stilbenes and Brain-Neoplasms

A brain tumor (BT) is a condition in which there is growth or uncontrolled development of the brain cells, which usually goes unrecognized or is diagnosed at the later stages. Since the mechanism behind BT is not clear, and the various physiological conditions are difficult to diagnose, the success rate of BT is not very high. This is the central issue faced during drug development and clinical trials with almost all types of neurodegenerative disorders. In the first part of this review, we focus on the concept of brain tumors, their barriers, and the types of delivery possible to target the brain cells. Although various treatment methods are available, they all have side effects or toxic effects. Hence, in the second part, a correlation was made between the use of resveratrol, a potent antioxidant, and its advantages for brain diseases. The relationship between brain disease and the blood-brain barrier, multi-drug resistance, and the use of nanomedicine for treating brain disorders is also mentioned. In short, a hypothetical concept is given with a background investigation into the use of combination therapy with resveratrol as an active ingredient, the possible drug delivery, and its formulation-based approach.

Topics: Antioxidants; Brain; Brain Neoplasms; Drug Delivery Systems; Humans; Pharmaceutical Preparations; Resveratrol; Stilbenes

Autophagy, cellular senescence, programmed cell death and necrosis are key responses of a cell facing a stress. These effects are partly interconnected, but regulation of their mutual interactions is not completely clear. That regulation seems to be especially important in cancer cells, which have their own program of development and demand more nutrition and energy than normal cells. Glioblastoma multiforme (GBM) belongs to the most aggressive and most difficult to cure cancers, so studies on its pathogenesis and new therapeutic strategies are justified. Using an animal model, it was shown that autophagy is required for GBM development. Temozolomide (TMZ) is the key drug in GBM chemotherapy and it was reported to induce senescence, autophagy and apoptosis in GBM. In some GBM cells, TMZ induces small toxicity despite its significant concentration and GBM cells can be intrinsically resistant to apoptosis. Resveratrol, a natural compound, was shown to potentiate anticancer effect of TMZ in GBM cells through the abrogation G2-arrest and mitotic catastrophe resulting in senescence of GBM cells. Autophagy is the key player in TMZ resistance in GBM. TMZ can induce apoptosis due to selective inhibition of autophagy, in which autophagic vehicles accumulate as their fusion with lysosomes is blocked. Modulation of autophagic action of TMZ with autophagy inhibitors can result in opposite outcomes, depending on the step targeted in autophagic flux. Studies on relationships between senescence, autophagy and apoptosis can open new therapeutic perspectives in GBM.

Topics: Animals; Antineoplastic Agents, Alkylating; Apoptosis; Autophagy; Brain Neoplasms; Cellular Senescence; Dacarbazine; Disease Models, Animal; DNA Damage; Glioblastoma; Humans; Mice; Resveratrol; Stilbenes; Temozolomide

There is growing interest in dietary phytochemicals as potential cancer chemopreventive agents. Resveratrol (3,4',5-trihydroxy-trans-stilbene), a naturally occurring phytoalexin that is present in grapes, red wine, berries and peanuts, has been studied extensively for its ability to interfere with multistage carcinogenesis. Resveratrol is known to have antioxidant, anti-inflammatory and antiproliferative effects on a variety of cancer cells in vitro and in various animal models. However, the effect(s) of resveratrol in vivo on humans are still controversial. This study discusses current knowledge with regard to the effects of resveratrol in relation to its potential as a chemopreventive and/or chemotherapeutic molecule against human gliomas.

Topics: Antineoplastic Agents; Brain Neoplasms; Glioma; Humans; Resveratrol; Ribonucleotide Reductases; Stilbenes

Topics: Animals; Antineoplastic Agents; Astrocytoma; Brain Neoplasms; Carcinogens; Carcinoma, Squamous Cell; Child; Ear Neoplasms; Ependymoma; Female; Humans; Immunosuppressive Agents; Isoniazid; Maternal-Fetal Exchange; Mice; Mycotoxins; Neoplasms; Nitrosourea Compounds; Occupational Diseases; Oligodendroglioma; Otorhinolaryngologic Diseases; Pregnancy; Rats; Stilbenes

The schweinfurthin family of natural compounds exhibit a unique and potent differential cytotoxicity against a number of cancer cell lines and may reduce tumor growth in vivo. In some cell lines, such as SF-295 glioma cells, schweinfurthins elicit cytotoxicity at nanomolar concentrations. However, other cell lines, like A549 lung cancer cells, are resistant to schweinfurthin treatment up to micromolar concentrations. At this time, the precise mechanism of action and target for these compounds is unknown. Here, we employ RNA sequencing of cells treated with 50 nM schweinfurthin analog TTI-3066 for 6 and 24 h to elucidate potential mechanisms and pathways which may contribute to schweinfurthin sensitivity and resistance. The data was analyzed via an interaction model to observe differential behaviors between sensitive SF-295 and resistant A549 cell lines. We show that metabolic and stress-response pathways were differentially regulated in the sensitive SF-295 cell line as compared with the resistant A549 cell line. In contrast, A549 cell had significant alterations in response genes involved in translation and protein metabolism. Overall, there was a significant interaction effect for translational proteins, RNA metabolism, protein metabolism, and metabolic genes. Members of the Hedgehog pathway were differentially regulated in the resistant A549 cell line at both early and late time points, suggesting a potential mechanism of resistance. Indeed, when cotreated with the Smoothened inhibitor cyclopamine, A549 cells became more sensitive to schweinfurthin treatment. This study therefore identifies a key interplay with the Hedgehog pathway that modulates sensitivity to the schweinfurthin class of compounds.

Topics: A549 Cells; Antineoplastic Agents, Phytogenic; Brain Neoplasms; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Energy Metabolism; Euphorbiaceae; Gene Expression Regulation, Neoplastic; Glioma; Hedgehog Proteins; Humans; Lung Neoplasms; Prenylation; RNA-Seq; Signal Transduction; Stilbenes; Transcription, Genetic; Transcriptome

Piceatannol (Pice), a natural analog of resveratrol, has been identified as an anticancer agent in various cancers by modulating the expression of microRNAs (miRNAs/miRs). However, the molecular mechanisms underlying the anticancer effects of Pice in osteosarcoma (OS) cells remain unclear. Thus, we hypothesized that Pice exerts anticancer effects on OS cells via the regulation of miRNA expression. Herein, we performed a MTT assay and flow cytometric analysis to determine cell viability and apoptosis in OS cells treated with Pice, respectively. Our results showed that Pice inhibits proliferation in a dose‑dependent manner induces the apoptosis of OS cells. More importantly, miRNA microarray analysis identified that Pice alters miRNA expression profiles in human OS cells after treatment with Pice, and miR‑21 was the most significantly downregulated. In addition, the therapeutic effects of Pice on OS cells were weakened by restoration of miR‑21. In addition, we further verified that phosphatase and tensin homolog (PTEN), a tumor suppressor gene, is the functional target of miR‑21 and Pice blocks the PTEN/AKT signaling pathway through inhibiting miR‑21 expression in OS cells. Our findings suggested that Pice may exert anticancer effects on OS cells via mediating the miR‑21/PTEN/AKT signaling pathway and could be considered to be a potential anticancer agent for treating OS.

Topics: Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Osteosarcoma; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Stilbenes

Topics: Adult; Aged; Amyloid; Aniline Compounds; Apolipoprotein E4; Brain; Brain Neoplasms; Chemoradiotherapy; Cognition; Cognition Disorders; Cohort Studies; Female; Glioma; Heterozygote; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Pilot Projects; Positron-Emission Tomography; Radiopharmaceuticals; Radiotherapy, Conformal; Stilbenes

The use of an optical resolution photoacoustic microscopy (OR-PAM) system to evaluate the vascular disruptive effect of combretastatin A4 Phosphate (CA4P) on a murine orthotopic glioma with intact skull is described here. Second generation optical-resolution photoacoustic microscopy scanner with a 532 nm pulsed diode-pumped solid-state laser that specifically matches the absorption maximum of hemoglobin in tissues was used to image orthotopic glioma inoculated in mouse brain. Two-dimensional maps of brain vasculature with a lateral resolution of 5 μm and a depth of 700 μm at a field of view 5 × 4 mm were acquired on normal brain and glioma brain. Longitudinal imaging of the brain pre- and post-administration of CA4P, a FDA approved drug for solid tumors, enabled the monitoring of hemodynamic changes in tumor vasculature revealing the well documented vascular shutdown and recovery associated with this drug. Our study marks the beginning of potential prospects of this technology as an imaging tool for preclinical and clinical study of pathologies characterized by changes in the vasculature.

