T98G Glioblastoma Multiforme Cell Research Articles

Inhibitory effect of temozolomide on apoptosis induction of cinnamaldehyde in human glioblastoma multiforme T98G cell line.

Glioblastoma is the most common primary malignant brain tumor in adults. Temozolomide (TMZ) is an FDA-approved drug used to treat this type of cancer. Cinnamaldehyde (CIN) is a derivative of cinnamon extract and makes up 99% of it. The aim of this study was to investigate the in vitro combined effect of CIN and TMZ on human glioblastoma multiforme T98G cell line viability. In this study, we used 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tertazolium bromide (MTT) method to evaluate the extent of IC50, acridine orange, Giemsa and Hoechst staining to evaluate the manner of apoptosis and the Western blotting method to examine the expression change of apoptotic proteins. Our results show that TMZ has an inhibitory effect on CIN when both used in combination at concentrations of 300 and 100 μM (P<0.05) and has a cytotoxic effect when used alone at the same concentrations (P<0.05). The western blotting result showed that TMZ at concentrations of 2,000 and 1,000 μM significantly increased Bax expression and decreased Bcl2 expression (P<0.05), indicating that TMZ induced apoptosis through the mitochondrial pathway. However, CIN had no effect on Bax and Bcl2 expressions, thus causing apoptosis from another pathway. Also, the Bax:Bcl2 expression ratio at concentrations combined was lower than that for TMZ 1,000 μM and higher than that for CIN 150 and 100 μM (P<0.05), which confirms the inhibitory effect of TMZ on CIN. From the present study, we conclude that TMZ in combination with CIN has an inhibitory effect on increasing the cytotoxicity rate.

α-Solanine Suppresses Glioblastoma Multiforme Growth and Metastatic Properties by Modulating the Apoptosis-autophagy Axis

Introduction: Glioblastoma multiforme (GBM) has a poor prognosis despite optimal treatment. Recent studies have shown the potential of phytochemicals as anti-cancer agents. α-solanine, derived from plants of the Solanum genus, is a promising molecule in this regard. This study investigated the efficacy of α-solanine compared to temozolomide (TMZ) against GBM cell lines (U87MG, U251, and T98G) in vitro.&#x0D; Methods: In-vitro assays were conducted to assess the viability, migration, invasion, and mode of cell death of U87MG, U251 and T98G GBM cell lines following α-solanine treatment in comparison to TMZ. Rt-qPCR and proteome profiling were conducted to investigate the changes induced by α-solanine on a molecular level.&#x0D; Results: α-solanine demonstrated potent cytotoxicity on all GBM lines, with IC50 values ranging from 19.66 µM to 22.87 µM between cell lines tested, and significantly inhibited GBM cell migration compared to TMZ treatment. RNA and protein level assays indicated upregulation of both apoptotic and autophagy proteins, suggesting the involvement of BECN1 and BNIP3L in α-solanine-induced cell death.&#x0D; Discussion and Conclusion: These findings contribute to the search for effective GBM treatments. Future studies should increase the number of biological replicates, employ alternative methods to strengthen the findings, and conduct in vivo experiments and testing using patient-derived GBM tissue to better evaluate any therapeutic suitability of and fully understand the mode of action of α-solanine on GBM.

Targeting glioblastoma multiforme using a novel fusion protein comprising interleukin-13 and staphylococcal enterotoxin B in vitro

