EP1102 - ECE_2948 - The inflammasome machinery is dysregulated and represents a therapeutic vulnerability in pituitary tumours causing Cushing's disease

Abstract

Introduction: Corticotroph pituitary tumours (ACTHomas) are the leading cause of Cushing's disease and remain clinically challenging due to their heterogeneous behavior and the limited medical options for refractory or aggressive cases. Growing evidence suggests that endocrine tumour phenotypes are strongly influenced by inflammatory cues; however, a comprehensive, mechanism-oriented characterization of the inflammasome dysregulation in human ACTHomas is still lacking. In this context, the inflammasome represents a key stress- and damage-responsive multiprotein machinery whose activation has been implicated in immune evasion, regulated cell-death programmes and tumour microenvironment (TME) remodelling. This study was performed to systematically characterize the inflammasome transcriptomic landscape in ACTHomas versus non-tumour pituitary tissues, to identify clinically relevant discriminant factors, and to functionally validate their therapeutic tractability in ACTHoma models. Specifically, a clinically well-characterized multicentric cohort and a microfluidic-based qPCR profiling was used/performed to quantify a curated panel of inflammasome-related genes encompassing priming, core, and effector components in ACTHomas (n = 81) versus non-tumour pituitary tissues (n = 15), followed by integrative bioinformatic analyses to prioritize key candidates. Candidate validation and functional interrogation were conducted through genetic modulation in vitro in the AtT-20 corticotroph cell line and in primary cultures derived from human ACTHomas, coupled with functional in vitro assays of proliferation and aggressiveness-related phenotypes. Our results revealed that ACTHomas exhibited a marked and coordinated deregulation of the inflammasome machinery compared with controls, which was independently reproduced in external validation cohorts. Top-ranked factors, robustly discriminated ACTHomas from non-tumour pituitaries, consistently clustering samples by disease status. Importantly, in vitro modulation of these top-ranked factors significantly impacted proliferation and aggressiveness-associated readouts in AtT-20 cells and in patient-derived ACTHoma primary cultures. Moreover, pharmacological blockade of the inflammasome machinery using anakinra (an IL1R1 antagonist) attenuated inflammasome-driven functional hallmarks of aggressiveness in vitro, supporting the druggability of this pathway in corticotroph tumours. Altogether, our data demonstrated a clinically relevant inflammasome-associated molecular dysregulation in ACTHomas and identify specific components as discriminant biomarkers and actionable therapeutic targets, providing a strong rationale for repurposing inflammasome inhibition as a precision-oriented therapeutic strategy in Cushing's disease. Fundings: Junta de Andalucia (PI-0117-2025, DGP_PIDI_2024_00134), ISCIII (CD24-00240), FSEEN.