Based on reporting in the last several years, an impressive but dismal list of cytotoxic chemotherapies that fail to prolong the median overall survival of patients with glioblastoma has prompted the development of treatment protocols designed to interfere with growth-facilitating signaling systems by using non-cytotoxic, non-oncology drugs. Recent recognition of the pro-mobility stimulus, interleukin-18, as a driver of centrifugal glioblastoma cell migration allows potential treatment adjuncts with disulfiram and ritonavir. Disulfiram and ritonavir are well-tolerated, non-cytotoxic, non-oncology chemotherapeutic drugs that are marketed for the treatment of alcoholism and human immunodeficiency virus (HIV) infection, respectively. Both drugs exhibit an interleukin-18-inhibiting function. Given the favorable tolerability profile of disulfiram and ritonavir, the unlikely drug-drug interaction with temozolomide, and the poor prognosis of glioblastoma, trials of addition of disulfiram and ritonavir to current standard initial treatment of glioblastoma would be warranted.
Antineoplastic Agents ; Dacarbazine ; analogs & derivatives ; Disulfiram ; Glioblastoma ; Humans ; Interleukin-18 ; Ritonavir

OBJECTIVETo observe the effect of RITA, a small molecule that targets p53, combined with temozolomide (TMZ) on proliferation, colony formation and apoptosis of human glioblastoma U87 cells and explore the underlying mechanism.

METHODSCultured U87 cells were treated with RITA (1, 5, 10, 20 µmol/L), TMZ, or RITA+TMZ (half dose) for 24, 48 or 72 h. MTS assay were used to detect the cell proliferation, and the cell proliferation rate and inhibitory rate were calculated. The effect of combined treatments was evaluated by the q value. The expressions of p53, p21 and other apoptosis-associated genes were detected by qRT-PCR and Western blotting; cell apoptosis was assayed using flow cytometry with Annexin V/PI double staining; colony formation of the cells was detected with crystal violet staining.

RESULTSMTS assay showed that RITA at the 4 doses more potently inhibited U87 cell viability than TMZ at 72 h (P=0.000) with inhibitory rates of 25.94%-41.38% and 3.84%-8.20%, respectively. RITA combined with TMZ caused a more significant inhibition of U87 cells (29.21%-52.11%) than RITA (P<0.01) and TMZ (P=0.000) alone. At the doses above 5 µmol/L, the combined treatments with RITA+TMZ for 48 h resulted in q values exceeding 1.2 and showed an obvious synergistic effect of the drugs. Both RITA and TMZ, especially the latter, significantly increased the expressions of p53, p21, puma, and other apoptosis-associated genes to accelerate apoptosis and inhibit the growth and colony formation of U87 cells, and the effect was more obvious with a combined treatment.

CONCLUSIONRITA inhibits the growth of human glioblastoma cells and enhance their sensitivity to TMZ by up-regulating p53 expression, and when combined, RITA and TMZ show a synergistic effect to cause a stronger cell inhibition.

Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; Dacarbazine ; analogs & derivatives ; pharmacology ; Furans ; pharmacology ; Glioblastoma ; drug therapy ; Humans

OBJECTIVETo investigate programmed cell death induced by temozolomide in rat glioma C6 cell line.

METHODSRat glioma C6 cell line was treated by temozolomide at different concentrations and for different time lengths. MTT assay was used to evaluate the cell inhibition rate to determine the optimal exposure time and concentration. After the exposure to 400 µg/ml temozolomide for 24 h, the cells were observed for programmed cell death using HE staining, Hochest and Tunnel assay, Western blotting, and immunohistochemistry.

RESULTSMTT, HE staining, and Hochest and Tunnel assay all showed temozolomide-induced apoptosis in rat glioma C6 cell line. Western blotting and immunohistochemistry revealed up-regulation of Bax and down-regulation of Bcl-2 expression in the exposed cells, where the expressions of caspases 3, 8, 9, and 12 remained unchanged.

CONCLUSIONTemozolomide induces apoptosis in rat glioma C6 cell line through a caspase- independent pathway.