Topics: Animals; Blood Vessels; Brain Neoplasms; Cell Line, Tumor; Cell Transformation, Neoplastic; Female; Glioma; Humans; Mice; Microscopy; Neovascularization, Pathologic; Photoacoustic Techniques; Stilbenes

Glioblastoma multiforme (GBM) is a grade IV astrocytoma and the most common form of malignant brain tumor in adults. GBM remains one of the most fatal and least successfully treated solid tumors: current therapies provide a median survival of 12-15 months after diagnosis, due to the high recurrence rate. Glioma Stem Cells (GSCs) are believed to be the real driving force of tumor initiation, progression and relapse. Therefore, better therapeutic strategies GSCs-targeted are needed. Resveratrol is a polyphenolic phytoalexin found in fruits and vegetables displaying pleiotropic health benefits. Many studies have highlighted its chemo-preventive and chemotherapeutic activities in a wide range of solid tumors. In this work, we analyzed the effects of Resveratrol exposure on cell viability, proliferation and motility in seven GSC lines isolated from GBM patients. For the first time in our knowledge, we investigated Resveratrol impact on Wnt signaling pathway in GSCs, evaluating the expression of seven Wnt signaling pathway-related genes and the protein levels of c-Myc and β-catenin. Finally, we analyzed Twist1 and Snail1 protein levels, two pivotal activators of epithelial-mesenchymal transition (EMT) program. Results showed that although response to Resveratrol exposure was highly heterogeneous among GSC lines, generally it was able to inhibit cell proliferation, increase cell mortality, and strongly decrease cell motility, modulating the Wnt signaling pathway and the EMT activators. Treatment with Resveratrol may represent a new interesting therapeutic approach, in order to affect GSCs proliferation and motility, even if further investigations are needed to deeply understand the GSCs heterogeneous response.

Topics: beta Catenin; Brain Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Epithelial-Mesenchymal Transition; Glioma; Humans; Neoplastic Stem Cells; Proto-Oncogene Proteins c-myc; Resveratrol; Stilbenes; Wnt Signaling Pathway

POK erythroid myeloid ontogenic factor (Pokemon), an important proto-oncoprotein, is a transcriptional repressor that regulates the expression of many genes and plays an important role in tumorigenesis. Resveratrol (RSV), a natural polyphenolic compound, has many beneficial biological effects on health. In this study, we investigated the role of Pokemon in RSV-induced biological effects and the effect of RSV on the expression of Pokemon in glioma cells. We found that overexpression of Pokemon decreased RSV-induced cell apoptosis, senescence, and anti-proliferative effects. Moreover, we showed that RSV could efficiently decrease the activity of the Pokemon promoter and the expression of Pokemon. Meanwhile, RSV also inhibited Sp1 DNA binding activity to the Pokemon promoter; whereas, it did not influence the expression and nuclear translocation of Sp1. In addition, we found that RSV could increase the recruitment of HDAC1, but decreased p300 to the Pokemon promoter. Taken together, all these results extended our understanding on the anti-cancer mechanism of RSV in glioma cells.

Topics: Apoptosis; Brain Neoplasms; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cellular Senescence; DNA-Binding Proteins; DNA, Neoplasm; E1A-Associated p300 Protein; Gene Expression Regulation, Neoplastic; Glioma; HEK293 Cells; Histone Deacetylase 1; Humans; Promoter Regions, Genetic; Protein Binding; Protein Transport; Resveratrol; Sp1 Transcription Factor; Stilbenes; Transcription Factors

Glioblastoma-initiating cells play crucial roles in the origin, growth, and recurrence of glioblastoma multiforme. The elimination of glioblastoma-initiating cells is believed to be a key strategy for achieving long-term survival of glioblastoma patients due to the highly resistant property of glioblastoma-initiating cells to temozolomide. Resveratrol, a naturally occurring polyphenol, has been widely studied as a promising candidate for cancer prevention and treatment. Whether resveratrol could enhance the sensitivity of glioblastoma-initiating cells to temozolomide therapy has not yet been reported. Here, using patient-derived glioblastoma-initiating cell lines, we found that resveratrol sensitized glioblastoma-initiating cells to temozolomide both in vitro and in vivo. Furthermore, we showed that resveratrol enhanced glioblastoma-initiating cells to temozolomide-induced apoptosis through DNA double-stranded breaks/pATM/pATR/p53 pathway activation, and promoted glioblastoma-initiating cell differentiation involving p-STAT3 inactivation. Our results propose that temozolomide and resveratrol combination strategy may be effective in the management of glioblastoma patients, particularly for those patients who have been present with a high abundance of glioblastoma-initiating cells in their tumors and show slight responsiveness to temozolomide.

Topics: Apoptosis; Ataxia Telangiectasia Mutated Proteins; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Dacarbazine; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Neoplastic Stem Cells; Phosphorylation; Resveratrol; Signal Transduction; Stilbenes; Temozolomide; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Glioblastoma (GBM) is the most common malignant brain tumor, and glioma stem cells (GSCs) are considered a major source of treatment resistance for glioblastoma. Identifying new compounds that inhibit the growth of GSCs and understanding their underlying molecular mechanisms are therefore important for developing novel therapy for GBM.. We investigated the potential inhibitory effect of isorhapontigenin (ISO), an anticancer compound identified in our recent investigations, on anchorage-independent growth of patient-derived glioblastoma spheres (PDGS) and its mechanism of action.. ISO treatment resulted in significant anchorage-independent growth inhibition, accompanied with cell cycle G0-G1 arrest and cyclin D1 protein downregulation in PDGS. Further studies established that cyclin D1 was downregulated by ISO at transcription levels in a SOX2-dependent manner. In addition, ISO attenuated SOX2 expression by specific induction of miR-145, which in turn suppressed 3'UTR activity of SOX2 mRNA without affecting its mRNA stability. Moreover, ectopic expression of exogenous SOX2 rendered D456 cells resistant to induction of cell cycle G0-G1 arrest and anchorage-independent growth inhibition upon ISO treatment, whereas inhibition of miR-145 resulted in D456 cells resistant to ISO inhibition of SOX2 and cyclin D1 expression. In addition, overexpression of miR-145 mimicked ISO treatment in D456 cells.. ISO induces miR-145 expression, which binds to the SOX2 mRNA 3'UTR region and inhibits SOX2 protein translation. Inhibition of SOX2 leads to cyclin D1 downregulation and PDGS anchorage-independent growth inhibition. The elucidation of the miR-145/SOX2/cyclin D1 axis in PDGS provides a significant insight into understanding the anti-GBM effect of ISO compound.

Topics: Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; MicroRNAs; SOXB1 Transcription Factors; Stilbenes

The clinical application of trans resveratrol (RSV) in glioma treatment is largely limited because of its rapid metabolism, fast elimination from systemic circulation and low biological half life. Therefore, the objectives of this study were to enhance the circulation time, biological half life and passive brain targeting of RSV using d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) coated liposomes (RSV-TPGS-Lipo). In addition to basic liposomal characterizations, in vitro anticancer potential against C6 glioma cell lines and cellular internalization of liposomes were carried out by MTT assay and confocal laser scanning microscopy (CLSM), respectively. Pharmacokinetics and tissue distribution studies were also carried out after intravenous administration in Charles Foster rats. RSV-TPGS-Lipo 2 showed significantly higher cytotoxicity than RSV-Lipo (uncoated liposomes) and RSV. Both uncoated and TPGS coated liposomes showed excellent cellular uptake. RSV, RSV-Lipo and RSV-TPGS-Lipo 2 were found to be haemocompatible and safe after i.v. administration. Area under the curve (AUC) and plasma half life (t1/2) after i.v. administration of RSV-TPGS-Lipo 2 was found to be approximately 5.73 and 6.72 times higher than that of RSV-Lipo as well as 29.94 and 29.66 times higher than that of RSV, respectively. Thus, the outcome indicates that RSV-TPGS-Lipo 2 is a promising carrier for glioma treatment with improved pharmacokinetic parameters. Moreover, brain accumulation of RSV-Lipo and RSV-TPGS-Lipo 2 was found to be significantly higher than that of RSV (P<0.05). Results are suggesting that both RSV-Lipo and RSV-TPGS-Lipo 2 are the promising tools of RSV for the treatment of brain cancer.

Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Cell Line, Tumor; Drug Carriers; Liposomes; Male; Nanomedicine; Polyethylene Glycols; Rats; Resveratrol; Stilbenes; Vitamin E

Like the anti-angiogenic strategy, anti-vascular mimicry is considered as a novel targeting strategy for glioma. In the present study, we used NGR as a targeting ligand and prepared NGR-modified liposomes containing combretastatin A4 (NGR-SSL-CA4) in order to evaluate their potential targeting of glioma tumor cells and vasculogenic mimicry (VM) formed by glioma cells as well as their anti-VM activity in mice with glioma tumor cells. NGR-SSL-CA4 was prepared by a thin-film hydration method. The in vitro targeting of U87-MG (human glioma tumor cells) by NGR-modified liposomes was evaluated. The in vivo targeting activity of NGR-modified liposomes was tested in U87-MG orthotopic tumor-bearing nude mice. The anti-VM activity of NGR-SSL-CA4 was also investigated in vitro and in vivo. The targeting activity of the NGR-modified liposomes was demonstrated by in vitro flow cytometry and in vivo biodistribution. The in vitro anti-VM activity of NGR-SSL-CA4 was indicated in a series of cell migration and VM channel experiments. NGR-SSL-CA4 produced very marked anti-tumor and anti-VM activity in U87-MG orthotopic tumor-bearing mice in vivo. Overall, the NGR-SSL-CA4 has great potential in the multi-targeting therapy of glioma involving U87-MG cells, and the VM formed by U87-MG cells as well as endothelial cells producing anti-U87-MG cells, and anti-VM formed by U87-MG cells as well as anti-endothelial cell activity.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Brain; Brain Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Endothelial Cells; Flow Cytometry; Glioma; Humans; Kaplan-Meier Estimate; Liposomes; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Multiple Chronic Conditions; Neovascularization, Pathologic; Oligopeptides; Optical Imaging; Stilbenes; Tissue Distribution; Xenograft Model Antitumor Assays

Brain metastasis is one of the chief causes of mortality in breast cancer patients, but the mechanisms that drive this process remain poorly understood. Here, we report that brain metastatic cells expressing high levels of c-Met promote the metastatic process via inflammatory cytokine upregulation and vascular reprogramming. Activated c-Met signaling promoted adhesion of tumor cells to brain endothelial cells and enhanced neovascularization by inducing the secretion of IL8 and CXCL1. Additionally, stimulation of IL1β secretion by activation of c-Met induced tumor-associated astrocytes to secrete the c-Met ligand HGF. Thus, a feed-forward mechanism of cytokine release initiated and sustained by c-Met fed a vicious cycle that generated a favorable microenvironment for metastatic cells. Reinforcing our results, we found that pterostilbene, a compound that penetrates the blood-brain barrier, could suppress brain metastasis by targeting c-Met signaling. These findings suggest a potential utility of this natural compound for chemoprevention. Cancer Res; 76(17); 4970-80. ©2016 AACR.

Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Breast Neoplasms; Cell Adhesion; Cell Line, Tumor; Female; Heterografts; Humans; Inflammation; Mice; Mice, Nude; Neoplasm Invasiveness; Neovascularization, Pathologic; Proto-Oncogene Proteins c-met; Signal Transduction; Stilbenes; Transcriptome; Tumor Microenvironment

Glioblastoma multiforme (GBM, astrocytoma grade IV) is the most common malignant primary brain tumor in adults. Addressing the shortage of effective treatment options for this cancer, we explored repurposing of existing drugs into combinations with potent activity against GBM cells. We report that the phytoalexin pterostilbene is a potentiator of two drugs with previously reported anti-GBM activity, the EGFR inhibitor gefitinib and the antidepressant sertraline. Combinations of either of these two compounds with pterostilbene suppress cell growth, viability, sphere formation and inhibit migration in tumor GBM cell (GC) cultures. The potentiating effect of pterostilbene was observed to a varying degree across a panel of 41 patient-derived GCs, and correlated in a case specific manner with the presence of missense mutation of EGFR and PIK3CA and a focal deletion of the chromosomal region 1p32. We identify pterostilbene-induced cell cycle arrest, synergistic inhibition of MAPK activity and induction of Thioredoxin interacting protein (TXNIP) as possible mechanisms behind pterostilbene's effect. Our results highlight a nontoxic stilbenoid compound as a modulator of anticancer drug response, and indicate that pterostilbene might be used to modulate two anticancer compounds in well-defined sets of GBM patients.

Topics: Aged; Aged, 80 and over; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Proliferation; DNA Copy Number Variations; Drug Synergism; Female; Gefitinib; Gene Expression Profiling; Gene Knockdown Techniques; Glioblastoma; Humans; Male; MAP Kinase Signaling System; Middle Aged; Mutation; Phenotype; Protein Kinase Inhibitors; Quinazolines; Stilbenes; Transcriptome

Combretastatin A-4 (CA4) is a natural product isolated from Combretum caffrum that inhibits tubulin polymerization by binding to the colchicine-binding site. A corresponding water soluble pro-drug (referred to as CA4P), has undergone extensive clinical trials and has been evaluated in pre-clinical studies using multiple modalities. We previously reported a novel assay based on dynamic bioluminescent imaging to assess tumor vascular disruption and now present its application to assessing multiple tumors simultaneously. The current study evaluated the vascular-disrupting activity of CA4P on subcutaneous 9L rat brain tumor xenografts in mice using dynamic bioluminescence imaging. A single dose of CA4P (120 mg/kg, intraperitoneally) induced rapid, temporary tumor vascular shutdown revealed by a rapid and reproducible decrease of light emission from luciferase-expressing 9L tumors following administration of luciferin as a substrate. A time-dependent reduction of tumor perfusion after CA4P treatment was confirmed by immunohistological assessment of the perfusion marker Hoechst 33342 and the tumor vasculature marker CD31. The vasculature showed distinct recovery within 24 h post therapy. Multiple tumors behaved similarly, although a size dependent vascular inhibition was observed. In conclusion, CA4P caused rapid, temporary tumor vascular shutdown and led to reduction of tumor perfusion in rat brain tumor xenografts and the multiple tumor approach should lead to more efficient studies requiring fewer animals and greater consistency.

Topics: Animals; Antineoplastic Agents, Phytogenic; Brain Neoplasms; Fluorescence; Humans; Image Processing, Computer-Assisted; Immunoenzyme Techniques; Luminescence; Mice; Mice, Nude; Neovascularization, Pathologic; Rats; Stilbenes; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Resveratrol possesses anti-tumor activities against central nervous system (CNS) tumors in vitro but has not yet been used clinically due to its low bioavailability, particularly in the CNS. This study thus aimed to elucidate brain bioavailability of trans-resveratrol by monitoring brain concentrations and dwell times following administration of resveratrol through intragastric, intraperitoneal, external carotid artery/ECA and intrathecal routes. In parallel, we evaluated the biological responses of rat RG2 glioblastoma cells as well as RG2-formed rat intracranial glioblastomas treated with resveratrol via intrathecal administration. The results revealed that resveratrol was detected in rat brains except when administered systemically. Intrathecal administration of reseveratrol led to abundant apoptotic foci and increased staining of the autophagy proteins, LC-3 and Beclin-1 and shrinkage of the intracranial tumors. In conclusion, the BBB penetrability of resveratrol is remarkably increased by intracthecal administration. Regular short-term resveratrol treatments suppress growth and enhance autophagic and apoptotic activities of rat RG2 glioblastoma cells in vitro and in vivo. Therefore, intrathecal administration of resveratrol could be an optimal intervention approach in the adjuvant management of brain malignancies.

Topics: Analysis of Variance; Animals; Anticarcinogenic Agents; Brain; Brain Neoplasms; Cell Line, Tumor; Cell Survival; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Routes; Female; Gene Expression Regulation, Neoplastic; Glioblastoma; Glucuronosyltransferase; Male; Rats; Rats, Sprague-Dawley; Resveratrol; Stilbenes

Resveratrol (Res), a natural polyphenolic compound, has anticancer activity in a variety of cancers. In the present study, the antitumor effect and underlying molecular mechanism of Res on rat C6 glioma growth was studied. The results demonstrated that Res inhibited glioma cell proliferation, arrested cell cycle in S phase and induced apoptosis in vitro. Res also suppressed intracranial C6 tumor growth in vivo and prolonged survival in a fraction of the rats bearing intracranial gliomas. Res significantly downregulated the specific miRs, including miR-21, miR-30a-5p and miR-19, which have been identified as oncomiRs in our previous studies, and altered the expression of their targeting and crucial genes for glioma formation and progression such as p53, PTEN, EGFR, STAT3, COX-2, NF-κB and PI3K/AKT/mTOR pathway. Therefore, the anti-glioma effect of Res, at least in part, is through the regulation of oncogenic miRNAs. The effect of Res on non-coding RNAs should be studied further. Res is a potential multi-targeting drug for the treatment of gliomas.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Glioma; MicroRNAs; Rats; Resveratrol; Signal Transduction; Stilbenes; Xenograft Model Antitumor Assays

