Eosinophils induces glioblastoma cell suppression and apoptosis - Roles of GM-CSF and cysteinyl-leukotrienes.

BACKGROUND: Glioblastoma is the most common and lethal primary brain tumor in adults. Despite the available cancer treatments, the recurrence of the tumor is high, and the survival rate is low. New approaches to antitumor therapies are needed. Eosinophils are prominent in allergic diseases and accumulate in several human brain tumors. Recently, the antitumor role of eosinophils has been targeted as eosinophils release several cytotoxic factors that induce cell impairment and death. OBJECTIVE: Here we aim to evaluate the interaction of the eosinophil and glioblastoma cells, the mechanism involved in the potential killing of the glioblastoma cells by the eosinophils, and how allergy/asthma could confer a better glioblastoma prognosis. METHODS: Eosinophils and serum from asthmatic and non-asthmatic donors were cultivated with different glioblastoma cell lines. RESULTS: Glioblastoma cells recruit eosinophils via GM-CSF signaling, activating and increasing eosinophil survivability and function on a GM-CSF-dependent manner. Eosinophils reduce glioblastoma cells metabolism, proliferation, and migration, via Fas/FasL. Cysteinyl-leukotrienes are accounted for the asthmatic serum enhancement of the glioblastoma cell migration and proliferation. Cysteinyl-leukotrienes enhance glioblastoma cell proliferation and migration, albeit activate eosinophils that suppress glioblastoma cells. CONCLUSION: Eosinophils have the potential to be key cells on glioblastoma therapeutics, as allergy and eosinophilia are correlated with a better glioblastoma prognosis. Eosinophils are elicited and attach to glioblastoma cells, where, by its cytotoxic function, via Fas/FasL, hind glioblastoma cell metabolism, proliferation, migration, and induce cell death.

Influence of Stem Cell Therapy on Thyroid Function and Reactive Oxygen Species Production in Diabetic Rats.

Cell therapy with mesenchymal stem cells (MSC) has been proposed for the treatment of diabetes mellitus (DM). It is known that the prevalence of thyroid disease is higher among diabetic patients than in general population. Therefore, our aim was to investigate the effect of the treatment with MSC on thyroid function and ROS generation in an experimental model of type 1 DM. Adult male Wistar rats were divided into the following groups: control, DM (80 mg/kg BW streptozotocin, iv.) and DM+MSC. MSC treatment occurred 4 weeks after DM induction and the animals were euthanized 4 weeks after MSC administration. We also evaluated the effect of co-culture with MSC or extracellular vesicles (EV) obtained from these cells on the rat thyroid cell line PCCL3 exposed to high glucose. Thyroid H2O2 generation was increased in DM, which was reversed by MSC treatment. These changes paralled a significant DuOx1 mRNA increase. The incubation of PCCL3 with high glucose increased extracellular H2O2 generation, which was reversed by both the co-culture with MSC and EV. Even though MSC treatment normalized thyroid ROS generation, serum thyroid hormone (TH) concentration remained low, along with increased serum TSH concentrations. Thyroperoxidase (TPO) activity, was reduced in DM, and MSC treatment did not normalize TPO. Therefore, we conclude that the treatment with MSC was able to reverse the increased thyroid H2O2 generation in diabetic animals and in PCCL3 cells exposed to high glucose, an effect probably mediated by EV produced by these cells, acting in a paracrine fashion.