EXPLORING 4-METHYILUMBELLIFERONE AS AN IMMUNE MODULATOR IN GLIOBLASTOMA TREATMENT

PIBUEL M.; POODTS D.; NOLI TRUANT S.; REDOLFI D.; SÍAS S.; ROSATO M.; BYRNE, A.; HAJOS S.; JANCIC C.; FRANCO P.; LOMPARDÍA S. L.

Congreso; Reunión Anual de la Sociedad Argentina de Inmunología; 2023

SAI

Glioblastoma (GBM) is the most aggressive primary brain tumor presenting therapeutic obstacles due to its complex immune microenvironment. The immune response against GBM initiates with microglial cells orchestrating early defenses. Subsequently, the blood-brain barriers disruption permits neutrophils and γδ T cells to infiltrate the tumor site.Temozolomide (TMZ) remains as the first-line drug for GBM treatment despite limited efficacy and adverse effects, underscoring the need for innovative therapies. In light of this, we previously demonstrated the anti-tumor effect of 4-methylumbelliferone (4MU), a natural compound without reported adverse effects, on GBM cells. Considering the previous, this study aimed to evaluate the impact of TMZ, 4MU, and theircombination on immune cell populations tied to the anti-GBM response. In vitro assays encompassed BV2 microglial cells, neutrophils, and γδ T cells isolated from GBM patients. Metabolic activity, cell proliferation, and cell death were assessed through the XTT assay, BrdU incorporation, and PI incorporation, respectively. Additionally, we measured cytokine secretion (IFN-γ and IL-12) using ELISA and γδ T cell activation by flow cytometry CD69 expression.Our results unveiled significant findings. Both TMZ and 4MU diminished metabolic activity and BV2 microglial cell proliferation. Notably, the different doses of TMZ induced nearly 40% of cell death, while 4MU triggered 17% only at higher doses. The effect of the TMZ-4MU combination resembled TMZ alone. Furthermore, 4MU enhanced IFN-γ and IL-12 secretion, whereas TMZ induced only IL-12 production. The combination yielded intermediate values. Within neutrophils, 4MU did not influence cell death, contrasting TMZ substantial elevation. Metabolic activity assays depicted an ascending trend with 4MU and a descending trend with TMZ. The combination exhibited intermediary effects between the single drugs. Notably, γδ T cells remained unchanged by TMZ treatment, while both 4MU alone and combined with TMZ triggered its activation. Significantly, we extended our study to conditioned media assays. Media from GBM cells (U251, U251-R, LN229, and LN229-R) treated for 48 h with 4MU, TMZ, their combination, or vehicle, was assessed on γδ T cells. Media from all GBM cell lines augmented γδ T cellactivation compared to control conditions (p