Human Brain Tumor Cells Research Articles

Rhythms in lipid droplet content driven by a metabolic oscillator are conserved throughout evolution

The biological clock in eukaryotes controls daily rhythms in physiology and behavior. It displays a complex organization that involves the molecular transcriptional clock and the redox oscillator which may coordinately work to control cellular rhythms. The redox oscillator has emerged very early in evolution in adaptation to the environmental changes in O2 levels and has been shown to regulate daily rhythms in glycerolipid (GL) metabolism in different eukaryotic cells. GLs are key components of lipid droplets (LDs), intracellular storage organelles, present in all living organisms, and essential for energy and lipid homeostasis regulation and survival; however, the cell bioenergetics status is not constant across time and depends on energy demands. Thus, the formation and degradation of LDs may reflect a time-dependent process following energy requirements. This work investigated the presence of metabolic rhythms in LD content along evolution by studying prokaryotic and eukaryotic cells and organisms. We found sustained temporal oscillations in LD content in Pseudomonas aeruginosa bacteria and Caenorhabditis elegans synchronized by temperature cycles, in serum-shock synchronized human embryonic kidney cells (HEK 293 cells) and brain tumor cells (T98G and GL26) after a dexamethasone pulse. Moreover, in synchronized T98G cells, LD oscillations were altered by glycogen synthase kinase-3 (GSK-3) inhibition that affects the cytosolic activity of the metabolic oscillator or by knocking down LIPIN-1, a key GL synthesizing enzyme. Overall, our findings reveal the existence of metabolic oscillations in terms of LD content highly conserved across evolutionary scales notwithstanding variations in complexity, regulation, and cell organization.Graphical abstract

Chitosan based niosomal hydrogel with polyethylene glycol and halloysite nanotubes for curcumin delivery

The use of curcumin (Cur) as an anticancer drug is restricted due to its poor solubility and bioavailability. In this study, a pH-sensitive niosomal hydrogel composed of halloysite nanotubes (HNTs), polyethylene glycol (PEG), and chitosan (Cs) was developed for Cur delivery. Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) analyses confirmed the successful synthesis of the nanocomposite and provided insights into the interactions between its components and its crystalline structure. Zeta potential analysis corroborated its colloidal stability, and scanning electron microscopy (SEM) images revealed its spherical shape and size in the range of 514–554 nm. The homogeneous size distribution was corroborated by dynamic light scattering (DLS) experiments. Cs/PEG/HNTs nanocarrier showed high Cur loading and encapsulation efficiencies (44.2 % and 84.0 %, respectively), as well as a smart, pH-sensitive release mechanism over a 96-hour period, highlighting its potential for sustained and targeted drug delivery. Cur release data were well-fitted to the Korsmeyer-Peppas and Zero-Order models at pH 5.4 and 7.4, respectively. The reduced survival of U-87 MG human brain tumor cells in the presence of Cs/PEG/HNTs@Cur samples compared to Cs, Cs/PEG, Cs/PEG/HNTs, and free Cur corroborates the hydrogel anti-cancer properties. The percentage of late apoptotic cells in Cs/PEG/HNTs@Cur was higher than in Cs/PEG/HNTs and free Cur, which is attributed to the sustained and smart release of Cur from Cs/PEG/HNTs@Cur. The biocompatibility, stability, biodegradability, ability to effectively encapsulate Cur and regulate its release to specifically target tumors makes the designed hydrogel a highly versatile and promising nanocarrier for Cur-based cancer therapies.

