Glioblastoma Cell Viability Research Articles

Comprehensive gene set enrichment and variation analyses identify SUV39H1 as a potential prognostic biomarker for glioblastoma immunorelevance

Glioblastoma (GBM) is the most common intracranial malignancy. SUV39H1 encodes a histone H3 lysine 9 methyltransferase that acts as an oncogene in several cancers; however, its role in GBM remains unknown. We obtained GBM transcriptome and clinical data from The Cancer Genome Atlas (TCGA) database on the UCSC Xena platform to perform differential and enrichment analyses of genes in the SUV39H1 high- and low-expression groups to construct a prognostic risk model. Analysis of SUV39H1 related biological processes in GBM was performed by gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA). High- and low-risk subgroup mutation signatures were analyzed using maftools. Immune infiltration was evaluated using IOBR and CIBERSORT algorithms. We analyzed the cell types and intercellular communication networks in glioma stem cells (GSCs) using scRNA-seq. The effects on GBM cells and GSCs after inhibition of SUV39H1 were investigated in vitro. SUV39H1 was significantly overexpressed in GBM and associated with poor prognosis. SUV39H1-related differentially expressed genes were enriched in immune and inflammation related pathways, and GSEA revealed that these genes were significantly enriched in signaling pathways such as IL-18, oxidative phosphorylation, and regulation of TP53 activity. Mutational analysis revealed frequent alterations in TP53 and PTEN expression. In addition, the infiltration abundances of the five immune cell types were significantly different between the high- and low-expression groups. Analysis of cellular communication networks by scRNA-seq revealed a strong interaction between CRYAB-GSC and PTPRZ1-GSC in GSCs. In vitro experiments verified that knockdown of SUV39H1 inhibited the viability and proliferation of U87 and U251 glioblastoma cells and downregulated the expression of stemness markers Nestin and SOX2 in CSC1589 and TS576 GSC lines. Increased SUV39H1 expression is associated with immune cell infiltration and poor prognosis in patients with GBM. Inhibition of SUV39H1 restrains GBM growth and reduces the stem cell properties of GSC. Thus, SUV39H1 might be a prognostic predictor and immunotherapeutic target in patients with GBM.

Design of Experiments to Tailor the Potential of BSA-Coated Peptide Nanocomplexes for Temozolomide/p53 Gene Co-Delivery

Background: Gene therapy can be viewed as a promising/valuable therapeutic approach directed to cancer treatment, including glioblastoma. Concretely, the combination of gene therapy with chemotherapy could increase its therapeutic index due to a synergistic effect. In this context, bovine serum albumin (BSA)-coated temozolomide (TMZ)-peptide (WRAP5)/p53 gene-based plasmid DNA complexes were developed to promote payload co-delivery. Methods: Design of experiments (DoE) was employed to unravel the BSA-coated TMZ-WRAP5/p53 nanocomplexes with the highest potential by considering the nitrogen to phosphate groups ratio (N/P), and the BSA concentration as inputs and the size, polydispersity index, surface charge and p53-based plasmid complexation capacity (CC) as DoE outputs. Results: The obtained quadratic models were statistically significant (p-value < 0.05) with an adequate coefficient of determination, and the correspondent optimal points were successfully validated. The optimal complex formulation had N/P of 1.03, a BSA concentration of 0.08%, a size of approximately 182 nm, a zeta potential of +9.8 mV, and a pDNA CC of 96.5%. The optimal nanocomplexes are approximately spherical. A cytotoxicity assay showed that these BSA-coated TMZ-WRAP5/p53 complexes did not elicit toxicity in normal brain cells, and a hemolysis study demonstrated the hemocompatibility of the complexes. The complexes were stable in cell culture medium and fetal bovine serum and assured pDNA protection and release. Moreover, the optimal BSA-coated complexes were able of gene transcription and promoted a significant inhibition of glioblastoma cell viability. Conclusions: The reported findings instigate the development of future research to evaluate their potential utility to TMZ/p53 co-delivery. The DoE tool proved to be a powerful approach to explore and tailor the composition of BSA-coated TMZ-WRAP5/p53 complexes, which are expected to contribute to the progress toward a more efficient therapy against cancer and, more specifically, against glioblastoma.

