U87 Tumor Research Articles

Donor Substitution Engineering of Hemicyanine Nanoparticles to Reprogram the Tumor Microenvironment and Enhance Fn14‐Targeted BiTE for Glioblastoma Photoimmunotherapy

AbstractGlioblastoma (GBM) is a highly malignant intracranial tumor with limited treatment options. Bispecific T‐cell engagers (BiTEs) are being explored for GBM treatment, but their success is hindered by inadequate T cell infiltration and activation due to the acidic and immunosuppressive microenvironment. Photothermal immunotherapy lyses tumors and activates immune responses, complementing BiTEs. This study innovatively employs a donor engineering strategy to develop hemicyanine dyes (Hcys) that emit from near‐infrared (NIR) I to NIR II. The Hcy with excellent properties is encapsulated in an amphiphilic micelle, forming a nano assembly with lactate oxidase (PLH1100). PLH1100 exhibits spectral absorption at 980 nm, a photothermal conversion efficiency of 58.7%, and capability for NIR‐II tumor imaging. Besides photothermal tumor ablation, PLH1100 regulates lactic acid metabolism and activates immunogenic cell death, improving the tumor microenvironment and promoting T cell infiltration and activation. Further studies demonstrate PLH1100 effectively kills human and murine GBM cells, inhibits orthotopic U87 tumor growth in BALB/c‐nu mice, and enhances the efficacy of Fn14‐targeted BiTE in orthotopic GL261 tumors in C57BL/6 mice, achieving a synergistic “1+1>2” therapeutic effect. Collectively, this work opens a new pathway for using Hcy‐based molecules combined with BiTE drugs for GBM therapy, with significant clinical potential.

An enzyme-responsive double-locked amonafide prodrug for the treatment of glioblastoma with minimal side effects.

Amonafide (ANF), a topoisomerase II inhibitor and DNA intercalator, has exhibited promise in phase II trials but faces significant limitations due to adverse side effects. Here, we have developed a novel enzyme-triggered fluorogenic prodrug, AcKLP, that incorporates dual-locked enzyme activation, ensuring that the prodrug remains inactive until it confronts the unique enzymatic environment of glioblastoma cells. This approach minimizes premature activation and reduces toxicity to normal cells, with an IC50 > 100 μM for human umbilical vein endothelial cells (HUVEC) and ∼2.3 μM for human glioblastoma cells (U87). Upon activation of AcKLP by two distinct enzymes prevalent in glioblastoma cells, amonafide is released and emits a fluorescence signal response, facilitating treatment and the monitoring of real-time drug distribution. Mechanistic studies indicate that AcKLP mainly induces autophagic cell death in U87 cells. Moreover, three-dimensional multicellular U87 tumor spheroid assays and in vivo experiments confirm the potent antiproliferative activity of AcKLP against glioblastoma cells. This work demonstrates a novel de-caging strategy to improve the selectivity and efficacy of amonafide for cancer therapy.

TME-Activated MnO2/Pt Nanoplatform of Hydroxyl Radical and Oxygen Generation to Synergistically Promote Radiotherapy and MR Imaging of Glioblastoma.

Radiotherapy (RT) is currently recognized as an important treatment for glioblastoma (GBM), however, it is associated with several challenges. One of these challenges is the radioresistance caused by hypoxia, whereas the other is the low conversion efficiency of the strongly oxidized hydroxyl radical (•OH), which is produced by the decomposition of water due to high-energy X-ray radiation. These factors significantly limit the clinical effectiveness of radiotherapy. To address these limitations, we developed a highly stable and efficient nanoplatform (MnO2/Pt@BSA). Compared to MnO2@BSA, this platform demonstrates high stability, a high yield of oxygen (O2), enhanced production of •OH, and reduced clearance of •OH. The system exhibited increased O2 production in vitro and significantly improved oxygen production efficiency within 100 s at the Pt loading of 38.7%. Furthermore, compared with MnO2, the expression rate of hypoxia-inducible factor (HIF-1α) in glioma cells treated with MnO2/Pt decreased by half. Additionally, the system promotes •OH generation and consumes glutathione (GSH), thereby inhibiting the clearance of •OH and enhancing its therapeutic effect. Moreover, the degradation of the nanoplatform produces Mn2+, which serves as a magnetic resonance imaging (MRI) contrast agent with a T1-weighted enhancement effect at the tumor site. The nanoplatform exhibited excellent biocompatibility and performed multiple functions related to radiotherapy, with simpler components. In U87 tumor bearing mice model, we utilized MnO2/Pt nanocatalysis to enhance the therapeutic effect of radiotherapy on GBM. This approach represents a novel and effective strategy for enhancing radiotherapy in gliomas, thereby advancing the field of catalytic radiotherapy and glioma treatment.

