Combination of alantolactone and temozolomide targets stemness and lipid metabolism in glioblastoma through YAP1-Hippo signaling.

Glioblastoma (GBM) remains a therapeutic challenge due to its resistance to standard chemotherapy and high recurrence rate. This study investigates the combined effects of alantolactone (ALT) and temozolomide (TMZ) on GBM cells, focusing on stemness, lipid metabolism, and the underlying Hippo signaling pathway. Human GBM cell lines U87 and U251 were treated with ALT and TMZ, either alone or in combination. Cell viability was assessed using the CCK-8 assay, stemness was evaluated by sphere formation assay, and gene and protein expression were analyzed by qPCR and Western blotting. A xenograft mouse model was established to evaluate in vivo efficacy. Phospho-kinase arrays and rescue experiments using the Hippo pathway inhibitor XMU-MP-1 were performed to explore the underlying mechanisms. The results showed that both ALT and TMZ inhibited cell proliferation in a dose-dependent manner. The combination treatment synergistically reduced cell viability, sphere formation, and the expression of stemness markers (CD133, NANOG, SOX2) and lipid metabolism regulators (PLIN2, FASN, SREBP1). In vivo, combined therapy significantly suppressed tumor growth and improved histopathological features. Mechanistically, ALT and TMZ promoted YAP1 phosphorylation and downregulated TEAD2, AXL, and c-MYC. Inhibition of Hippo signaling with XMU-MP-1 reversed the anti-tumor effects of the combination treatment. In conclusion, ALT and TMZ synergistically inhibit GBM growth and stemness by activating the Hippo pathway and suppressing lipid metabolism. These findings provide a rationale for the combined use of ALT and TMZ as a potential therapeutic strategy against GBM.