Glioblastoma multiforme (GBM) is the most aggressive type characterized by relapse and resistance even with the combination of radio- and chemotherapy. The presence of glioma stem cells (GSCs) has been shown to contribute to tumorigenesis, recurrence and treatment resistance. Particularly, CD133-positive glioma cells have been shown to represent the subpopulation that confers glioma radioresistance and suggested to be the source of tumor recurrence after radiation. Thus, a better understanding and the development of agents which target GSCs could potentially lead to a significant improvement in treating GBM patients. Here, we demonstrated that GRP78 (an antistress protein) was highly expressed in GBM cells along with β-catenin and Notch and correlated to the development of GSCs. CD133+ GSCs exhibited enhanced migration/invasion and self-renewal abilities. When GRP78 was silenced, GSC properties were suppressed and the sensitivity towards irradiation increased. In addition, the level of microRNA 205 appeared to be negatively associated with GRP78 expression. Our previous study indicated that pterostilbene (PT) possessed anticancer stem cell properties in hepatocellular carcinoma. Thus, we examined whether PT is also effective against GSCs. We found that PT-treated GSCs exhibited suppressed self-renewal and irradiation-resistant abilities. PT-mediated effects were associated with an increase of miR-205. Finally, we showed that PT treatment suppressed tumorigenesis in GSC xenograft mice. In conclusion, we provided evidence that GRP78/miR-205 axis played an important role in GSC maintenance and irradiation resistance. PT treatment suppressed GSC development via negatively modulating GRP78 signaling. PT may be considered for combined therapeutic agent to enhance irradiation efficacy in GBM patients.

Topics: Animals; Brain Neoplasms; Endoplasmic Reticulum Chaperone BiP; Female; Glioma; Heat-Shock Proteins; Heterografts; Humans; Mice, Inbred NOD; Mice, SCID; MicroRNAs; Neoplastic Stem Cells; Pterocarpus; Radiation Tolerance; Stilbenes

Tumor growth is not solely a consequence of autonomous tumor cell properties. Rather, tumor cells act upon and are acted upon by their microenvironment. It is tumor tissue biology that ultimately determines tumor growth. Thus, we developed a compound library screen for agents that could block essential tumor-promoting effects of the glioblastoma (GBM) perivascular stem cell niche (PVN). We modeled the PVN with three-dimensional primary cultures of human brain microvascular endothelial cells in Matrigel. We previously demonstrated stimulated growth of GBM cells in this PVN model and used this to assay PVN function. We screened the Microsource Spectrum Collection library for drugs that specifically blocked PVN function, without any direct effect on GBM cells themselves. Three candidate PVN-disrupting agents, Iridin, Tigogenin and Triacetylresveratrol (TAR), were identified and evaluated in secondary in vitro screens against a panel of primary GBM isolates as well as in two different in vivo intracranial models. Iridin and TAR significantly inhibited intracranial tumor growth and prolonged survival in these mouse models. Together these data identify Iridin and TAR as drugs with novel GBM tissue disrupting effects and validate the importance of preclinical screens designed to address tumor tissue function rather than the mechanisms of autonomous tumor cell growth.

Topics: Animals; Brain Neoplasms; Cell Communication; Cell Line, Tumor; Cells, Cultured; Coculture Techniques; Endothelial Cells; Female; Glioblastoma; Humans; Mice, Nude; Phytotherapy; Plant Extracts; Protamines; Resveratrol; Small Molecule Libraries; Spirostans; Stilbenes; Survival Analysis; Tumor Burden; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Tristetraprolin (TTP) is an AU-rich elements (AREs)-binding protein, which regulates the decay of AREs-containing mRNAs such as proto-oncogenes, anti-apoptotic genes and immune regulatory genes. Despite the low expression of TTP in various human cancers, the mechanism involving suppressed expression of TTP is not fully understood. Here, we demonstrate that Resveratrol (3,5,4'-trihydroxystilbene, Res), a naturally occurring compound, induces glioma cell apoptosis through activation of tristetraprolin (TTP). Res increased TTP expression in U87MG human glioma cells. Res-induced TTP destabilized the urokinase plasminogen activator and urokinase plasminogen activator receptor mRNAs by binding to the ARE regions containing the 3' untranslated regions of their mRNAs. Furthermore, TTP induced by Res suppressed cell growth and induced apoptosis in the human glioma cells. Because of its regulation of TTP expression, these findings suggest that the bioactive dietary compound Res can be used as a novel anti-cancer agent for the treatment of human malignant gliomas.

Topics: 3' Untranslated Regions; Apoptosis; AU Rich Elements; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Fibroblasts; Gene Expression Regulation; Glioma; Humans; Receptors, Urokinase Plasminogen Activator; Resveratrol; RNA Stability; RNA, Messenger; Stilbenes; Tristetraprolin; Up-Regulation; Urokinase-Type Plasminogen Activator

The development of novel therapeutic strategies to treat gliomas remains critical as a result of the poor prognoses, inef-. ficient therapies and recurrence associated with these tumors. In this context, biodegradable nanoparticles are emerging as efficient drug delivery systems for the treatment of difficult-to-treat diseases such as brain tumors. In the current study, we evaluated the antiglioma effect of trans-resveratrol-loaded lipid-core nanocapsules (RSV-LNC) based on in vitro (C6 glioma cell line) and in vivo (brain-implanted C6 cells) models of the disease. In vitro, RSV-LNC decreased the viability of C6 glioma cells to a higher extent than resveratrol in solution. Interestingly, RSV-LNC treatment was not cytotoxic to hippocampal organotypic cultures, a model of healthy neural cells, suggesting selectivity for cancer cells. RSV-LNC induced losses in glioma cell viability through induction of apoptotic cell death, as assessed by Annexin-FITC/PI assay, which was preceded by an early arrest in the S and G1 phases of the cell cycle. In brain-implanted C6 tumors, treatment with RSV-LNC (5 mg/kg/day, i.p.) for 10 days promoted a marked decrease in tumor size and also reduced the incidence of some malignant tumor-associated characteristics, such as intratumoral hemorrhaging, intratumoral edema and pseudopalisading, compared to resveratrol in solution. Taken together, the results presented herein suggest that nanoencapsulation of resveratrol improves its antiglioma activity, thus providing a provocative foundation for testing the clinical usefulness of nanoformulations of this natural compound as a new chemotherapeutic strategy for the treatment of gliomas.

Topics: Animals; Apoptosis; Brain Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chemical Phenomena; Chemistry, Pharmaceutical; Disease Models, Animal; G1 Phase; Glioma; Hippocampus; Humans; Lipids; Male; Nanocapsules; Neoplasm Transplantation; Rats; Rats, Wistar; Resveratrol; S Phase; Solutions; Stilbenes; Tumor Burden

Glioblastoma is the most common and aggressive primary brain tumor. Glioma stem cells (GSCs) are relatively resistant to chemo-radiotherapy and are responsible for tumor progression and the recurrence of glioblastomas after conventional therapy. Thus, the control of the GSC population is considered key to realizing long-term survival of glioblastoma patients. Here, we identified that resveratrol significantly reduced the self-renewal and tumor-initiating capacity of patient-derived GSCs. Furthermore, resveratrol promoted Nanog suppression via proteasomal degradation, which was inhibited by MG132, a proteasome inhibitor. p53 activation is an important factor in Nanog suppression and treatment with resveratrol was also found to activate the p53/p21 pathway. Importantly, inhibition of Nanog by siRNA provoked inhibitory effects on both the self-renewal and tumor-forming capacity of GSCs. Our findings indicate that Nanog is an essential factor for the retention of stemness and may contribute to the resveratrol-induced differentiation of GSCs. Our results also suggest that targeting GSCs via the p53-Nanog axis, with resveratrol for instance, could be a therapeutic strategy against glioblastoma.