Combined Oxygen-Enhanced MRI and Perfusion Imaging Detect Hypoxia Modification from Banoxantrone and Atovaquone and Track Their Differential Mechanisms of Action.

Oxygen-enhanced MRI (OE-MRI) has shown promise for quantifying and spatially mapping tumor hypoxia, either alone or in combination with perfusion imaging. Previous studies have validated the technique in mouse models and in patients with cancer. Here, we report the first evidence that OE-MRI can track change in tumor oxygenation induced by two drugs designed to modify hypoxia. Mechanism of action of banoxantrone and atovaquone were confirmed using in vitro experiments. Next, in vivo OE-MRI studies were performed in Calu6 and U87 xenograft tumor models, alongside fluorine-18-fluoroazomycin arabinoside PET and immunohistochemistry assays of hypoxia. Neither drug altered tumor size. Banoxantrone reduced OE-MRI hypoxic fraction in Calu6 tumors by 52.5% ± 12.0% (P = 0.008) and in U87 tumors by 29.0% ± 15.8% (P = 0.004) after 3 days treatment. Atovaquone reduced OE-MRI hypoxic fraction in Calu6 tumors by 53.4% ± 15.3% (P = 0.002) after 7 days therapy. PET and immunohistochemistry provided independent validation of the MRI findings. Finally, combined OE-MRI and perfusion imaging showed that hypoxic tissue was converted into necrotic tissue when treated by the hypoxia-activated cytotoxic prodrug banoxantrone, whereas hypoxic tissue became normoxic when treated by atovaquone, an inhibitor of mitochondrial complex III of the electron transport chain. OE-MRI detected and quantified hypoxia reduction induced by two hypoxia-modifying therapies and could distinguish between their differential mechanisms of action. These data support clinical translation of OE-MRI biomarkers in clinical trials of hypoxia-modifying agents to identify patients demonstrating biological response and to optimize treatment timing and scheduling. Significance: For the first time, we show that hypoxic fraction measured by oxygen-enhanced MRI (OE-MRI) detected changes in tumor oxygenation induced by two drugs designed specifically to modify hypoxia. Furthermore, when combined with perfusion imaging, OE-MRI hypoxic volume distinguished the two drug mechanisms of action. This imaging technology has potential to facilitate drug development, enrich clinical trial design, and accelerate clinical translation of novel therapeutics into clinical use.

Magnetic lipid-poly(lactic-co-glycolic acid) nanoparticles conjugated with epidermal growth factor receptor antibody for dual-targeted delivery of CPT-11

