Ophiopogonin B induces reactive oxygen species-dependent apoptosis through the Hippo pathway in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in South China and is characterized by a high death rate. Ophiopogonin B (OP-B) is a bioactive component of Radix Ophiopogon japonicus, which is frequently used in traditional Chinese medicine to treat cancer. The present study aimed to examine the anti-cancer properties of OP-B on NPC cells. Cell viability and cell proliferation were measured using MTT and EdU assays. Flow cytometry was used to measure cell apoptosis, reactive oxygen species and mitochondrial membrane potential. Western blotting was used to investigate the expression of apoptosis and Hippo signaling pathway proteins. OP-B inhibited the proliferation of NPC cells by inducing apoptosis and disturbing the mitochondrial integrity. OP-B enhanced ROS accumulation. In addition, OP-B promoted the expression of mammalian STE20-like kinase 1, large tumor suppressor 1 and phosphorylated yes-associated protein (YAP) and suppressed the expression of YAP and transcriptional enhanced associate domain in NPC cells. OP-B increased the expression of forkhead box transcription factor O1 in the nuclear fraction. In conclusion, OP-B has therapeutic potential and feasibility in the development of novel YAP inhibitors for NPC.