10168-BOT-2 ANTITUMOR AROMA THERAPY WITH LEMONGRASS ESSENTIAL OIL FOR GLIOBLASTOMA

Abstract Aromatic essential oils have been used in cancer treatment to enhance immunity, induce sedation, and reduce the side effects of chemotherapy. Recently, essential oils have been reported to have anti-tumor effects. We have been investigating anti-tumor aroma of essential oils as a novel treatment for glioblastoma and have found that hiba essential oil has a proliferation inhibitory effect. In this study, we investigated the antitumor effect of lemongrass essential oil for glioblastoma and its antitumor aromatherapy. Human glioblastoma cells (U87, T98G) and mouse brain tumor cells (RSV-M) were used. Lemongrass essential oil was added to each tumor cell line, and growth inhibition was observed in all cell lines. In addition, lemon grass essential oil showed growth inhibition effect when the tumor cells were separated from the oil, as was the case with direct administration, suggesting that the lemongrass essential oil components that evaporated acted on tumor cells in the surrounding area. The antitumor component of lemongrass essential oil was isolated and identified as citral, an antitumor factor, by gas chromatography. Analysis of the effects of citral showed that it strongly inhibited MARK4 activity and growth in three cell lines. The mechanism revealed that citral decreased the phosphorylation of Tau protein. MARK4 is highly expressed in glioblastoma and has been reported to be involved in cell proliferation. This study suggests a potential mechanism for citral to inhibit tumor cell proliferation via MARK4 in malignant gliomas. Citral is a volatile monoterpene and may exert its antitumor effect by evaporation diffusion. Lemongrass essential oil contains citral, which shows antitumor effects, and is expected to be applied to a new glioblastoma therapy using "aroma".

Phenotypic diversity of T cells in human primary and metastatic brain tumors revealed by multiomic interrogation

The immune-specialized environment of the healthy brain is tightly regulated to prevent excessive neuroinflammation. However, after cancer development, a tissue-specific conflict between brain-preserving immune suppression and tumor-directed immune activation may ensue. To interrogate potential roles of T cells in this process, we profiled these cells from individuals with primary or metastatic brain cancers via integrated analyses on the single-cell and bulk population levels. Our analysis revealed similarities and differences in T cell biology between individuals, with the most pronounced differences observed in a subgroup of individuals with brain metastasis, characterized by accumulation of CXCL13-expressing CD39+ potentially tumor-reactive T (pTRT) cells. In this subgroup, high pTRT cell abundance was comparable to that in primary lung cancer, whereas all other brain tumors had low levels, similar to primary breast cancer. These findings indicate that T cell-mediated tumor reactivity can occur in certain brain metastases and may inform stratification for treatment with immunotherapy.

CSIG-29. EMPLOYING THE ZIKA VIRUS AS ONCOLYTIC VIROTHERAPY AGAINST PAEDIATRIC NERVOUS SYSTEM CANCER CELLS

Abstract BACKGROUND Malignant paediatric nervous system tumours, such as medulloblastoma, ATRT and high-risk neuroblastoma commonly harbour tumour cells with stem-like features which are highly tumorigenic and resistant to conventional therapies. These tumours can exhibit high lethality and may result in severe sequelae that significantly affect paediatric patients' quality of life. Oncolytic virotherapy exploits viruses that preferentially infect and destroy tumour cells. These viruses present a unique advantage in targeting highly heterogeneous cancers as they possess a secondary mechanism of action, through which they induce an anti-tumoral immune response. The Zika virus (ZIKV) is capable of infecting and destroying aggressive human paediatric brain tumour and neuroblastoma cells in vitro. ZIKV effectively reduces brain tumour size in mice (xenograft model) and canines (naturally occurring) and can induce an immune response against canine brain tumours. METHODS Employing global expression omics profiling of ZIKV infection and mapping of viral protein-host protein interactions, we aim to elucidate the mechanisms which underpin ZIKVs therapeutic properties, both at the molecular and cellular pathway levels. RESULTS Through extensive transcriptome profiling of ZIKV-infected paediatric brain tumour, neuroblastoma and NPCs, we have identified a variety of pathways which are involved in the ZIKV oncolytic response in the tumour cells and its neuro-dysregulation of NPCs. Despite both brain tumour and neuroblastoma cells undergoing ZIKV-induced oncolysis, we observed there to be a heterogeneous response within these different tumour cells at the molecular level to lead to oncolysis. Additionally, the infected tumour cells demonstrate elevated immune system profiles which alludes to the immune response that ZIKV may raise within the patient’s body against the paediatric tumour. Analysing our findings alongside the neuro-dysregulation we observe in our ZIKV-infected NPCs is allowing us to build a safety profile for employing a ZIKV-based therapy, whilst contributing to the growing knowledge of Congenital ZIKV Syndrome.

Expression and estrogen regulation of G protein-coupled estrogen receptor in human glioblastoma cells.