Topics: Animals; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Gene Silencing; Glioma; Homeodomain Proteins; Humans; Male; Mice; Mice, Inbred BALB C; Nanog Homeobox Protein; Neoplastic Stem Cells; Proteasome Endopeptidase Complex; Resveratrol; RNA, Small Interfering; Signal Transduction; Stilbenes; Transfection; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. Patients diagnosed with GBM have a poor prognosis, and it has been reported that tumor malignancy and GBM recurrence are promoted by STAT3 signaling. As resveratrol (RV), a polyphenol in grapes, is reported to be a potent and non-toxic cancer-preventive compound, the aim of this study was to investigate the therapeutic effect and molecular mechanisms of RV on GBM-derived radioresistant tumor initiating cells (TIC). Firstly, our results showed that primary GBM-CD133(+) TIC presented high tumorigenic and radiochemoresistant properties as well as increased protein levels of phosphorylated STAT3. We consistently observed that treatment with shRNA-STAT3 (sh-STAT3) or AG490, a STAT3 inhibitor, significantly inhibited the cancer stem-like cell properties and radioresistance of GBM-CD133(+) in vitro and in vivo. Furthermore, treatment of GBM-CD133(+) with 100 µM RV induced apoptosis and enhanced radiosensitivity by suppressing STAT3 signaling. Microarray results suggested that RV or AG490 inhibited the stemness gene signatures of GBM-CD133(+) and facilitated the differentiation of GBM-CD133(+) into GBM-CD133(-) or astrocytoma cells. Finally, xenotransplant experiments indicated that RV or sh-STAT3 therapy could significantly improve the survival rate and synergistically enhance the radiosensitivity of radiation-treated GBM-TIC. In summary, RV can reduce in vivo tumorigenicity and enhance the sensitivity of GBM-TIC to radiotherapies through the STAT3 pathway.

Topics: Aged; Animals; Antineoplastic Agents, Phytogenic; Astrocytoma; Brain Neoplasms; Chemoradiotherapy; Female; Glioblastoma; Humans; Male; Mice; Mice, SCID; Middle Aged; Resveratrol; Signal Transduction; STAT3 Transcription Factor; Stilbenes; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The alkylating agent temozolomide (TMZ) is the major chemotherapeutic drug used clinically in the treatment of malignant gliomas. This study investigated the mechanism behind TMZ-induced cell death and the possibility that resveratrol might increase TMZ efficacy. TMZ induced both apoptotic cell death and cytoprotective autophagy through a reactive oxygen species (ROS) burst and extracellular signal-regulated kinase (ERK) activation, which was suppressed by resveratrol, resulting in a decrease in autophagy and an increase in apoptosis, suggesting that the ROS/ERK pathway plays a crucial role in the fate of cells after TMZ treatment. Isobolographic analysis indicated that the combination of TMZ and resveratrol has a synergistic effect. Moreover, an in vivo mouse xenograft study also showed that coadministration of resveratrol and TMZ reduced tumor volumes by suppressing ROS/ERK-mediated autophagy and subsequently inducing apoptosis. Taken together, our data indicate that TMZ-induced ROS/ERK-mediated autophagy protected glioma cells from apoptosis, and the combination of resveratrol with TMZ could improve the efficacy of chemotherapy for brain tumors.

Topics: Animals; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Brain Neoplasms; Cell Line, Tumor; Cell Survival; Dacarbazine; Drug Synergism; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Female; Glioma; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Phosphorylation; Reactive Oxygen Species; Resveratrol; Stilbenes; Temozolomide; Tumor Burden; Xenograft Model Antitumor Assays

Glioblastoma multiforme (GBM) cells show different responses to resveratrol, for unknown reasons. Our data from human medulloblastoma cells and primary cultures of rat brain cells revealed an inverse correlation of sulfonation activity with resveratrol sensitivities, providing a clue to the underlying mechanisms of the variable sensitivities of GBM cells to resveratrol. In this study, we found that U251 cells were sensitive and LN229 cells were insensitive to resveratrol. Thus, these two cell lines were taken as comparable models for elucidating the influence of sulfonation activities on resveratrol sensitivity. HPLC showed identical resveratrol metabolic patterns in both cell lines. LC/MS and high-resolution mass MS analyses further demonstrated that resveratrol monosulfate generated by sulfotransferases (SULTs) was the major metabolite of human GBM cells. The levels of brain-associated SULT (SULT1A1, SULT1C2, and SULT4A1) expression in U251 cells were lower than those in LN229 cells, suggesting the inverse relationship of SULT-mediated sulfonation activity with high intracellular resveratrol bioavailability and resveratrol sensitivity of human GBM cells. Furthermore, immunohistochemical staining revealed reductions in expression of the three brain-associated SULTs in 72.8%, 47.5% and 66.3% of astrocytomas, respectively. Therefore, the levels of brain-associated SULTs and sulfonation activity mediated by them could be important parameters for evaluating the potential response of human GBM cells to resveratrol, and may have value in the personalized treatment of GBMs with resveratrol.

Topics: Antineoplastic Agents, Phytogenic; Arylsulfotransferase; Blotting, Western; Brain Neoplasms; Chromatography, High Pressure Liquid; Drug Resistance, Neoplasm; Flow Cytometry; Glioblastoma; Humans; Immunoenzyme Techniques; Mass Spectrometry; Neoplasm Grading; Real-Time Polymerase Chain Reaction; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stilbenes; Sulfonic Acids; Sulfotransferases; Tissue Array Analysis; Tumor Cells, Cultured

Malignant glioblastoma represents a challenge in the chemotherapy of brain tumors, because of its aggressive behavior characterized by chemoresistance, infiltrative diffusion, and high rate of recurrence and death. In this study, we used cultured human U87MG cells and primary human glioblastoma cultures to test the anticancer properties of resveratrol (RV), a phytoalexin abundantly present in a variety of dietary products. In U87MG cells, 100 μM RV elicited cell growth arrest by 48 h and bax-mediated cell toxicity by 96 h and greatly limited cell migration and invasion through matrigel. Both in U87MG cells and in primary glioblastoma cultures, the chronic administration of RV (100 μM for up to 96 h) decreased the expression of nestin (a brain (cancer) stem cells marker) but increased that of glial acidic fibrillary protein (a mature glial cell marker) and of βIII-tubulin (a neuronal differentiation marker). Chronic treatment with RV increased the proportion of cells positive for senescence-associated β-galactosidase activity. This is the first report showing the ability of RV to induce glial-like and neuronal-like differentiation in glioblastoma cells. The beneficial effects of chronic RV supplementation lasted up to 96 h after its withdrawal from the culture medium. The present findings support the introduction of pulsed administration of this food-derived molecule in the chemotherapy regimen of astrocytomas.

Topics: Antineoplastic Agents, Phytogenic; Brain Neoplasms; Cell Differentiation; Cell Division; Cell Line, Tumor; Glioblastoma; Humans; Microscopy, Fluorescence; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Stilbenes; Wound Healing

Glioblastoma is the most malignant form of adult brain tumor and is associated with a dismal prognosis. Emerging data suggest that Notch signaling participates principally in the formation and malignant progression of glioblastoma. Resveratrol is a terpenoid that exhibits broad pro-apoptotic activity in various types of cancers, including glioblastoma. However, the effects of resveratrol on Notch signaling in glioblastomas have not yet been fully elucidated. We demonstrated that resveratrol strongly suppressed cell growth and induced apoptosis in A172 and T98G glioblastoma cells, which have low active Notch-1 expression and a heterozygous p53 mutation. Our results suggest that resveratrol significantly activates intracellular Notch-1 and restores wild-type p53 expression in a time-dependent manner. Significant de-phosphorylation of Akt, increased Bax expression, decreased Bcl-2 expression and cleavage of caspase-3 were also observed in resveratrol-induced apoptosis in glioblastoma cells. Moreover, simultaneous treatment with resveratrol and a Notch-1 inhibitor (MRK-003) partially attenuated the apoptosis and completely blocked the activation of Notch-1 and the increase in wild-type p53. This suggests that restoration of wild-type p53 expression depends on Notch-1 activation. In addition, the de-phosphorylation of Akt, increased expression of Bax and cleavage of caspase-3 were not fully reversed by MRK-003 treatment, suggesting that p53 restoration is not the only mechanism underlying resveratrol-induced apoptosis. Taken together, we confirmed the anti-proliferative and pro-apoptotic effects of resveratrol on glioblastoma cells and revealed Notch-1 activation-dependent restoration of p53 as an important causative mechanism.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Astrocytes; bcl-2-Associated X Protein; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Genes, p53; Glioblastoma; Humans; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Receptor, Notch1; Resveratrol; Signal Transduction; Stilbenes; Tumor Suppressor Protein p53

Erucylphosphohomocholine (ErPC3, Erufosine) was reported previously to induce apoptosis in otherwise highly apoptosis-resistant malignant glioma cell lines while sparing their non-tumorigenic counterparts. We also previously found that the mitochondrial 18 kDa Translocator Protein (TSPO) is required for apoptosis induction by ErPC3. These previous studies also suggested involvement of reactive oxygen species (ROS). In the present study we further investigated the potential involvement of ROS generation, the participation of the mitochondrial respiration chain, and the role of the mitochondrial F(O)F(1)-ATP(synth)ase in the pro-apoptotic effects of ErPC3 on U87MG and U118MG human glioblastoma cell lines. For this purpose, cells were treated with the ROS chelator butylated hydroxyanisole (BHA), the mitochondrial respiration chain inhibitors rotenone, antimycin A, myxothiazol, and the uncoupler CCCP. Also oligomycin and piceatannol were studied as inhibitors of the F(O) and F(1) subunits of the mitochondrial F(O)F(1)-ATP(synth)ase, respectively. BHA was able to attenuate apoptosis induction by ErPC3, including mitochondrial ROS generation as determined with cardiolipin oxidation, as well as collapse of the mitochondrial membrane potential (Deltapsi(m)). Similarly, we found that oligomycin attenuated apoptosis and collapse of the Deltapsi(m), normally induced by ErPC3, including the accompanying reductions in cellular ATP levels. Other inhibitors of the mitochondrial respiration chain, as well as piceatannol, did not show such effects. Consequently, our findings strongly point to a role for the F(O) subunit of the mitochondrial F(O)F(1)-ATP(synth)ase in ErPC3-induced apoptosis and dissipation of Deltapsi(m) as well as ROS generation by ErPC3 and TSPO.

