Clinicopathological and molecular landscape of 5-year IDH-wild-type glioblastoma survivors: A multicentric retrospective study.

Five-year glioblastoma (GBM) survivors (LTS) are the minority of the isocitrate dehydrogenase (IDH)-wild-type GBM patients, and their molecular fingerprint is still largely unexplored. This multicenter retrospective study analyzed a large LTS-GBM cohort from nine Italian institutions and molecularly characterized a subgroup of patients by mutation, DNA methylation (DNAm) and copy number variation (CNV) profiling, comparing it to standard survival GBM. Mutation scan allowed the identification of pathogenic variants in most cases, showing a similar mutational spectrum in both groups, and highlighted TP53 as the most commonly mutated gene in the LTS group. We confirmed DNAm as a valuable tool for GBM classification with a diagnostic refinement by using brain tumor classifier v12.5. LTS were more heterogeneous with more cases classified as diffuse pediatric high-grade glioma subtypes and having peculiar CNVs. We observed a global higher methylation in CpG islands and in gene promoters of LTS with methylation levels of distinct gene promoters correlating with prognosis.

Microglial Senescence and Activation in Healthy Aging and Alzheimer's Disease: Systematic Review and Neuropathological Scoring.

The greatest risk factor for neurodegeneration is the aging of the multiple cell types of human CNS, among which microglia are important because they are the "sentinels" of internal and external perturbations and have long lifespans. We aim to emphasize microglial signatures in physiologic brain aging and Alzheimer's disease (AD). A systematic literature search of all published articles about microglial senescence in human healthy aging and AD was performed, searching for PubMed and Scopus online databases. Among 1947 articles screened, a total of 289 articles were assessed for full-text eligibility. Microglial transcriptomic, phenotypic, and neuropathological profiles were analyzed comprising healthy aging and AD. Our review highlights that studies on animal models only partially clarify what happens in humans. Human and mice microglia are hugely heterogeneous. Like a two-sided coin, microglia can be protective or harmful, depending on the context. Brain health depends upon a balance between the actions and reactions of microglia maintaining brain homeostasis in cooperation with other cell types (especially astrocytes and oligodendrocytes). During aging, accumulating oxidative stress and mitochondrial dysfunction weaken microglia leading to dystrophic/senescent, otherwise over-reactive, phenotype-enhancing neurodegenerative phenomena. Microglia are crucial for managing Aß, pTAU, and damaged synapses, being pivotal in AD pathogenesis.

Are Thalamic Intrinsic Lesions Operable? No-Man's Land Revisited by the Analysis of a Large Retrospective, Mono-Institutional, Cohort.

Thalamic gliomas represent a heterogeneous subset of deep-seated lesions for which surgical removal is advocated, although clear prognostic factors linked to advantages in performance status or overall survival are still lacking. We reviewed our Institutional Cancer Registry, identifying patients who underwent surgery for thalamic gliomas between 2006 and 2020. Associations between possible prognostic factors such as tumor volume, grade, the extent of resection and performance status (PS), and overall survival (OS) were evaluated using univariate and multivariate survival analyses. We found 56 patients: 31 underwent surgery, and 25 underwent biopsy. Compared to biopsy, surgery resulted positively associated with an increase in the OS (hazard ratio, HR, at multivariate analysis 0.30, 95% confidence interval, CI, 0.12-0.75). Considering the extent of resection (EOR), obtaining GTR/STR appeared to offer an OS advantage in high-grade gliomas (HGG) patients submitted to surgical resection if compared to biopsy, although we did not find statistical significance at multivariate analysis (HR 0.53, 95% CI 0.17-1.59). Patients with a stable 3-month KPS after surgery demonstrated to have a better prognosis in terms of OS if compared to biopsy (multivariate HR 0.17, 95% CI, 0.05-0.59). Age and histological grades were found to be prognostic factors for this condition (p = 0.04 and p = 0.004, respectively, chi-square test). Considering the entire cohort, p53 positivity (univariate HR 2.21, 95% CI 1.01-4.82) and ATRX positivity (univariate HR 2.69, 95% CI 0.92-7.83) resulted associated with a worse prognosis in terms of OS. In this work, we demonstrated that surgery aimed at tumor resection might offer a stronger survival advantage when a stable 3-month KPS after surgery is achieved.

Pleomorphic xanthoastrocytoma is a heterogeneous entity with pTERT mutations prognosticating shorter survival.

