(824) In Vitro Characterization of Glioblastoma Inflammatory Signatures: Insights into Resistance and Model Selection

Introduction/Rationale: Glioblastoma multiforme (GBM) is a highly aggressive neurological cancer marked by treatment resistance and recurrence. Inflammatory profiling is essential to reveal mechanisms of immune evasion and molecular remodeling in GBM that drive the need for cancer subtype-specific treatments. This study examines inflammation-associated gene expression and stress responses in two immortalized GBM cell lines in a model of treatment-induced inflammation, with correlations to glioblastoma tumor subtypes, to advance patient treatment decision-making.

Methods: LN-18 and LN-229 human GBM cells were cultured and stimulated with lipopolysaccharide (LPS). Total RNA was extracted and expression of key immune genes (CCL2, STAT3, IL-33, CD274, TGF-β, IL-10) and angiogenic neuropilin-1 (NRP1) was assessed by RT-qPCR.

Results: At baseline, LN-18 cells expressed 40% more CD274 than LN-229 cells, while NRP1 was nearly five times greater in LN-229. LPS exposure reduced NRP1 in LN-229 by >70%, eliminating previous differences with LN-18. The same treatment increased CCL2 sevenfold in LN-229 versus an untreated control and ~11-fold compared to treated LN-18 cells, indicating a strong immune response in LN-229 cells. STAT3 was significantly upregulated in LN-18 cells after LPS exposure compared to LN-229, suggesting differential inflammatory signaling between subtypes. TGF-β, IL-10, and IL-33 levels were low across all cell lines and conditions.

Conclusion: LN-229 cells present a distinct inflammatory and mesenchymal-like gene signature relative to LN-18. These unique profiles emphasize the importance of model selection in advancing our understanding of GBM. Our findings support LN-229 as a valuable model of aggressive glioblastoma and implicate NRP1 as a critical target for understanding mechanisms of resistance. Expanded inflammatory profiling will advance clinical translation opportunities, guide targeted immunotherapies, and ultimately improve outcomes for patients living with glioblastoma.