Isoalantolactone inhibits pancreatic ductal adenocarcinoma progression via direct targeting of NLRP3-mediated inflammation-angiogenesis axis

Abstract

Background Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common malignancy globally, with tumor uncontrolled angiogenesis being major causes of therapeutic failure and patient death. Isoalantolactone (IATL), a natural compound, exhibits antioxidant, anti-inflammatory, anti-proliferative, and anti-tumor properties. However, its role in inhibiting tumor angiogenesis in pancreatic cancer and the underlying mechanisms remain unclear. This study aims to investigate the anti-angiogenic effects of IATL in PDAC and elucidate the associated molecular pathways. Methods In vitro experiments were performed using PDAC cell lines (Panc02, PANC-1, and SW 1990) and HUVECs. In vivo studies were conducted using an orthotopic pancreatic cancer model in C57BL/6 mice. Cell viability, wound-healing, tube formation, in vivo imaging system analysis, laser speckle contrast imaging, immunohistochemistry, immunofluorescence, RT-qPCR, ELISA, and Western blot assays were used to evaluate the effects of IATL on tumor growth, angiogenesis, and inflammatory responses. Molecular docking and cellular thermal shift assay were performed to assess the interaction between IATL and NLRP3. Results IATL significantly inhibited the proliferation and migration of Panc02, PANC-1, and SW1990 cells. In the orthotopic pancreatic cancer model, IATL dose-dependently suppressed tumor growth, as evidenced by reduced IVIS fluorescence signals and tumor volume. IATL also markedly inhibited angiogenesis, as shown by reduced HUVECs migration and tube formation, decreased tumor blood perfusion detected by laser speckle imaging, and downregulated CD34 and VEGFA expression both in vivo and in vitro. Network pharmacology, molecular docking, and cellular thermal shift assay identified NLRP3 as a direct target of IATL. Mechanistically, IATL suppressed NLRP3 inflammasome activation, reduced ASC speck formation, inhibited the NLRP3/IL-1β signaling axis, and decreased the expression of inflammatory cytokines, including IL-6, TNF-α, IL-1β, and IL-18. NLRP3 knockdown mimicked the effects of IATL, whereas NLRP3 overexpression partially reversed its anti-tumor, anti-angiogenic, and anti-inflammatory effects, further supporting the target specificity of IATL. Conclusion IATL functions as a novel NLRP3 pathway inhibitor, suppressing angiogenesis through anti-inflammatory mechanisms, thereby effectively inhibiting PDAC progression. These findings suggest that IATL holds potential as a therapeutic agent for pancreatic cancer.