Tumor Cell Lines Research Articles

Response to systemic therapies in patient-derived cell lines from primary and recurrent adult granulosa cell tumors.

In patients with the rare adult-type granulosa cell tumors (aGCT), surgery is the primary treatment for both primary and recurrent disease. In cases of inoperable disease, systematic therapy is administered, but variable response rates and drug resistance complicate predicting the most effective therapy. Drug screen testing on patient-derived cell lines may offer a solution. In a national prospective study on aGCT, fresh tissue was cultured into 2D cell lines, testing 27 clinically and experimental drugs. Dose-response curves and synergy were calculated using GraphPad Prism and Compusyn software. We established 34 patient-derived cell lines from tissue of 20 adult granulosa cell tumor patients. Of these, seven patients had a primary diagnosis of adult granulosa cell tumor and 13 patients had recurrent disease. In eight patients multiple tumor locations were cultured. On each cell line 10 monotherapies and 17 combinations of drugs were tested. Carboplatin/gemcitabine showed efficacy and synergy in almost all patient-derived cell lines. Synergy could not be detected in the regular carboplatin/paclitaxel and carboplatin/etoposide combinations. Experimental combinations alpelisib/fulvestrant and alpelisib/gemcitabine showed efficacy of more than 75%. Drug screens on patient-derived tumor cell lines reflects the reality of the variable response of systemic therapy in aGCT patients. In future research, this technique may be used to personalize the systemic treatment of aGCT patients in a clinical study. The good response to carboplatin/gemcitabine in our patient-derived cell lines can then be confirmed in a clinical setting.

Therapeutic Potential of Solenopsis invicta Venom: A Scoping Review of Its Bioactive Molecules, Biological Aspects, and Health Applications

Solenopsis invicta, a South American ant species from the Formicidae family (subfamily Myrmicinae), has recently established a stable settlement in Europe, raising public health concerns due to its venomous stings. The venom of S. invicta is rich in bioactive molecules, particularly piperidine alkaloids such as solenopsin A and peptides (Sol 1–4). These compounds have been implicated in various health applications, including antimicrobial, anti-inflammatory, and antitumour activities. While previous reviews have focused on the ecological and allergenic risks posed by S. invicta, this scoping review aims to evaluate the potential therapeutic uses of S. invicta venom by summarizing existing scientific evidence and providing a novel synthesis of recent research on its bioactive components. Furthermore, this study, by describing the unique biological aspects of S. invicta, provides an overview of its direct impact on public health, highlighting new findings on the venom’s role in inhibiting bacterial biofilm formation and modulating cancer growth pathways through gene regulation. A search of databases (PubMed, Scopus, Science Direct, and Cochrane Library) identified 12,340 articles, from which 11 studies met the eligibility criteria. These studies included seven microbiological investigations and four studies on tumour cell lines and animal models. The findings suggest that S. invicta venom could inhibit biofilm formation, combat fungal infections, and suppress tumour growth. However, further research, including clinical trials, is required to fully elucidate the safety and efficacy of these bioactive molecules in human medicine, for their potential use in drug discovery to counteract several diseases, including cancer.

LncRNA H19 Activates the RAS-MAPK Signaling Pathway via miR-140-5p/SOS1 Axis in Malignant Liver Tumors.

To study the influences of LncRNA H19 (H19) on malignant liver tumor cells and elucidate the underlying molecular mechanisms. H19 expression in liver tumor tissues, matched normal liver tissues, human liver malignant tumor cell lines and the human hepatocyte line LO2 was assessed via quantitative RT-PCR. Cell viability analysis and Matrigel invasion analysis were performed to evaluate the effects of H19 on cell proliferation and invasion. Luciferase reporter analysis was carried out to assess the interaction between miR-140-5p and SOS Ras/Rac guanine nucleotide exchange factor 1 (SOS1). The influence of H19 on the Ras-MAPK signalling pathway was evaluated by detecting key protein levels via active Ras pull-down analysis and Western blot analysis. H19 expression was lower in liver cancer samples than in matched normal liver tissue samples. H19 overexpression enhanced the proliferation and invasion of HepG2 and SMMC-7721 cells. H19 overexpression increased the level of activated Ras. The expression levels of phosphorylated Raf, phosphorylated ERK and phosphorylated MEK were increased by H19 overexpression. H19 knockdown had the opposite effect. Treatment with a MAPK inhibitor significantly reversed the influence of H19 overexpression on liver malignant tumor cell growth and invasion. The MAPK activator reversed the opposing effects of H19 silencing. H19 overexpression increased the protein level of SOS1, and miR-140-5p directly targeted SOS1. H19 can activate the Ras-MAPK signalling pathway via the miR-140-5p/SOS1 axis in malignant liver tumour cells.