Topics: Adenosine Triphosphate; Antineoplastic Agents; Apoptosis; Brain Neoplasms; Butylated Hydroxyanisole; Caspases; Cell Line, Tumor; Cyclosporine; Electron Transport; Enzyme Inhibitors; Erucic Acids; Glioblastoma; Humans; Membrane Potential, Mitochondrial; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Oligomycins; Phosphorylcholine; Proton-Translocating ATPases; Reactive Oxygen Species; Receptors, GABA; Stilbenes

Resveratrol, a stilbene found in grapes and wine, is one of the most interesting natural compound due to its role exerted in cancer prevention and therapy. In particular, resveratrol is able to delay cell cycle progression and to induce apoptotic death in several cell lines. Here we report that resveratrol treatment of human glioblastoma cells induces a delay in cell cycle progression during S phase associated with an increase in histone H2AX phosphorylation. Furthermore, with an in vitro assay of topoisomerase IIalpha catalytic activity we show that resveratrol is able to inhibit the ability of recombinant human TOPO IIalpha to decatenate kDNA, so that it could be considered a TOPO II poison.

Topics: Antigens, Neoplasm; Antineoplastic Agents, Phytogenic; Brain Neoplasms; Cell Cycle; Cell Line, Tumor; DNA Breaks, Double-Stranded; DNA Topoisomerases, Type II; DNA-Binding Proteins; Dose-Response Relationship, Drug; Glioma; Histones; Humans; Phosphorylation; Resveratrol; Stilbenes; Topoisomerase II Inhibitors

Neurofibromatosis type 1 (NF1) is the most common genetic disease affecting the nervous system. Patients typically develop many tumors over their lifetime, leading to increased morbidity and mortality. The NF1 gene, mutated in NF1, is also commonly mutated in sporadic glioblastoma multiforme (GBM). Because both NF1 and GBM are currently incurable, new therapeutic approaches are clearly needed. Natural products represent an opportunity to develop new therapies, as they have been evolutionarily selected to play targeted roles in organisms. Schweinfurthin A is a prenylated stilbene natural product that has previously shown specific inhibitory activity against brain and hematopoietic tumor lines. We show that patient-derived GBM and NF1 malignant peripheral nerve sheath tumor (MPNST) lines, as well as tumor lines derived from the Nf1-/+;Trp53-/+ (NPcis) mouse model of astrocytoma and MPNST are highly sensitive to inhibition by schweinfurthin A and its synthetic analogs. In contrast, primary mouse astrocytes are resistant to the growth inhibitory effects of schweinfurthin A, suggesting that schweinfurthin A may act specifically on tumor cells. Stable transfection of the GTPase-activating protein related domain of Nf1 into Nf1-/-;Trp53-/- astrocytoma cells confers resistance to schweinfurthin A. In addition, the profound effect of schweinfurthin A on dynamic reorganization of the actin cytoskeleton led us to discover that schweinfurthin A inhibits growth factor-stimulated Rho signaling. In summary, we have identified a class of small molecules that specifically inhibit growth of cells from both central and peripheral nervous system tumors and seem to act on NF1-deficient cells through cytoskeletal reorganization correlating to changes in Rho signaling.

Topics: Animals; Animals, Newborn; Brain Neoplasms; Cell Proliferation; Cells, Cultured; Drug Evaluation, Preclinical; Genes, Neurofibromatosis 1; Glioma; Humans; Mice; Mice, Transgenic; Models, Biological; Neurofibromatosis 1; Neurofibromin 1; Protein Structure, Tertiary; rho GTP-Binding Proteins; Signal Transduction; Stilbenes; Substrate Specificity

Glioblastoma multiforme (GBM) is the most malignant intracranial tumour that develops in both adults and children. Microarray gene analyses have confirmed that the human YKL-40 gene is one of the most over-expressed genes in these tumours but not in normal brain tissue. Clinical studies have shown that serum YKL-40 levels are positively correlated with tumour burden in addition to being an independent prognostic factor of a short relapse-free interval as well as short overall survival in patients with various cancers. Our previous study revealed that YKL-40 was closely correlated with the pathological grades of human primary astrocytomas and played a crucial role in glioma cell proliferation. Hence, YKL-40 could be an attractive target in the design of anti-cancer therapies.. Cell viability and invasion assays were performed to detect the cell proliferation and invasive ability of U87 cells induced by resveratrol (3, 5, 4'-trihydroxystilbene; Res) or YKL-40 small-interfering RNAs (siRNAs). In addition, the luciferase assay, real-time RT-PCR, western blotting, and ELISA were used to measure YKL-40 promoter activity, mRNA, and protein expression, respectively. The expressions of phosphor-ERK1/2 and ERK1/2 were determined by western blotting.. Res inhibited U87 cell proliferation and invasion in vitro and repressed YKL-40 in U87 cells by decreasing the activity of its promoter and reducing mRNA transcription and protein expression in vitro. YKL-40 siRNA treatment also impaired the invasiveness of U87 cells. When U87 cells were cultured with 20 μM PD98059 (an ERK1/2 inhibitor) alone, with 20 μM PD98059 and 100 μM Res, or with 100 μM Res alone for 48 h, YKL-40 protein expression decreased most significantly in the Res-treated group. PD98059 partially reversed the decrease of YKL-40 protein expression induced by Res. Furthermore, phosphor-ERK1/2 expression was reduced by Res treatment in a time-dependent manner.. We demonstrated for the first time that Res represses YKL-40 expression in vitro; in addition, the ERK1/2 pathway is involved in this repression. This finding could extend the prospective use of Res in glioma research and enlarge the armamentarium for treating gliomas.

Topics: Adipokines; Antineoplastic Agents, Phytogenic; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chitinase-3-Like Protein 1; Culture Media; Disease-Free Survival; Gene Expression Regulation, Neoplastic; Glioma; Glycoproteins; Humans; Lectins; Prognosis; Promoter Regions, Genetic; Recurrence; Resveratrol; Stilbenes

Previous study reported that resveratrol has anti-tumor activity. In this study, we investigated the involvement of autophagy in the resveratrol-induced apoptotic death of human U251 glioma cells.. The growth inhibition of U251 cells induced by resveratrol was assessed with methyl thiazolyl tetrazolium (MTT). The activation of autophagy and proapoptotic effect were characterized by monodansylcadaverine labeling and Hoechst stain, respectively. Mitochondrialtransmembrane potential (DeltaPsim) was measured as a function of drug treatment using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1). The role of autophagy and apoptosis in the resveratrol-induced death of U251 cells was assessed using autophagic and caspase inhibitors. Immunofluorescence, flow cytometry, and Western blot analysis were used to study the apoptotic and autophagic mechanisms.. Methyl thiazolyl tetrazolium (MTT) assays indicated that resveratrol decreased the viability of U251 cells in a dose- and time-dependent manner. Flow cytometry analysis indicated that resveratrol increased cell population at sub-G1 phase, an index of apoptosis. Furthermore, resveratrol-induced cell death was associated with a collapse of the mitochondrial membrane potential. The pan-caspase inhibitor Z-VAD-fmk suppressed resveratrol-induced U251 cell death. Resveratrol stimulated autophagy was evidenced by punctuate monodansylcadaverine(MDC) staining and microtubule-associated protein light chain 3 (LC3) immunoreactivty. Resveratrol also increased protein levels of beclin 1 and membrane form LC3 (LC3-II). Autophagy inhibitors 3-methylademine (3-MA) and bafilomycin A1 sensitized the cytotoxicity of resveratrol.. Together, these findings indicate that resveratrol induces autophagy in human U251 glioma cells and autophagy suppressed resveratrol-induced apoptosis. This study thus suggests that autophagy inhibitors can increase the cytotoxicity of resveratrol to glioma cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Autophagy; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Coloring Agents; Glioma; Humans; Membrane Potentials; Microscopy, Fluorescence; Mitochondrial Membranes; Resveratrol; Stilbenes; Tetrazolium Salts; Thiazoles