Evidence for the Quercetin Binding Site of Glycogen Phosphorylase as a Target for Liver-Isoform-Selective Inhibitors against Glioblastoma: Investigation of Flavanols Epigallocatechin Gallate and Epigallocatechin.

Glycogen phosphorylase (GP) is the rate-determining enzyme in glycogenolysis, and its druggability has been extensively studied over the years for the development of therapeutics against type 2 diabetes (T2D) and, more recently, cancer. However, the conservation of binding sites between the liver and muscle isoforms makes the inhibitor selectivity challenging. Using a combination of kinetic, crystallographic, modeling, and cellular studies, we have probed the binding of dietary flavonoids epigallocatechin gallate (EGCG) and epigallocatechin (EGC) to GP isoforms. The structures of rmGPb-EGCG and rmGPb-EGC complexes were determined by X-ray crystallography, showing binding at the quercetin binding site (QBS) in agreement with kinetic studies that revealed both compounds as noncompetitive inhibitors of GP, with EGCG also causing a significant reduction in cell viability and migration of U87-MG glioblastoma cells. Interestingly, EGCG exhibits different binding modes to GP isoforms, revealing QBS as a promising site for GP targeting, offering new opportunities for the design of liver-selective GP inhibitors.

MELATONIN ENHANCES TEMOZOLOMIDE-INDUCED APOPTOSIS IN GLIOBLASTOMA AND NEUROBLASTOMA CELLS.

The combination of temozolomide (TMZ) and paclitaxel (PTX) is the most commonly used chemotherapy regimen for glioblastoma, but there is no specific treatment for neuroblastoma due to the acquired multidrug resistance. Approximately half of treated glioblastoma patients develop resistance to TMZ and experience serious side effects. Melatonin (MEL), a multifunctional hormone long known for its antitumor effects, has a great advantage in combination cancer therapy thanks to its ability to affect tumors differently than normal cells. This study aims to evaluate the in vitro inhibitory effects of MEL in combination with TMZ on cancer cell viability and to elucidate the underlying mechanisms in the glioblastoma and neuroblastoma cell lines. C6 (Rattus norvegicus) and N1E-115 (Mus musculus) cancer cell lines and C8-D1A (mice) healthy cell lines were used. Cell proliferation was evaluated using the MTT test. IC50 values were determined by probit analysis. Two concentrations of TMZ (IC50 and 1/2 IC50) were used to induce cytotoxicity in the C6 and N1E-115 cell lines, both alone and in combination with PXT and MEL (all at IC50). The viable, dead, and apoptotic cells were determined by image-based cytometry using Annexin V/PI staining. The gene expression related to signaling pathways was assessed by the quantitative reverse transcription polymerase chain reaction (qRT-PCR), and key proteins were identified by the Western blot analysis. MTT assay showed that the combination of TMZ and MEL significantly reduces the viability of both glioblastoma and neuroblastoma cells compared to the vehicle-treated controls. Notably, MEL combined with 1/2 IC50 TMZ showed a significant death rate of cancer cells compared to controls and PTX. According to qRT-PCR data, the TMZ + MEL combination resulted in the upregulation of the genes of antioxidative enzymes (Sod1 and Sod2) and DNA repair genes (Mlh1, Exo1, and Rad18) in both cell lines. Moreover, the levels of Nfkb1 and Pik3cg were significantly reduced following the TMZ + MEL treatment. The combination of MEL with TMZ also enhanced the cell cycle arrest and increased the expression of p53 and pro-apoptotic proteins (Bax and caspase-3), while significantly decreasing the expression of anti-apoptotic protein Bcl-2. Our findings indicate that the combination of MEL with a low dose of TMZ may serve as an upstream inducer of apoptosis. This suggests the potential development of a novel selective therapeutic strategy as an alternative to TMZ for the treatment of both glioblastoma and neuroblastoma.

