Maslinic acid induces apoptosis in thyroid cancer cells via endoplasmic reticulum stress

Background Thyroid cancer is one of the most common malignant tumors of the endocrine system. Studies have demonstrated that maslinic acid (MA) has a wide range of antitumor activities via multiple cellular pathways. However, the role of MA in thyroid cancer remains poorly investigated. Objective To investigate the effects and underlying mechanisms of MA on thyroid cancer cells. Results MA inhibited cell viability and increased apoptosis in TPC1 and Cal62 cells. MA promoted apoptosis in TPC1 and Cal62 cells in a dose-dependent manner evidenced by flow cytometry and Western blotting. In addition, treatment with MA increased the expression of endoplasmic reticulum (ER) stress markers, such as Binding-immunoglobulin protein (BIP) and C/EBP homologous protein 10 (CHOP), in thyroid cancer cells. In cells treated with 4-phenylbutyric acid, an inhibitor of ER stress, MA-induced apoptosis was partially reversed. Finally, treatment with MA inhibited thyroid cancer growth in a TPC1 cell xenograft model. Conclusion Results indicated that MA promoted apoptosis in thyroid cancer cells via ER stress. These findings may provide new insights into novel therapeutic strategies for thyroid cancer.