Abstract LB131: The role of the proinflammatory cytokine IL-1β and its signaling cascade in glioblastoma pathogenesis and the therapeutic effect of IL-1RA and Tolcapone as anticancer agents

Introduction: Interleukin-1 beta (IL-1β) is the major driving force in neuroinflammation. Here, we report on (i) the role of IL-1β in activating a signaling cascade that leads to proliferation and metastasis in glioblastoma cancer pathogenesis, and (ii) the potential of a therapeutic role for IL-1Receptor Antagonist (IL-1 RA) and Tolcapone against these untoward aspects of tumor pathogenesis. Materials and Methods: U87 glioblastoma cells were used to study the effect of IL-1β on proliferation and metastasis in vitro. RT-PCR was used to assess the gene expression levels of IL-1β-treated U87 cells for the TLR-MYD88-NF-κB signaling cascade in comparison to these levels in U87 cells treated with IL-1RA or Tolcapone. Western blotting analysis was used to assess the expression levels of signaling proteins involved in cancer proliferation and metastasis. Fluorescent Microscopy was used to identify the Glial fibrillary acidic protein (GFAP) expression in IL-1β-treated U87cells. Results: IL-1β increased the proliferation of U87 glioblastoma cells in vitro. IL-1β at 50ng/mL increased the proliferation at 48h (30 times (p≤0.05; t-test) which led to the formation of clones where rapidly dividing cancer cells aggregate together leading to the formation of organized GFAP-positive, clone-like structures with protruding spikes. RT-PCR results showed that IL-1β treatment at 50ng/mL significantly increased the expression of mRNA levels of TLR-MyD88-NF-κB-TNFα and IL-6 (p≤0.05; t-test) which are known to stimulate the over expression of growth factors including VEGF or EGF and cell adhesion molecules like Collagen, fibronectin and vimentin which help in tumor growth and metastasis. IL-1β also increased autophagy by upregulating cathepsin B, LAMP-2 and LC3B levels both at the mRNA and protein levels as well as increased expression of TLR2, MyD88, NF-κB, Calcineurin and IL-6 in IL-1β treated cells. In contrast, IL-1RA and Tolcapone inhibited the proliferation and the expression of these proteins, inhibiting autophagy by down regulating autophagy proteins and inducing apoptosis by upregulating the expression of apoptotic markers like caspase-8 and caspase-3. Further, IL-1β at 50ng/mL increased the expression of GFAP (1.5X; p≤0.05; t-test) at 48h. Conclusion: Our findings support our contention that neuroinflammation, read as elevated levels of IL-1β, increases the proliferation and metastasis of U87 glioblastoma, via the TLR-MyD88-NF-κB- TNFα and IL-6 signaling cascade. IL-1β increased the expression of GFAP in glioblastoma cells which may be correlated with its high metastatic and invasive nature. Our findings are consistent with our hypothesis (i) that IL-1β is responsible for increased proliferation and metastasis of U87 glioblastoma cells; and (ii) that IL-1β and its receptor can be targets of successful anticancer therapy such as shown here with the use of IL-1RA and/or Tolcapone as agents that as shown here may be useful in inhibiting these effects. Citation Format: Jagadeesh Narasimhappagari, Ling Liu, Meenakshisundaram Balasubramaniam, Srinivas Srinivas Ayyadevara, Orwa Aboud, W Sue T Griffin. The role of the proinflammatory cytokine IL-1β and its signaling cascade in glioblastoma pathogenesis and the therapeutic effect of IL-1RA and Tolcapone as anticancer agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited s); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2): nr LB131.