To entrap sparingly water-soluble drugs like CPT-11 (irinotecan), the poly(lactic-co-glycolic acid) (PLGA) nanoparticle (NP) is highly favored due to its low cytotoxicity and approval for clinical use. On the other hand, entrapping hydrophobic oleic acid-coated iron oxide magnetic nanoparticles (OMNP) in PLGA NP can provide a nanovehicle for magnetically targeted drug delivery. Our goal in this study is to develop a new dual-targeted magnetic lipid-polymer NP for the delivery of CPT-11. We first co-entrap OMNP and CPT-11 in self-assembled lipid-PLGA NP to prepare OLNP@CPT-11. The OLNP@CPT-11 surface was modified with an epidermal growth factor receptor (EGFR) antibody Cetuximab (CET), which can actively target the overexpressed EGFR on the U87 glioblastoma cell surface. The OLNP-CET@CPT-11 enables dual targeting through both external magnetic guidance and CET-mediated active targeting. The NP was characterized for physicochemical properties using various analytical techniques. In vitro study confirms ligand-receptor interaction results in enhanced endocytosis of OLNP-CET@CPT-11 by U87 cells, which offers increased cytotoxicity and elevated cell apoptosis rates. Furthermore, magnetic guidance of OLNP-CET@CPT-11 to U87 cells can induce cell death exclusively in the magnetically targeted zone. The dual-targeted strategy also provides the best therapeutic efficacy against subcutaneously implanted U87 tumors in nude mice with intravenously delivered OLNP-CET@CPT-11.

Two New Phenylpropanoids and a Polyphenol with Anti-Cervical Cancer Activity from Smilax china L.

Two novel phenylpropanoids (compounds 1 and 2) and 11 known compounds were isolated from Smilax china L. Their structures were determined by NMR (1D and 2D) and high-resolution electrospray ionization mass spectrometry. Further, the cytotoxic activity of all the isolated compounds against HeLa, 4T1, and U251 tumor cells was evaluated using the cell counting kit-8 assay, revealing that compound 13 showed significant cytotoxicity toward HeLa cells. Further investigations explored the impact of compound 13 on the mitochondrial membrane potential, concentration of reactive oxygen species, wound-healing distance, and cell cycle of HeLa cells. Notably, compound 13 significantly decreased mitochondrial membrane potential, suppressed cell migration, and increased intracellular reactive oxygen species levels in HeLa cells. Furthermore, compound 13 inhibited HeLa cell-cycle progression in the S phase. These findings indicate that compound 13 is a potential drug lead for the treatment of cervical cancer.

Changes in perfusion and permeability in glioblastoma model induced by the anti-angiogenic agents cediranib and thalidomide.

The poor delivery of drugs to infiltrating tumor cells contributes to therapeutic failure in glioblastoma. During the early phase of an anti-angiogenic treatment, a remodeling of the tumor vasculature could occur, leading to a more functional vessel network that could enhance drug delivery. However, the restructuration of blood vessels could increase the proportion of normal endothelial cells that could be a barrier for the free diffusion of drugs. The net balance, in favor or not, of a better delivery of compounds during the course of an antiangiogenic treatment remains to be established. This study explored whether cediranib and thalidomide could modulate perfusion and vessel permeability in the brain U87 tumor mouse model. The dynamic evolution of the diffusion of agents outside the tumor core using the fluorescent dye Evans Blue in histology and Gd-DOTA using dynamic contrast-enhanced (DCE)-MRI. CD31 labelling of endothelial cells was used to measure the vascular density. Cediranib and thalidomide effectively reduced tumor size over time. The accessibility of Evans Blue outside the tumor core continuously decreased over time. The vascular density was significantly decreased after treatment while the proportion of normal vessels remained unchanged over time. In contrast to histological studies, DCE-MRI did not tackle any significant change in hemodynamic parameters, in the core or margins of the tumor, whatever the parameter used or the pharmacokinetic model used. While cediranib and thalidomide were effective in decreasing the tumor size, they were ineffective in transiently increasing the delivery of agents in the core and the margins of the tumor.

UBE2D3 regulated by WTAP-mediated m6A modification inhibits temozolomide chemosensitivity in glioblastoma.