Animals ; Apoptosis ; Caspases ; Cell Line, Tumor ; Dacarbazine ; analogs & derivatives ; pharmacology ; Down-Regulation ; Glioma ; pathology ; Rats ; Up-Regulation

BACKGROUNDGlioma is the most common primary brain tumor with poor prognosis. Temozolomide has been used with thalidomide to treat gliomas. We investigated the synergistic mechanism of these two drugs in vitro.

METHODSHuman malignant glioma cells U251-MG were cultured and assigned to four groups with different treatments for 3 days: temozolomide group (100 micromol/L), thalidomide group (100 microg/L), temozolomide (100 micromol/L) plus thalidomide group (100 microg/L) and control group. MTT assay was applied to evaluate the cell viability. Cell cycle was analyzed by flow cytometry. The ultra-structural features of autophagosomes were observed with electron microscope. Acridine orange and monodansylcadaverine were adopted to label autophagosomes and flow cytometry was applied for quantification of autophagosomes. The expression of autophagy-associated protein was detected by Western blotting.

RESULTSProliferation of tumor cell was obviously suppressed by temozolomide with thalidomide treatment than by either drug used alone (P = 0.000 for each day). The combination treatment induced cell cycle arrest at G0/G1 phase. Typical autophagic ultra-structural character was found after the combined treatment. Thalidomide promoted the autophagy induced by temozolomide. The autophagy-associated proteins-microtubule associated protein 1 light chain 3 (MAP1LC3) and Beclin1 were more significantly up-regulated by the combined treatment than temozolomide used alone (MAP1LC3, P = 0.000; Beclin1, P = 0.004). The expression level of phosphatase and tensin homolog deleted on chromosome ten (PTEN), which promoted autophagy by suppressing PI3K/Akt/mTOR signaling pathway, was elevated by thalidomide (thalidomide group: P = 0.000; combined group: P = 0.002).

CONCLUSIONSThalidomide enhances the cytotoxicity of temozolomide by promoting the autophagy induced by temozolomide. Contributing to the up-regulation of PTEN by thalidomide, the expression of autophagy associated protein-MAP1LC3 and Beclin1 was enhanced, which leads to a reinforced autophagy in the combined treatment of temozolomide and thalidomide in vitro.

Antineoplastic Agents, Alkylating ; pharmacology ; Autophagy ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dacarbazine ; analogs & derivatives ; pharmacology ; Glioma ; pathology ; Humans ; Thalidomide ; pharmacology

BACKGROUNDThe radiochemotherapy regimen concomitantly employing temozolomide (TMZ) chemotherapy and radiotherapy (RT) 4 weeks after surgery, followed by 6 cycles of TMZ is a common treatment for glioblastoma (GBM). However, its median overall survival (OS) is only 14.6 months. This study was to explore the effectiveness and safety of early TMZ chemotherapy between surgery and chemoradiotherapy plus the standard concomitant radiochemotherapy regimen.

METHODSA randomized, parallel group, open-label study of 99 newly diagnosed GBM patients was conducted at 10 independent Chinese neurosurgical departments from June 2008 to June 2012. Patients were treated with concomitant radiochemotherapy regimen plus early postsurgical temozolomide (early TMZ group) or standard concomitant radiochemotherapy regimen (control group). Overall response was assessed based on objective tumor assessments, administration of corticosteroid and neurological status test. Hematological, biochemical, laboratory, adverse event (AE), and neurological condition were measured for 24 months of follow-up. The primary efficacy endpoint of this study was overall survival (OS). The secondary endpoint was progression free survival (PFS).

RESULTSThe median OS time in the early TMZ group was 17.6 months, compared with 13.2 months in the control group (log-rank test P = 0.021). In addition, the OS rate in the early TMZ group was higher at 6, 12, and 18 months than in the control group, respectively (P < 0.05). The median PFS time was 8.7 months in the early TMZ group and 10.4 months in the control group (log-rank test P = 0.695). AEs occurred in 29 (55.8%) and 31(73.8%) patients respectively in early and control groups, including nausea (15.4% vs. 33.3%), vomiting (7.7% vs. 28.6%), fever (7.7% vs. 11.9%), and headache (3.8% vs. 23.8%). Only 30.8% and 33.3% were drug-related, respectively.

CONCLUSIONSAddition of TMZ chemotherapy in the early break of the standard concomitant radiochemotherapy regimen was well tolerated and significantly improved the OS of the GBM patients, compared with standard concomitant radiochemotherapy regimen. However, a larger randomized trial is warranted to verify these results.