Cytotoxicity, Proapoptotic Activity and Drug-like Potential of Quercetin and Kaempferol in Glioblastoma Cells: Preclinical Insights

Despite the increasing understanding of the pathogenesis of glioblastoma (GBM), treatment options for this tumor remain limited. Recently, the therapeutic potential of natural compounds has attracted great interest. Thus, dietary flavonoids quercetin (QCT) and kaempferol (KMF) were investigated as potential cytostatic agents in GBM. Moreover, the physicochemical properties of QCT and KMF, determining their bioavailability and therapeutic efficiency, were evaluated. We proved that both polyphenols significantly reduced the viability of GBM cells. We also demonstrated that both QCT and KMF evoked the cytotoxic effect in T98G cells via induction of apoptotic cell death as shown by increased activity of caspase 3/7 and caspase 9 together with an overexpression of the cleaved form of PARP. Apoptosis was additionally accompanied by the activation of stress responses in QCT- and KMF-treated cells. Both polyphenols caused oxidative stress and endoplasmic reticulum (ER) stress, as demonstrated by the increased generation of reactive oxygen species (ROS), deregulated expressions of superoxide dismutases (SOD2 and Sod1 on protein and transcriptomic levels, respectively), as well as an overexpression of ERO1α, GRP78, p-JNK, and an up-regulation of Chop, Atf4 and Atf6α genes. The antitumor effect of QCT and KMF was also confirmed in vivo, showing reduced growth of tumor xenografts in the chick chorioallantoic membrane (CAM) experiment. Moreover, electrophoretic light scattering (ELS) was used to measure the zeta potential of cell membranes upon exposition to QCT and KMF. Additionally, on the basis of existing physicochemical data, the drug-likeness score of QCT and KMF was evaluated. Analyses showed that both compounds accomplish Lipinski’s Rule of 5, and they both fit into the criteria of good central nervous system (CNS) drugs. Altogether, our data support the idea that QCT and KMF might be plausible candidates for evaluation as therapeutic agents in preclinical models of glioblastoma.

Chlorin e6-Loaded Nanostructured Lipid Carriers Targeted by Angiopep-2: Advancing Photodynamic Therapy in Glioblastoma.

Glioblastoma (GBM) is a highly aggressive brain tumor known for its resistance to standard treatments. Despite surgery being a primary option, it often leads to incomplete removal and high recurrence rates. Photodynamic therapy (PDT) holds promise as an adjunctive treatment, but safety concerns and the need for high-power lasers have limited its widespread use. This research addresses these challenges by introducing a novel PDT approach, using chlorin e6 (Ce6) enclosed in nanostructured lipid carriers (Ang-Ce6-NLCs) and targeted to GBM with the angiopep-2 peptide. Remarkably, a single 5-min irradiation session with LEDs at 660nm and low power density (10mW cm- 2) proves effective against GBM, while reducing safety risks associated with high-power lasers. Encapsulation improves Ce6 stability and performance in physiological environments, while angiopep-2 targeting enhances delivery to GBM cells, maximizing treatment efficacy and minimizing off-target effects. The findings demonstrate that Ang-Ce6-NLCs-mediated PDT brings about a significant reduction in GBM cell viability, increases oxidative stress, reduces tumor migration, and enhances apoptosis. Overall, such treatment holds potential as a safe and efficient intraoperative removal of GBM infiltrating cells that cannot be reached by surgery, using low-power LED light to minimize harm to surrounding healthy tissue while maximizing tumor treatment.

Bufotalin Induces Oxidative Stress-Mediated Apoptosis by Blocking the ITGB4/FAK/ERK Pathway in Glioblastoma.

Bufotalin (BT), a major active constituent of Chansu, has been found to possess multiple pharmacological activities. Although previous studies have shown that BT could inhibit the growth of glioblastoma (GBM), the safety of BT in vivo and the potential mechanism are still unclear. We conducted a systematic assessment to investigate the impact of BT on GBM cell viability, migration, invasion, and colony formation. Furthermore, in vivo results were obtained to evaluate the effect of BT on tumor growth. The preliminary findings of our study demonstrate the effective inhibition of GBM cell growth and subcutaneous tumor development in mice by BT, with tolerable levels of tolerance observed. Mechanistically, BT treatment induced mitochondrial dysfunction, bursts of reactive oxygen species (ROS), and subsequent cell apoptosis. More importantly, proteomic-based differentially expressed proteins analysis revealed a significant downregulation of integrin β4 (ITGB4) following BT treatment. Furthermore, our evidence suggested that the ITGB4/focal adhesion kinase (FAK)/extracellular signal-related kinase (ERK) pathway involved BT-induced apoptosis. Overall, our study demonstrates the anti-GBM effects of BT and elucidates the underlying mechanism, highlighting BT as a potential therapeutic option for GBM.