Targeting cell surface receptors with immunotoxins provides a novel, unique and highly potent treatment against cancers. A high expression of interleukin-13 (IL13) receptor α2 (IL13Rα2) has been reported in different types of cancers including glioblastoma multiforme (GBM). In this paper, to target IL13Rα2 on GBM cells, a fusion protein was generated comprising human IL13 and staphylococcal enterotoxin B (SEB), termed IL13-linker-SEB. The fusion protein was cloned into pET28a(+) and expressed in Escherichia coli strain BL21 (DE3); U251 (IL13Rα2-positive) and T98G (IL13Rα2-negative) GBM cell lines were employed and the functional activity of IL13-linker-SEB was evaluated by cell ELISA, cytotoxicity (MTT and LDH), apoptosis (flow cytometry and caspase-3 activity), adhesion, scratch and RT-PCR tests. SEB and chemotherapeutic drugs were employed to be compared to IL13-linker-SEB function. The IL13-linker-SEB exhibited higher binding affinity and cytotoxicity compared to SEB on U251 cells, although both recombinant proteins had shown similar behavior regarding T98G cells. Furthermore, the highest induction of apoptosis was observed in U251 cells treated with IL13-linker-SEB which was confirmed by Bax/Bcl-2 ratio. The expression of MMP2, MMP9 and VEGFR2 in U251 cells experienced a significant reduction after treatment with IL13-linker-SEB compared to SEB and T98G treated cells. The data showed that IL13-linker-SEB can be considered as a novel potential agent for GBM treatment; however, further research is needed to investigate the efficacy.

Quercetin induces MGMT+ glioblastoma cells apoptosis via dual inhibition of Wnt3a/β-Catenin and Akt/NF-κB signaling pathways

BackgroundSurgical resection combined with radiotherapy and chemotherapy remains a common clinical treatment for glioblastoma multiforme (GBM). However, the therapeutic outcomes have not been satisfying due to drug resistance and other factors. Quercetin, a phytoingredient capable of crossing the blood-brain barrier, has shown effectiveness in the treatment of various solid tumors. Nevertheless, the potential of quercetin in GBM treatment has not been adequately explored. PurposeThis study aims to investigate the effects and mechanisms of quercetin on MGMT+GBM cells. MethodsThe potential targets and mechanisms of quercetin in glioma treatment were predicted based on network pharmacology and molecular docking. The effects of quercetin on cell inhibition rate, cell migration ability, cell cycle arrest, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), Mitochondrial superoxide formation and apoptosis were measured by the CCK8 assay, wound healing assay, PI/RNase staining, JC-1 assay, DCFH-DA assay, MitoSOX staining and Annexin V-FITC/PI double staining, respectively. The methylation status of the MGMT promoter was assessed through methylation-specific polymerase chain reaction (MS-PCR). DNA damage was quantified by alkaline/neutral comet assay and TUNEL assay. The intracellular localization and expression of NF-κB and MGMT were revealed by immunofluorescence. The expression of migration-related proteins, matrix metalloproteinases, apoptosis-related proteins, cyclins, DNA damage/repair enzymes and related pathway proteins was detected by Western blot. ResultsNetwork pharmacology identified 96 targets and potential molecular mechanisms of quercetin in glioma treatment. Subsequent experiments confirmed the synergistic effect of quercetin in combination with temozolomide (TMZ) on T98G cells. Quercetin significantly suppressed the growth and migration of human GBM T98G cells, induced apoptosis, and arrested cells in the S-phase cell cycle. The collapse of mitochondrial membrane potential, ROS generation, enhanced Bax/Bcl-2 ratio, and strengthened cleaved-Caspase 9 and cleaved-Caspase 3 suggested the involvement of ROS-mediated mitochondria-dependent apoptosis in the process of quercetin-induced apoptosis. In addition, quercetin-induced apoptosis was accompanied by intense DNA double-strand breaks (DSBs), γH2AX foci formation, methylation of MGMT promoter, increased cleaved-PARP, and reduced MGMT expression. Quercetin may influence the expression of the key DNA repair enzyme, MGMT, by dual suppression of the Wnt3a/β-Catenin and the Akt/NF-κB signaling pathways, thereby promoting apoptosis. Inhibition of Wnt3a and Akt using specific inhibitors hindered MGMT expression. ConclusionOur study provides the first evidence that quercetin may induce apoptosis in MGMT+GBM cells via dual inhibition of the Wnt3a/β-Catenin pathway and the Akt/NF-κB signaling pathway. These findings suggest that quercetin could be a novel agent for improving GBM treatment, especially in TMZ-resistant GBM with high MGMT expression.

SREBP2/Rab11s/GLUT1/6 network regulates proliferation and migration of glioblastoma.