Glioblastoma (GB) is the most frequent primary brain tumor with a very poor prognosis. Sex hormones are crucial players in the development of GBs. 17 β-estradiol (E2) signaling is involved through its corresponding intracellular receptors [estrogen receptor α (ERα) and β (ERβ)] in GB cell proliferation and progression. E2 activates G-protein coupled estrogen receptor (GPER), leading to rapidly occurring effects, independently of gene transcription. GPER activation is involved in tumor progression in various cancer types. Currently, available data concerning the occurrence and role of GPER in GB are very limited. In the present study, it was observed that GPER was expressed in human brain tumor cell lines [U251 (astrocytoma-derived cell line), U87, LN229 and T98 (glioblastoma-derived cell line)]. Immunofluorescence assays revealed that GPER localizes in the plasma membrane, cytoplasm and nucleus. An in silico analysis identified two potential E2 response elements in the promoter region of the GPER gene. E2 increased GPER expression in the U251, U87 and LN229 cell lines. Molecular modeling data derived from in silico analysis predicted the three-dimensional conformation of GPER, and docking analysis identified potential binding sites of E2 and its specific agonist, G1. Taken together, these results indicate that GPER may be differentially expressed in human GB cell lines with E2 possibly upregulating GPER expression. The present study raises further questions about the implications of GPER-mediated E2 signaling in the biology of GBs.

Strigolactone Analogs: Two New Potential Bioactiphores for Glioblastoma

Strigolactones (SLs), carotenoid-derived phytohormones, control the plant response and signaling pathways for stressful conditions. In addition, they impact numerous cellular processes in mammalians and present new scaffolds for various biomedical applications. Recent studies demonstrated that SLs possess potent antitumor activity against several cancer cells. Herein, we sought to elucidate the inhibitory effects of SL analogs on the growth and survival of human brain tumor cell lines. Among four tested SLs, we showed for the first time that two lead bioactiphores, indanone-derived SL and EGO10, can inhibit cancer cell proliferation, induce apoptosis, and induce G1 cell cycle arrest at low concentrations. SL analogs were marked by increased expression of Bax/Caspase-3 genes and downregulation of Bcl-2. In silico studies were conducted to identify drug-likeness, blood–brain barrier penetrating properties, and molecular docking with Bcl-2 protein. Taken together, this study indicates that SLs may be promising antiglioma agents, presenting novel pharmacophores for further preclinical and clinical assessment.

BRAIN Surgical Tissue for Advanced Tumour models in Precision medicine: Developing the BRAIN-STAT pathway

AimsThere are approximately four thousand neuro-oncology procedures in the UK per annum. Many of these result in tissue and biofluid specimens that are surplus to diagnostic requirement and can be collected as standard of clinical care. However, developing technologies and treatments for precision medicine require access to a range of individualised biospecimens paired with deep clinical phenotyping data. Here, we present Brain Surgical Tissue for Advanced Tumour Models (BRAINSTAT) programme, an infrastructure that has been established between Queen Elizabeth Hospital, Birmingham and the University of Birmingham, to collect, structure and store these resources and also maximise their value for research over the long-term. Using this approach our aim is to provide high-quality, annotated resources to help develop novel treatments for patients with brain tumours.MethodBRAINSTAT infrastructure allows:Prospective consentBiospecimens, including tumour tissue (brain and other primary in the case of metastasis), cyst fluid, dura, skin, CSF, blood (matched “germ-line” and for circulating cell free tumour DNA analysis), urine and saliva can be collected. Consent for long term follow-up, is either via clinic or NHS digital. More limited consent for non-oncological neurosurgical cohorts (e.g. epilepsy or vascular) and healthy volunteers allow healthy access-tissue and biofluids to be collected.B. Rapid transfer of fresh surgical tissue samples:Strong collaborative links and close physical proximity between operating theatre and laboratory allows rapid transfer of biospecimens minimising transit time.C. Standardised annotation across disciplinesThe RedCAP database system allows granular control over data-access, and each specialist research team is provided access only to the sub-sections relevant to them. All users must have Good Clinical Practice certification and GDPR training, prior to access of the BRAINSTAT database.ResultsBetween 25/11/2019-16/03/2020 and 27/07/2020-16/11/2020, 65 patients were consented for BRAINSTAT at the weekly neurosurgical oncology clinic. (Recruitment gaps due to the SARS-COVID 19 pandemic). Pathological diagnosis of surplus tissue collected included: 37 high grade glioma, 3 low grade glioma and 16 brain metastasis including: (6 lung, 6 breast, 2 colorectal, 1 oesophageal, 1 endometrial). Meningioma (5 WHO I; 1 WHO III) 1 patient undergoing anterior temporal lobectomy for hippocampal sclerosis contributed access tissue from the lateral neocortex. 1 patient had a non- neoplastic, non-diagnostic sample. All patients had matched “germ-line” blood samples.Median time from resection to arrival in the laboratory was 10 minutes (range 4-31). Standardised operating protocols to optimise this have been developed.Glioblastoma and breast-brain metastasis tumourspheres and cerebral organoids are currently being validated.ConclusionDespite the challenges of the pandemic we have established a viable tissue pipeline from neurosurgical operating theatre to our university laboratories. We are developing clinically annotated human brain tumour cell lines, stem cells and 3D organoid models, principally for commonly encountered brain tumours such as glioma and metastasis.The research sets the foundation for a multitude of downstream applications including:- Building more complex organoid cultures e.g. by including other cell types such as healthy brain cells and endothelial cells allowing future experiments to more accurately model tumour growth.- Developing high-throughput, patient-specific drug screens of novel drugs and drug combinations using these 3D tumour models aiming to more effectively treat tumour proliferation and spread. These patient avatars will help inform and test more “stratified” personal medical treatments and will provide opportunities to allow earlier intervention with the aim of improving survival, coupled with a better quality of life.