The stilbene resveratrol (RV) initiates p53-dependent apoptosis via plasma membrane integrin alphaVbeta3 in human cancer cells. A thyroid hormone (L-thyroxine, T(4)) membrane receptor also exists on alphaVbeta3. Stilbene and T(4) signals are both transduced by extracellular-regulated kinases 1 and 2 (ERK1/2); however, T(4) promotes cell proliferation in cancer cells, whereas RV is pro-apoptotic. Thyroid hormone has been shown to interfere with RV-induced apoptosis. However, the mechanisms involved are not fully understood. In this study, we examined the mechanism whereby T(4) inhibits RV-induced apoptosis in glioma cells. RV activated conventional protein kinase C and ERK1/2 and caused nuclear localization of cyclooxygenase-2 (COX-2), consequent p53 phosphorylation and apoptosis. RV-induced ERK1/2 activation is involved in not only COX-2 expression but also nuclear COX-2 accumulation. NS-398, a COX-2 inhibitor, did not affect ERK1/2 activation, but reduced the nuclear abundance of COX-2 protein and the formation of complexes of nuclear COX-2 and activated ERK1/2 that are required for p53-dependent apoptosis in RV-treated cells. T(4) inhibited RV-induced nuclear COX-2 and cytosolic pro-apoptotic protein, BcLx-s, accumulation. Furthermore, T(4) inhibited RV-induced apoptosis by interfering with the interaction of nuclear COX-2 and ERK1/2. This effect of T(4) was prevented by tetraiodothyroacetic acid (tetrac), an inhibitor of the binding of thyroid hormone to its integrin receptor. Tetrac did not, in the absence of T(4), affect induction of apoptosis by RV. Thus, the receptor sites on alphaVbeta3 for RV and thyroid hormone are discrete and activate ERK1/2-dependent downstream effects on apoptosis that are distinctive.

Topics: Apoptosis; Brain Neoplasms; Cyclooxygenase 2; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Glioma; Humans; Integrin alphaVbeta3; Phosphorylation; Protein Kinase C; Resveratrol; Stilbenes; Thyroxine

Resveratrol (3,4',5-trihydroxystilbene) is a polyphenol synthesized by a wide variety of plant species in response to injury, UV irradiation and fungal attack. Many studies have revealed a variety of resveratrol intracellular targets whose modulation gives rise to overlapping responses leading to growth arrest and death. Many authors have reported different human cancer cell lines, treated with resveratrol at micromolar concentrations, arrested their proliferative cycle in the G1/S boundary or in the S phase and this cell cycle arrest was followed by apoptotic death. Less is known about the ability of resveratrol to modify the effect of radiation exposure in normal and cancer cells. Considering that controlled exposure to ionizing radiation is one of the most used treatments in cancer patients and that these schedules are not always effective in medical practice, as in the case of glioma patients, the testing of combined treatment protocols (resveratrol and ionizing radiation) could be of interest, opening the door to future studies which would examine the pharmacological activity of resveratrol. In this study we have looked into whether resveratrol is able to modulate cell cycle progression in human glioblastoma cells and to regulate GJs expression in cancer cells. With this aim in mind we have performed a cytofluorimetric multiparameter assay to quantify the presence of GJs in U87 glioma cells treated with resveratrol and/or X rays. We report that resveratrol induces a delay in cell cycle progression and both alone and in combination with X rays is able to enhance gap junction Intercellular Communications.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Brain Neoplasms; Cell Communication; Cell Cycle; Cell Line, Tumor; Cell Survival; Connexin 43; Gap Junctions; Glioblastoma; Humans; Microscopy, Fluorescence; Mutation; Resveratrol; Stilbenes; X-Rays

Plant polyphenols like flavonoids and hydroxystilbens have been found to possess radical scavenging/antioxidative activity, especially when studied in cell-free systems. A positive effect in such assays, however, does not necessarily indicate a protective activity against deleterious effects of oxidative stress in intact cells. In fact it has been shown that polyphenols can act as anti-oxidants as well as pro-oxidants. The aim of the present study was to investigate whether and with what potency selected polyphenols are able to inhibit cellular radical generation in C6 cells and whether they can induce oxidative stress themselves. Cumene hydroperoxide (CHP) was used as a model to induce radical generation which was measured by means of a fluorometric 2',7'-dichlorodihydro-fluorescein assay. CHP-induced, time and concentration dependent, a manifold increase of DCF fluorescence indicating intracellular radical generation. This process was inhibited by all the flavonoids and the hydroxystilben resveratrol, at low micromolar concentrations. The most potent compounds, luteolin and galangin, already at concentrations of 5 to 10 microM nearly completely abolished the radical generation in the presence of 500 microM CHP. The following ranking of anti-oxidative potency was obtained: luteolingalangin>kaempferol>quercetin>resveratrolgenisteintaxifolin. This ranking is completely different from that obtained by means of a trolox equivalent antioxidant capacity (TEAC) assay in a cell-free system, thus putting the biological relevance of the latter in question. Remarkably, one compound induced oxidative stress itself, namely genistein. This flavonoid inhibited the cellular radical generation in the presence of CHP while it significantly enhanced it in the absence of the peroxide.

Topics: Astrocytoma; Benzene Derivatives; Brain Neoplasms; Dose-Response Relationship, Drug; Flavonoids; Free Radical Scavengers; Free Radicals; Genistein; Luteolin; Oxidants; Oxidative Stress; Phenols; Plant Extracts; Polyphenols; Resveratrol; Stilbenes

Altered Notch signaling seems linked with medulloblastoma (MB) formation and resveratrol exhibits anti-medulloblastoma effects. However, the influence of resveratrol in Notch signaling of MB cells has not been described. This issue was addressed here by checking Notch1 and Notch2 statuses in three MB cell lines with and without resveratrol treatment. Notch1 and Notch2 were detected in the cytoplasm of three cell lines under normal condition, which were up-regulated by resveratrol along with differentiation, apoptosis and enhanced Hes1 nuclear translocation. Nevertheless, blockage of Notch enzymatic cleavage with gamma-seacretase inhibitors, DAPT and L-685,458, neither interrupted resveratrol-caused cellular events nor affected MB cell growth. These results demonstrate that Notch signaling has little relevance with resveratrol-induced differentiation and apoptosis and may not be a universal critical factor of MB cells.

Topics: Active Transport, Cell Nucleus; Amyloid Precursor Protein Secretases; Antineoplastic Agents; Antioxidants; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cytoplasm; Enzyme Inhibitors; Homeodomain Proteins; Humans; Medulloblastoma; Receptor, Notch1; Receptor, Notch2; Receptors, Notch; Resveratrol; Signal Transduction; Stilbenes; Transcription Factor HES-1; Up-Regulation

Resveratrol (Res) has been reported to inhibit tumor initiation, promotion, and progression in a variety of cell culture systems depending on the specific cell type and cellular environment. In the present study, we determined the effect of Res on the cell growth and apoptosis of rat glioma C6 cell line as well as mouse fibroblast 3T3 cell line, in vitro. Concurrently, we investigated whether caspase-3 is involved in the Res-induced apoptosis of rat glioma cells. Exposure to Res exhibits a significant anti-proliferative effect and induces an increase in the population of apoptotic cells on C6 cells in a concentration- and time-dependent manner, but not for normal 3T3 fibroblast cells, as measured by methyl thiazolyl tetrazolium assay and flow cytometer. Distinguished increase of C6 cells in S phase is observed after the treatment of Res as compared to insignificant change in cell cycle distribution of 3T3 cells. TdT-mediated dUTP nick end labeling fluorescence staining, HE staining, and scanning electron microscope revealed abnormal morphology and ultrastructure in C6 cells treated with Res. Our data showed that Res can increase the expression and induced the activation of caspase-3 in rat glioma C6 cells. These results suggest that Res has significant apoptosis-inducing effect on C6 glioma cells other than normal fibroblast 3T3 cells in vitro and caspase-3 may act as a potential mediator in the process.