Drug repurposing of fluoroquinolones as anticancer agents in 2023.

Drug developers are currently focusing on investigating alternative strategies, such as "drug repositioning", to address issues associated with productivity, regulatory obstacles, and the steadily rising cost of pharmaceuticals. Repositioning is the best strategy to stop searching for new drugs because it takes less time and money to investigate new indications for already approved or unsuccessful drugs. Although there are several potent Topo II inhibitors available on the market as important drugs used in the therapy of many types of cancer, more may be required in the future. The current inhibitors have drawbacks including acquired resistance and unfavorable side effects such as cardiotoxicity and subsequent malignancy. A substantial body of research documented the cytotoxic potential of experimental fluoroquinolones (FQs) on tumor cell lines and their remarkable efficacy against eukaryotic Topo II in addition to optimized physical and metabolic characteristics. The FQ scaffold has a unique ability to potentially resolve every major issue associated with traditional Topo II inhibitors while maintaining a highly desirable profile in crucial drug-likeness parameters; therefore, there is a significant chance that FQs will be repositioned as anticancer candidates. This review offers a summary of the most recent research on the anticancer potential of FQs that was published in 2023. Along with discussing structural activity relationship studies and the mechanism underlying their antiproliferative activity, this review aims to provide up-to-date information that will spur the development of more potent FQs as viable cancer treatment candidates.

Cage Architecture and Reactivity are Preserved in Cysteine‐Mutated Ferritin

AbstractThe role of solvent‐exposed cysteines as reactive sites for bioconjugation with a variety of metal drugs or fluorescent probes is emerging in the use of human H‐ferritin (HuHf) as a nanocarrier for targeting various tumor cell lines. Here, we have investigated the role of these residues in controlling the structural stability and ferroxidase activity by analyzing the properties of three variants: C90A, C90AC102A, and C130A. Protein folding and cage assembly were unchanged. Ferroxidase activity was also unaffected, indicating that these cysteines are not involved in either the catalytic activity or the overall iron(II) uptake process. For comparison, activity measurements were also performed on two derivatives involving the solvent‐exposed cysteine residues.

Hsa_circ_0088036 promotes tumorigenesis and chemotherapy resistance in hepatocellular carcinoma via the miR-140-3p/KIF2A axis.

Hepatocellular carcinoma (HCC) is a cancer with high morbidity and mortality. There are limited treatment options, particularly for chemotherapy-resistant HCC patients. Circular RNA hsa_circ_0088036 was associated with the development of bladder cancer and non-small cell lung cancer. However, whether it might be a potential therapeutic target for HCC remains elusive. Hsa_circ_0088036 expression was detected in HCC tumor tissues and cell lines using real-time PCR. The influences of hsa_circ_0088036 on proliferation and invasion as well as chemotherapy sensitivity in HCC cells were investigated by gain- and loss-of-function analyses. Associations among hsa_circ_0088036, miR-140-3p, and KIF2A were validated by real-time PCR, miRNA pull-down assay, dual-luciferase reporter assay, and western blot. Furthermore, a rescue experiment using KIF2A overexpression was performed to evaluate the regulatory mechanism of hsa_circ_0088036 in HCC cells. Additionally, the effect and mechanism of hsa_circ_0088036 were confirmed in a xenograft mouse model. Hsa_circ_0088036 was highly expressed in HCC tissues and cells, with even higher expression in oxaliplatin-resistant cells. This expression was positively correlated with tumor size and TNM stage of the patients. Overexpression of hsa_circ_0088036 promoted the proliferation and invasion of HCC cells, while silencing mediated the opposite effects. Meanwhile, knockdown of hsa_circ_0088036 enhanced chemotherapy sensitivity, including oxaliplatin, doxorubicin, and sorafenib, in HCC cells. Furthermore, hsa_circ_0088036 silencing inhibited tumor growth and increased oxaliplatin sensitivity in vivo. Mechanically, hsa_circ_0088036 functioned via the miR-140-3p/KIF2A axis with the activation of PI3K/Akt and Notch signaling pathways. Hsa_circ_0088036 promoted HCC tumorigenesis and chemotherapy resistance by activating the PI3K/Akt and Notch pathways through regulating miR-140-3p/KIF2A signaling. Thus, hsa_circ_0088036 may be a potential therapeutic target in chemotherapy-resistant HCC.