Effects of electroporation on anticancer activity of 5-FU and newly synthesized zinc(II) complex in chemotherapy-resistance human brain tumor cells.

Zn(II) complex of Schiff base derived from the condensation of 4-aminopyrimidine-2(1H)-one with salicylaldehyde was prepared and characterized by various physico-chemical and spectral methods for structure determination. The cytotoxic activity of the Zn(II) complex was investigated in comparison with 5-fluorouracil (5-FU) against two different human brain tumor cell lines (T98G and U118), while primer human dermal fibroblast cells (HDF) was used as control for biocompatibility. Then, the effectiveness of electroporation (EP) on cytotoxic activities of these compounds has been examined. The cytotoxicities of the 5-FU and new Zn(II) complex, alone or in combination with electroporation, were determined by MTT assay. The Zn(II) complex showed good cytotoxicity against T98G and U118 brain tumor cell lines with IC50 = 282.47 and 297.91μM respectively, while it was safe on HDF healthy cells with IC50 = 826.72μM. The 5-FU exhibited less cytotoxicity compared to the Zn(II) complex against T98G (IC50 = 382.35μM) and U118 (IC50 = 396.56μM) tumor cell lines. The combined application of Zn (II) + EP decreased the IC50 value by 5.96-fold in T98G cells and 4.76-fold in U118 cells. EP showed a similar effect in its combined application with 5-FU, resulting in a decrease of the IC50 value of 4.22-fold in the T98G cells and 3.84-fold in the U118 cells. In a conclusion, the Zn(II) complex exhibited an anticancer potential against both brain tumor cell lines (T98G and U118) and EP greatly increased the cytotoxicity of Zn(II) complex and 5-FU on these chemotherapy-resistant cells.

Abstract 2806: Development of an iRFP713-based orthotopic patient derived brain cancer model to study tumor development in vivo

Abstract While the use of bioluminescent proteins for molecular imaging is a powerful technology to support our knowledge of complex processes, with the advent of near infrared-labeling capabilities optical imaging can be pursuit with deeper tissue penetration, a better signal to background ratio and a quicker image acquisition without the need to inject substrates in preclinical oncology mouse models. This is specifically important in orthoptic brain tumors, when the substrate concentration in the tumor tissue might be influenced by the blood-brain barrier. In our recent study, we validated the feasibility of stable or transient transfection of human brain tumor cell lines and patient derived xenografts to determine tumor load in an intracranial setting. As a proof-of principle, we stably transfected the human glioblastoma cell line U87MG with an iRFP713 construct and followed tumor growth of intracranially implanted NSG mice. As a follow-up, five PDX of pediatric brain tumors (two Ependymoma, two Medulloblastoma, one high grade Glioblastoma) were transiently transfected with the same construct 24h before intracranial implantation. Tumor load was determined twice a week with the Pearl trilogy system (LiCor, Germany) and animals were examined for neurological symptoms every day. When the overall condition of the mice got deteriorated, animals were taken down and brains fixed in formalin. The tumor load and localization was confirmed by H&E and human-specific IHC for LamininB. The comparison between non-transfected and transfected lines of one specific tumor model, revealed that the tumor growth was very similar in both settings. The tumor take rate was as well not affected. In the subsequent analyses we could show that the tumor load linearly correlated with the imaging signal. Moreover, the iRFP713 signal was stable post-resection of the tumor. Thus, it was possible to correlate the tumor load quantification via iRFP713-Protein expression and LamininB-IHC within one slide. The transient transfection was successful for the five tested models. When termination criteria were reached, over 90% of the tumor tissue were expressing the iRFP713 protein. The more general applicability for larger cohorts of mice (> 20) and drug testing experiments will be evaluated soon. We believe the superior optical properties of iRFP713 will be a valuable asset to overcome some of the complications inherent to imaging live animals and a powerful tool for preclinical drug development in clinical relevant mouse models of brain cancer. Citation Format: Kanstantsin Lashuk, Jacqueline Bersano, Dorothee Lenhard, Eva Oswald, Kerstin Klingner, Julia Schüler. Development of an iRFP713-based orthotopic patient derived brain cancer model to study tumor development in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2806.