Topics: Animals; Anticarcinogenic Agents; Apoptosis; Blotting, Western; Brain Neoplasms; Caspase 3; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Fibroblasts; Flow Cytometry; Glioma; In Situ Nick-End Labeling; Mice; Rats; Resveratrol; Stilbenes

The correlation of c-Myc expression with resveratrol-induced turnover of medulloblastoma cells was investigated in this study by checking (1) c-Myc expression in medulloblastoma tissues and cell lines (UW228-2 and UW228-3), (2) the in vitro effect of resveratrol on c-Myc expression and (3) the influences of c-Myc inhibition in cell growth and survival. Immunohistochemical staining of human medulloblastomas and noncancerous cerebellar tissues revealed that 8 out of 11 tumor tissues (72.7%) expressed c-Myc, in which 4 cases (50%) showed intensified nuclear labeling. RT-PCR, Western blotting, immunocytochemical and immunofluorescence stainings revealed c-Myc downregulation accompanied with growth suppression and apoptosis. Flow cytometry analysis showed S phase arrest in resveratrol-treated cell populations. Transfection of c-Myc directed antisense oligonucleotides to the cultured medulloblastoma cells could reduce c-Myc expression, inhibit cell growth and arrest the cell cycle at S phase. Our results thus for the first time demonstrate that c-Myc downregulation is a critical molecular event of resveratrol-mediated anti-medulloblastoma activity, which is closely associated with growth suppression, cell cycle arrest and apoptosis of medulloblastoma cells.

Topics: Antioxidants; Apoptosis; Blotting, Western; Brain Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Survival; Down-Regulation; Flow Cytometry; Fluorescent Antibody Technique; Genes, myc; Humans; Immunohistochemistry; Medulloblastoma; Neoplasm Proteins; Oligonucleotides, Antisense; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; RNA, Neoplasm; S Phase; Stilbenes; Transfection

In previous studies we demonstrated that resveratrol acts in an antiapoptotic manner on the paclitaxel-treated human neuroblastoma (HN) SH-SY5Y cell line inhibiting the apoptotic pathways induced by the antineoplastic drug. In the present study we evaluated the antiapoptotic effect of resveratrol, studying its activity on cell cycle progression. We determined the mitotic index of cultures exposed to resveratrol and paclitaxel alone or in combination, the cell cycle distribution by flow cytometric analysis (FACS), and the modulation of some relevant cell cycle regulatory proteins. Resveratrol is able to induce S-phase cell arrest and this interference with the cell cycle is associated with an increase of cyclin E and cyclin A, a downregulation of cyclin D1, and no alteration in cyclin B1 and cdk 1 activation. The resveratrol-induced S-phase block prevents SH-SY5Y from entering into mitosis, the phase of the cell cycle in which paclitaxel exerts its activity, explaining the antiapoptotic effect of resveratrol.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Apoptosis; Brain Neoplasms; Cell Cycle; Cell Division; Cell Line, Tumor; Cyclin B; Cyclin B1; Cyclins; Flow Cytometry; G2 Phase; Humans; Immunoblotting; Maturation-Promoting Factor; Mitosis; Neuroblastoma; Paclitaxel; Resveratrol; Stilbenes

Survivin is a member of the inhibitor of apoptosis proteins that is expressed at high levels in most human cancers and may facilitate evasion from apoptosis and aberrant mitotic progression. Naturally occurring dietary compounds such as resveratrol have gained considerable attention as cancer chemopreventive agents. Here, we discovered a novel function of the chemopreventive agent resveratrol: resveratrol is a potent sensitizer of tumor cells for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis through p53-independent induction of p21 and p21-mediated cell cycle arrest associated with survivin depletion. Concomitant analysis of cell cycle, survivin expression, and apoptosis revealed that resveratrol-induced G(1) arrest was associated with down-regulation of survivin expression and sensitization for TRAIL-induced apoptosis. Accordingly, G(1) arrest using the cell cycle inhibitor mimosine or induced by p21 overexpression reduced survivin expression and sensitized cells for TRAIL treatment. Likewise, resveratrol-mediated cell cycle arrest followed by survivin depletion and sensitization for TRAIL was impaired in p21- deficient cells. Also, down-regulation of survivin using survivin antisense oligonucleotides sensitized cells for TRAIL-induced apoptosis. Importantly, resveratrol sensitized various tumor cell lines, but not normal human fibroblasts, for apoptosis induced by death receptor ligation or anticancer drugs. Thus, this combined sensitizer (resveratrol)/inducer (e.g., TRAIL) strategy may be a novel approach to enhance the efficacy of TRAIL-based therapies in a variety of human cancers.

Topics: Anticarcinogenic Agents; Apoptosis; Apoptosis Regulatory Proteins; Base Sequence; Brain Neoplasms; Breast Neoplasms; Caspase Inhibitors; Caspases; Cell Cycle; Cell Division; Cell Line, Tumor; Cysteine Proteinase Inhibitors; DNA Primers; Female; Humans; Male; Melanoma; Membrane Glycoproteins; Pancreatic Neoplasms; Prostatic Neoplasms; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Stilbenes; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha

trans-Resveratrol (3,4',5-trihydroxystilbene) is able to significantly reduce paclitaxel-induced apoptosis in the human neuroblastoma (HN) SH-SY5Y cell line, acting on several cellular signaling pathways that are involved in paclitaxel-induced apoptosis. trans-Resveratrol reverses phosphorylation of Bcl-2 induced by paclitaxel and concomitantly blocks Raf-1 phosphorylation, also observed after paclitaxel exposure, thus suggesting that Bcl-2 inactivation may be dependent on the activation of the Raf/Ras cascade. trans-Resveratrol also reverses the sustained phosphorylation of JNK/SAPK, which specifically occurs after paclitaxel exposure.Overall, our observations demonstrate that (a) the toxic action of paclitaxel on neuronal-like cells is not only related to the effect of the drug on tubulin, but also to its capacity to activate several intracellular pathways leading to inactivation of Bcl-2, thus causing cells to die by apoptosis, (b) trans-resveratrol significantly reduces paclitaxel-induced apoptosis by modulating the cellular signaling pathways which commit the cell to apoptosis.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Brain Neoplasms; Caspase 7; Caspases; Cell Death; Cell Line; DNA; Humans; Immunoblotting; Mitogen-Activated Protein Kinases; Neuroblastoma; Paclitaxel; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-raf; Resveratrol; Signal Transduction; Stilbenes; Tumor Cells, Cultured

Quercetin and resveratrol are weak inhibitors of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE) activity of the neuroblastoma cell line SK-N-SH. The long term incubation of the cells for 4 days with quercetin, resveratrol and a combination of both substances in concentrations lower than necessary for inhibition of NEP and ACE activity induced the cellular enzyme activity of NEP and ACE associated with an inhibition of cellular proliferation. The long term treatment of neuroblastoma cells with quercetin and resveratrol enhanced the differentiation state of the cells. Taking into account the significance of NEP and ACE for the degradation of amyloid beta peptides, the effect of quercetin and resveratrol as constituents of red wine for a neuroprotective activity is discussed.

Topics: Angiotensin-Converting Enzyme Inhibitors; Brain Neoplasms; Cell Count; Cell Division; Cell Line; Enzyme Induction; Enzyme Inhibitors; Humans; Kinetics; Neprilysin; Neuroblastoma; Peptidyl-Dipeptidase A; Protease Inhibitors; Quercetin; Resveratrol; Stilbenes; Tumor Cells, Cultured; Wine

Expression of voltage-activated ion channels was studied in primary cultures from seven freshly resected human primary brain tumors and in an established human astrocytoma cell line, STTG1. Astrocytoma cells consistently expressed voltage-dependent outwardly rectifying currents. Currents activated at potentials > 45 mV and showed outward transients on termination of voltage steps. Currents reversed at the Cl equilibrium potential, suggesting that they were largely carried by Cl-. Altering extracellular K- or Na+ concentration did not alter currents; neither did replacement of intracellular K+ by Cs+ or intracellular Na+ by N-methyl-D-glucosamine. Anion-substitution experiments suggest the following permeability sequence, determined from shifts in tail current reversal potential: I- > NO3- > Br- > Cl- > acetate > isethionate > F- > glutamate. Currents were sensitive to the Cl- channel blockers chlorotoxin, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), and 4,4'-dinitrostilbene-2,2' disulfonic acid (DNDS), with chlorotoxin being most effective, yielding > 80% block at 590 nM. DIDS (100 microM) and DNDS (100 microM) reduced currents by 33.5 and 38.2%, respectively. Currents were also sensitive to Zn2+ (100 microM, 47% block) and Cd2- (25 microM, 42% block). Reducing extracellular Ca2+ concentration decreased outward currents by 58% and almost completely eliminated transients, suggesting that Cl- currents are Ca2+ dependent. Cl channel block resulted in altered cell proliferation as determined by [3H]thymidine incorporation, suggesting that these channels may be involved in astrocytoma growth control.

Topics: 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Astrocytoma; Brain Neoplasms; Cell Division; Chloride Channels; Chlorides; Electric Conductivity; Humans; Scorpion Venoms; Stilbenes; Tumor Cells, Cultured