Home

12:00 – 12:30 Paz Boix

Optimization of Accurate Breast Cancer Models for the Advanced Preclinical Evaluation of Polymer Therapeutics Polymer therapeutics-based approaches provide advantage over the “free” form of a given drug, including enhanced passive tumor targeting, altered pharmacokinetics, and specific release of drugs at the tumor site thanks to the use of bioresponsive linkers. In vitro characterization of polymer therapeutics commonly employs traditional two-dimensional (2D) cell culture approaches that fail to fully recapitulate important in vivo tumor characteristics. Therefore, we developed optimized three-dimensional (3D) breast cancer culture systems growing in basement membrane matrix extract as a robust platform for the characterization of novel anti-cancer polymer therapeutics. We first established and optimized patient-derived breast cancer organoid and cell line-derived spheroid cultures and then confirmed the maintenance of breast cancer subtype-defining biomarkers. We next characterized the 2D and 3D models and encountered significant differences in metabolic profiles, the epithelial-to-mesenchymal transition, and the expression of breast cancer biomarkers linked to prognosis. We also compared specific drug release-triggering stimuli such as reactive oxygen species (ROS) and cathepsin B levels between breast cancer subtypes, which revealed that 3D cultures of MCF7, MDA-MB-453, and ZR75 breast cancer cell lines displayed significantly increased ROS levels compared to 2D, while cathepsin B levels tended to decrease in 3D ZR75 cultures when compared to 2D. Finally, we evaluated the internalization and lysosomal colocalization of the polyglutamic acid carrier in breast cancer spheroids and characterized the toxicity of a polymer-based combination conjugate carrying a curcuminoid and endocrine therapy both in 3D culture than in 2D culture, obtaining promising results. Our findings highlight the need to employ 3D culture conditions to generate robust characterization data for polymer therapeutics-based anti-cancer strategies. We now aim to apply our 3D models derived from cell lines and patient samples to evaluate both single-drug and combination polymer therapeutics in the hope that this platform will accelerate clinical translation.

12:30 – 13:00 Paco Ibáñez

Role of Extracellular Vesicles during ethanol induced neuroinflammation in adolescence Current evidence indicates that extracellular vesicles (EVs) participate in intercellular signaling and in the regulation and amplification of neuroinflammation. We have demonstrated that ethanol is able to induce an inflammatory immune response through the toll-like receptor 4 (TLR4) activation. But how ethanol alters EVs physiology is not well understood. In the first part of the study, we evaluated if ethanol, through TLR4 response, could change the release and inflammatory content of astrocyte-derived EVs, and whether these vesicles were capable to communicate with neurons and spread neuroinflammation. Previous results of the lab showed that the female brain is more vulnerable to the inflammatory effects of binge ethanol drinking in adolescence than the male brain, and these differences can be detected in plasma. Since EVs can cross the blood brain barrier and the EV miRNAs are highly stable in peripheral circulation, for the second part of the study we analyzed gender differences in the levels of several inflammatory-related miRNAs in plasma EVs derived from alcohol-intoxicated female and male adolescents and whether these miRNAs of EVs could be used as biomarkers of the neuroinflammation induced by ethanol in adolescence.

Age-mediated changes in plasma membrane fluidity: how these changes occur and how they contribute to the cognitive deficits of the old.

Speaker: Carlos G. Dotti
Institution: Centro de Biología Molecular Severo Ochoa, CSIC/AUM, Madrid
Place: CIPF conference room

Abstract: Aging determines the occurrence of changes in a panoply of biochemical / molecular hubs, each contributing to the typical deficits of age. In fact, aging comes with alterations in genomic and non-genomic activities, including among the latter, but not only, defects in mitochondrial function, intracellular trafficking, proteostasis, in the response to cellular stress and in the control of intracellular calcium. What mechanism could act upstream of these defects, responsible for each of them occurring? In other words: is there a “master” change with age, upstream of all (or some) defects that occur with age? A defect that could fulfill the “upstream” role is membrane signaling: it occurs early after cell maturation and follows a gradual course, it occurs in all cells of our organs and tissues and influences genomic activity. Although the best-known example of defective membrane signalling with age is brain insulin resistance, age is also accompanied by resistance to thyroid stimulating hormone (TSH), to growth hormone, orexin, corticosteroid hormones, fibroblast growth factor and more. Moreover, defective membrane signalling is also evident for neurotransmitter signalling. Therefore, understanding the mechanisms underlying the changes in plasma membrane signalling with age could open avenues of intervention to reduce the sensory, motor and cognitive deficits that occur with age. In my talk I will present data that suggest that small but persistent changes in the lipid composition of the plasma membrane with aging cause different types of receptors to lose functional capacity, and how these changes occur.