THOC1 complexes with SIN3A to regulate R-loops and promote glioblastoma progression.

Glioblastoma (GBM), the most common and aggressive malignant brain tumor in adults, has a median survival of 21 months. To identify drivers of GBM proliferation, we conducted a CRISPR-knockout screen, which revealed THO Complex 1 (THOC1) as a key driver. Knocking down THOC1 significantly reduced GBM cell viability across patient-derived xenograft (PDX) lines, enhancing survival (p<0.01) in primary PDX models. Conversely, overexpressing THOC1 in non-cancerous cells bolstered viability, decreasing survival and causing tumor engraftment in vivo (p<0.01). Further investigation revealed THOC1's robust interaction with SIN3A, a histone deacetylase complex. Histone deacetylation has been previously shown to prevent the buildup of R-loops, structures that form normally during transcription but can be lethal in excess. We found that THOC1-knockdown leads to elevated R-loop levels and reduced histone deacetylation levels. Next, to understand the networks specifically regulated by THOC1-mediated R-loop prevention, we conducted unbiased RNA-sequencing on control and THOC1-knockdown GBM cells. We found that THOC1's role in R-loop prevention primarily affects telomeres, critical regions for cell replication. We further show that THOC1-knockdown results in significantly increased telomeric R-loop levels and shortened telomeres. Ultimately, this study suggests that targeting THOC1 shows promise as a therapeutic strategy to disrupt the delicate R-loop landscape and undermine GBM's replicative potential.

Dexmedetomidine inhibits the migration, invasion, and glycolysis of glioblastoma cells by lactylation of c-myc

ABSTRACT Background Glioblastoma (GBM) is a brain tumor with poor prognosis. Dexmedetomidine (Dex) regulates the biological behaviors of tumor cells to accelerate or decelerate cancer progression. Objective We investigated the effects of Dex on the migration, invasion, and glycolysis in GBM. Methods The concentration of Dex was determined using the cell counting kit-8 assay. The impacts of Dex on biological behaviors of GBM cells were assessed using Transwell assay, XF96 extracellular flux analysis, and western blot. The expression of c-Myc was examined using reverse transcription-quantitative polymerase chain reaction. The lactylation or stability of c-Myc was measured by western blot after immunoprecipitation or cycloheximide treatment. Results We found that Dex (200 nM) inhibited GBM cell viability, migration, invasion, and glycolysis. C-Myc was highly expressed in GBM cells and was decreased by Dex treatment. Moreover, Dex suppressed lactylated c-Myc levels via suppressing glycolysis, thereby reducing the protein stability of c-Myc. Sodium lactate treatment abrogated the effects of Dex on the biological behaviors of GBM cells. Conclusion Dex suppressed the migration, invasion, and glycolysis of GBM cells via inhibiting lactylation of c-Myc and suppressing the c-Myc stability, suggesting that Dex may be a novel therapeutic drug for GBM treatment.

5-Aminolevulinic acid-mediated photodynamic therapy in combination with kinase inhibitor lapatinib enhances glioblastoma cell death