Cholesterol serves a vital role in the occurrence and development of glioblastoma multiforme (GBM). Furthermore, cholesterol synthesis is regulated by sterol regulatory element-binding protein 2 (SREBP2), and certain glucose transporters (GLUTs) and Ras-related protein Rab11 (Rab11) small GTPase family members (Rab11s) may contribute to the process. The Cancer Genome Atlas was used to analyze the relationship between prognosis and GLUT gene expressions. To investigate the regulatory effect of Rab11s and SREBP2 on GLUTs during tumor progression, single cell RNA sequencing (scRNA-seq), western blotting and reverse transcription-quantitative PCR were performed on glioma tissues and the T98G GBM cell line. Cell viability and migration were assessed by performing MTT and wound healing assays, respectively. Moreover, the dual-luciferase reporter gene assay was conducted to predict the sterol regulatory elements in the promoter regions of the target genes. The results demonstrated that high SREBP2, GLUT1 and GLUT6 expression was associated with poor survival of patients with GBM. ScRNA-seq distinguished glioblastoma cells by EGFR and indicated the related lipid metabolism signaling pathways. Moreover, the results indicated that GLUT1 and GLUT6 were regulated by SREBP2 and Rab11s. Rab11s and SREBP2 also contributed to T98G cell viability and migration. Additionally, the results indicated that Rab11s, GLUT1 and GLUT6 were transcriptionally regulated by SREBP2. Therefore, the present study suggested that the SREBP2/Rab11/GLUT network promoted T98G cell growth, thus, identifying potential therapeutic targets for GBM.

Synthesis and Inhibitory Activity of Machaeridiol-Based Novel Anti-MRSA and Anti-VRE Compounds and Their Profiling for Cancer-Related Signaling Pathways.

Three unique 5,6-seco-hexahydrodibenzopyrans (seco-HHDBP) machaeridiols A–C, reported previously from Machaerium Pers., have displayed potent activities against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium, and E. faecalis (VRE). In order to enrich the pipeline of natural product-derived antimicrobial compounds, a series of novel machaeridiol-based analogs (1–17) were prepared by coupling stemofuran, pinosylvin, and resveratrol legends with monoterpene units R-(−)-α-phellandrene, (−)-p-mentha-2,8-diene-1-ol, and geraniol, and their inhibitory activities were profiled against MRSA ATCC 1708, VRE ATCC 700221, and cancer signaling pathways. Compounds 5 and 11 showed strong in vitro activities with MIC values of 2.5 μg/mL and 1.25 μg/mL against MRSA, respectively, and 2.50 μg/mL against VRE, while geranyl analog 14 was found to be moderately active (MIC 5 μg/mL). The reduction of the double bonds of the monoterpene unit of compound 5 resulted in 17, which had the same antibacterial potency (MIC 1.25 μg/mL and 2.50 μg/mL) as its parent, 5. Furthermore, a combination study between seco-HHDBP 17 and HHDBP machaeriol C displayed a synergistic effect with a fractional inhibitory concentrations (FIC) value of 0.5 against MRSA, showing a four-fold decrease in the MIC values of both 17 and machaeriol C, while no such effect was observed between vancomycin and 17. Compounds 11 and 17 were further tested in vivo against nosocomial MRSA at a single intranasal dose of 30 mg/kg in a murine model, and both compounds were not efficacious under these conditions. Finally, compounds 1–17 were profiled against a panel of luciferase genes that assessed the activity of complex cancer-related signaling pathways (i.e., transcription factors) using T98G glioblastoma multiforme cells. Among the compounds tested, the geranyl-substituted analog 14 exhibited strong inhibition against several signaling pathways, notably Smad, Myc, and Notch, with IC50 values of 2.17 μM, 1.86 μM, and 2.15 μM, respectively. In contrast, the anti-MRSA actives 5 and 17 were found to be inactive (IC50 > 20 μM) across the panel of these cancer-signaling pathways.

