Personalized regulation of glioblastoma cancer stem cells based on biomedical technologies: From theory to experiment (Review)

Unveiling the anticancer potential of the ethanolic extract from Trichoderma asperelloides

The discovery of new therapeutic alternatives for cancer treatment is essential for improving efficacy and specificity, overcoming resistance, and enabling a more personalized approach for each patient. We investigated the antitumor activity of the crude ethanolic extract of the fungus Trichoderma asperelloides (ExtTa) and its interaction with chemotherapeutic drugs. It was observed, by MTT cytotoxicity assay, that ExtTa significantly reduced cell viability in breast adenocarcinoma, glioblastoma, lung carcinoma, melanoma, colorectal carcinoma, and sarcomas cell lines. The highest efficacy and selectivity of ExtTa were found against glioblastoma T98G and colorectal HCT116 cell lines. ExtTa is approximately four times more cytotoxic to those tumor cells than to non-cancer cell lines. A synergistic effect between ExtTa and doxorubicin was found in the treatment of osteosarcoma Saos-2 cells, as well as with 5-fluorouracil in the treatment of HCT116 colorectal carcinoma cells using CompuSyn software. Our data unravel the presence of bioactive compounds with cytotoxic effects against cancer cells present in T. asperelloides ethanolic crude extract, with the potential for developing novel anticancer agents.

Hyperbaric Oxygen Therapy as a Complementary Treatment in Glioblastoma-A Scoping Review

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. The mainstay of management for GBM is surgical resection, radiation (RT), and chemotherapy (CT). Even with optimized multimodal treatment, GBM has a high recurrence and poor survival rates ranging from 12 to 24 months in most patients. Recently, relevant advances in understanding GBM pathophysiology have opened new avenues for therapies for recurrent and newly diagnosed diseases. GBM's hypoxic microenvironment has been shown to be highly associated with aggressive biology and resistance to RT and CT. Hyperbaric oxygen therapy (HBOT) may increase anticancer therapy sensitivity by increasing oxygen tension within the hypoxic regions of the neoplastic tissue. Previous data have investigated HBOT in combination with cytostatic compounds, with an improvement of neoplastic tissue oxygenation, inhibition of HIF-1α activity, and a significant reduction in the proliferation of GBM cells. The biological effect of ionizing radiation has been reported to be higher when it is delivered under well-oxygenated rather than anoxic conditions. Several hypoxia-targeting strategies reported that HBOT showed the most significant effect that could potentially improve RT outcomes, with higher response rates and survival and no serious adverse events. However, further prospective and randomized studies are necessary to validate HBOT's effectiveness in the 'real world' GBM clinical practice.

Alantolactone suppresses the metastatic phenotype and induces the apoptosis of glioblastoma cells by targeting LIMK kinase activity and activating the cofilin/G‑actin signaling cascade

Glioblastoma (GBM) is the most common aggressive brain tumor and is associated with an extremely poor prognosis, as the current standard of care treatments have limited efficacy. Natural compounds have attracted increasing attention as potential anticancer drugs. Alantolactone (ATL) is a natural small molecule inhibitor, that has antitumor properties. In the present study, U87MG and U251 cells were treated ATL and changes in actin/G-actin/F-actin/cofilin pathway were detected in whole cells, in the cytoplasm and mitochondria by western blot analysis. Immunofluorescence and immunoprecipitation analysis identified changes in the expression levels of target proteins and interactions, respectively. A LIMK enzyme inhibitor was also applied to assess the effects of ATL on the migration and invasion of GBM cells. Flow cytometry was used to detect the levels of apoptosis of GBM cells. The expression of matrix metalloproteinase (MMP)-2/MMP-9, caspase-3/caspase-9/poly(ADP-ribose) polymerase (PARP)/cytochrome c, were determined by western blot analysis to assess the effects of targeting LIMK. The in vitro findings were verified in vivo by characterizing changes in the expression of cofilin/LIMK in xenograft tumors in immunodeficient mice. It was found that ATL activated cofilin through the targeted inhibition of LIMK enzyme activity and it thus upregulated the ratio of G/F actin, and inhibited GBM cell migration and invasion. Conversely, the activation of cofilin and G-actin could be co-transferred to the mitochondria to initiate the mitochondrial-cytochrome c pathway to induce apoptosis. On the whole, the findings of the present study further illustrate the molecular mechanisms through which ATL inhibits the metastatic phenotype of GBM cells and induces apoptosis. Given previous findings, it can be deduced that ATL can function through multiple pathways and has multiple targets in GBM models, highlighting its potential for use in clinical applications.