5-Aminolevulinic acid (ALA) is an intraoperative imaging agent approved for protoporphyrin IX (PpIX) fluorescence-guided resection of glioblastoma (GBM). It is currently under clinical evaluation for photodynamic therapy (PDT) after the completion of GBM surgery. We previously showed that lapatinib, a clinical kinase inhibitor of epidermal growth factor receptor 1 & 2 (EGFR and HER2), enhanced PpIX fluorescence in a panel of GBM cell lines by blocking ABCG2 (ATP-binding cassette super-family G member 2)-mediated PpIX efflux, which suggests its potential for improving ALA for GBM surgery and PDT. Here we show that lapatinib enhanced PDT-induced cytotoxicity by promoting GBM cell death with the induction of apoptosis followed by necrosis. While the induction of tumor cell apoptosis was massive and rapid in the H4 cell line with no detectable Bcl-2 and a low level of Bcl-xL, it was delayed and much less in extent in A172, U-87 and U-118 cell lines with higher levels of pro-survival Bcl-2 family proteins. Lapatinib treatment alone neither reduced GBM cell viability nor had any significant effect on EGFR downstream signaling. Its enhancement of ALA–PDT was largely due to the increase of intracellular PpIX particularly in the mitochondria, resulting in the activation of mitochondria-mediated apoptosis in H4 cells. Our present study demonstrates that lapatinib inhibits ABCG2-mediated PpIX efflux and sensitizes GBM cells to ALA–PDT by inducing tumor cell death.

Polθ Inhibitor (ART558) Demonstrates a Synthetic Lethal Effect with PARP and RAD52 Inhibitors in Glioblastoma Cells.

DNA repair proteins became the popular targets in research on cancer treatment. In our studies we hypothesized that inhibition of DNA polymerase theta (Polθ) and its combination with Poly (ADP-ribose) polymerase 1 (PARP1) or RAD52 inhibition and the alkylating drug temozolomide (TMZ) has an anticancer effect on glioblastoma cells (GBM21), whereas it has a low impact on normal human astrocytes (NHA). The effect of the compounds was assessed by analysis of cell viability, apoptosis, proliferation, DNA damage and cell cycle distribution, as well as gene expression. The main results show that Polθ inhibition causes a significant decrease in glioblastoma cell viability. It induces apoptosis, which is accompanied by a reduction in cell proliferation and DNA damage. Moreover, the effect was stronger when dual inhibition of Polθ with PARP1 or RAD52 was applied, and it is further enhanced by addition of TMZ. The impact on normal cells is much lower, especially when considering cell viability and DNA damage. In conclusion, we would like to highlight that Polθ inhibition used in combination with PARP1 or RAD52 inhibition has great potential to kill glioblastoma cells, and shows a synthetic lethal effect, while sparing normal astrocytes.

ORY-1001 inhibits glioblastoma cell growth by downregulating the Notch/HES1 pathway via suppressing lysine-specific demethylase 1 expression

To explore the inhibitory effect ORY-1001, a lysine-specific histone demethylase 1 (LSD1) inhibitor, on growth of glioblastoma (GBM) and the underlying mechanism. We analyzed LSD1 expressions in GBM and normal brain tissues based on data from TCGA and HPA databases. Female BALB/c mouse models bearing xenografts derived from U87 cells or cells with lentivirus-mediated LSD1 silencing or Notch overexpression were treated with saline or 400 µg/kg ORY-1001 by gavage every 7 days, and GBM formation and survival time of the mice were recorded. The effect of ORY-1001 on GBM cell viability was assessed, and its effect on LSD1 expression was analyzed with Western blotting. The genes and pathways associated with LSD1 were analyzed using bioinformatics methods. Western blotting and qRT-PCR were used to detect Notch/HES1 pathway expression after LSD1 silencing and ORY-1001 treatment. The impact of ORY-1001 on viability of U87 cells with Notch1 silencing or overexpression was assessed, and the regulatory effects of ORY-1001 on Notch/HES1 pathway were analyzed using chromatin immunoprecipitation assay. A high expression of LSD1 in GBM was negatively correlated with patient survival (P < 0.001). ORY-1001 and LSD1 silencing obviously reduced tumor burden and prolonged the survival time of GBM-bearing mice. ORY-1001 treatment significantly inhibited the viability and dose-dependently decreased LSD1 expression in GBM cells, and such inhibitory effect of ORY-1001 was attenuated by LSD1 silencing. The Notch pathway enriched the differential genes related to LSD1, and Notch/HES1 pathway expression was significantly down-regulated after LSD1 silencing and ORY-1001 treatment. Notch1 overexpression significantly attenuated the anti-tumor effect of ORY-1001 on GBM. Mechanistically, ORY-1001 disrupted the interaction between LSD1 and the Notch pathway target genes including Notch3, HES1 and CR2. ORY-1001 down-regulates the Notch/HES1 pathway by inhibiting LSD1 expression to suppress the growth of GBM in mice.

