The Effect of Shikonin on U87 Cells Through Notch2 Signaling Pathway and Its Mechanism

Background: The paper explored the inhibitory effect of Shikonin on Notch2 signaling pathway of U87 cells and elucidated the mechanism. Material and methods: CCK-8 was used to determine the viability of U87 cells. The Kit was used to detect the levels of ROS and GSH in the cells. After Annexin V-FITC/PI staining, flow cytometry was used to detect the effect of Shikonin on U87 cell apoptosis. Western Blotting was used to detect the expressions of Notch2, Notch3, Hes1 and Hey1. The levels of NH4Cl and MG132 were determined to measure the effect of Shikonin inhibiting Notch2 protein level in U87 cells, and the effect of Shikonin on Itch inhibiting Notch2 protein level. Results: Shikonin can inhibit the expressions of Notch2 and Notch3 proteins and the levels of downstream signaling molecules Hes1 and Hey1 in U87 cells, and in a concentration- and time-dependent manner. Shikonin can promote the degradation of Notch2 via the lysosomal pathway, which is associated with the up-regulation of the Itch expression. The inhibition of Notch2 and cell viability is related to the levels of GSH and ROS in cells, and Shikonin can down-regulate Notch2 to inhibit the proliferation of U87 cells. Conclusion: Shikonin inhibits the malignancy of glioma cells by promoting the degradation of Notch2 through the lysosomal pathway, which is related to the antioxidant effect. The results of our experiments provided certain experimental and theoretical basis for Shikonin treating glioma.