Tumor-specific overexpression of histone gene, H3C14 in gastric cancer is mediated through EGFR-FOXC1 axis

Incorporation of different H3 histone isoforms/variants have been reported to differentially regulate gene expression via alteration in chromatin organization during diverse cellular processes. However, the differential expression of highly conserved histone H3.2 genes, H3C14 and H3C13 in human cancer has not been delineated. In this study, we investigated the expression of H3.2 genes in primary human gastric, brain, breast, colon, liver, and head and neck cancer tissues and tumor cell lines. The data showed overexpression of H3.2 transcripts in tumor samples and cell lines with respect to normal counterparts. Furthermore, TCGA data of individual and TCGA PANCAN cohort also showed significant up-regulation of H3.2 genes. Further, overexpressed H3C14 gene coding for H3.2 protein was regulated by FOXC1 transcription factor and G4-cassette in gastric cancer cell lines. Elevated expression of FOXC1 protein and transcripts were also observed in human gastric cancer samples and cell lines. Further, FOXC1 protein was predominantly localized in the nuclei of neoplastic gastric cells compared to normal counterpart. In continuation, studies with EGF induction, FOXC1 knockdown, and ChIP-qPCR for the first time identified a novel axis, EGFR-FOXC1-H3C14 for regulation of H3C14 gene overexpression in gastric cancer. Therefore, the changes the epigenomic landscape due to incorporation of differential expression H3 variant contributes to change in gene expression pattern and thereby contributing to pathogenesis of cancer.

Nucleolin targeted delivery of aptamer tagged Trichoderma derived crude protein coated gold nanoparticles for improved cytotoxicity in cancer cells

The present work demonstrates how the fungal crude protein extract (FE) mediated gold nanoparticles (AuNPs) functionalized with aptamer (APT) improved cytotoxicity in human lung cancer cell line (A549) and brain tumor cell line (LN229). The agarose gel electrophoresis (AGE) confirmed the conjugation of APT in FE-AuNPs. The FTIR results revealed the involvement of FE in the amalgamation of FE-AuNPs. FE-AuNPs (λmax 521 nm) had Z-average size of 19.72 ± 0.26 d. nm and PDI of 0.58 ± 0.01 with a zeta potential of -22.20 mV, whereas APT-FE-AuNPs (λmax521 nm) had the Z-average size of 167.63 ± 1.40 d. nm and PDI of 0.21 ± 0.01 with a zeta potential of -36.36 mV. Both synthesized nanoparticles exhibited less cytotoxicity in normal NIH3T3 cells, while the APT-FE-AuNPs (λmax 521 nm) showed significant cytotoxicity in A549 and LN229 cells. The cells treated with APT-FE-AuNPs (λmax 521 nm) displayed higher percentage of early apoptosis (6.97 %), apoptosis (7.08 %), and necrosis (6.63 %) than those treated with bare or APT-FE-AuNPs (λmax 565 nm) in A549 cells. The results demonstrated that the DNA aptamer (AS1411) tagged with FE-AuNPs (λmax 521 nm) increased their accumulation in cancer cells, which triggered nucleolin targeted cell cytotoxicity through nucleus damage and induction of oxidative stress.

In Vitro Macrophage-Mediated Phagocytosis Assay of Brain Tumors.

