Characterization of the Inflammasome in Breast Cancer Cell Lines: Analysis in 2D and 3D Models

Abstract

[ES] Los inflamasomas son complejos multiproteicos que desempeñan un papel fundamental en la respuesta inmune innata. Están formados por receptores intracelulares, como NLRP3 (Nucleotide-binding oligomerization domain, Leucine-rich Repeat, and Pyrin domain containing 3), que responden a varios estímulos proinflamatorios, lo que lleva a la oligomerización de la proteína de andamiaje ASC (Apoptosis-associated Speck-like protein containing a Caspase recruitment domain), que a su vez recluta y activa a procaspasa-1. Esta proteasa procesa a proIL-1beta y proIL-18, causando su secreción e iniciando la señal proinflamatoria. Caspasa-1 también procesa a la proteína Gasdermina D, y su fragmento N-terminal migra a la membrana celular, induciendo la formación de poros dando lugar a la muerte celular proinflamatoria. La desregulación de los inflamasomas se ha asociado con el inicio de enfermedades inflamatorias y autoinmunes, así como enfermedades neurodegenerativas y cáncer. Inicialmente, los componentes del inflamasoma solo se detectaban en células inmunes innatas profesionales; sin embargo, también se ha descrito su presencia en células endoteliales y epiteliales. Nuestro grupo ha detectado diferentes fenotipos migratorios en células de cáncer de mama en respuesta a estímulos proinflamatorios, lo que podría ser relevante en términos de potencial metastásico y respuesta a terapia. Este estudio tiene como objetivo elucidar los elementos responsables de este diferente comportamiento. Con este propósito, hemos caracterizado la presencia de los diferentes componentes del inflamasoma en un amplio panel de líneas celulares de cáncer de mama humano (MCF7, HCC1954, MDA-MB-231, MDA-MB-468), tanto en modelos 2D como 3D. Además, hemos estudiado las interacciones del microambiente tumoral en mamósferas de líneas celulares de cáncer de mama con respuesta inflamatoria y sin respuesta inflamatoria.

[EN] Inflammasomes are multiprotein complexes that play a fundamental role in the innate immune response. They are formed by intracellular receptors, such as NLRP3 (Nucleotide-binding oligomerization domain, Leucine-rich Repeat, and Pyrin domain containing 3), which respond to various proinflammatory stimuli, leading to the oligomerization of the scaffold ASC protein (Apoptosis-associated Speck-like protein containing a Caspase recruitment domain), which, in turn, recruits and triggers the activation of procaspase-1. This protease processes proIL-1beta and proIL-18, causing their secretion and initiating the proinflammatory signal. Caspase-1 also processes the Gasdermin D protein, and its N-terminal fragment migrates to the cellular membrane, inducing pore formation and leading to proinflammatory cell death. Dysregulation of inflammasomes has been associated with the onset of inflammatory and autoimmune diseases, as well as neurodegenerative diseases and cancer. Initially, the components of the inflammasome were only detected in professional innate immune cells; however, their presence in endothelial and epithelial cells has also been described. Our group has detected different migratory phenotypes in breast cancer cells in response to proinflammatory stimuli, which could be relevant in terms of metastatic potential and therapy response. This study aims to elucidate the elements responsible for this different behaviour. For this purpose, in this work we have characterized the presence of the different inflammasome components in a broad panel of human breast cancer cell lines (MCF7, HCC1954, MDA-MB-231, MDA-MB-468), in both 2D and 3D models. Additionally, we have studied the tumour microenvironment interactions in mammospheres from inflammatory responders and non-responders breast cancer cell lines.