Pleomorphic xanthoastrocytoma (PXA) in its classic manifestation exhibits distinct morphological features and is assigned to CNS WHO grade 2 or grade 3. Distinction from glioblastoma variants and lower grade glial and glioneuronal tumors is a common diagnostic challenge. We compared a morphologically defined set of PXA (histPXA) with an independent set, defined by DNA methylation analysis (mcPXA). HistPXA encompassed 144 tumors all subjected to DNA methylation array analysis. Sixty-two histPXA matched to the methylation class mcPXA. These were combined with the cases that showed the mcPXA signature but had received a histopathological diagnosis other than PXA. This cohort constituted a set of 220 mcPXA. Molecular and clinical parameters were analyzed in these groups. Morphological parameters were analyzed in a subset of tumors with FFPE tissue available. HistPXA revealed considerable heterogeneity in regard to methylation classes, with methylation classes glioblastoma and ganglioglioma being the most frequent mismatches. Similarly, the mcPXA cohort contained tumors of diverse histological diagnoses, with glioblastoma constituting the most frequent mismatch. Subsequent analyses demonstrated the presence of canonical pTERT mutations to be associated with unfavorable prognosis among mcPXA. Based on these data, we consider the tumor type PXA to be histologically more varied than previously assumed. Histological approach to diagnosis will predominantly identify cases with the established archetypical morphology. DNA methylation analysis includes additional tumors in the tumor class PXA that share similar DNA methylation profile but lack the typical morphology of a PXA. DNA methylation analysis also assist in separating other tumor types with morphologic overlap to PXA. Our data suggest the presence of canonical pTERT mutations as a robust indicator for poor prognosis in methylation class PXA.

In vivo 2-hydroxyglutarate-proton magnetic resonance spectroscopy (3 T, PRESS technique) in treatment-naïve suspect lower-grade gliomas: feasibility and accuracy in a clinical setting.

Isocitrate dehydrogenase 1/2 (IDH1/2) mutations are often detected in lower-grade gliomas (LGG) and result into 2-hydroxyglutarate (2HG) synthesis. Prior studies showed that 2HG can be detected in vivo using magnetic resonance spectroscopy (MRS), but its accuracy and translational impact are still under investigation. PURPOSE: To investigate the clinical feasibility of MRS for in vivo detection and quantification of 2HG on consecutive treatment-naïve suspect LGG patients and to compare MRS accuracy with tissue IDH1/2 analysis. METHODS: MRS spectra at 3 T were acquired with 1H-MRS single-voxel PRESS 2HG-tailored sequences with TE 30 (group 1) or TE 97 (groups 2A and B). Voxel sizes were 1.5 × 1.5 × 1.5 cm3 for group 1 (n = 13) and group 2A (n = 14) and 2 × 2 × 2 cm3 for group 2B (n = 32). Multiple metabolites' concentrations were analyzed with LCModel. Tumors were assessed for IDH status and main molecular markers. 2HG levels in urine/blood were measured by liquid chromatography-mass spectrometry. RESULTS: The larger voxel TE 97 sequence resulted in highest specificity (100%), sensitivity (79%), and accuracy (87%). Urine and blood 2HG did not result predictive. CONCLUSION: Our data confirm that 2 × 2 × 2-cm3 voxel TE 97 MRS shows high accuracy for 2HG detection, with good sensitivity and 100% specificity in distinguishing IDH mutant gliomas. Main limits of the technique are small tumor volume and low cellularity. Integrating 2HG-MRS with other metabolites may help non-invasive diagnosis of glioma, prognostic assessment, and treatment planning in clinical setting.

Long and Very-Long-Chain Ceramides Correlate with A More Aggressive Behavior in Skull Base Chordoma Patients.

BACKGROUND: Skull base chordomas are rare tumors arising from notochord. Sphingolipids analysis is a promising approach in molecular oncology, and it has never been applied in chordomas. Our aim is to investigate chordoma behavior and the role of ceramides. METHODS: Ceramides were extracted and evaluated by liquid chromatography and mass spectrometry in a cohort of patients with a skull base chordoma. Clinical data were also collected and correlated with ceramide levels. Linear regression and correlation analyses were conducted. RESULTS: Analyzing the association between ceramides level and MIB-1, total ceramides and dihydroceramides showed a strong association (r = 0.7257 and r = 0.6733, respectively) with MIB-1 staining (p = 0.0033 and p = 0.0083, respectively). Among the single ceramide species, Cer C24:1 (r = 0.8814, p ≤ 0.0001), DHCer C24:1 (r = 0.8429, p = 0.0002) and DHCer C18:0 (r = 0.9426, p ≤ 0.0001) showed a significant correlation with MIB-1. CONCLUSION: Our lipid analysis showed ceramides to be promising tumoral biomarkers in skull base chordomas. Long- and very-long-chain ceramides, such as Cer C24:1 and DHCer C24:1, may be related to a prolonged tumor survival and aggressiveness, and the understanding of their effective biological role will hopefully shed light on the mechanisms of chordoma radio-resistance, tendency to recur, and use of agents targeting ceramide metabolism.

