognosis of patients. Methods Differentially expressed genes (DEGs) related to ferroptosis in recurrent GBM were screened by CGGA and FerrDb databases. Key genes were obtained by Lasso regression. Then, nomogram was constructed according to the key risk genes, and the prediction efficiency was verified using the TCGA database. GO, KEGG, and GSEA databases were used in exploring the mechanism of prognosis. ESTIMATE and TIMER were used in studying tumor immune infiltration and the expression of immune check points. Results WWTR1, PLIN2, and BID were important prognostic factors for GBM recurrence. The nomogram was constructed according to gender and age, and the observed values were in good agreement with the predicted values. The AUC values were 0.65 (1 year), 0.66 (3 years), and 0.63 (5 years) for CGGA and 0.68 (1 year), 0.76 (3 years), and 0.79 (5 years) for TCGA. Epithelial mesenchymal transition, KRAS pathway, and inflammatory response were significantly upregulated in the high-risk subtypes (P < 0.05). Immune cell infiltration was lower (P < 0.05). Risk score was positively correlated with the expression of immunosuppression check points. Conclusion Ferroptosis-related genes WWTR1, PLIN2, and BID can be used in constructing a nomogram with good predictive performance. These risk genes may affect prognosis through tumor-infiltrating immune cells and immune check points.

Construction and functional analysis of EGFRvIII CAR-T cells co-expressing IL-15 and CCL19 / 生物工程学报

The aim of this study was to investigate the functional characteristics and in vitro specific killing effect of EGFRvIII CAR-T cells co-expressing interleukin-15 and chemokine CCL19, in order to optimize the multiple functions of CAR-T cells and improve the therapeutic effect of CAR-T cells targeting EGFRvIII on glioblastoma (GBM). The recombinant lentivirus plasmid was obtained by genetic engineering, transfected into 293T cells to obtain lentivirus and infected T cells to obtain the fourth generation CAR-T cells targeting EGFRvIII (EGFRvIII-IL-15-CCL19 CAR-T). The expression rate of CAR molecules, proliferation, chemotactic ability, in vitro specific killing ability and anti-apoptotic ability of the fourth and second generation CAR-T cells (EGFRvIII CAR-T) were detected by flow cytometry, cell counter, chemotaxis chamber and apoptosis kit. The results showed that compared with EGFRvIII CAR-T cells, EGFRvIII-IL-15-CCL19 CAR-T cells successfully secreted IL-15 and CCL19, and had stronger proliferation, chemotactic ability and anti-apoptosis ability in vitro (all P < 0.05), while there was no significant difference in killing ability in vitro. Therefore, CAR-T cells targeting EGFRvIII and secreting IL-15 and CCL19 are expected to improve the therapeutic effect of glioblastoma and provide an experimental basis for clinical trials.

The effect and mechanism of Xihuang pill inhibits the formation of vasculogenic mimicry in human glioblastoma cells by down-regulating HIF-1α/VEGFA/VEGFR2 signaling pathway / 药学学报

Our studies were aimed to explore the effect and mechanism of the inhibition of the formation of vasculogenic mimicry (VM) in human glioblastoma cells by Xihuang pill (XHP) medicated serum through regulating the hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor A (VEGFA)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling pathway. The medicated serum of XHP was prepared by gavage for 7 days to male SD rats (approval number of animal experiment ethics: 202105A051). The hypoxia model of U251 cells was established using 200 μmol·L-1 of CoCl2. After treatment with XHP-medicated serum, cell viability and proliferation of U251 cells were detected by CCK-8 and cell cloning experiment. Cell apoptosis and cell cycle of U251 cells were determined by flow cytometry. Cell migration and invasion were evaluated by wound healing and Transwell invasion assay. The formation of VM was assessed by three-dimensional cell culture of U251 cells. The protein expression levels of HIF-1α, VEGFA, VEGFR2, phosphorylated-VEGFR2 (p-VEGFR2), vascular endothelial-cadherin (VE-cadherin), Eph receptor tyrosine kinases A2 (EphA2), matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 14 (MMP14) and laminin γ2 in U251 cells were detected by Western blot. The results showed that 10% XHP-medicated serum had little effect on the cell viability, proliferation, apoptosis and cell cycle of U251 cells under hypoxia. Compared with the model group, 10% XHP-medicated serum at 1.0, 1.5 and 2.0 h significantly decreased the migration rate (P < 0.01) and the number of invading U251 cells (P < 0.01). 10% XHP-medicated serum at 2.0 h significantly suppressed the formation of VM tubular structures in U251 cells under the condition of hypoxia (P < 0.01). Western blot experiment showed that 10% XHP-medicated serum significantly down-regulated the expression of HIF-1α, VEGFA, phospho-VEGFR2, VE-cadherin, EphA2 and MMP14 proteins (P < 0.05). In conclusion, XHP could inhibit the formation of VM in human glioblastoma U251 cells to suppress the angiogenesis by down-regulating the HIF-1α/VEGFA/VEGFR2 signaling pathway.

