Tumor-neutrophil crosstalk promotes in vitro and in vivo glioblastoma progression.

Introduction: The tumor microenvironment (TME) of glioblastoma (GB) is characterized by an increased infiltration of immunosuppressive cells that attenuate the antitumor immune response. The participation of neutrophils in tumor progression is still controversial and a dual role in the TME has been proposed. In this study, we show that neutrophils are reprogrammed by the tumor to ultimately promote GB progression. Methods: Using in vitro and in vivo assays, we demonstrate the existence of bidirectional GB and neutrophil communication, directly promoting an immunosuppressive TME. Results and discussion: Neutrophils have shown to play an important role in tumor malignancy especially in advanced 3D tumor model and Balb/c nude mice experiments, implying a time- and neutrophil concentration-dependent modulation. Studying the tumor energetic metabolism indicated a mitochondria mismatch shaping the TME secretome. The given data suggests a cytokine milieu in patients with GB that favors the recruitment of neutrophils, sustaining an anti-inflammatory profile which is associated with poor prognosis. Besides, glioma-neutrophil crosstalk has sustained a tumor prolonged activation via NETs formation, indicating the role of NFκB signaling in tumor progression. Moreover, clinical samples have indicated that neutrophil-lymphocyte ratio (NLR), IL-1ß, and IL-10 are associated with poor outcomes in patients with GB. Conclusion: These results are relevant for understanding how tumor progression occurs and how immune cells can help in this process.

Characterization of macrophage phenotype, redox, and purinergic response upon chronic treatment with methionine and methionine sulfoxide in mice.

Hypermethioninemia is a disorder characterized by high plasma levels of methionine (Met) and its metabolites such as methionine sulfoxide (MetO). Studies have reported associated inflammatory complications, but the mechanisms involved in the pathophysiology of hypermethioninemia are still uncertain. The present study aims to evaluate the effect of chronic administration of Met and/or MetO on phenotypic characteristics of macrophages, in addition to oxidative stress, purinergic system, and inflammatory mediators in macrophages. In this study, Swiss male mice were subcutaneously injected with Met and MetO at concentrations of 0.35-1.2 g/kg body weight and 0.09-0.3 g/kg body weight, respectively, from the 10th-38th day post-birth, while the control group was treated with saline solution. The results revealed that Met and/or MetO induce an M1/classical activation phenotype associated with increased levels of tumor necrosis factor alpha and nitrite, and reduced arginase activity. It was also found that Met and/or MetO alter the activity of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, as well as the levels of thiol and reactive oxygen species in macrophages. The chronic administration of Met and/or MetO also promotes alteration in the hydrolysis of ATP and ADP, as indicated by the increased activity of ectonucleotidases. These results demonstrate that chronic administration of Met and/or MetO promotes activated pro-inflammatory profile by inducing M1/classical macrophage polarization. Thus, the changes in redox status and purinergic system upon chronic Met and/or MetO exposure may contribute towards better understanding of the alterations consistent with hypermethioninemic patients.

Tannic Acid Ameliorates STZ-Induced Alzheimer's Disease-Like Impairment of Memory, Neuroinflammation, Neuronal Death and Modulates Akt Expression.

Tannic acid (TA) is a hydrolysable glycosidic polyphenol polymer of gallic acid, which possesses neuroprotective properties. The aim of this study was to evaluate the effect of TA treatment on cognitive performance and neurochemical changes in an experimental model of sporadic dementia of Alzheimer's type (SDAT) induced by intracerebroventricular (ICV) injection of streptozotocin (STZ) and to explore the potential cellular and molecular mechanisms underlying these effects. Adult male rats were divided into four groups: control, TA, STZ, and TA + STZ. Animals from TA and TA + STZ groups were treated with TA (30 mg/kg) daily, by gavage, for 21 days; others groups received water (1 mL/kg). Subsequently, an ICV injection of STZ (3 mg/kg) was administered into the lateral ventricles of animals from STZ and TA + STZ groups, while other groups received citrate buffer. Cognitive deficits (short-term memory), neuronal survival, neuroinflammation as well as expression of SNAP-25, Akt, and pAkt were evaluated in the cerebral cortex. TA treatment protected against the impairment of memory in STZ-induced SDAT. STZ promoted an increase in neuronal death and the levels of proinflammatory cytokines (IL-6 and TNF-α) and a decrease in Akt and pAkt expression; TA was able to restore these changes. Neither STZ nor TA altered SNAP-25 expression or the levels of IL-12 and IL-4 in the cerebral cortex. Our study highlights that treatment with TA prevents memory deficits and reestablishes Akt and pAkt expression, protecting against neuronal death and neuroinflammation in STZ-induced SDAT in rats.

Development and characterization of CD73-siRNA-loaded nanoemulsion: effect on C6 glioma cells and primary astrocytes.