Tumor-associated macrophages (TAMs) have recently emerged as potentially crucial therapeutic targets for cancer. Thus, the development of macrophage-mediated phagocytosis assays is vital for preclinical drug screening of different tumor cells. This assay can be used to evaluate the effect of anti-cancer therapy, such as immunotherapy, radiotherapy, and chemotherapy, on different tumor cells. Here, we describe the in-vitro phagocytosis assay in detail. As an example of immunotherapy treatment, we used a monoclonal antibody to block an anti-phagocytic signal (CD47) to evaluate the assay using human brain tumor cells and monocyte-derived macrophages. We also demonstrated that this assay can be used to evaluate the effect of different irradiation doses on the phagocytosis of brain tumor cells. This functional assay is fast, accurate, and highly reproducible. Furthermore, the results successfully demonstrate that anti-CD47 antibodies and irradiation can enhance the macrophage-mediated phagocytosis of brain tumors.

Abstract 4176: Involvement of the lysosome in the cytotoxicity of Gallium Maltolate in human pediatric brain tumor cell lines

Abstract Introduction: Gallium maltolate (GaM) is a novel small molecule metallocompound that acts as an iron mimetic Trojan Horse to disrupt iron-dependent proteins essential in tumor biology. We recently reported that GaM retards the growth of orthotopically implanted adult human glioblastoma (GBM) xenografts in a rodent brain tumor model and is cytotoxic to glioblastoma stem cells (Mol Cancer Ther 17:1240, 2018). GaM's mechanisms of action include inhibition of both mitochondrial function and iron-dependent ribonucleotide reductase. In the present study, we further explored whether GaM has antitumor activity in pediatric brain tumor cells. Experimental procedures: The cytotoxicity of GaM in pediatric GBM and Atypical Teratoid Rhabdoid Tumor (ATRT) cell lines was examined by MTT and clonogenic assays. Apoptotic cell death was assessed by flow cytometry with annexin V (AV) and propidium iodide (PI) staining. Cellular bioenergetics was measured using a Seahorse XF96 Extracellular Flux Analyzer. GaM interaction with lysosomes was analyzed by immunofluorescence and electron microscopy (EM). Results: In a panel of pediatric brain tumor cell lines, CHLA-266 ATRT and GBM cells displayed the greatest sensitivity to GaM. Complete inhibition of colony growth was achieved with 6 - 7 µM GaM over a 96-hour incubation. With a shorter incubation of 48-h, 25 µM GaM induced apoptosis in > 60% of CHLA-266 ATRT cells. In contrast, a longer incubation of 96-h with 25 µM GaM was required to induce apoptosis in > 50% of CHLA-200 GBM, 69% of SF188 GBM and 60% of SJ-GBM2 cell lines. After a 24-h of incubation with GaM, prior to detectable cell death, CHLA-266 and GBM cells displayed a marked reduction in mitochondrial reserve capacity, glycolysis, and glycolytic capacity. Immunofluorescence staining for the lysosomal marker LAMP1 showed that GaM produced an increase in lysosome size and number after a 24-h or 48-h incubation relative to control cells. EM studies demonstrated a gallium signal within the lysosomal compartment as early as 6-h of incubation. EM findings consistent with GaM-induced apoptosis were noted after a 24-h incubation, thus confirming the results of the AV/PI assay. After 24-h however, gallium was no longer detectable in the lysosomes, suggesting that lysosomal disruption led to the release of gallium into the cytoplasm. Conclusions: Our results identify GaM as a novel compound with significant activity against a panel of cell lines representative of pediatric brain tumors. Most of the cell lines used in our study were derived from tumors taken from heavily pre-treated patients and were resistant to conventional chemotherapeutic drugs. Their sensitivity of GaM suggests that GaM does not share cross-resistance with other antineoplastic drugs. Our study also provides new insight into the lysosomes as a target for gallium. The prognosis of adult and pediatric brain tumors is dismal and there is an urgent need to develop newer drugs for this malignancy. Further investigation of GaM as a therapeutic agent for brain tumors is warranted. Citation Format: Salvatore Molino, Christopher R. Chitambar. Involvement of the lysosome in the cytotoxicity of Gallium Maltolate in human pediatric brain tumor cell lines [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4176.

Water-Extracted Ganoderma lucidum Induces Apoptosis and S-Phase Arrest via Cyclin-CDK2 Pathway in Glioblastoma Cells.