Analysis of the cytotoxic effects, cellular uptake and cellular distribution of paclitaxel-loaded nanoparticles in glioblastoma cells in vitro

Glioblastoma is the most common and aggressive type of brain tumor. Although treatments for glioblastoma have been improved recently, patients still suffer from local recurrence in addition to poor prognosis. Previous studies have indicated that the efficacy of chemotherapeutic or bioactive agents is severely compromised by the blood-brain barrier and the inherent drug resistance of glioblastoma. The present study developed a delivery system to improve the efficiency of delivering therapeutic agents into glioblastoma cells. The anticancer drug paclitaxel (PTX) was packed into nanoparticles that were composed of amphiphilic poly (γ-glutamic-acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolaminecopolymer conjugated with targeting moiety transferrin (Tf). The Tf nanoparticles (Tf-NPs) may enter glioblastoma cells via transferrin receptor-mediated endocytosis. MTT assay and flow cytometry were used to explore the cytotoxic effects, cellular uptake and cellular distribution of paclitaxel-loaded nanoparticles. The results indicated that both PTX and PTX-Tf-NPs inhibited the viability of rat glioblastoma C6 cells in a dose-dependent manner, but the PTX-Tf-NPs exhibited a greater inhibitory effect compared with PTX, even at higher concentrations (0.4, 2 and 10 µg/ml). However, both PTX and PTX-Tf-NPs exhibited a reduced inhibitory effect on the viability of mouse hippocampal neuronal HT22 cells compared with that on C6 cells. Additionally, in contrast to PTX alone, PTX-Tf-NPs treatment of C6 cells at lower concentrations (0.0032, 0.0160 and 0.0800 µg/ml) induced increased G₂/M arrest, although this difference did not occur at a higher drug concentration (0.4 µg/ml). It was observed that FITC-labeled PTX-Tf-NPs were endocytosed by C6 cells within 4 h. Furthermore, FITC-labeled PTX-Tf-NPs or Tf-NPs co-localized with a lysosomal tracker, Lysotracker Red DND-99. These results of the present study indicated that Tf-NPs enhanced the cytotoxicity of PTX in glioblastoma C6 cells, suggesting that PTX-Tf-NPs should be further explored in animal models of glioblastoma.

Different Mechanisms Underlie the Metabolic Response of GBM Stem-Like Cells to Ionizing Radiation: Biological and MRS Studies on Effects of Photons and Carbon Ions

Glioblastoma multiforme (GBM) is a malignant primary brain tumor with very poor prognosis, high recurrence rate, and failure of chemo-radiotherapy, mainly due to a small fraction of cells with stem-like properties (GSCs). To study the mechanisms of GSCs resistance to radiation, two GSC lines, named line #1 and line #83, with different metabolic patterns and clinical outcome, were irradiated with photon beams and carbon ions and assessed by ¹H Magnetic Resonance Spectroscopy (MRS). Both irradiation modalities induced early cytotoxic effects in line #1 with small effects on cell cycle, whereas a proliferative G2/M cytostatic block was observed in line #83. MR spectroscopy signals from mobile lipids (ML) increased in spectra of line #1 after photon and C-ion irradiation with effects on lipid unsaturation level, whereas no effects were detected in line #83 spectra. Gamma-Aminobutyric Acid (GABA), glutamic acid (glu) and Phosphocreatine (pCr) signals showed a significant variation only for line #1 after carbon ion irradiation. Glucose (glc) level and lactate (Lac) extrusion behaved differently in the two lines. Our findings suggest that the differences in irradiation response of GSCs #1 and #83 lines are likely attributable to their different metabolic fingerprint rather than to the different radiation types.