Efficient Biomarker for Immunotherapy: Measuring Broad Clones Effector Tumor Antigen-Specific T Cells in the Blood of Esophageal Cancer Patients.

Cancer is the result of the interactions between tumor cells and tumor-specific immune responses. The current biomarkers detect tumor cells' properties, but accurate measurement of tumor-specific immunity is lacking. Most immunotherapies work by activating new effector tumor antigen-specific T cells (ETASTs) or reactivating pre-existing ETASTs' repertoire. The responses to immunotherapy depend on the increase of ETASTs. The amount of ETASTs, especially in blood, is critical for therapeutic efficacy. Distinguishing ETASTs from other T cells by their structural characteristics is difficult. Therefore, nanoparticles loading whole tumor antigens are utilized to activate broad clones ETASTs pre-existing in peripheral blood, followed by detecting them. Thus, the differences between ETASTs and other T cells are transformed to the differences between activated states and unactivated states. By measuring the markers of activated states and cytotoxic functions, we can distinguish ETASTs from other T cells. Nanoparticles loading mixed multiple allogeneic tumor tissue lysates or mixed multiple tumor cell lines can be utilized as universal nanoparticles to replace nanoparticles loading personalized tumor tissue. ETASTs (TATAN-activated CD8+IFN-γ+) in esophageal cancer patients are more than those in healthy people. Measurement of the ETASTs in the blood of esophageal cancer patients before and after ongoing therapy showed that ETATSs increased in the blood of patients who were responsive to immunotherapy but did not increase in the blood of nonresponders. These illustrated that therapeutic efficacy was positively correlated with the level of ETASTs in PBMC. Altogether, this study provides us a highly accurate and specific biomarker for predicting the therapeutic efficacy of cancer immunotherapy and potentially other therapies, such as radiotherapy.

Increased cell killing effect in neutron capture enhanced proton beam therapy

Thermal neutrons generated in the body during proton beam therapy (PBT) can be used to cause boron neutron capture reactions and have recently been proposed as neutron capture enhanced PBT (NCEPBT). However, the cell killing effect of NCEPBT remains underexplored. Here, we show an increase in the cell killing effect of NCEPBT. Using Monte Carlo simulations, we showed that neutrons generated by proton beam irradiation are uniformly spread on tissue culture plates. Human salivary gland tumor cell line (HSG), human osteosarcoma cell line (MG63), human tongue squamous cell carcinoma cell line (SAS), and human malignant melanoma cell line (G-361) were irradiated with X-rays, proton beams, and proton beams with 10B-enriched boronophenylalanine (boron concentration of 20 and 80 ppm). The relative biological effectiveness (RBE) values of proton beams alone, proton beams with 20 ppm boron, and proton beams with 80 ppm boron for HSG, MG63, SAS, and G-361 were 1.02, 1.07, and 1.23; 1.01, 1.08, and 1.44; 1.05, 1.09, and 1.46; and 1.04, 1.13, and 1.63, respectively. NCEPBT with high boron concentration showed high RBE and a high sensitizing effect. Our results confirm an increase in the cell killing effect of NCEPBT, should aid in its clinical use, and warrant its further investigation.

Abstract B015: Targeting CX3CL1 transforms a cold tumor microenvironment into a hot one by enhancing T cells and DCs locally and systemically