Adult ; Aged ; Antineoplastic Agents, Alkylating ; therapeutic use ; Chemoradiotherapy ; methods ; Dacarbazine ; analogs & derivatives ; therapeutic use ; Glioblastoma ; drug therapy ; radiotherapy ; Humans ; Middle Aged ; Treatment Outcome ; Young Adult

TMZ-SLN were prepared by emulsification-low temperature solidification method with stearic acid. The formulation and the preparation conditions were optimized by orthogonal experiments using entrapment efficiency as the evaluation index. The morphology was detected by transmission electron microscope. The Zeta potentials and the particle size distribution were evaluated by Laser Doppler Anemometry. The entrapment efficiencies and the drug release characteristics in vitro were assessed. The result showed that TMZ-SLN were concinnous and spherical in shape. The mean diameter (d(av) ) was 65.0 +/- 6.2 nm and the Zeta potential was -37.2 mV. The average entrapment efficiency was 58.9% +/- 1.21 %. The drug release behavior in vitro conformed to Higuchi Equation. The formation of a new material phase was testified by analysis of differential scanning calorimetry.
Antineoplastic Agents, Alkylating ; administration & dosage ; chemistry ; Dacarbazine ; administration & dosage ; analogs & derivatives ; chemistry ; Drug Carriers ; chemistry ; Lipids ; chemistry ; Nanoparticles ; chemistry ; Particle Size ; Stearic Acids ; chemistry

In gliomas, the canonical Wingless/Int (WNT)/β-catenin pathway is increased while peroxisome proliferator-activated receptor gamma (PPAR-γ) is downregulated. The two systems act in an opposite manner. This review focuses on the interplay between WNT/β-catenin signaling and PPAR-γ and their metabolic implications as potential therapeutic target in gliomas. Activation of the WNT/β-catenin pathway stimulates the transcription of genes involved in proliferation, invasion, nucleotide synthesis, tumor growth, and angiogenesis. Activation of PPAR-γ agonists inhibits various signaling pathways such as the JAK/STAT, WNT/β-catenin, and PI3K/Akt pathways, which reduces tumor growth, cell proliferation, cell invasiveness, and angiogenesis. Nonsteroidal anti-inflammatory drugs, curcumin, antipsychotic drugs, adiponectin, and sulforaphane downregulate the WNT/β-catenin pathway through the upregulation of PPAR-γ and thus appear to provide an interesting therapeutic approach for gliomas. Temozolomide (TMZ) is an antiangiogenic agent. The downstream action of this opposite interplay may explain the TMZ-resistance often reported in gliomas.
Animals ; Brain Neoplasms ; metabolism ; therapy ; Dacarbazine ; analogs & derivatives ; pharmacology ; Down-Regulation ; drug effects ; Glioma ; metabolism ; therapy ; Humans ; PPAR gamma ; metabolism ; Temozolomide ; Wnt Signaling Pathway ; drug effects ; physiology

OBJECTIVETo study the therapeutic effect of intranasal administration of temozolomide (TMZ) for brain-targeting delivery in a rat model bearing orthotopic C6 glioma xenografts.

METHODSForty Wistar rat bearing brain C6 glioma xenograft were randomly divided into 4 groups and treated with physiological saline solution or with TMZ by intravenous injection, gavage or intranasal administration. The tumor size, rat survival time and pathological changes were observed in each group.

RESULTSMagnetic resonance imaging showed a significantly reduced volume of glioma in intranasal TMZ group compared with that in the control, intraveneous TMZ injection group and TMZ gavage groups (12.45∓2.49 mm(3) vs 60.16∓4.12, 33.17∓3.56, and 35.16∓4.36 mm(3), respectively, P<0.05). The median survival time of the C6 glioma-bearing rats was also significantly longer in intranasal TMZ group than in the other 3 groups (31.0 days vs 20, 19, and 21.5 days, respectively, P<0.05). In the glioma xenografts, PCNA expression was the lowest and tumor cell apoptosis rate the highest in intranasal TMZ group.

CONCLUSIONIntranasal TMZ administration can suppress the growth of C6 glioma in rats and may serve as an effective strategy for glioma treatment.