Up-regulation of LPCAT1 is correlated with poor prognosis and promotes tumor progression in glioblastoma.

Glioblastoma (GBM) is a cancer with high malignancy because of its rapid proliferation and high metastatic ability. LPCAT1 is reported to play a tumor-promoting role in multiple cancers, but its precise molecular mechanism in GBM remains to be further explored. We aim to explore the biological role of LPCAT1 in GBM. In this study, the expression of LPCAT1 and its correlation with clinicopathological characteristics of GBM patients were analyzed based on The Cancer Genome Atlas (TCGA) dataset. Kaplan-Meier approach was adopted for plotting survival curves for patients showing different expression levels of LPCAT1. Meanwhile, LPCAT1 expression within 50 GBM tumor tissues and 30 non-tumor clinical samples was analyzed by qRT-PCR and western blot assays, respectively. Later, LPCAT1's effect on GBM tumorigenesis was analyzed in vivo and in vitro by CCK8, EdU proliferation, clone forming, scratch, TUNEL assays, and subcutaneous xenograft experiments. As a result, LPCAT1 expression elevated within GBM tumor tissues and cells. Overexpression of LPCAT1 enhanced GBM cell growth, invasion and migration, while accelerating cell cycle progression. LPCAT1 silencing significantly inhibited cell motility and proliferation in vivo and in vitro, and arrested U251 cells at G0/G1 phase. Moreover, LPCAT1 might play a role in GBM progression by activating the p-AKT-MYC signaling pathway. LPCAT1 activated AKT, which were synchronously up-regulated MYC to accelerate cancer progression. Knockdown of LPCAT1 induced the opposite changes to repress the viability and motility of GBM cells. LPCAT1 contributed to the progression of GBM by participating in the p-AKT-MYC axis.

The combination of temozolomide and perifosine synergistically inhibit glioblastoma by impeding DNA repair and inducing apoptosis

Temozolomide (TMZ) is widely utilized as the primary chemotherapeutic intervention for glioblastoma. However, the clinical use of TMZ is limited by its various side effects and resistance to chemotherapy. The present study revealed the synergistic inhibition of glioblastoma through the combined administration of TMZ and perifosine. This combination therapy markedly diminished BRCA1 expression, resulting in the suppression of DNA repair mechanisms. Furthermore, the combination of TMZ and perifosine elicited caspase-dependent apoptosis, decreasing glioblastoma cell viability and proliferation. The observed synergistic effect of this combination therapy on glioblastoma was validated in vivo, as evidenced by the substantial reduction in glioblastoma xenograft growth following combined treatment with TMZ and perifosine. In recurrent glioma patients, higher BRCA1 expression is associated with worse prognosis, especially the ones that received TMZ-treated. These findings underscore the potent antitumor activity of the AKT inhibitor perifosine when combined with TMZ and suggest that this approach is a promising strategy for clinical glioblastoma treatment.

Evidence That a Peptide-Drug/p53 Gene Complex Promotes Cognate Gene Expression and Inhibits the Viability of Glioblastoma Cells.

Glioblastoma multiform (GBM) is considered the deadliest brain cancer. Conventional therapies are followed by poor patient survival outcomes, so novel and more efficacious therapeutic strategies are imperative to tackle this scourge. Gene therapy has emerged as an exciting and innovative tool in cancer therapy. Its combination with chemotherapy has significantly improved therapeutic outcomes. In line with this, our team has developed temozolomide-transferrin (Tf) peptide (WRAP5)/p53 gene nanometric complexes that were revealed to be biocompatible with non-cancerous cells and in a zebrafish model and were able to efficiently target and internalize into SNB19 and U373 glioma cell lines. The transfection of these cells, mediated by the formulated peptide-drug/gene complexes, resulted in p53 expression. The combined action of the anticancer drug with p53 supplementation in cancer cells enhances cytotoxicity, which was correlated to apoptosis activation through quantification of caspase-3 activity. In addition, increased caspase-9 levels revealed that the intrinsic or mitochondrial pathway of apoptosis was implicated. This assumption was further evidenced by the presence, in glioma cells, of Bax protein overexpression-a core regulator of this apoptotic pathway. Our findings demonstrated the great potential of peptide TMZ/p53 co-delivery complexes for cellular transfection, p53 expression, and apoptosis induction, holding promising therapeutic value toward glioblastoma.