To explore how the ubiquitin-conjugating enzyme E2D3 (UBE2D3) influences temozolomide (TMZ) resistance in glioblastoma (GBM), and to clarify the association between UBE2D3 and WTAP. The UBE2D3 protein expression in GBM tissues were detected using immunohistochemistry (IHC) through tissue microarrays. The potential pathways of UBE2D3 in TCGA-GBM were predicted via Gene Set Enrichment Analysis (GSEA). To investigate UBE2D3's role in TMZ resistance, GBM cells were transduced with UBE2D3 shRNA or overexpression lentivirus, followed by assessments of CCK-8, flow cytometry, comet assay, and western blot analysis. Furthermore, a subcutaneous tumor model was established in nude mice using U87 cells transduced with interfering lentivirus to observe tumor growth and assess cell apoptosis using TUNEL staining. Mechanically, m6A content analysis, m6A methylated RNA immunoprecipitation quantitative PCR, reporter gene assay, mRNA stability measurements, RNA immunoprecipitation, quantitative Real-Time PCR, and Western blot assays were carried out to verify the role of WTAP/IGF2BP1 in regulating UBE2D3 expression. UBE2D3 exhibited elevated expression levels in GBM tissues compared with normal brain tissues and was associated with the DNA repair signaling pathway. In both in vitro and in vivo studies, it was demonstrated that TMZ treatment combined with reduced UBE2D3 expression further suppressed U87 cell viability and tumor growth, with a notable increase in apoptosis rate and DNA damage. Conversely, the overexpression of UBE2D3 had the opposite impact. Furthermore, our findings revealed that WTAP promotes the m6A modification of UBE2D3 via an IGF2BP1-dependent mechanism. The WTAP-IGF2BP1 axis regulates UBE2D3 stability in an m6A-dependent manner, influencing tumor malignancy and TMZ chemosensitivity in GBM via the DNA repair signaling pathway.

Auto-loaded TRAIL-exosomes derived from induced neural stem cells for brain cancer therapy

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate of their parental fibroblasts, and TRAIL produced by iNSCs was naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed that Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays demonstrated that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts by approximately 3000-fold compared to treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a novel, easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

Auto-loaded TRAIL-exosomes derived from induced neural stem cells for brain cancer therapy.

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate as their parental fibroblasts, and the TRAIL produced by iNSCs were naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays showed that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts around 3000-fold greater than treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a new easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

Fluorine-18 labeling PEGylated 6-boronotryptophan for PET scanning of mice for assessing the pharmacokinetics for boron neutron capture therapy of brain tumors

Two tryptophan compound classes 5- and 6-borono PEGylated boronotryptophan derivatives have been prepared for assessing their aqueous solubility as formulation of injections for boron neutron capture therapy (BNCT). The PEGylation has improved their aqueous solubility thereby increasing their test concentration in 1 mM without suffering from toxicity. In-vitro uptake assay of PEGylated 5- and 6-boronotryptophan showed that the B-10 concentration can reach 15–50 ppm in U87 cell whereas the uptake in LN229 cell varies. Shorter PEG compound 6-boronotryptophanPEG200[18F] was obtained in 1.7 % radiochemical yield and the PET-derived radioradioactivity percentage in 18 % was taken up by U87 tumor at the limb of xenograft mouse. As high as tumor to normal uptake ratio in 170 (T/N) was obtained while an inferior radioactivity uptake of 3 % and T/N of 8 was observed in LN229 xenografted mouse.