Glioblastoma is one of the most common and most aggressive brain cancers. The current treatment is mainly surgery, chemotherapy, and radiation therapy, but the results are not satisfactory. Ganoderma lucidum (G. lucidum), also called “Lingzhi”, is a medicinal mushroom that has been used as a therapeutic agent for the treatment of numerous diseases, including cancer. However, whether it is effective for treating cancer is still unclear. In the present study, the anti-tumor effect of a water extract of G. lucidum was investigated using brain tumor cells. We used an analysis of cell viability, flow cytometry, the IncuCyte live-cell analysis system, and Western blotting to study its effects. The water extract from G. lucidum inhibited cell proliferation in a dose- and time-dependent manner, and it induced mitochondria-mediated apoptosis and cell cycle arrest at S phase via the cyclin-CDK2 pathway in human brain tumor cells. In addition, the G. lucidum extract significantly inhibited cell migration and mesenchymal marker expression based on the IncuCyte live-cell assay and qRT-PCR analysis. In summary, these anti-tumor effects in brain tumor cells suggest that G. lucidum may be useful for treating brain tumors.

Colorimetric determination of tumor cells via peroxidase-like activity of a cell internalizable nanozyme: Hyaluronic acid attached-silica microspheres containing accessible magnetite nanoparticles

A simple colorimetric protocol for determination of tumor cell concentration was developed based on a cell internalizable nanozyme functionalized with hyaluronic acid (HA) as a ligand sensitive to CD44 receptors of tumor cells. Monodisperse-porous silica microspheres containing immobilized Fe3O4 nanoparticles (Fe3O4@SiO2 microspheres) were synthesized 6.25 μm in size, by “staged sol-gel templating protocol”. HA attached form of Fe3O4@SiO2 microspheres (HA@Fe3O4@SiO2 microspheres) was obtained via carbodiimide activation. HA@Fe3O4@SiO2 microspheres were effectively uptaken by human cervical cancer (HeLa) cells and primary brain tumor cells (T98 G glioblastoma) via pinocytosis in Dulbecco's modified eagle's medium, depending on the interaction of HA with CD44 receptors. The number of HA@Fe3O4@SiO2 microspheres uptaken by HeLa and T98 G cells increased with the increasing cell concentration. HA@Fe3O4@SiO2 microspheres also acted as a nanozyme and exhibited peroxidase-like activity due to Fe3O4 nanoparticles tightly immobilized within their porous interiors in the accessible form. The decrease of peroxidase-like activity of nanozyme due to the specifically uptaken microspheres was used as a new tool for determination of tumor cell concentration. In the developed colorimetric protocol, the constant number of HA@Fe3O4@SiO2 microspheres were interacted with HeLa and T98 G cell suspensions prepared with different cell concentrations for completion of pinocytosis. The synthetic substrate (3,3’,5,5’-tetramethylbenzidine, TMB) was converted to a colored product (oxidized TMB) by peroxidase-like activity of both cell internalized and non-internalized microspheres. The apparent peroxidase-like activity was determined by measuring visible region absorbance of reaction medium after removal of HA@Fe3O4@SiO2 microspheres. The observed peroxidase-like activity (i.e. the visible region absorbance) exhibited almost a linear decrease with the increasing tumor cell concentration. The increase in the number of HA@Fe3O4@SiO2 microspheres uptaken by tumor cells with the increasing cell concentration was the reason of the decrease observed in the apparent peroxidase-like activity of nanozyme. The proof of concept, “the decrease of peroxidase-like activity of cell internalizable nanozyme depending upon the increasing number of uptaken microspheres” was termed as a general tool utilized for determination of various kinds of tumor cells, for the first time. Proposed method is a promising start for development of facile liquid biopsy protocols instead of currently used complex systems.

A Xenotransplant Model of Human Brain Tumors in Wild-Type Mice.

SummaryThe development of adequate model systems to study human malignancies is crucial for basic and preclinical research. Here, we exploit the “immune-privileged” developmental time window to achieve orthotopic xenotransplantation of human brain tumor cells in wild-type (WT) mice. We find that, when transplanted in utero, human glioblastoma (GBM) cells readily integrate in the embryonic mouse brain mirroring key tumor-associated pathological features such as infiltration, vascularization, and complex tumor microenvironment including reactive astrocytes and host immune cell infiltration. Remarkably, activation of the host IBA1 tumor-associated microglia/macrophages depends on the type of glioma cell transplanted, suggesting our approach allows one to study human GBM interactions with the immune system of WT host mice. The embryonic engraftment model complements existing ones, providing a rapid and valuable alternative to study fundamental biology of human brain tumors in immune competent mice.