Prognostic Characterization of Higher-Grade Meningiomas: A Histopathological Score to Predict Progression and Outcome.

Higher-grade meningiomas (WHO grade II and III) represent a diagnostic and prognostic challenge. We assessed the pathological and molecular characteristics of 94 higher-grade meningiomas (85 grade II, 9 grade III) to identify novel prognostic parameters. Higher mitotic count (p = 0.018), diffuse (≥50%) prominent nucleoli (p < 0.001), and sheeting (p < 0.001) were associated with recurrence. Lower SSTR2a-positive cells median rate (p = 0.048) and TERT promoter mutations (p = 0.014) were associated with recurrence and patient death, respectively; further analyses did not identify other outcome associations. Presence of Ki67 hot spots was associated with a shorter progression-free survival (PFS), independently of WHO grade at multivariate analysis (HR = 3.35, p = 0.008). Necrosis was related to a poorer overall survival (OS) at univariate (focal: HR = 4.55, p = 0.041 and diffuse: HR = 7.38, p = 0.020) and Kaplan-Meier analyses. A prognostic score was designed based on previous results: Presence of diffuse (≥50%) prominent nucleoli (0/1 point), diffuse (≥50%) sheeting (0/1 point), focal (<50%) or diffuse (≥50%) necrosis (0/1/2 points), and Ki67 hot spots (0/1 point). A total score ≥4 predicted poorer PFS and OS by Kaplan-Meier (PFS: 1.7 vs 6.4 years, p < 0.001 and OS: 5.2 vs 10.8 years, p = 0.001) and multivariate (PFS: HR = 5.98, p < 0.001 and OS: HR = 2.99, p = 0.048) analyses. These results were confirmed in an independent series of 58 grade II meningiomas (PFS: HR = 7.22, p = 0.002 and OS: HR = 9.69, p = 0.003). These associations and the integrated score could complement WHO grading.

Multidrug resistance proteins expression in glioma patients with epilepsy.

Epilepsy occurs in glioma, especially in low-grade glioma (LGG), but also in glioblastoma (GBM). In about 20 % of patients pharmacological treatment with anti-epileptic drugs (AEDs) fails. Refractory epilepsy is a multifactorial phenomenon not yet completely understood. The multidrug resistance phenotype was initially associated to P-glycoprotein (Pgp), an ATP-dependent transporter belonging to the same superfamily of multidrug resistance-associated proteins (MRPs). Glutathione-S-transferase-π (GST-π) is also involved in refractory epilepsy. In the present work we investigated the expression of Pgp, MRP1, MRP3 and GST-π in surgical specimens obtained from 35 patients with glioma and epilepsy. We observed MRP1 expression in tumor and endothelial cells (EC), MRP3 and Pgp expression mainly in ECs and GST-π predominantly in tumor cells (TC). MRP1 and MRP3 were more expressed in high grade glioma (HGG) than in LGG. In 6 cases we could compare tumor and periphery detecting the same MRP1 and Pgp expression, while MRP3 was mainly expressed in the tumor. We observed a trend of a better outcome in seizure control associated with a lower expression of MRP1 and MRP3. MRP3 was statistically more expressed in TCs of HGG than LGG (p = 0.0401) and more expressed in tumor than in periphery, in agreement with recent works that identify MRP3 as a potential target in GBM. Moreover, MRP3 was investigated in association with refractory epilepsy for the first time in our study and it was less expressed in patients with complete response to AEDs (p = 0.0550). Our preliminary data show an association between multidrug resistance transporters and refractory epilepsy in glioma.

Decrease in circulating endothelial progenitor cells in treated glioma patients.