Potential Neurotoxic Effects of Glioblastoma-Derived Exosomes in Primary Cultures of Cerebellar Neurons via Oxidant Stress and Glutathione Depletion

High-grade gliomas are the most fatal brain tumors. Grade 4 gliomas are called glioblastoma multiforme (GBM), which are associated with the poorest survival and a 5-year survival rate of less than 4%. Many patients with GBM developed concomitant cognitive dysfunctions and epilepsy. Although the cognitive decline is well defined in glioblastomas, the neurotoxic factors underlying this pathology are not well understood in GBM patients. In this study, we aimed to investigate whether GBM-derived exosomes play a role in neuronal toxicity. For this purpose, exosomes obtained from T98G and U373 GBM cells were applied to primary neuron culture at different concentrations. Subsequently, MTT, LDH, GSH, TAS, and TOS tests were performed. Both GBM-derived exosomes induced a dose-dependent and statistically significant increase of LDH release in cerebellar neurons. MTT assay revealed as both T98G and U373 GBM-derived exosomes induced dose-dependent neurotoxic effects in cerebellar neurons. To the best of our knowledge, this study is the first study demonstrating the toxic potential of GBM-derived exosomes to primary neurons, which may explain the peritumoral edema and cognitive decline in GBM patients.

Design and synthesis of novel caffeic acid phenethyl ester (CAPE) derivatives and their biological activity studies in glioblastoma multiforme (GBM) cancer cell lines

Glioblastoma Multiforme (GBM) is the most aggressive brain tumor and classified as one of the deadliest cancers. The current treatment plans for GBM remains to be ineffective because of its rapid progress and inability of the drugs used to cross the blood-brain barrier (BBB). Thus, developing more effective and potent medicines for GBM are needed. There have been several reports demonstrating that CAPE presents reasonably good anti-cancer activity in certain cancer cell lines and can penetrate the blood-brain barrier. Accordingly, in this study we synthesized several novel CAPE analogs with the addition of more druggable handles and solubilizing entities and subsequently evaluated their in vitro therapeutic efficacies in GBM cell lines (T98G and LN229). The most potent compound was then examined extensively and results showed that the 50 μM novel CAPE analog (compound 10) significantly decreases the viability of both T98G and LN229 GBM cells as compared to CAPE itself. Moreover, the compound 10 was not cytotoxic to healthy human cells (fibroblast-like mesenchymal stem cells) at the same concentration. Apoptotic (32.8%, and 44.6%) cell populations were detected in the compound 10 treated groups for LN229 and T98G, respectively. As an indication of apotosis, significantly increased PARP cleavage was detected in compound 10 versus CAPE treated LN229. In addition, we conducted molecular docking and molecular dynamics (MD) simulations studies on certain targets playing roles on GBM disease pathway such as NF-κB, EGFR, TNF-α, ERK2, PAPR1, hCA IX and hCA XII. Our findings demonstrated that designed CAPE analogs have anti-cancer activity on GBM cells and in silico studies also demonstrate the inhibitory ability of suggested compounds via interactions with critical residues in binding pockets of studied targets. Here, we suggest the novel CAPE analog to study further against GBM. Therefore, identification of the compound related molecular signature may provide more to understand the mechanism of action.

Anticancer Potential of Lipophilic Constituents of Eleven Shellfish Species Commonly Consumed in Korea.

The present study was aimed to investigate the composition and contents and the major lipophilic compounds, including the sterols, fatty acids, and tocols of shellfish species. Moreover, to explore the antitumor activity of these lipophilic constituents, their cytotoxicity potentials were determined against five different human cancer cells, including colon carcinoma (HCT116), epithelial melanoma (A2058), glioblastoma multiforme (T98G), lung carcinoma (A549), and adenocarcinoma (HeLa). The results show a significant variation in the contents and composition of lipophilic constituents among the studied species. The highest omega-3 (n-3) polyunsaturated fatty acids (PUFAs) were recorded from arrow squid and pacific oysters, accounting for 53.2% and 53.0% of their total fatty acids, respectively. However, the highest cholesterol content was also recorded in arrow squid (154.4 mg/100 g; 92.6% of total sterols). In contrast, in the Japanese littleneck, Yesso scallop, and common orient clam, cholesterol was just 17.1%, 18.3%, and 18.9% of total sterols, respectively, making them the richest source of non-cholesterol sterols (NCS). Lipids extracted from shellfish species showed ABTS+•- and DPPH•-scavenging activities. In the cytotoxicity analysis, lipids extracted from the Argentine red shrimp showed the highest cytotoxicity against glioblastoma multiforme T98G cells, with an IC50 value of 12.3 µg/mL. The composition and cytotoxicity data reported herein may help explore the nutritional and anticancer potentials of shellfish species.