Abstract Intratumoral heterogeneity (ITH) is associated with immunotherapy failure and a weaker anti- tumor immune response. Using a series of carcinogen-induced tumor (CIT) squamous cell skin carcinoma cell lines, our lab has sought to identify tumor-intrinsic factors—particularly chemokines and cytokines—which can have a “dominant negative” effect on the immune microenvironment when present within a heterogeneous tumor. We identified CX3CL1 as a one such critical mediator of a cold (T cell low) immune microenvironment and found that tumors containing as few as 10% CX3CL1high tumor cells exhibit a diminished T cell response compared to tumors which lack CX3CL1high tumor cells. We predicted that targeting CX3CL1 could therefore transform a cold tumor microenvironment (TME) into an inflammatory hot (T cell high) TME. Supporting this, we found that CRISPR-Cas9-mediated deletion of CX3CL1 in a tumor cell line that typically gives rise to cold tumors led to higher T cell infiltration and fewer immunosuppressive macrophages in the TME of CX3CL1-/- tumors. Building on this, we further explored T cell populations in the TME and found that CX3CL1-/- tumors had significantly increased activation and decreased exhaustion markers on T cells. Flow cytometry analysis showed higher expression of CD44 on effector CD4 T cells and an increase in the number of activated CD44+ PD1low CD4 T cells. By contrast, the frequency of CD4 T cells which were PD1High TIM3+ and PD1High TIM3+ TIGIT+ which represent a likely exhausted effector CD4 population was lower in CX3CL1-/- tumors than in counterpart control tumors. An interrogation of DC subsets in the TME further revealed a higher number of cDC1 and cDC2 populations in CX3CL1−/− tumors. To determine the effect of tumor-produced CX3CL1 on immune activity in lymphoid organs, we investigated T cell and DC markers in the spleen and tumor-draining lymph nodes during early tumor development. Spleens harvested 10 days after tumor injection showed higher infiltration of cDC1 CCR7+ and cDC2 CCR7+ mature DCs in CX3CL1-/- tumor-bearing mice. Thus, in the absence of tumor-produced CX3CL1, both cDC1 and cDC2 dendritic cell subsets attain more mature phenotypes in both the TME and the spleen. At the same time point, tumor-draining lymph nodes also exhibited a shift in immune cell composition characterized by an increased frequency of T cells, particularly CD4+ T cells, and a decreased frequency of B cells. Moreover, the percentage of PD1+ CD8 cells was also higher, indicating better priming and activation of CD8 T cells via DCs in tumor-draining lymph nodes. These findings indicate that tumor-produced CX3CL1 drives a cold immune microenvironment through both tumor-localized and systemic effects. These studies suggest therapeutically targeting CX3CL1 particularly in tumors where tumor cells produce high levels of CX3CL1 holds promise to transform a cold TME into a hot immune inflammatory TME and potentiate better anti-tumor immunity. Citation Format: Piyush Chaudhary, Savannah Hughes, Joshua Tay, Robert Letchworth, Miho Tanaka, Melissa Reeves. Targeting CX3CL1 transforms a cold tumor microenvironment into a hot one by enhancing T cells and DCs locally and systemically [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B015.

Targeting mitochondrial metabolism by the mitotoxin bromoxib in leukemia and lymphoma cells

Targeting mitochondrial metabolism represents a promising approach for cancer treatment. Here, we investigated the mitotoxic potential of the polybrominated diphenyl ether bromoxib, a natural compound isolated from the marine sponge Dysidea family. We could show that bromoxib comprised strong cytotoxicity in different leukemia and lymphoma cell lines (such as HL60, HPBALL, Jurkat, K562, KOPTK1, MOLT4, SUPB15 and Ramos), but also in solid tumor cell lines (such as glioblastoma cell lines SJ-GBM2 and TP365MG). Bromoxib activated the mitochondrial death pathway as evidenced by the rapid translocation of Bax to the mitochondria and the subsequent mitochondrial release of Smac. Accordingly, bromoxib-induced apoptosis was blocked in caspase 9 deficient Jurkat cells and Jurkat cells overexpressing the antiapoptotic protein Bcl-2. In addition, we could show that bromoxib functioned as an uncoupler of the electron transport chain with similar rapid kinetics as CCCP in terms of dissipation of the mitochondrial membrane potential (ΔΨm), processing of the dynamin-like GTPase OPA1 and subsequent fragmentation of mitochondria. Beyond that, bromoxib strongly abrogated ATP production via glycolysis as well as oxidative phosphorylation (OXPHOS) by targeting electron transport chain complexes II, III, and V (ATP-synthase) in Ramos lymphoma cells. Thus, bromoxib’s potential to act on both cytosolic glycolysis and mitochondrial respiration renders it a promising agent for the treatment of leukemia and lymphoma.

