Glioblastoma multiforme (GBM) is the most malignant primary brain tumor in adulthood, characterized by very high recurrence. Following the limited results for conventional therapies, novel therapeutic agents are under investigation. Among the putative new molecules, gallic acid (GA) represents a promising new anticancer drug. The anticancer effect of this drug has been based on its antioxidant effects. The aim of the present study was to investigate the toxic effects of GA on the T98G human glioblastoma cell line and its capacity to modulate the expression of microRNAs targeting the genes involved in tumor growth and invasion. Cytotoxicity, clonogenic ability and cell migration after GA treatment were tested. Moreover, the expression of miRNAs that target genes for antioxidant mitochondrial enzymes (miR-17-3p), p-21 protein (miR-21-5p) and ATM (miR-421-5p) was determined by qRT-PCR. The results confirmed in the T98G cells the anti-proliferative effect of GA reported for other glioma cell lines and showed that the miRNA expression changes depending on GA concentrations. Different GA concentrations can determine a protective or a toxic effect on tumor cells. Thus, the key for GA to induce a specific anticancer action is to use an optimal concentration that avoids these twin effects.

The success of chemo- and radiotherapy in glioblastoma multiforme, the most common and lethal primary brain tumour, could rely on the induction of immunogenic tumour cell death and on the induction of anticancer immune response. In this study we investigated cell survival to single treatments or combination of X-rays and temozolomide in glioblastoma cell lines (T98G and U251MG) and we attempted to identify danger signals (HMGB1 and HSP70) released by dying cells in the microenvironment that could activate antitumour immunity contributing to the therapeutic efficacy of conventional treatments. Our data suggest that HSP70 translocates from cytoplasm to extracellular environment after an increase in radiation dose and HMGB1 translocates from the nucleus to the cytoplasm and subsequently is released into the extracellular space, confirming a role of these proteins as signals released after radiation-induced damage in glioblastoma cells. We also could state that TMZ had limited effectiveness in activating HMGB1 and HSP70 signalling and, instead, an adjuvant effect was observed in some combined treatments, depending on schedule, cell line, and timing. A big challenge in tumour therapy is, therefore, to identify the most beneficial combination and chronology of multiple treatment options to contribute to the improvement of the therapeutic outcome.

This study solved some of the methodological doubts concerning the study of bystander effects by means of the medium transfer technique; moreover it also highlighted some experimental aspects that need to be considered when approaching this sort of experiments.

Treatment with pulsed electromagnetic fields (PEMFs) is emerging as an interesting therapeutic option for patients with cancer. The literature has demonstrated that low-frequency/low-energy electromagnetic fields do not cause predictable effects on DNA; however, they can epigenetically act on gene expression. The aim of the present work was to study a possible epigenetic effect of a PEMF, mediated by miRNAs, on a human glioblastoma cell line (T98G). We tested a PEMF (maximum magnetic induction, 2 mT; frequency, 75 Hz) that has been demonstrated to induce autophagy in glioblastoma cells. In particular, we studied the effect of PEMF on the expression of genes involved in cancer progression and a promising synergistic effect with temozolomide, a frequently used drug to treat glioblastoma multiforme. We found that electromagnetic stimulation in combination with temozolomide can elicit an epigenetic pro-apoptotic effect in the chemo- and radioresistant T98G glioblastoma cell line.

Advanced nanostructured materials, such as gold nanoparticles, magnetic nanoparticles, and multifunctional materials, are nowadays used in many state-of-the-art biomedical application. However, although the engineering in this field is very advanced, there remain some fundamental problems involving the interaction mechanisms between nanostructures and cells or tissues. Here we show the potential of (1)H NMR in the investigation of the uptake of two different kinds of nanostructures, that is, maghemite and gold nanoparticles, and of a chemotherapy drug (Temozolomide) in glioblastoma tumor cells. The proposed experimental protocol provides a new way to investigate the general problem of cellular uptake for a variety of biocompatible nanostructures and drugs.

BackgroundDespite complex treatment of surgery, radiotherapy and chemotherapy, high grade gliomas often recur. Differentiation between post-treatment changes and recurrence is difficult. 18F-methyl-choline (18F-FCH) is frequently used in staging and detection of recurrent prostate cancer disease as well as some brain tumours; however accumulation in inflammatory tissue limits its specificity. The 18F-ethyl-tyrosine (18F-FET) shows a specific uptake in malignant cells, resulting from increased expression of amino acid transporters or diffusing through the disrupted blood-brain barrier. 18F-FET exhibits lower uptake in machrophages and other inflammatory cells. Aim of this study was to evaluate 18F-FCH and 18F-FET uptake by human glioblastoma T98G cells.Material and methodsHuman glioblastoma T98G or human dermal fibroblasts cells, seeded at a density to obtain 2 × 105 cells per flask when radioactive tracers were administered, grew adherent to the plastic surface at 37°C in 5% CO2 in complete medium. Equimolar amounts of radiopharmaceuticals were added to cells for different incubation times (20 to 120 minutes) for 18F-FCH and 18F-FET respectively. The cellular radiotracer uptake was determined with a gamma counter. All experiments were carried out in duplicate and repeated three times. The uptake measurements are expressed as the percentage of the administered dose of tracer per 2 × 105 cells. Data (expressed as mean values of % uptake of radiopharmaceuticals) were compared using parametric or non-parametric tests as appropriate. Differences were regarded as statistically significant when p<0.05.ResultsA significant uptake of 18F-FCH was seen in T98G cells at 60, 90 and 120 minutes. The percentage uptake of 18F-FET in comparison to 18F-FCH was lower by a factor of more than 3, with different kinetic curves.18F-FET showed a more rapid initial uptake up to 40 minutes and 18F-FCH showed a progressive rise reaching a maximum after 90 minutes.Conclusions18F-FCH and 18F-FET are candidates for neuro-oncological PET imaging. 18F-FET could be the most useful oncological PET marker in the presence of reparative changes after therapy, where the higher affinity of 18F-FCH to inflammatory cells makes it more difficult to discriminate between tumour persistence and non-neoplastic changes. Additional studies on the influence of inflammatory tissue and radionecrotic cellular components on radiopharmaceutical uptake are necessary.

The migratory behavior of Aspc-1 cells is modulated by factors released by normal fibroblasts and tumor cells, and this is in turn modulated by both the radiation dose and the radiation quality.

A plasma focus device, devoted to the study of a possible application to the radiotherapy treatment of malignant cells, has been recently put into operation. The low-energy (up to 200 keV) X-rays are produced by conversion of the electron beam generated by the device during the pinch phase. The X-ray spectrum has already been fully characterized, and an initial campaign of irradiation of specific cell cultures has been completed. At present, the links between the operational parameters of the actual device, the beam intensity, and the cell irradiation effects are being analyzed, trying to evaluate the advantage of the very high dose rate that can be delivered, of the order of several Gy in a few tens of nanoseconds. Preliminary results on radiobiological effectiveness are presented and discussed.