503 Engineering GBM-specific T Cells Using Photothermal Prussian Blue Nanoparticles

INTRODUCTION: Adoptive T cell therapy (ATCT) has successfully treated hematological malignancies and is currently under investigation for solid tumor therapy. In contrast to existing chimeric antigen receptor (CAR) T cell and/or antigen-specific T cell approaches, which target defined antigens, our PBNP-based approach can target a broad repertoire of antigens in GBM in an antigen-agnostic manner. METHODS: We treated GBM cells with PBNP-based photothermal therapy (PBNP-PTT) prior to culturing with dendritic cells (DCs), and subsequent stimulation of T cells. RESULTS: When PBNP-PTT was administered to U87 cells at an immunogenic thermal dose, we effectively expanded U87-specific T cells. DCs cultured ex vivo with PBNP-PTT-treated U87 cells enabled 15- 30-fold expansion of CD4+ and CD8+ T cells. Upon co-culture with target U87 cells, these T cells secreted IFN-G in a specific and dose-dependent manner (up to 647-fold over controls). T cells manufactured using PBNP-PTT elicited specific cytolytic activity against target U87 cells (33-93% killing at an E:T ratio of 20:1), while sparing normal human astrocytes. Similarly, PBNP-PTT on SNB19 cells resulted in a 7-39-fold expansion of T cells, which elicited 25-66% killing of SNB19 cells at an E:T ratio of 20:1. U87-luc cells were then orthotopically inoculated into NSG mice to establish xenograft GBM, and U87-specific T cells developed via PBNP-PTT were intracranially injected. These T cells eliminated U87 tumors in vivo and significantly improved mouse survival compared to mice treated with PBS (p = 0.0047) or non-specific T cells (p = 0.0123) from the same donor. CONCLUSIONS: These findings provide proof-of-concept data supporting the use of PBNP-PTT to stimulate and expand tumor-specific T cells ex vivo for potential use as an ATCT approach for patients with GBM. We are currently using patient-derived tumor samples to generate IND-enabling data.

Phytochemical Characterization, Antioxidant, and Anti-Proliferative Activities of Wild and Cultivated Nigella damascena Species Collected in Sicily (Italy).

The use of Nigella damascena seeds in the culinary field or as aerial parts infusions in the pharmaceutical and cosmetic fields is widely reported. The biological activity of this plant, as demonstrated over the years, is closely related to its phytochemical content. This investigation focused on the comparative study of the same plants of N. damascena, one totally wild (WND), while the other two, one with white flowers (CWND) and the other with blue flowers (CBND), were subject to cultivation, irrigation, and manual weeding. Using the potential of 1D and 2D-NMR spectroscopy, coupled with MS/MS spectrometric studies, the three methanolic extracts of N. damascena were investigated. Chemical studies have highlighted the presence of triterpene saponin compounds and various glycosylated flavonoids. Finally, the in vitro antiproliferative and antioxidant activities of the three individual extracts were evaluated. The antiproliferative activity performed on U-937, HL-60, and MCF-7 tumor cell lines highlighted a greater anticancer effect of the CBND and CWND extracts compared to the data obtained using WND. The antioxidant activity, however, performed to quantify ROS generation is comparable among the extracts used.

Bi2S3/Ti3C2-TPP nano-heterostructures induced by near-infrared for photodynamic therapy combined with photothermal therapy on hypoxic tumors

BackgroundPhotodynamic therapy (PDT) efficacy of bismuth sulfide (Bi2S3) semiconductor has been severely restricted by its electron–hole pairs (e−−h+) separation inefficiency and oxygen (O2) deficiency in tumors, which greatly hinders reactive oxygen species (ROS) generation and further clinical application of Bi2S3 nanoparticles (NPs) in biomedicine.ResultsHerein, novel Bi2S3/titanium carbide (Ti3C2) two-dimensional nano-heterostructures (NHs) are designed to realize multimode PDT of synchronous O2 self-supply and ROS generation combined with highly efficient photothermal tumor elimination for hypoxic tumor therapy. Bi2S3/Ti3C2 NHs were synthesized via the in situ synthesis method starting from Ti3C2 nanosheets (NSs), a classical type of MXene nanostructure. Compared to simple Bi2S3 NPs, Bi2S3/Ti3C2 NHs significantly extend the absorption to the near-infrared (NIR) region and enhance the photocatalytic activity owing to the improved photogenerated carrier separation, where the hole on the valence band (VB) of Bi2S3 can react with water to supply O2 for the electron on the Ti3C2 NSs to generate ·O2− and ·OH through electron transfer. Furthermore, they also achieve 1O2 generation through energy transfer due to O2 self-supply. After the modification of triphenylphosphium bromide (TPP) on Bi2S3/Ti3C2 NHs, systematic in vitro and in vivo evaluations were conducted, revealing that the synergistic-therapeutic outcome of this nanoplatform enables complete eradication of the U251 tumors without recurrence by NIR laser irradiation, and it can be used for computed tomography (CT) imaging because of the strong X-ray attenuation ability.ConclusionThis work expands the phototherapeutic effect of Bi2S3-based nanoplatforms, providing a new strategy for hypoxic tumor theranostics.