High-grade gliomas are highly vascularized tumors, in which the amount of new blood vessels is closely related with the degree of malignancy. The role of endothelial progenitor cells (EPCs) in the neoangiogenesis of gliomas and the effects of post-surgical therapies (i.e., radiotherapy (RT) and chemotherapy) have not yet been fully elucidated. The aim of the present study was to evaluate the effect of surgery and post-surgical treatment on the levels of circulating EPCs in glioma patients and their correlation with vascular endothelial growth factor (VEGF). In this study, we assessed by flow cytometry the number of EPCs in the peripheral blood of 78 high-grade glioma patients (both untreated and treated with RT and chemotherapy) and 34 age- and sex-matched healthy controls. EPCs were markedly decreased in all treated glioma patients as compared to untreated ones. VEGF levels were significantly higher in patients as compared to controls, and surgery, but not chemotherapy, significantly decreased VEGF concentrations. We found no relationship between VEGF plasma levels and EPCs. In conclusion, the reliability of EPCs as a biomarker for monitoring angiogenesis in glioma patients needs further studies of correlations of this parameter with other markers of tumor-related vasculature.

Increased migration of a human glioma cell line after in vitro CyberKnife irradiation.

A human glioblastoma multiforme cell line (U87) and its derived-spheroids were irradiated either using a conventional irradiation (CIR) or a CK-like irradiation (IIR) in which the 8 Gy was delivered intermittently over a period of 40 minutes. The ability of glioma cells to migrate into a matrigel matrix was evaluated on days 1-8 from irradiation. Irradiation with CK-driven IIR significantly increased the invasion potential of U87 cells in a matrigel-based assay. In contrast to CIR, IIR was associated with increased levels of TGF-ß at four days (Real time PCR), ß1-integrin at 4-5 days (real-time PCR and western blot) and no elevation in phosphorylated AKT at days 4 and 5 (western blot). Our data suggests that glioma cell invasion as well as elevations of TGF-ß and ß1-integrin are associated with IIR and not CIR.

Expression of the new CXCL12 receptor, CXCR7, in gliomas.

Gliomas are very invasive brain tumors with poor prognosis and therefore any attempt to limit tumor cell dissemination in the brain is expected to improve glioma treatment. The recent deorphanization of CXCR7 as additional receptor for CXCL12 and CXCL11 has raised key issues on its interaction with the CXCL12/CXCR4 axis as a mechanism to modulate glioma cell migration. In this work we investigated protein and mRNA expression of the two chemokines CXCL12 and CXCL11, together with their receptors CXCR4 and CXCR7 in human glioma specimens and cell lines by immunohistochemistry, flow cytometry and quantitative real-time PCR. The main purpose of this study was to find out whether and at what extent CXCR4 and CXCR7 are differentially expressed in glioma cells. In human glioma specimens the levels of CXCL11 and CXCR4 mRNA were significantly higher in glioblastomas compared to non-tumor controls or low grade gliomas, whilst no difference was found for CXCL12 and CXCR7 mRNA expression. In cell lines, flow cytometry and immunocytochemical experiments showed CXCR4 was mainly expressed irrespective of its membrane or intracellular localization. In contrast, a predominant intracellular localization together with a negligible membrane expression of CXCR7 was found in all cells examined. In in vitro experiments CXCR4 and CXCR7 antagonists and the silencing of CXCR4 showed complete inhibition of glioma proliferation. Our findings, in agreement with previous data, suggest that in human glioma cells the prevalent intracellular localization of CXCR7 might modulate the functionality of CXCL11/12 either acting as a scavenger for these chemokines or interfering with the signaling pathways activated by the stimulation of CXCR4.

CXCL12, CXCR4 and CXCR7 expression in brain metastases.

Brain metastases occur in about 25% of patients who die of cancer. The most common sources of brain metastases in adults are lung, breast, kidney, colorectal cancer and melanoma. The chemokine/receptor system CXCL12/CXCR4 plays a key role in multiple biological functions; among these, homing of neoplastic cells from the primary site to the target and metastasis progression. Recently, an alternative CXCL12 receptor CXCR7 has been discovered. The aim of our study was to investigate the expression of CXCL12 and its receptors CXCR4 and CXCR7 by immunohistochemistry in 56 patients with metastatic brain disease from different non-CNS primary tumors and evaluate their prognostic relevance as well as that of other patient/treatment-related features on patient survival. CXCL12 showed an expression in tumor cells and in tumor vessels; CXCR7 was expressed by tumor and endothelial cells (both within the tumor and in the adjacent brain tissue), while CXCR4 showed a positivity in all samples with a nuclear pattern. Among the investigated immunohistochemical parameters, only CXCL12 expression in tumor endothelial cells showed a statistically significant correlation with shorter survival (p = 0.04 log-rank), perhaps identifying more aggressive tumors. Thus, this is the first study evaluating at the same time the expression of CXCL12 and its two receptors in a cohort of brain metastases.