Exploiting the anticancer effects of a nitrogen bisphosphonate nanomedicine for glioblastoma multiforme

Glioblastoma multiforme (GBM) is an incurable aggressive brain cancer in which current treatment strategies have demonstrated limited survival benefit. In recent years, nitrogen-containing bisphosphonates (N-BPs) have demonstrated direct anticancer effects in a number of tumour types including GBM. In this study, a nano-formulation with the RALA peptide was used to complex the N-BP, alendronate (ALN) into nanoparticles (NPs) < 200 nm for optimal endocytic uptake. Fluorescently labelled AlexaFluor®647 Risedronate was used as a fluorescent analogue to visualise the intracellular delivery of N-BPs in both LN229 and T98G GBM cells. RALA NPs were effectively taken up by GBM where a dose-dependent response was evidenced with potentiation factors of 14.96 and 13.4 relative to ALN alone after 72 h in LN229 and T98G cells, respectively. Furthermore, RALA/ALN NPs at the IC50, significantly decreased colony formation, induced apoptosis and slowed spheroid growth in vitro. In addition, H-Ras membrane localisation was significantly reduced in the RALA/ALN groups compared to ALN or controls, indicative of prenylation inhibition. The RALA/ALN NPs were lyophilised to enhance stability without compromising the physiochemical properties necessary for functionality, highlighting the suitability of the NPs for scale-up and in vivo application. Collectively, these data show the significant potential of RALA/ALN NPs as novel therapeutics in the treatment of GBM.

Identification of imidazo[4,5-c]pyridin-2-one derivatives as novel Src family kinase inhibitors against glioblastoma

Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumour in the central nervous system (CNS). As the ideal targets for GBM treatment, Src family kinases (SFKs) have attracted much attention. Herein, a new series of imidazo[4,5-c]pyridin-2-one derivatives were designed and synthesised as SFK inhibitors. Compounds 1d, 1e, 1q, 1s exhibited potential Src and Fyn kinase inhibition in the submicromolar range, of which were next tested for their antiproliferative potency on four GBM cell lines. Compound 1s showed effective activity against U87, U251, T98G, and U87-EGFRvIII GBM cell lines, comparable to that of lead compound PP2. Molecular dynamics (MDs) simulation revealed the possible binding patterns of the most active compound 1s in ATP binding site of SFKs. ADME prediction suggested that 1s accord with the criteria of CNS drugs. These results led us to identify a novel SFK inhibitor as candidate for GBM treatment.

Over‐expression of BICD1 gene as a marker for clinically predicting Temozolomide resistance in Glioblastomas

Glioblastoma multiforme (GBM) is a highly malignant tumor with a median survival of only 14 months, for which surgical resection, radiotherapy, and chemotherapy are the major clinical treatments. Temozolomide (TMZ) is currently the only FDA approved effective chemotherapy drug for treatment of GBM; however, cancer cells often develop drug resistance after TMZ treatment and eventually lead to treatment failure. Here, we demonstrated that Bicaudal D Homolog 1 (BICD1) gene would be a potential biomarker for predicting TMZ resistance in GBM patients. In our study, we found that T98G GBM cell is highly resistant to TMZ (IC50&gt;200μM), while U87 GBM cell is highly sensitive to TMZ (IC50&lt;100μM) by MTT assay. After treated with TMZ, gene expression of BICD1 was significantly upregulated in T98G cells and downregulated in U87. The available clinical datasets of the Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) indicated that over‐expression of BICD1 correlates with a poor outcome of GBM patients. Moreover, the TMZ sensitivity was recruited in T98G and SF126 GBM cells after their BICD1 genes were knocked down. Thus, over‐expression of BICD1 plays an important role in TMZ resistance when treating GBM.

Essential Oil from Arnica Montana L. Achenes: Chemical Characteristics and Anticancer Activity.