Targeting the Tumour Antigen 5T4 using CAR-T Cells for the Treatment of Acute Myeloid Leukaemia.

Chimeric antigen receptor (CAR) T cells represent a novel targeted approach to overcome deficits in the ability of the host immune system to detect and eradicate tumours. 5T4 is a tumour-associated antigen expressed on the cell surface of most solid tumours. However, very little is known about its expression in haematological malignancies. Herein, we assess the expression of 5T4 in different types of leukaemias, specifically Acute Myeloid Leukaemia (AML), and normal haematopoietic stem cells (HSCs). We also provide an in vitro assessment of safety and efficacy of 5T4-targeting CAR-T cells against HSCs and AML tumour cell lines. 5T4 expression was seen in about 50% of AML cases, specifically AML with mutated NPM1, AML-MR and NOS. 5T4 CAR-T cells efficiently and specifically killed AML tumour cell lines, including the Leukaemic Stem Cells. Co-culture of 5T4 CAR-T cells with HSCs from healthy donors showed no impact on subsequent colony formation, thus confirming the safety profile of 5T4. A murine model for AML demonstrated that CAR-T cells recognise and kill in vivo 5T4-expressing tumour cells. These results highlight 5T4 as a promising target for immune intervention in AML and that CAR-T cells can be considered a powerful personalised therapeutic approach to treat AML.

TMOD-34. GENERATION OF BRAIN-VESSEL-GBM ASSEMBLOIDS USING PATIENT-DERIVED GLIOBLASTOMA TISSUE

Abstract Glioblastoma (GBM) is the most common malignant brain tumor of the central nervous system and has a significantly low survival rate of approximately 15 months. Current preclinical GBM models are limited by the lack of a normal human microenvironment and the inability of many tumor cell lines to accurately reproduce GBM biology. To address these limitations, we describe a detailed procedure to generate brain-vessel- GBM assembloids, which are fusions of glioblastoma organoids (GBOs) from resected patient tumor tissue and cerebral and vessel organoids derived from human pluripotent stem cells. The proposed methodology will be used to detect and treat brain tumors, which will enable personalized treatment for brain tumor diseases. By universalizing the methodology we present, we aim to encourage other scientists to further develop existing models for studying these lethal tumors.

DDDR-47. TARGETING HTR2B SUPPRESSES NON-FUNCTIONING PITUITARY ADENOMA GROWTH AND SENSITIZES CABERGOLINE TREATMENT VIAINHIBITING GΑQ/PLC/PKCΓ/STAT3 AXIS

Abstract BACKGROUND Managing non-functioning pituitary adenomas (NFPAs) is difficult due to limited drug treatments. Cabergoline’s (CAB) effectiveness for NFPAs is debated. This study explores the role of HTR2B in NFPAs and its therapeutic potential. METHODS We conducted screening of bulk RNA-sequencing data to analyze HTR2B expression levels in NFPA samples. In vitro and in vivo experiments were performed to evaluate the effects of HTR2B modulation on tumor growth and cell cycle regulation. Mechanistic insights into the HTR2B-mediated signaling pathway were elucidated using pharmacological inhibitors and molecular interaction assays. RESULTS Elevated HTR2B expression was detected in NFPA samples, which was associated with increased tumor survival. Inhibition of HTR2B activity resulted in the suppression of tumor growth through modulation of the G2M cell cycle. The inhibition of HTR2B with PRX-08066 was found to block STAT3 phosphorylation and nuclear translocation by interfering with the Gαq/PLC/PKC pathway. A direct interaction between PKC-γ and STAT3 was critical for STAT3 activation. CAB was shown to activate pSTAT3 via HTR2B, reducing its therapeutic potential. However, the combination of an HTR2B antagonist with CAB significantly inhibited tumor cell proliferation in HTR2B-expressing pituitary tumor cell lines, a xenografted pituitary tumor model, and patient-derived samples. Analysis of patient-derived data indicated that a distinct molecular pattern characterized by upregulated HTR2B/PKC-γ and downregulated BTG2/GADD45A may benefit from combination treatment with CAB and PRX-08066.