Preclinical and early clinical studies of a novel compound SYHA1813 that efficiently crosses the blood-brain barrier and exhibits potent activity against glioblastoma

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults and is poorly controlled. Previous studies have shown that both macrophages and angiogenesis play significant roles in GBM progression, and co-targeting of CSF1R and VEGFR is likely to be an effective strategy for GBM treatment. Therefore, this study developed a novel and selective inhibitor of CSF1R and VEGFR, SYHA1813, possessing potent antitumor activity against GBM. SYHA1813 inhibited VEGFR and CSF1R kinase activities with high potency and selectivity and thus blocked the cell viability of HUVECs and macrophages and exhibited anti-angiogenetic effects both in vitro and in vivo. SYHA1813 also displayed potent in vivo antitumor activity against GBM in immune-competent and immune-deficient mouse models, including temozolomide (TMZ) insensitive tumors. Notably, SYHA1813 could penetrate the blood-brain barrier (BBB) and prolong the survival time of mice bearing intracranial GBM xenografts. Moreover, SYHA1813 treatment resulted in a synergistic antitumor efficacy in combination with the PD-1 antibody. As a clinical proof of concept, SYHA1813 achieved confirmed responses in patients with recurrent GBM in an ongoing first-in-human phase I trial. The data of this study support the rationale for an ongoing phase I clinical study (ChiCTR2100045380).

ACAT1 deficiency in myeloid cells promotes glioblastoma progression by enhancing the accumulation of myeloid-derived suppressor cells

Glioblastoma (GBM) is a highly aggressive and lethal brain tumor with an immunosuppressive tumor microenvironment (TME). In this environment, myeloid cells, such as myeloid-derived suppressor cells (MDSCs), play a pivotal role in suppressing antitumor immunity. Lipometabolism is closely related to the function of myeloid cells. Here, our study reports that acetyl-CoA acetyltransferase 1 (ACAT1), the key enzyme of fatty acid oxidation (FAO) and ketogenesis, is significantly downregulated in the MDSCs infiltrated in GBM patients. To investigate the effects of ACAT1 on myeloid cells, we generated mice with myeloid-specific (LyzM-cre) depletion of ACAT1. The results show that these mice exhibited a remarkable accumulation of MDSCs and increased tumor progression both ectopically and orthotopically. The mechanism behind this effect is elevated secretion of C-X-C motif ligand 1 (CXCL1) of macrophages (Mφ). Overall, our findings demonstrate that ACAT1 could serve as a promising drug target for GBM by regulating the function of MDSCs in the TME.

An injectable signal-amplifying device elicits a specific immune response against malignant glioblastoma

Despite exciting achievements with some malignancies, immunotherapy for hypoimmunogenic cancers, especially glioblastoma (GBM), remains a formidable clinical challenge. Poor immunogenicity and deficient immune infiltrates are two major limitations to an effective cancer-specific immune response. Herein, we propose that an injectable signal-amplifying nanocomposite/hydrogel system consisting of granulocyte-macrophage colony-stimulating factor and imiquimod-loaded antigen-capturing nanoparticles can simultaneously amplify the chemotactic signal of antigen-presenting cells and the "danger" signal of GBM. We demonstrated the feasibility of this strategy in two scenarios of GBM. In the first scenario, we showed that this simultaneous amplification system, in conjunction with local chemotherapy, enhanced both the immunogenicity and immune infiltrates in a recurrent GBM model; thus, ultimately making a cold GBM hot and suppressing postoperative relapse. Encouraged by excellent efficacy, we further exploited this signal-amplifying system to improve the efficiency of vaccine lysate in the treatment of refractory multiple GBM, a disease with limited clinical treatment options. In general, this biomaterial-based immune signal amplification system represents a unique approach to restore GBM-specific immunity and may provide a beneficial preliminary treatment for other clinically refractory malignancies.

Brain endothelial cell-derived extracellular vesicles with a mitochondria-targeting photosensitizer effectively treat glioblastoma by hijacking the blood‒brain barrier

Glioblastoma (GBM) is the most aggressive malignant brain tumor and has a high mortality rate. Photodynamic therapy (PDT) has emerged as a promising approach for the treatment of malignant brain tumors. However, the use of PDT for the treatment of GBM has been limited by its low blood‒brain barrier (BBB) permeability and lack of cancer-targeting ability. Herein, brain endothelial cell-derived extracellular vesicles (bEVs) were used as a biocompatible nanoplatform to transport photosensitizers into brain tumors across the BBB. To enhance PDT efficacy, the photosensitizer chlorin e6 (Ce6) was linked to mitochondria-targeting triphenylphosphonium (TPP) and entrapped into bEVs. TPP-conjugated Ce6 (TPP-Ce6) selectively accumulated in the mitochondria, which rendered brain tumor cells more susceptible to reactive oxygen species-induced apoptosis under light irradiation. Moreover, the encapsulation of TPP-Ce6 into bEVs markedly improved the aqueous stability and cellular internalization of TPP-Ce6, leading to significantly enhanced PDT efficacy in U87MG GBM cells. An in vivo biodistribution study using orthotopic GBM-xenografted mice showed that bEVs containing TPP-Ce6 [bEV(TPP-Ce6)] substantially accumulated in brain tumors after BBB penetration via transferrin receptor-mediated transcytosis. As such, bEV(TPP-Ce6)-mediated PDT considerably inhibited the growth of GBM without causing adverse systemic toxicity, suggesting that mitochondria are an effective target for photodynamic GBM therapy.

Research progress on tumor treating fields combined with radiation therapy in the treatment of glioblastoma / 中华放射肿瘤学杂志

For patients with newly diagnosed glioblastoma, tumor treating fields (TTF) combined with temozolomide after radiation therapy is currently one of the standard therapeutic regimens. Recently, TTF has been increasingly applied in combination with radiation therapy since it can delay tumor DNA repair and increase DNA replication stress. The efficacy of TTF has been proven in clinical studies. However, no consensus has been reached regarding the theoretical basis, radiation dose, actual clinical operation, patients' benefit and safety, which remain controversial. In this article, research progress on these topics was reviewed.