Resveratrol and AG490 Overcome Glioblastoma Cells' Resistance to Monotherapy by Inhibiting JAK2/STAT3 Signalling...

Background: Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system (CNS) and is characterized by poor prognosis and significant resistance to available treatments. Surgery, radiation therapy, and chemotherapy are the standard treatments; however, their efficacy is often limited by resistance. Resveratrol (RES), a naturally occurring polyphenol with antioxidant properties, has shown significant anticancer effects through inhibition of multiple cellular pathways. However, our earlier research revealed that the LN428 cell exhibited resistance, while the U251 cell showed sensitivity to RES monotherapy. Hence, RES and AG490, a JAK2 inhibitor, were used to overcome GBM cell resistance, which might enhance therapeutic efficacy. Methods: Human GBM cell lines LN428 and U251 were used. CCK-8, H&E staining, transwell, wound healing, calcein AM/PI, and flow cytometry assays were performed to evaluate cell proliferation, migration, and apoptosis. Molecular docking was performed to analyze the binding energy. Western blot, immunocytochemistry (ICC), and immunofluorescence (IF) were used to assess protein expression following treatment with RES, AG490, and their combination. Results: The results revealed that U251 cells were more sensitive to RES, AG490, and RES + AG490 than LN428 cells. Additionally, the combination of both compounds significantly reduced cell viability, proliferation, and migration, while increasing apoptosis in the LN428 and U251 cell lines. Moreover, the combination of RES and AG490 led to increased BAX protein expression while decreasing BCL-2 expression in LN428 and U251 cell lines. Notably, the monotherapy administration of RES did not significantly inhibit STAT3 or pSTAT3 protein expression in LN428 cells, while combination therapy significantly inhibited the expression of these proteins in LN428 and U251 cell lines. Conclusions: The concurrent administration of RES and AG490 effectively inhibited the JAK2/STAT3 signalling pathway and enhanced antitumor effects in GBM cells, indicating their potential as a therapeutic strategy.