Introduction: Glioblastoma (GB) is the most common malignant brain tumor and is characterized by high invasiveness, poor prognosis, and limited therapeutic options. Silencing gene expression, through the use of small interfering RNA (siRNA), has been proposed as an alternative to conventional cancer therapy. Here, we evaluated the potential of CD73 as a new therapeutic target, since it is overexpressed in solid tumors and has emerged as a promising target to control GB progression.Methods: A cationic nanoemulsion (NE) as an intravenous siRNA-CD73 delivery system was developed and its effect on C6 glioma cell viability was determined.Results: The nanostructured system was effective in complexing oligonucleotides for delivery to target cells. In addition, we observed that the NE-siRNA-CD73 complex was effective in reducing CD73 protein levels and AMPase activity, which were related to decreased C6 glioma cell viability.Conclusions: These findings indicate the potential of siRNA-CD73-loaded cationic NE as a therapeutic alternative for glioma treatment.

Proteomic of goat milk whey and its bacteriostatic and antitumour potential.

Goat whey is normally discarded in the milk processing industry. However, several studies have addressed its biological properties and possible use in human or animal diet. The present study aimed to analysis the protein profile of goat whey to evaluate its possible oxidant, antioxidant, antibacterial, antitumour, and cytotoxic activities in vitro against human erythrocytes. Goat whey was skimmed, and crude protein extract (CPE) was obtained. Next, protein fractions (F) were obtained using ammonium sulphate precipitation method. The proteins were characterized by SDS-PAGE, two-dimensional electrophoresis and soluble protein measurements. No significant differences were observed in protein profile of CPE, F 30-60% and F 60-90%. The highest protein content was found in F 60-90% (0.41mgP/mL). All samples, except F 0-30% showed bacteriostatic activity against different bacterial strains. Only CPE at a concentration of 1000µg/mL was haemolytic against human erythrocytes. Oxidant activity against erythrocytes was not observed. Antioxidant activity was observed only for CPE. Cytotoxicity against C6 rat glioma cell line that was performed with CPE revealed tumour cell death>70% at concentrations of 0.05 and 0.1µg/mL. These results demonstrate at first time that CPE may be used as an antioxidant, bacteriostatic and cytotoxic compound against tumour cells.

Synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones exhibit selective in vitro antitumoral activity and inhibit cancer cell growth in a preclinical model of glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the worst form of primary brain tumor, which has a high rate of infiltration and resistance to radiation and chemotherapy, resulting in poor prognosis for patients. Recent studies show that thiazolidinones have a wide range of pharmacological properties including antimicrobial, anti-inflammatory, anti-oxidant and anti-tumor. Here, we investigate the effect antiglioma in vitro of a panel of sixteen synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones where 13 of these decreased the viability of glioma cells 30-65% (100 µM) compared with controls. The most promising compounds such as 4d, 4l, 4m and 4p promoted glioma reduction of viability greater than 50%, were further tested at lower concentrations (12.5, 25, 50 and 100 µM). Also, the data showed that the compounds 4d, 4l, 4m and 4p induced cell death primarily through necrosis and late apoptosis mechanisms. Interestingly, none of these 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones were cytotoxic for primary astrocytes, which were used as a non-transformed cell model, indicating selectivity. Our results also show that the treatment with sub-therapeutic doses of 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones (4d, 4l and 4p) reduced in vivo glioma growth as well as malignant characteristics of implanted tumors such as intratumoral hemorrhage and peripheral pseudopalisading. Importantly, 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones treatment did not induce mortality or peripheral damage to animals. Finally, 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones also changed the nitric oxide metabolism which may be associated with reduced growth and malignity characteristics of gliomas. These data indicates for the first time the therapeutic potential of synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones to GBM treatment.

Ketoprofen-loaded polymeric nanocapsules selectively inhibit cancer cell growth in vitro and in preclinical model of glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the worst and most common brain tumor, characterized by high proliferation and invasion rates. Nanoparticles of biodegradable polymers for anticancer drug delivery have attracted interest in recent years since they provide targeted delivery and may overcame the obstacle imposed by blood-brain barrier. Here we investigated the antitumoral effect of ketoprofen-loaded nanocapsules (Keto-NC) treatment on in vitro and in vivo glioma progression. We observed that Keto-NC treatment decreased selectively the cell viability of a panel of glioma cell lines, while did not exhibited toxicity to astrocytes. We further demonstrate that the treatment with sub-therapeutic dose of Keto-NC reduced the in vivo glioma growth as well as reduced the malignity characteristics of implanted tumors. Keto-NC treatment improved the weight, the locomotion/exploration behavior of glioma-bearing rats. Importantly, Keto-NC treatment neither induced mortality or peripheral damage. Finally, Ketoprofen also altered the extracellular nucleotide metabolism of peripheral lymphocytes, suggesting that antiinflammatory effects of ketoprofen could also be associated with the modulation of the adenine nucleotide metabolism in lymphocytes. Data indicate at first time the potential of Keto-NC as a promising therapeutic alterative to GBM treatment.