Mountain arnica Arnica montana L. is a source of several metabolite classes with diverse biological activities. The chemical composition of essential oil and its major volatile components in arnica may vary depending on the geographical region, environmental factors, and plant organ. The objective of this study was to characterize the chemical composition of essential oil derived from A. montana achenes and to investigate its effect on induction of apoptosis and autophagy in human anaplastic astrocytoma MOGGCCM and glioblastoma multiforme T98G cell lines. The chemical composition of essential oil extracted from the achenes was examined with the use of Gas Chromatography–Mass Spectrometry GC-MS. Only 16 components of the essential oil obtained from the achenes of 3-year-old plants and 18 components in the essential oil obtained from the achenes of 4-year-old plants constituted ca. 94.14% and 96.38% of the total EO content, respectively. The main components in the EO from the arnica achenes were 2,5-dimethoxy-p-cymene (39.54 and 44.65%), cumene (13.24 and 10.71%), thymol methyl ether (8.66 and 8.63%), 2,6-diisopropylanisole (8.55 and 8.41%), decanal (7.31 and 6.28%), and 1,2,2,3-tetramethylcyclopent-3-enol (4.33 and 2.94%) in the 3- and 4-year-old plants, respectively. The essential oils were found to exert an anticancer effect by induction of cell death in anaplastic astrocytoma and glioblastoma multiforme cells. The induction of apoptosis at a level of 25.7–32.7% facilitates the use of this secondary metabolite in further studies focused on the development of glioma therapy in the future. Probably, this component plays a key role in the anticancer activity against the MOGGCCM and T98G cell lines. The present study is the first report on the composition and anticancer activities of essential oil from A. montana achenes, and further studies are required to explore its potential for future medicinal purposes.

P11.15 Exosomal MicroRNA expression profiling altered by high TRAP1 expression in glioblastoma

Abstract BACKGROUND Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial molecular chaperone, which regulates the steady state transition between cellular aerobic glycolysis and oxidative phosphorylation. In contrast to normal brain, Glioblastoma multiforme (GBM) shows increased TRAP1 expression. However, the mechanisms responsible for metabolic switch mediated by TRAP1 have not been fully elucidated. Exosomes have been recently implicated in an emerging hallmark of cancer, the cancer cell metabolism. In this study, we studied whether the high expression of TRAP1 can affect the expression profile of miRNAs in the exosomes released by GBM, thus affecting the cell metabolism in the tumor microenvironment. MATERIAL AND METHODS We examined the expression profile of miRNAs in exosomes secreted by T98G GBM cell lines or T98G GBM cell lines depleted of TRAP1. The cancer-secreted exosomes were isolated by ultracentrifugation of the culture supernatant, and total RNAs, including miRNAs, were extracted from the isolated exosomes and subjected to miRNA microarray, and 3 miRNAs were further validated using qPCR. Target genes of differentially expressed miRNAs were the intersection predicted with 3 databases(Targetscan,microRNAorg,PITA). GO analysis and KEGG analysis were applied to determine the roles of these target genes. RESULTS Expression profiling of exosomal miRNA revealed significant downregulation of 237 miRNAs and upregulation of 134 miRNAs after deletion of TRAP1 in T98G GBM cell lines, while 3 of the upregulated miRNAs were further validated using qPCR. We found that these 3 miRNAs (hsa-miR-30e-5p,hsa-miR-1291,hsa-miR-300) showed a correlation with tumor cell glycolysis through literature searching and cross-searching of three microRNA databases. CONCLUSION We demonstrate high expression of TRAP1 can affect the expression profile of miRNAs in the exosomes released by GBM, that might reprogram the metabolic machinery following their uptake by other cells in the tumor microenvironment.

Gene Expression of Molecules Regulating Apoptotic Pathways in Glioblastoma Multiforme Treated with Umbilical Cord Stem Cell Conditioned Medium.