Human adult skeletal muscle stem cells differentiate into cardiomyocyte phenotype in vitro.

Cell transplantation to repair or regenerate injured myocardium is a new frontier in the treatment of cardiovascular disease. Most studies on stem cell transplantation therapy in both experimental heart infarct and in phase-I human clinical trials have focused on the use of undifferentiated stem cells. Based on our previous observations demonstrating the presence of multipotent progenitor cells in human adult skeletal muscle, in this study we investigated the capacity of these progenitors to differentiate into cardiomyocytes. Here we show an efficient protocol for the cardiomyogenic differentiation of human adult skeletal muscle stem cells in vitro. We found that treatment with Retinoic Acid directed cardiomyogenic differentiation of skeletal muscle stem cells in vitro. After Retinoic Acid treatment, cells expressed cardiomyocyte markers and acquired spontaneous contraction. Functional assays exhibited cardiac-like response to increased extracellular calcium. When cocultured with mouse cardiomyocytes, Retinoic Acid-treated skeletal muscle stem cells expressed connexin43 and when transplanted into ischemic heart were detectable even 5 weeks after injection. Based on these results, we can conclude that human adult skeletal muscle stem cells, if opportunely treated, can transdifferentiate into cells of cardiac lineage and once injected into infarcted heart can integrate, survive in cardiac tissue and improve the cardiac function.

Nestin, PDGFRbeta, CXCL12 and VEGF in glioma patients: different profiles of (pro-angiogenic) molecule expression are related with tumor grade and may provide prognostic information.

Angiogenesis is a key event in the natural progression of gliomas. Nestin, a marker for multipotential neuroepithelial stem cells, is detected in neuroepithelial tumors and in proliferating endothelial cells (ECs) and is involved in the early stages of lineage commitment, proliferation and differentiation. Nestin expression is correlated with proangiogenic chemokines (CXCL12 and its receptor CXCR4) and growth factors (VEGF, PDGF-B and its receptor PDGFRbeta). VEGF expression upregulates CXCR4 on endothelial cells, binding the chemokine SDF1/CXCL12 (Stromal Derived Factor) that has a role on angiogenesis and chemotaxis of endothelial cells; PDGF (platelet-derived growth factor) and PDGFRbeta are also crucial by increasing the expression of VEGF. We performed a retrospective study on the presence and role of nestin-expressing cells in 102 patients with glioma, relating the findings to VEGF, CXCL12, PDGFRbeta expression and to clinical outcome (time to tumor progression-TTP and survival time-ST). Our results suggest that in gliomas the detection of proliferating ECs expressing nestin correlates to histological malignancy grade and clinical outcome. Also, the expression of CXCL12 in low-grade gliomas was the only factor associated with a significantly shorter TTP, suggesting a role of this chemokine in angiogenic shift and/or disease progression.

Valproic acid increases the in vitro effects of nitrosureas on human glioma cell lines.

Valproic acid (VPA) has been recently investigated for its anticancer properties in different tumors, including malignant gliomas. The aim of the present work was to evaluate the effects of VPA, alone or in combination with other chemotherapeutic drugs, on in vitro growth of human glioma cell lines. A172, U373, U138, U87, and SW1783 were treated with VPA alone or in combination with mitoxantrone, etoposide, or 1,3-bis(2-chloroethyl)-l-nitrosourea (BCNU). The effects of treatments on cell growth were assessed with crystal violet staining and analyzed using the combination index (CI). The percentage of apoptotic cells and the DNA content for cell cycle phases detection were also investigated by flow cytometry. Despite a certain variability, glioma cell lines were rather resistant to the drugs tested. Addition of VPA decreased the IC50 of the chemotherapeutic agents in all cell lines tested. This effect was more evident with BCNU. The synergic effect of the association of VPA and BCNU was related to an increased block of cell cycle with accumulation in S-G2/M phases of cell cycle rather than an increased programmed cell death. In our experimental model, VPA showed anticancer properties per se on human glioma cell lines and our data support the hypothesis that, if used in association with conventional chemotherapy, it might improve the effects of single chemotherapeutic agents.

Glioblastoma-derived tumorospheres identify a population of tumor stem-like cells with angiogenic potential and enhanced multidrug resistance phenotype.