SURG-58. COLD ATMOSPHERIC PLASMA (CAP) CAUSES SELECTIVE TUMOR CELL DEATH VIA APOPTOSIS AND FERROPTOSIS IN MALIGNANT GLIOMA CELLS

Abstract BACKGROUND High-grade gliomas (HGGs) are primary brain tumors associated with significant morbidity and mortality, and despite advances in neuro-oncology, the prognosis remains poor. Cold atmospheric plasma, a novel experimental anti-cancer therapeutic tool, is a near-room temperature ionized gas generated at atmospheric pressure. It has many promising results in vitro and in vivo with a variety of cancers. CAP cytotoxicity appears to be selective to cancer cells without significant damage to surrounding healthy tissues. We aim to evaluate the efficacy of CAP in generating tumor-selective cytotoxicity against high-grade glioma. METHODS B16, U87, GL261, patient derived high grade glioma, human neural stem cells (LM-NSC008) and astrocytes (NHA hTERT) were treated with CAP. Proliferation and propidium iodide (PI)/annexin V flow cytometry assays were employed to quantify cytotoxicity, cell cycle phases and apoptosis. Cells were pre-treated with ferroptosis inhibitors Ferrostatin-1 and Deferoxamine (DFO) in rescue assays. Cerebral organoids were transplanted with fluorescent tumor cell lines and stained with cleaved caspase-3, ki67 and transferrin receptor. RESULTS CAP induces dose dependent cell death in all glioma cell lines tested. CAP induces an accumulation of intracellular ROS, most prominent in glioma cells. CAP-mediated cell death involves apoptosis and ferroptosis. CAP selectively leads to apoptosis in tumor implanted organoids and leads to decreased proliferation in malignant and non-malignant cells. CAP leads to a shift into G0 phase of all treated cells, malignant and non-malignant. CONCLUSIONS CAP treatment induces dose-dependent increases in ROS and apoptosis in HGG lines tested more significantly than in NHAs and hNSCs. CAP induces decreased proliferation and G0 phase cell cycle arrest in all CAP-treated cells. CAP-mediated cytotoxicity was significantly mitigated with DFO pre-treatment in HGG cells, suggesting that ferroptosis plays a critical role in the mechanism of CAP treatment in HGG. CAP led to selective glioma cell death in tumor implanted cerebral organoids.

EXTH-55. ANTI-TUMOR ACTIVITY OF A NEW ONCOLYTIC ADENOVIRUS DELTA-24-RGDOX-IL15 CO-EXPRESSING OX40L AND IL-15

Abstract Accumulating evidence show that the interaction between oncolytic viruses (OVs) and host immune system plays an essential role in cancer virotherapy. Compared to lytic potency of OVs, enhancement of OV-mediated anti-tumor immunity has become a more attractive strategy to improve OV efficacy. To this end, we have reported that the third-generation oncolytic adenovirus (OA), Delta-24-RGDOX, which expresses the immune co-stimulator OX40 ligand (OX40L), is more potent to elicit anti-tumor immunity than the second-generation OA Delta-24-RGD. Since IL-15 activates T and NK cells and promotes persistence of CD8+ memory T cells, we hypothesize that co-expression of OX40L and IL-15 by OAs will further potentiate their efficacy. For this purpose, we constructed the next generation OA Delta-24-RGDOX-IL15. In cultured human and murine tumor cell lines, this new virus effectively expressed the two molecules and displayed comparable potency in viral replication and oncolysis as OAs expressing either of the two (Delta-24-RGDOX, Delta-24-RGD-IL15). Then, we tested the anti-tumor activity of Delta-24-RGDOX-IL15 (two doses, intratumorally, one week interval) in two syngeneic tumor models in C57BL/6 mice: 1) intracranial (i.c.) gliomas from GL261-5 cells; 2) subcutaneous (s.c.)/i.c. melanomas from B16 cells (virus injected into s.c. tumors only). We found Delta-24-RGDOX-IL15 was more efficacious than the other two OAs to inhibit tumor growth of both treated tumor and the untreated i.c. tumors in the second model, leading to long-term survivors (p < 0.05). Different from adoptive cell therapies with cells engineered to express IL-15, we haven’t observed any obvious toxicity with this new virus when it was injected intratumorally into either the i.c. or s.c. tumors. Further studies are in progress to analyze the modifications of the tumor microenvironment induced by the addition of IL-15 to Delta-24-RGDOX. We expect this virus to be a good candidate to be combined with CAR T cell therapies.