Design, synthesis and biological evaluation of Nrf2 modulators for the treatment of glioblastoma multiforme

Glioblastoma multiforme (GBM) is a prevalent primary brain tumor. However, no specific therapeutic drug has been developed for it. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a crucial transcription factor involved in the cellular response to oxidative stress. Numerous studies have demonstrated that Nrf2 plays a pivotal role in GBM angiogenesis, and inhibiting Nrf2 can significantly enhance patient prognosis. Using virtual screening technology, we examined our in-house library and identified pinosylvin as a potential compound with high activity. Pinosylvin exhibited robust hydrogen bond and Π-Π interaction with Nrf2. Cell experiments revealed that pinosylvin effectively reduced the proliferation of U87 tumor cells by regulating Nrf2 and demonstrated greater inhibitory activity than temozolomide. Consequently, we believe that this study will offer valuable guidance for the future development of highly efficient therapeutic drugs for GBM.

The Delivery of Mimic miRNA-7 into Glioblastoma Cells and Tumour Tissue by Graphene Oxide Nanosystems.

The use of nanotechnology in medicine has gained attention in developing drug delivery systems. GO has the potential to deliver microRNA (miRNA) mimics or antisense structures. MiRNAs regulate gene expression and their dysregulation is implicated in diseases, including cancer. This study aims to observe changes in morphology, viability, mRNA expression of mTOR/PI3K/Akt and PTEN genes in U87, U118, U251, A172 and T98 glioblastoma cells and xenograft models after GO self-assembly with mimic miRNA-7. Colloidal suspension of graphene oxide (GO) was used for obtaining the GO-mimic miRNA-7 nanosystems by self-assembly method. The ultrastructure, size distribution and ATR-FTIR and UV-Vis spectrum were analyzed. The Zeta potential was measured to verify the stability of obtained nanosystem. The entrapment efficiency, loading capacity and released kinetics of mimic miRNA-7 form GO-mimic miRNA-7 nanosystems were analyzed. The transfection efficiency into the glioblastoma cell lines U87, U118, U251, A172 and T98 of mimic miRNA-7 delivered by GO nanosystems was measure by confocal microscopy and flow cytometry. The changes at mRNA expression level of mTOR, PI3K, AKT1 and PTEN genes was measured by qPCR analysis. The xenograft model of U87 and A172 tumour tissue was performed to analyze the effect at tumor size and volume after GO- mimic miRNA-7 nanosystem administration. The ultrastructure of GO-mimic miRNA-7 nanosystems showed high affinity of mimic miRNA into the GO. The results of transfection efficiency, cell morphology and viability showed that GO -miRNA-7 effectively deliver mimics miRNA-7 into U87, U118, U251, A172 and T98 glioblastoma cells. This approach can reverse miRNA-7 expression's downstream effects and target the mTOR PI3K/Akt pathway observed at gene expression level, reducing xenograft tumour size and volume. The findings of the study could have significant implications for the development of advanced and precise GO based nanosystems specifically designed for miRNA therapy in cancer treatment.

Photothermal Prussian blue nanoparticles generate potent multi-targeted tumor-specific T cells as an adoptive cell therapy.

Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) is an effective tumor treatment capable of eliciting an antitumor immune response. Motivated by the ability of PBNP-PTT to potentiate endogenous immune responses, we recently demonstrated that PBNP-PTT could be used ex vivo to generate tumor-specific T cells against glioblastoma (GBM) cell lines as an adoptive T cell therapy (ATCT). In this study, we further developed this promising T cell development platform. First, we assessed the phenotype and function of T cells generated using PBNP-PTT. We observed that PBNP-PTT facilitated CD8+ T cell expansion from healthy donor PBMCs that secreted IFNγ and TNFα and upregulated CD107a in response to engagement with target U87 cells, suggesting specific antitumor T cell activation and degranulation. Further, CD8+ effector and effector memory T cell populations significantly expanded after co-culture with U87 cells, consistent with tumor-specific effector responses. In orthotopically implanted U87 GBM tumors in vivo, PBNP-PTT-derived T cells effectively reduced U87 tumor growth and generated long-term survival in >80% of tumor-bearing mice by Day 100, compared to 0% of mice treated with PBS, non-specific T cells, or T cells expanded from lysed U87 cells, demonstrating an enhanced antitumor efficacy of this ATCT platform. Finally, we tested the generalizability of our approach by generating T cells targeting medulloblastoma (D556), breast cancer (MDA-MB-231), neuroblastoma (SH-SY5Y), and acute monocytic leukemia (THP-1) cell lines. The resulting T cells secreted IFNγ and exerted increased tumor-specific cytolytic function relative to controls, demonstrating the versatility of PBNP-PTT in generating tumor-specific T cells for ATCT.

Evaluation of the effects of simulated hypoxia by CoCl2 on radioresistance and change of hypoxia-inducible factors in human glioblastoma U87 tumor cell line

PurposeGlioblastoma (GBM) is considered the most common and lethal type of brain tumor with a poor prognosis. GBM treatment has challenges due to its aggressive nature, which often causes treatment failure and recurrence. Hypoxia is one of the characteristics of glioblastoma tumors that contribute to radioresistance and malignant phenotypes of GBM. In this study, we aimed to determine the effects of hypoxia on the radiosensitivity of U87 GBM cells by the hypoxia-mimicking model. MethodsFollowing the treatment of cells with different concentrations of CoCl2, an MTT assay was used to evaluate the cytotoxicity of CoCl2. To understand the effects of Ionizing radiation on CoCl2-treated groups, cells were exposed to irradiation after pretreating with 100 μM CoCl2, and a clonogenic survival assay was performed to determine the radiosensitivity of U87 cells. Also, the intracellular Reactive oxygen level was measured by 2′,7′–dichlorofluorescein diacetate (DCFDA) probe staining. Additionally, the expression of hypoxia-associated genes, including HIF-1α, HIF-2α, and their target genes (GLUT-1), was monitored by reverse transcription polymerase chain reaction (RT-PCR). ResultsOur study revealed that the cell viability of CoCl2-treated cells was decreased in a concentration-dependent manner. Also, CoCl2 did not cause any cytotoxicity on U87 cells at a concentration of 100 μM after treatment for 24 h. Colony formation assay showed that CoCl2 pretreatment induced radioresistance of tumor cells compared to non-treated cells. Also, CoCl2 can protect cells against irradiation by the clearance of ROS. Moreover, Real-time results showed that the mRNA expression of HIF-1α and GLUT-1 were significantly upregulated following hypoxia induction and/or irradiation condition. However, the level of HIF-2α mRNA did not change significantly in hypoxia or irradiation alone conditions, but it increased significantly only in hypoxia + irradiation conditions. ConclusionTaken together, our results indicated that simulating hypoxia by CoCl2 can effectively increase hypoxia-associated genes, specially HIF-1α and GLUT-1, but did not affect HIF-2α gene expression. Also, it can increase the clearance of ROS, respectively, and it leads to inducing radioresistance of U87 cells.

