Mecanismo antitumoral del ácido 2-hidroxioleico en glioblastomaidentificación de nuevos roles mediante análisis ómicos de membranas subcelulares y estudios biofísicos de membranas modelo

Abstract

Glioblastoma multiforme (GBM) is the most common tumor of central nervous system (CNS). It shows high malignancy and lethality and its treatment is based on tumor surgical resection combined with radiotherapy and chemotherapy (temozolomide), the standard of care treatment for glioblastoma. Newly diagnosed GBM has devastating prognostic and implies low life expectancy (14 months) and high risk of relapse. Developing new therapeutic strategies is therefore crucial to improve patient’s recovery while maintaining life quality. Biological membranes act as selective barriers and in many other cellular processes. The transient interaction of proteins with membranes is responsible for the regulation of multiple intracellular signaling pathways and ultimately for the physiological state of the cell. This interaction mainly depends on the membrane lipid composition. In this context, melitherapy or membrane lipid therapy emerged as a new therapeutic approach which uses lipid molecules to modify the composition and structure of membranes. Melitherapy would allow to reverse a pathological lipid state and consequently regulate the activity of proteins involved in intracellular signaling pathways which were perturbed in disease. 2-OHOA (natural analogue of oleic acid) is able to change membrane lipid composition and structure consequently modulating different cellular processes and exerting an antiproliferative effect. Furthermore, in its clinical development, 2-OHOA is in advanced clinical phases both in adults (phase IIb/III trial) and paediatric patients (phase I/IIa trial) and has showed pharmacological efficacy and safety in cellular and animal models. This work focuses in the identification of new roles for 2-OHOA and its derived products on membrane structure and protein interaction with membrane in glioma cell line U118-MG. The main objective is to further investigate 2-OHOA’s mechanism of action, specially its role as lipid proliferation switch. Here, we confirmed 2-OHOA and derivatives incorporation in membranes and subcelular membrane lipid modulation. A differential distribution pattern between 2-OHOA and its metabolite cis-8-heptadecenoic acid (C17:1n-9), generated by α-oxidation and a potential biomarker or effector molecule of 2-OHOA treatment was described. We also found a characteristic proteomic signature for the different subcellular compartments of glioma cells, which is altered under treatment with 2-OHOA, causing changes in the subcelular membrane localisation of these proteins. Finally, we linked the changes in membrane lipidome to the physicochemical alterations induced by 2-OHOA, subsequently confirming the ability of 2-OHOA to modulate the lipid proliferation switch.