TMIC-52. DECODING METABOLIC INTERACTIONS IN GLIOBLASTOMA TUMOR MICROENVIRONMENT THROUGH COMPREHENSIVE SPATIAL TRANSCRIPTOMIC AND PROTEOMIC ANALYSIS

Abstract INTRODUCTION Within the GBM microenvironment, distinct micro-niches arise from independent cancer cell lineages with unique metabolic needs, characterized as Fast Cycling Cells (FCCs) and Slow Cycling Cells (SCCs). FCCs preferentially utilize aerobic glycolysis for energy, whereas treatment-resistant SCCs depend on lipid metabolism. Our study decodes the molecular and spatial heterogeneity within the GBM microenvironment, focusing on the dichotomy of immune infiltrates and the metabolic interactions between SCCs and the immune compartment in human GBM patients. METHODS We performed spatial transcriptomics and proteomics combined with geospatially resolved single-cell neighborhood analysis of IHC-stained GBM tissues using CellProfiler and the SNAQ algorithm that we developed to investigate the specific immune microenvironment of SCCs and FCCs. Holotomography and fluorescence-based time-lapse imaging coupled with flow cytometry were used to study lipid transfer between immune cells and GBM cells. Finally, the effects of pharmacological and genetic targeting of lipid transfer were investigated both in vitro and in vivo. RESULTS Our study establishes a connection between spatial metabolic heterogeneity and immune diversity, highlighting how specific tumor cell lineages correlate with characteristic immune micro-niches. In particular, SCCs exploit the metabolic properties of recruited immunosuppressive myeloid-derived cells, which metabolically support tumor cells by facilitating lipid transport and supporting SCC metabolism. Our results show that inhibiting lipid transfer affect SCCs, remodels the immune microenvironment, delays tumor growth and improves disease outcome. Our study also demonstrates a correlation between predicted sensitivity to lipid-modifying drugs, such as statins, and the SCC phenotype. This correlation could enable stratification and selection of patients most likely to benefit from such treatments. CONCLUSIONS This study establishes critical connections between the TME, cellular metabolism, anti-tumor immunity, and treatment vulnerabilities. Our research provides novel insights into how metabolic exchanges contribute to tumor progression and suggests that targeting metabolic interactions could be an effective therapeutic strategy for GBM.

Silver nanoparticle induced immunogenic cell death can improve immunotherapy

Cancer immunotherapy is often hindered by an immunosuppressive tumor microenvironment (TME). Various strategies are being evaluated to shift the TME from an immunologically ‘cold’ to ‘hot’ tumor and hereby improve current immune checkpoint blockades (ICB). One particular hot topic is the use of combination therapies. Here, we set out to screen a variety of metallic nanoparticles and explored their in vitro toxicity against a series of tumor and non-tumor cell lines. For silver nanoparticles, we also explored the effects of core size and surface chemistry on cytotoxicity. Ag-citrate-5 nm nanoparticles were found to induce high cytotoxicity in Renca cells through excessive generation of reactive oxygen species (ROS) and significantly increased cytokine production. The induced toxicity resulted in a shift of the immunogenic cell death (ICD) marker calreticulin to the cell surface in vitro and in vivo. Subcutaneous Renca tumors were treated with anti-PD1 or in combination with Ag-citrate-5 nm. The combination group resulted in significant reduction in tumor size, increased necrosis, and immune cell infiltration at the tumor site. Inhibition of cytotoxic CD8 + T cells confirmed the involvement of these cells in the observed therapeutic effects. Our results suggest that Ag-citrate-5 nm is able to promote immune cell influx and increase tumor responsiveness to ICB therapies.

Stability of immobilized L-arginine deiminase from Penicillium chrysogenum and evaluation of its anticancer activity