NIMG-19. TUMOR PARAMETERS AFFECTED BY NANOCOMBRESTATIN THERAPY IN AN EXPERIMENTAL RAT MODEL OF GLIOMA

Abstract INTRODUCTION: of polymeric nanoparticles in cancer therapeutics is widely investigated since nanomedicine often enables the intratumoral delivery of drugs with increased efficacy with minimal side effects. In this study magnetic resonance imaging (MRI) monitoring was employed to study the therapeutic effect of nanocombretastatin (G3-CA4) in an orthotopic glioma model. Water insoluble combretastatin (CA4) was conjugated to a small-sized water soluble G3-succinimic acid PAMAM dendrimer. Tumor growth and vascular parameters were assessed non-invasively using MRI. In the brain, intravenously (iv) administered magnetic resonance (MR) contrast agents (CAs) can be used to measure the biomarkers of tumor perfusion - the blood-to-brain transvascular transfer constant (K-trans), tumor plasma volume (Vp), the extravascular extracellular space (Ve) and the blood volume (VD) in cerebral tumors. K-trans, Vp, Ve and VD showed the discrimination of tumorous vasculature responding to CA4 and G3-CA4 therapies from tumorous tissues. The average K-trans, Vp, Ve and VD decreased significantly 24 hours after G3-CA4 treatment. The results showed that G3-CA4 caused a change in tumor vasculature as measured with DCE-MRI. These effects were homogenous throughout the U-251 tumor. However, CA4 did not show any change in tumor vasculature. Imaging, histological and molecular signatures of the primary glioblastoma were compared. Large necrotic area was found together with destroyed blood vessels at the core of the tumor leaving viable tissue at the rim of the tumor. In vivo studies proved that the cytotoxicity of G3-CA4 conjugate was more effective against human U-251 tumor while CA4 alone was ineffective. Therefore, we have accomplished the effective transvascular delivery of G3-CA4 into human U251 glioma tumor with a compromised blood brain tumor barrier. In vivo studies proved that the cytotoxicity of G3-CA4 conjugate is more effective against human U-251 tumor than that of free CA4.

EXTH-67. LP-184, AN MGMT-AGNOSTIC SMALL MOLECULE, HAS POTENT SYNERGY WITH SPIRONOLACTONE TO EFFECTIVELY INHIBIT ORTHOTOPIC GBM XENOGRAFT TUMORS

Abstract Temozolomide (TMZ) is currently the most effective standard-of-care chemotherapy based on its ability to extend survival of patients with newly diagnosed MGMT-methylated glioblastoma (GBM). Blood-brain barrier (BBB) permeable agents effective against TMZ-resistant GBMs (i.e. recurrent GBM, MGMT-unmethylated GBM) are needed. Lantern Pharma is advancing LP-184, an acylfulvene prodrug activated by the enzyme PTGR1. In MGMT-expressing TMZ-resistant GBM cultures, LP-184 was found to be ~5000X more potent than TMZ with LP-184 IC50s ranging from 20-200 nM. DNA damage induced by acylfulvenes is primarily repaired via transcription-coupled nucleotide excision repair (TC-NER) mediated by ERCC complexes. ERCC3 is proteolytically degraded in response to the FDA approved BBB permeable diuretic, spironolactone (SP). We found that SP induces rapid ERCC3 degradation by up to 95% in GBM cells and validated that SP-induced ERCC3 loss led to substantial increases in LP-184 responses (DNA damage, tumor cell death) in vitro and in subcutaneous (s.c.) tumor xenografts. Co-treatment of GBM cells with LP-184 and SP resulted in a 3-6 fold decrease in LP-184 IC50s in PDX-derived (M1123 and Mayo39) and cell line (U87) cultures in vitro. Systemic SP sensitized pre-established s.c. and orthotopic (i.c.) GBM xenografts to LP-184 therapy. Pre-established s.c. U87 tumors recurred after initial regression in 5/5 animals following treatment with LP-184 alone whereas tumors showed durable complete regression without recurrence in 4/5 animals following treatment with LP-184 + SP. Pre-established M1123 i.c. xenografts treated with LP-184 + SP were ~3-fold smaller than those treated with LP-184 alone. LP-184 is a promising agent with potential clinical translation in GBM patients. Our results indicate that LP-184 is MGMT-agnostic and effective in TMZ-resistant preclinical GBM models. The first-in-human LP-184 dose escalation Phase 1A trial enrolling solid tumor patients including GBM is planned to launch Q3 2023.