Administration, Intranasal ; Animals ; Antineoplastic Agents, Alkylating ; administration & dosage ; Apoptosis ; Brain Neoplasms ; drug therapy ; Cell Line, Tumor ; Dacarbazine ; administration & dosage ; analogs & derivatives ; Drug Delivery Systems ; Glioma ; drug therapy ; Magnetic Resonance Imaging ; Neoplasm Transplantation ; Rats ; Rats, Wistar

INTRODUCTIONDespite aggressive multidisciplinary interventions, patients with high-grade astrocytomas experience tumour progression or recurrence. Treatment for this group of patients remains a formidable challenge. We describe our experience of salvage chemotherapy for these patients.

MATERIALS AND METHODSA retrospective review of relevant clinical and radiographic information of patients who received at least one cycle of salvage chemotherapy for progressive high-grade astrocytoma at the National Cancer Center, Singapore, from March 2004 to September 2006, was conducted. Patients underwent regular assessment with clinical examination and magnetic resonance brain imaging to gauge response to salvage chemotherapy. Survival and progression free interval data were analysed via Kaplan-Meier method.

RESULTSTwenty-four patients (13 glioblastomas, 11 anaplastic astrocytomas) had received chemotherapy as salvage treatment following progression of their high-grade astrocytoma. Among 20 patients assessable for tumour response, there were 4 patients with partial responses and 9 with stable responses. The 12-month survival rate for the entire group from time of onset of tumour progression was 49.6%. Eight patients had survived more than 12 months at the time of writing. Among patients with glioblastoma, the 12-month survival rate was 30% and the median survival was 11.2 months. For patients with anaplastic astrocytoma, the 12-month survival rate was 73%.

CONCLUSIONDurable disease control and prolonged survival were seen in a significant portion of selected patients with progressive high-grade astrocytoma who received salvage chemotherapy.

Adult ; Astrocytoma ; drug therapy ; Brain Neoplasms ; drug therapy ; Dacarbazine ; analogs & derivatives ; therapeutic use ; Female ; Glioblastoma ; drug therapy ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Salvage Therapy ; methods ; Singapore ; Survival Analysis

INTRODUCTIONThe use of adjuvant temozolomide (TMZ) in patients managed with surgery and adjuvant radiation therapy (RT) for glioblastoma multiforme (GBM) has been demonstrated to improve median and 2-year survival in a recent large international multicentre study. To confirm this result in routine clinical practice, an audit of the management and outcome of patients with GBM at The Cancer Institute Radiation Oncology was performed.

MATERIALS AND METHODSAll patients with GBM managed radically at The Cancer Institute Radiation Oncology from May 2002 to 2006 were entered into a prospective database. Patient, tumour and treatment factors were analysed for association with the outcome of median survival (MS). Survival was calculated using the Kaplan-Meier technique and correlation was assessed using Cox proportional hazards regression.

RESULTSForty-one patients with GBM were managed with radical intent over the 4- year period. The median age was 54 years and 66% were Eastern Cooperative Oncology Group (ECOG) 0-1 performance status. Macroscopic, subtotal and biopsy alone procedures were performed in 61%, 29% and 10% of patients, respectively. The median time from surgery to RT was 26 days. Adjuvant TMZ was used in 44% of patients (n = 18). The MS of the total group was 13.6 months, with a 24% 2-year overall survival. The use of TMZ was associated with improved MS (19.6 versus 12.8 months; P = 0.035) and improved 2-year survival (43% versus 0%). A requirement of dexamethasone dose greater than 4 mg at the end of RT (P = 0.012) was associated with worse survival, but there was no association of MS with age, ECOG, tumour size or extent of surgery.

CONCLUSIONThe median and 2-year survival outcomes are comparable to the results of the European Multicentre Study and justify the continued use of TMZ in routine clinical practice.

Antineoplastic Agents, Alkylating ; administration & dosage ; therapeutic use ; Brain Neoplasms ; drug therapy ; radiotherapy ; surgery ; Chemotherapy, Adjuvant ; Dacarbazine ; administration & dosage ; analogs & derivatives ; therapeutic use ; Female ; Glioblastoma ; drug therapy ; radiotherapy ; surgery ; Humans ; Male ; Middle Aged ; Prospective Studies ; Singapore ; Survival Analysis