We investigated in vitro the properties of selected populations of cancer stem-like cells defined as tumorospheres that were obtained from human glioblastoma. We also assessed their potential and capability of differentiating into mature cells of the central nervous system. In vivo, their tumorigenicity was confirmed after transplantation into the brain of non-obese diabetic/severe combined immunodeficient (NOD-SCID) mice. The angiogenic potential of tumorospheres and glioblastoma-derived cells grown as adherent cells was revealed by evaluating the release of angiogenic factors such as vascular endothelial growth factor and CXCL12 by ELISA, as well as by rat aortic ring assay. The proliferative response of tumorospheres in the presence of CXCL12 was observed for the first time. Multidrug resistance-associated proteins 1 and 3 as well as other molecules conferring multidrug resistance were higher when compared with primary adherent cells derived from the same tumor. Finally, we obtained cells from the tumor developing after grafting that clearly expressed the putative neural stem cell marker CD133 as shown by FACS analysis and also nestin and CXCR4. The cells' positivity for glial fibrillary acidic protein was very low. Moreover these cells preserved their angiogenic potential. We conclude that human glioblastoma could contain tumor cell subsets with angiogenic and chemoresistance properties and that this chemoresistance potential is highly preserved by immature cells whereas the angiogenic potential is, to a higher extent, a property of mature cells. A better understanding of the features of these cell subsets may favor the development of more specifically targeted therapies.

Prognostic value of CXCL12 expression in 40 low-grade oligodendrogliomas and oligoastrocytomas.

Both clinical and biological features have been reported as prognostic factors in low-grade gliomas. Among these, histotype, tumor size, enhancement, age and genetic pattern. Microvessel density (MVD) has been correlated to clinical outcome in astrocytomas, but its impact in oligodendrogliomas and mixed tumors is not sure. The pro-angiogenic chemokine stromal cell-derived factor (SDF-1/CXCL12) and its receptor CXC chemokine receptor 4 (CXCR4) have been described in low-grade gliomas, with a correlation between CXCL12 expression and shorter time to progression (TTP). The intermediate filament Nestin is expressed in proliferating vessels. Platelet-derived growth factor B (PDGF-B) and its receptor PDGFR-beta are also involved in angiogenesis and malignant progression in gliomas.

In vitro effects of topotecan and ionizing radiation on TRAIL/Apo2L-mediated apoptosis in malignant glioma.

The survival of patients with malignant gliomas is still unsatisfactory despite multimodality treatment, therefore new therapeutic strategies are required. Tumor necrosis factor apoptosis related ligand (TRAIL/Apo2L), a member of the tumor necrosis factor superfamily, may induce apoptotic cell death in several tumors, but not in normal cells, upon binding with specific receptors. In the present study, the expression and function of TRAIL receptors (TRAIL-R1/DR4 and TRAIL-R2/DR5) has been investigated in five human glioma cell lines (U87, U138, U373, A172, SW1783) in ex vivo tumors and in primary cultures obtained from the tumors. Our data show that gliomas preferentially express TRAIL R2 and that treatment with topotecan, a topoisomerase I inhibitor, significantly up-regulates its expression as detected by flow cytometry and western blotting. Moreover, in most cases, treatment with topotecan resulted in an increased sensitivity to TRAIL-dependent apoptosis, although cyclohexymide had to be added to induce apoptosis. On glioma cell lines, the effects of irradiation on TRAIL receptors were also analysed. In our experimental conditions, irradiation with 2 Gy had a modest additive effect on TRAIL-dependent apoptosis and was not able to modulate TRAIL receptor expression.

Effect of association of temozolomide with other chemotherapic agents on cell growth inhibition in glioma cell lines.

Despite progresses in surgery and treatments of malignant gliomas, prognosis of these tumors remains poor, with a median life expectancy of 12 months in glioblastomas. Chemotherapy (mostly with nitrosoureas) has been demonstrated to prolong overall survival, but the entity of this improvement is slight and disease recurrence/progression is the rule, stressing the need for multimodality treatment. In this work we investigated the effect of association of temozolomide (TMZ), an orally bioavailable alkylating agent, with three chemotherapeutic drugs, liposomal doxorubicin (DOXO), cis-platinum (CDDP). and topotecan (TP), on cell growth of A 172, U373, U138, U87, and SW1783 (all human glioma cell lines). Results indicate a synergistic effect (CI < 1) of TMZ in association with liposomal DOXO and CDDP on cell growth inhibition in most of the studied cell lines (A172, U373, U138, U87). Synergistic effect also has been obtained after treatment of A 172 and U373 with TMZ and TP in association. In conclusion, our results confirm the potential effect of association of chemotherapic drugs with different mechanisms of action in the treatment of gliomas.