Assessment of silver nanoparticles' antitumor effects: Insights into cell number, viability, and morphology of glioblastoma and prostate cancer cells

Silver nanoparticles (AgNPs) hold promise for cancer therapy. This study aimed to evaluate their impact on tumor and non-tumor cell number, viability, and morphology. Antitumor activity was tested on U-87MG (glioblastoma) and DU-145 (prostate cancer) cell lines. Treatment with AgNPs notably reached a reduction of U-87MG and DU-145 cell growth by 89.30% and 79.74%, respectively, resulting in slower growth rates. AgNPs induced DNA damage, evidenced by reduced nuclear area and DNA content via fluorescent image-based analyses. Conversely, HFF-1 non-tumor cells displayed no significant changes post-AgNPs exposure. Viability assays revealed substantial reductions in U-87MG and DU-145 cells (79% and 63% in MTT assays, 30% and 52.2% in high-content analyses), while HFF-1 cells exhibited lower sensitivity. Tumor cells had notably lower IC50 values than non-tumor cells, indicating selective susceptibility. Transmission electron microscopy (TEM) showed morphological changes post-AgNPs administration, including increased vacuoles, myelin figures, membrane ghosts, cellular extravasation, and membrane projections. The findings suggest the potential of AgNPs against glioblastoma and prostate cancer, necessitating further exploration across other cancer cell lines.

Discovery of Potent Multikinase Type-II Inhibitors Targeting CDK5 in the DFG-out Inactive State with Promising Potential against Glioblastoma.

Kinases have proven valuable targets in successful cancer drug discovery projects, but not yet for malignant brain tumors where type-II inhibition of cyclin-dependent kinase 5 (CDK5) stabilizing the DFG-out inactive state has potential for design of selective and clinically efficient drug candidates. In the absence of crystallographic evidence for a CDK5 DFG-out inactive state protein-ligand complex, for the first time, a model was designed using metadynamics/molecular dynamics simulations. Glide docking of the ZINC15 biogenic database identified [pyrimidin-2-yl]amino-furo[3,2-b]-furyl-urea/amide hit chemical scaffolds. For four selected analogues (4, 27, 36, and 42), potent effects on glioblastoma cell viability in U87-MG, T98G, and U251-MG cell lines and patient-derived cultures were generally observed (IC50s ∼ 10-40 μM at 72 h). Selectivity profiling against 11 homologous kinases revealed multikinase inhibition (CDK2, CDK5, CDK9, and GSK-3α/β), most potent for GSK-3α in the nanomolar range (IC50s ∼ 0.23-0.98 μM). These compounds may therefore have diverse anticancer mechanisms of action and are of considerable interest for lead optimization.

Antitumoral Activity of the Universal Methyl Donor S-Adenosylmethionine in Glioblastoma Cells.

Glioblastoma (GBM), the most frequent and lethal brain cancer in adults, is characterized by short survival times and high mortality rates. Due to the resistance of GBM cells to conventional therapeutic treatments, scientific interest is focusing on the search for alternative and efficient adjuvant treatments. S-Adenosylmethionine (AdoMet), the well-studied physiological methyl donor, has emerged as a promising anticancer compound and a modulator of multiple cancer-related signaling pathways. We report here for the first time that AdoMet selectively inhibited the viability and proliferation of U87MG, U343MG, and U251MG GBM cells. In these cell lines, AdoMet induced S and G2/M cell cycle arrest and apoptosis and downregulated the expression and activation of proteins involved in homologous recombination DNA repair, including RAD51, BRCA1, and Chk1. Furthermore, AdoMet was able to maintain DNA in a damaged state, as indicated by the increased γH2AX/H2AX ratio. AdoMet promoted mitotic catastrophe through inhibiting Aurora B kinase expression, phosphorylation, and localization causing GBM cells to undergo mitotic catastrophe-induced death. Finally, AdoMet inhibited DNA repair and induced cell cycle arrest, apoptosis, and mitotic catastrophe in patient-derived GBM cells. In light of these results, AdoMet could be considered a potential adjuvant in GBM therapy.

