EP951 - ECE_3328 - Targeting the inflammasome machinery: a multi-omic approach to identify new diagnostic markers and therapeutic strategies in brain tumors

Abstract

Glioblastoma (GBM) remains the most prevalent and lethal primary brain endocrine-related cancer in adults. Despite current gold standard therapies, late-stage diagnosis and inherent therapeutic resistance result in a bad prognosis, with median survival rates limited to 10-12 months. Consequently, there is an urgent clinical need to identify novel diagnostic/prognostic biomarkers and therapeutic targets to improve patient management and quality of life. GBM is characterized by profound cellular heterogeneity and a complex tumor microenvironment (TME), wherein the immune system plays a key role in modulating tumor-associated inflammation. An essential component of this inflammatory response is the inflammasome machinery, a multiprotein complex activated by cellular stress and damage, being closely linked to immune evasion, cell death, and TME remodeling. In this study, we characterized the expression pattern of inflammasome components using a high-throughput qPCR array based on microfluidic technology. We analyzed a well-characterized cohort of GBM patients (n = 63) compared to non-tumor brain (NTB; n = 19) samples. Our results revealed a profound and widespread dysregulation of the inflammasome machinery in GBM tissue. These findings were subsequently validated in multiple independent external cohorts using RNA-seq, microarray and proteomic data, confirming the robustness of the observed expression patterns. To further address the complexity of this tumor, we characterized specific cell populations using an external single-cell sequencing dataset. Remarkably, the expression of key inflammasome components (highlighting MYD88) correlated significantly with aggressive clinical parameters and poor prognosis, including reduced survival rates, higher recurrence, EGFR amplification, and MGMT promoter methylation status. In silico pathway analysis further demonstrated that MYD88 expression is associated with critical pathways in GBM pathophysiology, such as epithelial-to-mesenchymal transition (EMT), hypoxia, angiogenesis, and NF-κB signaling. To evaluate the functional relevance of these findings, we performed in vitro modulation of MYD88 through transient silencing (siRNA) and pharmacological inhibition. Notably, we also addressed the challenge of chemoresistance by evaluating these modulations in a temozolomide (TMZ)-resistant GBM cell model developed within our laboratory. These interventions significantly reduced key oncogenic parameters, including cell proliferation, migration rate, and colonies and tumorspheres formation. In conclusion, this study demonstrates that the inflammasome machinery is a critical driver of GBM progression. Our data highlights MYD88 as a potential master regulator of tumor aggressiveness, positioning it as a novel diagnostic/prognostic biomarker and a promising therapeutic target to improve outcomes for patients suffering from this devastating disease.