BackgroundGlioblastoma multiforme (GBM) is the most malignant primary brain tumour and there is no definite cure. It has been suggested that there are significant interactions among mesenchymal stem cells (MSCs), their released factors and tumour cells that ultimately determine GBM’s growth pattern. This study aims to analyse the expression of molecules involved in GBM cell apoptotic pathways following treatment with the MSC secretome.MethodsA conditioned medium of umbilical cord-derived MSCs (UCMSC-CM) was generated by culturing the cells on serum-free αMEM for 24 h. Following this, human GBM T98G cells were treated with UCMSC-CM for 24 h. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was then performed to measure the mRNA expression of survivin, caspase-9, TNF-related apoptosis-inducing ligand (TRAIL), DR4 and DcR1.ResultsmRNA expression of caspase-9 in CM-treated T98G cells increased 1.6-fold (P = 0.017), whereas mRNA expression of survivin increased 3.5-fold (P = 0.002). On the other hand, TRAIL protein expression was upregulated (1.2-fold), whereas mRNA expression was downregulated (0.4-fold), in CM-treated cells. Moreover, there was an increase in the mRNA expression of both DR4 (3.5-fold) and DcR1 (1,368.5-fold) in CM-treated cells.ConclusionThe UCMSC-CM was able to regulate the expression of molecules involved in GBM cell apoptotic pathways. However, the expression of anti-apoptotic molecules was more upregulated than that of pro-apoptotic molecules.

The impact of conditioned medium of umbilical cord-derived mesenchymal stem cells toward apoptosis and proliferation of glioblastoma multiforme cells

Glioblastoma multiforme (GBM) is the human malignant and highly invasive brain tumor. Tumor growth and invasive property are affected by mesenchymal stem cells (MSCs) as a part of tumor microenvironment. However, accumulating evidences describe that MSCs could act as pro and anti tumorigenic. The different action of MSCs in regulating tumor growth is mediated by secreted factor. This research purpose was to analyze the impact of MSCs secreted factor in conditioned medium (CM) on apoptosis and proliferation of GBM cells. Primary culture of umbilical cord-derived MSCs (UCSCs) was conducted in this research. CM-UCSCs was prepared by culturing the UCSCs in serum free aMEM for 24 hours. Those CM-UCSCs was 2-fold diluted by Dulbecco’s Modified Eagle Medium (DMEM) high glucose (50% concentration) and used to treat human GBM T98G cells for 24 hours. Following this treatment, apoptosis was detected using annexin V-FITC and cells proliferation was analyzed using trypan blue exclusion test. The results showed that early apoptosis occurred in 14.4 % of control cells and 14.8 % of CM-treated T98G cells, as well as late apoptosis occurred in 7.8 % of control cells and 7.2 % of CM-treated T98G cells. Whereas, GBM cells proliferation was tend to higher in the CM treated cells (3.85×105 cells) compared to the control (2.97×105 cells). In conclusion, CM-UCSCs does not seems to affect apoptosis, but tend to increase cells proliferation. Further research is needed to elaborate the mechanism of UCSCs secretome in stimulating cells proliferation.

Analysis of Human Nuclear Protein Complexes by Quantitative Mass Spectrometry Profiling.

Analysis of protein complexes provides insights into how the ensemble of expressed proteome is organized into functional units. While there have been advances in techniques for proteome-wide profiling of cytoplasmic protein complexes, information about human nuclear protein complexes are very limited. To close this gap, we combined native size exclusion chromatography (SEC) with label-free quantitative MS profiling to characterize hundreds of nuclear protein complexes isolated from human glioblastoma multiforme T98G cells. We identified 1794 proteins that overlapped between two biological replicates of which 1244 proteins were characterized as existing within stably associated putative complexes. co-IP experiments confirmed the interaction of PARP1 with Ku70/Ku80 proteins and HDAC1 (histone deacetylase complex 1) and CHD4. HDAC1/2 also co-migrated with various SIN3A and nucleosome remodeling and deacetylase components in SEC fractionation including SIN3A, SAP30, RBBP4, RBBP7, and NCOR1. Co-elution of HDAC1/2/3 with both the KDM1A and RCOR1 further confirmed that these proteins are integral components of human deacetylase complexes. Our approach also demonstrated the ability to identify potential moonlighting complexes and novel complexes containing uncharacterized proteins. Overall, the results demonstrated the utility of SEC fractionation and LC-MS analysis for system-wide profiling of proteins to predict the existence of distinct forms of nuclear protein complexes.