Controlling distinct signaling states in cultured cancer cells provides a new platform for drug discovery.

Cancer cells can switch between signaling pathways to regulate growth under different conditions. In the tumor microenvironment, this likely helps them evade therapies that target specific pathways. We must identify all possible states and utilize them in drug screening programs. One such state is characterized by expression of the transcription factor Hairy and Enhancer of Split 3 (HES3) and sensitivity to HES3 knockdown, and it can be modeled in vitro. Here, we cultured 3 primary human brain cancer cell lines under 3 different culture conditions that maintain low, medium, and high HES3 expression and characterized gene regulation and mechanical phenotype in these states. We assessed gene expression regulation following HES3 knockdown in the HES3-high conditions. We then employed a commonly used human brain tumor cell line to screen Food and Drug Administration (FDA)-approved compounds that specifically target the HES3-high state. We report that cells from multiple patients behave similarly when placed under distinct culture conditions. We identified 37 FDA-approved compounds that specifically kill cancer cells in the high-HES3-expression conditions. Our work reveals a novel signaling state in cancer, biomarkers, a strategy to identify treatments against it, and a set of putative drugs for potential repurposing.-Poser, S. W., Otto, O., Arps-Forker, C., Ge, Y., Herbig, M., Andree, C., Gruetzmann, K., Adasme, M. F., Stodolak, S., Nikolakopoulou, P., Park, D. M., Mcintyre, A., Lesche, M., Dahl, A., Lennig, P., Bornstein, S. R., Schroeck, E., Klink, B., Leker, R. R., Bickle, M., Chrousos, G. P., Schroeder, M., Cannistraci, C. V., Guck, J., Androutsellis-Theotokis, A. Controlling distinct signaling states in cultured cancer cells provides a new platform for drug discovery.

RETRACTED ARTICLE: One-Dimensional Ag(I) and Cu(I) Coordination Polymers Constructed from the Two N-donor Ligands: Structural Insights and Anti-brain Tumor Activity Evaluation

This study reports the synthesis and characterization of two new Ag(I) and Cu(I)-based coordination polymers (CPs) with the chemical formulas of [Ag(bipp)(ClO4)]n (1, bipp = bis(4-pyridyl) propane) and [Cu2(bib)(CN)](NO3)(H2O)2 (2, bib = 4,4′-bisimidazolylbiphenyl). The molecular structures of the as-prepared CPs were determined by the single crystal X-ray diffraction studies and their phase purities have been confirmed via the power X-day diffraction analysis. The crystal structure analysis reveals that the both CPs reveal 1D chain-like structures and their frameworks are stabilized via the π–π interactions and H-bonding interactions. Furthermore, the size of the two CPs could be easily downsized into the nanometer via a simple reflux treatment. In connection to these, the as-prepared two nanostructural CPs were tested for their in vitro anticancer activities against three human brain tumor cell lines (SF17, SF767 and F126) via the MTT assay.

A water stable metal–organic framework with 1D nanotube pores for 5-fluorouracil delivery and anti-brain tumor activity

The employment of porous carriers for anticancer drug delivery has gained much attention in recent years for their excellent drug-loading capacity and controlled release performance. In this work, by utilizing a rigid organic aromatic carboxylic acid ligand, a new Zn(II)–organic framework {[Zn2(bptc)(H2O)]·(DMAc)3(H2O)4}n (1, DMAc is in short of N,N-dimethylacetamide, H4bptc is in short of biphenyl-3,3′,5,5′-tetracarboxylic acid ligand), with considerable water stability has been prepared using the solvothermal technology. The structural analysis result reveals that complex 1 is constructed from fourfold helical metal chains whose net could be simplified into a (6,8)-connected topology. Moreover, complex 1 shows 1D nanotube channels with a window size of 10.7 × 10.7 A2 along the [001] direction and reveals a large accessible voids of 51.7%. The desolvated 1 (1a) was used to study the loading and releasing of the 5-fluorouracil (5-Fu), which reveals that 1a could uptake around 51.2 wt% of 5-Fu and nearly 85.6% of the absorbed 5-Fu could be released in PBS (7.4 for the pH value) in 100 h at 37 °C. In connection to these, in vitro cytotoxicity of compound 1 together with the anticancer performance of 5-Fu-loaded 1a was evaluated against human oral epidermal cells and human brain tumor cells SF17 via MTT assays.