The aim of the present work was to immobilize L-arginine deiminase on suitable supports such as chitosan, alginate, and silica gel to study its stability. Additionally, the study aims to investigate the anticancer effects of the free purified enzyme on hepatocellular carcinoma (Hep-G2) and breast cancer (MCF-7) cell lines. L-arginine deiminase (ADI: EC 3.5.3.6) was immobilized on chitosan, Ca-alginate, and silica gel, with immobilization efficiencies of 89.0%, 72.8%, and 66.5%, respectively. The optimal immobilization time for the highest efficiency was 4 h. Increasing the concentration of glutaraldehyde improved the immobilization efficiency of ADI on chitosan. The chitosan-immobilized ADI retained about 45% of its activity after 8 cycles. The optimal pH values were 6 for the free purified ADI and 7 for the chitosan-immobilized ADI. The optimal temperature increased from 40 °C for the free enzyme to 45 °C after immobilization. The activation energies for the free and chitosan-immobilized enzymes were 71.335 kJ/mol and 64.011 kJ/mol, respectively. The Km values for the free and chitosan-immobilized ADI were 0.76 mM and 0.77 mM, respectively, while the Vmax values were 80.0 U/mg protein for the free ADI and 71.4 U/mg protein for the chitosan-immobilized ADI. After 30 days of storage at 4 °C, the residual activities were 40% for the free purified ADI and 84% for the chitosan-immobilized ADI. At 25 °C, the residual activities were 10% for the free ADI and 75% for the chitosan-immobilized ADI. The chitosan-immobilized ADI exhibited significantly higher stability against proteases such as pepsin and trypsin compared to the free enzyme. The purified ADI also demonstrated enhanced potential anticancer effects and significant cytotoxicity against the Hep-G2 and MCF-7 tumor cell lines compared to doxorubicin. These findings suggest that purified ADI has potential as an anticancer agent, though further in-depth studies are required.

Biological activities of Elaeagnus umbellata methanol extract

Elaeagnus umbellata, known as Autumn olive and growing widely in Asia and Southern Europe, is a shrub tree used in the traditional treatment of many diseases, including cancer. In this study, it was aimed to investigate the several biological effects of methanol extract of E. umbellate. The activity of the extract on 11 microorganisms was determined by the agar well diffusion technique. The anti-quorum sensing activity of the extract was tested using Chromobacterium violaceum ATCC 12472. The anti-biofilm and anti-swarming activities were tested using Pseudomonas aeruginosa PAO1. Cytotoxic effect of the extract against pancreatic tumoral cell line (AR42J), breast cancer cell line (MDA-MB-231), lung adenocarcinoma cell line (A549), and normal epithelial cell line (Vero), and antiviral effect of the extract against herpes simplex virus type 1 was analyzed using the MTT method. It was determined that the extract was moderately effective against 6/11 microorganisms and showed anti-quorum sensing activity. While the extract did not have a cytotoxic effect on cancer cell lines, it was found to have a cytotoxic effect on Vero cells at concentrations of 100 µg/mL and above. However, no anti-biofilm, anti-swarming, and antiviral activity of the extract was observed. The study shows that E. umbellata fruit has limited biological activity.

Design and synthesis of glycofullerene derivatives as novel photosensitizer for potential application in PDT to treat cancer

Cancer is one of the most aggressive diseases known to humanity, characterized by low survival rates and poor prognoses. Currently, platinum-based anticancer drugs and traditional photosensitizers used in photodynamic therapy (PDT) are the most widely employed treatment modalities. However, the platinum-based medications, particularly cisplatin, the most commonly used agent, have several drawbacks. These drawbacks may include systemic toxicity, which can manifest as nephrotoxicity, neurotoxicity, ototoxicity, or emesis during treatment. Such side effects can severely impair patients and significantly diminish the overall effectiveness of therapeutic interventions. In contrast, photodynamic therapy does not present these disadvantages. PDT offers numerous benefits, including reduced long-term morbidity, minimal systemic toxicity, low invasiveness, negligible drug resistance, and temporal and geographic selectivity, all of which enhance patients' quality of life. Consequently, the search for novel, effective, and practical photosensitizers is essential. Fullerenes possess unique physicochemical properties that make them highly suitable as photosensitizers. In this study, we developed a comprehensive and straightforward synthesis for two water-soluble sugar fullerene derivatives, designated as 12 and 13. Multiple analytical techniques, including 1H NMR, 13C NMR, high-resolution mass spectrometry (HRMS), Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet–visible (UV–Vis) spectroscopy, collectively confirmed the chemical structures of these derivatives and validated their successful synthesis. Upon exposure to white light irradiation at an intensity of 2.5J/cm2, compound 13 demonstrated significant biological activity against three distinct tumor cell lines: HepG2, MKN45, and RPMI 4788, with IC50 values of 5.65 μM, 2.43 μM, and 1.82 μM, respectively. This study establishes a foundation for the development of innovative clinical photosensitizers.