Analysis of pluripotency marker expression in human glioblastoma multiforme cells treated with conditioned medium of umbilical cord-derived mesenchymal stem cells

Background: Glioblastoma multiforme (GBM) is the most aggressive form of malignant glioma and is also known as grade IV astrocytoma. This might be due to the presence of cancer stem cells with high pluripotency and ability of self-renewal. Recently, it has been reported that tumor stroma cells, including mesencyhmal stem cells (MSCs), secrete factors that affect cancer cell growth. Until now, the role of MSC secretomes in cancer stem cell pluripotency remains unclear. The aim of this study was to analyze the effect of MSC secretomes in conditioned medium (CM) on the expression of pluripotency markers of GBM cells. Methods: Umbilical cord-derived MSCs (UCSCs) were grown on serum-free alphaMEM for 24 hours to prepare the UCSC-CM. Human GBM T98G cells were treated with UCSC-CM for 24 hours. Following this treatment, expression of pluripotency markers SOX2, OCT4 and NANOG genes was analyzed using quantitative RT-PCR. Results: SOX2 and OCT mRNA expression was 4.7-fold (p=0.02) and 1.3-fold (p=0.03) higher in CM-treated cells compared to the control. However, there was no change in NANOG mRNA expression. This might be due to there being others factors regulating NANOG mRNA expression. Conclusions: UCSC-CM could affect the expression of SOX2 and OCT4 in human glioblastoma multiforme T98G cells. Further research is needed to elucidate the mechanism by which pluripotency markers are expressed when induced by the UCSC secretome.

FOXK1 promotes glioblastoma proliferation and metastasis through activation of Snail transcription.

Forkhead box K1 (FOXK1) has been identified to have a crucial function in development and oncogenesis. However, its role in glioblastoma has remained largely elusive and was therefore assessed in the present study. In human glioblastoma multiforme (GBM) tissue samples, FOXK1 was determined to be highly expressed compared with adjacent normal tissue samples. In addition, high levels of FOXK1 were detected in the T98G and LN18 GBM cell lines as compare with those in normal human astrocytes. Of note, high expression of FOXK1 was revealed to be associated with metastasis and tumor size. Loss- and gain-of-function experiments were then performed to determine whether FOXK1 regulates epithelial to mesenchymal transition (EMT) and cell proliferation. Knockdown of FOXK1 significantly suppressed EMT and metastasis of GBM cells, while ectopic expression of FOXK1 promoted them. A luciferase reporter assay and a chromatin immunoprecipitation assay revealed that FOXK1 activated the transcription of Snail. In addition, as the results indicated that FOXK1 promotes GBM cell proliferation, the potential effect of FOXK1 on the cell cycle and apoptosis were further assessed. While FOXK1 had no effect on apoptosis, it promoted cell proliferation via enhancing the S-phase population. In brief, the present study indicated that FOXK1 acts as an oncogene with a key function in glioblastoma cell proliferation and EMT.

Metformin and temozolomide, a synergic option to overcome resistance in glioblastoma multiforme models.

Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor with poor survival. Cytoreduction in association with radiotherapy and temozolomide (TMZ) is the standard therapy, but response is heterogeneous and life expectancy is limited. The combined use of chemotherapeutic agents with drugs targeting cell metabolism is becoming an interesting therapeutic option for cancer treatment. Here, we found that metformin (MET) enhances TMZ effect on TMZ-sensitive cell line (U251) and overcomes TMZ-resistance in T98G GBM cell line. In particular, combined-treatment modulated apoptosis by increasing Bax/Bcl-2 ratio, and reduced Reactive Oxygen Species (ROS) production. We also observed that MET associated with TMZ was able to reduce the expression of glioma stem cells (GSC) marker CD90 particularly in T98G cells but not that of CD133. In vivo experiments showed that combined treatment with TMZ and MET significantly slowed down growth of TMZ-resistant tumors but did not affect overall survival of TMZ-sensitive tumor bearing mice. In conclusion, our results showed that metformin is able to enhance TMZ effect in TMZ-resistant cell line suggesting its potential use in TMZ refractory GBM patients. However, the lack of effect on a GBM malignancy marker like CD133 requires further evaluation since it might influence response duration.