Linagliptin decreased the tumor progression on glioblastoma model

PurposeDipeptidyl peptidase-4 (DPP-4) inhibitors are oral hypoglycemic drugs and are used for type II diabetes. Previous studies showed that DPP-4 expression is observed in several tumor types and DPP-4 inhibitors suppress the tumor progression on murine tumor models. In this study, we evaluated the role of DPP-4 and the antitumor effect of a DPP-4 inhibitor, linagliptin, on glioblastoma (GBM). MethodsWe analyzed DPP-4 expression in glioma patients by the public database. We also analyzed DPP-4 expression in GBM cells and the murine GBM model. Then, we evaluated the cell viability, cell proliferation, cell migration, and expression of some proteins on GBM cells with linagliptin. Furthermore, we evaluated the antitumor effect of linagliptin in the murine GBM model. ResultsThe upregulation of DPP-4 expression were observed in human GBM tissue and murine GBM model. In addition, DPP-4 expression levels were found to positively correlate with the grade of glioma patients. Linagliptin suppressed cell viability, cell proliferation, and cell migration in GBM cells. Linagliptin changed the expression of phosphorylated NF-kB, cell cycle, and cell adhesion-related proteins. Furthermore, oral administration of linagliptin decreases the tumor progression in the murine GBM model. ConclusionInhibition of DPP-4 by linagliptin showed the antitumor effect on GBM cells and the murine GBM model. The antitumor effects of linagliptin is suggested to be based on the changes in the expression of several proteins related to cell cycle and cell adhesion via the regulation of phosphorylated NF-kB. This study suggested that DPP-4 inhibitors could be a new therapeutic strategy for GBM.

392 Targeting One-Carbon Metabolism in Brain Cancer

OBJECTIVES/GOALS: Glioblastoma (GBM) is the most malignant brain tumor in adults and remains incurable with an average survival of 15 months after diagnosis. There is great need for treatment options without side effects that are devastating to the quality of life for patients. GBM tumors can circumvent cellular damage by upregulating antioxidant production. METHODS/STUDY POPULATION: Highly aggressive tumors tend to exhibit increased oxidative metabolism, and thus rely on a mechanism to eliminate reactive oxygen species (ROS) in order for cells to evade autophagy and cell death. We propose that recurrent GBM cells achieve this is by promoting methionine metabolism, upregulating glutathione production and preventing ROS accumulation. We investigated the expression of AHCY and MAT2A, two key enzymes in the methionine pathway, at the gene and protein level in both GBM and non-GBM tissues. We probed for markers of cell death following pharmacological inhibition and siRNA knockdown, and performed metabolite-mediated rescue experiments. Finally, we evaluated changes in cellular respiration using the Seahorse XFe96 real-time mitochondrial stress test following inhibitor treatment. RESULTS/ANTICIPATED RESULTS: The selective AHCY inhibitor markedly reduced cell viability in different cancer cell types, but significantly reduced cell viability in recurrent GBM cells compared to newly diagnosed GBM (p=.009; MD: -0.828, 95% CI -1.350 to -0.306) and normal astrocytes (p=.073; MD: -0.609, 95% CI -1.305 to 0.085). AHCY and MAT2a protein expression appeared to be higher in GBM cells compared to normal astrocytes, medulloblastoma cells and other cancer cell lines. Genetic knockdown of AHCY and MAT2A demonstrated reduced cell viability, increased Caspase, SOD2, LC3-II and Transferrin receptor expression. Acute treatment with the AHCY inhibitor induced cell death, markedly reduced oxygen consumption rate and ablated spare respiratory capacity in recurrent GBM cells compared to newly diagnosed GBM cells. DISCUSSION/SIGNIFICANCE: Oxidative damage was induced following interference with key methionine pathway enzymes by pharmacological inhibition, while a similar concentration of drug largely preserved normal astrocyte viability. These results point to a novel targetable mechanism of disease progression and expand the realm of treatment options for recurrent GBM.