TY - JOUR AB - A strategy to suppress the expression of the DNA repair enzyme O6‑methylguanine‑DNA methyltransferase (MGMT) by inhibition of Wnt/β‑catenin signaling may be useful as a novel treatment for pituitary adenoma. Previous studies have reported that Tanshinone IIA (TSA), a major quinone compound isolated from Salvia miltiorrhiza, had antitumor effects. However, whether TSA has antitumor effects against pituitary adenoma and whether the mechanisms are associated with the Wnt/β‑catenin/MGMT pathway remains to be clarified. In the present study, TSA treatment caused apoptosis in AtT‑20 cells in a concentration‑dependent manner, as demonstrated by cell viability reduction, phophatidylserine externalization detected by Annexin V staining and mitochondrial membrane potential disruption detected by JC‑1 staining, which were associated with activation of caspase‑3 and DNA fragmentation detected by TUNEL in AtT‑20 cells. T‑cell factor (TCF)‑lymphoid‑enhancing factor (LEF) reporter activity was determined by dual luciferase reporter assay and the interaction between β‑catenin and TCF‑4 were detected using a co‑immunoprecipitation kit. The results indicated TSA treatment increased β‑catenin phosphorylation, inhibited β‑catenin nuclear translocation, reduced β‑catenin/TCF‑4 complex formation and TCF‑LEF luciferase reporter activity, and subsequently reduced the expression of cyclin D1 and MGMT. Notably, overexpression of MGMT in β‑catenin knock down AtT‑20 cells abrogated the TSA‑mediated effects in AtT‑20 cells. In conclusion, TSA induced apoptosis via inhibition of Wnt/β‑catenin‑dependent MGMT expression, which may provide novel insights into the understanding of the mechanism of the antitumor effects of Salvia miltiorrhiza. AD - Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China AU - Li,Zong‑Yang AU - Huang,Guo‑Dong AU - Chen,Lei AU - Zhang,Ce AU - Chen,Bao‑Dong AU - Li,Qing‑Zhong AU - Wang,Xiang AU - Zhang,Xie‑Jun AU - Li,Wei‑Ping DA - 2017/11/01 DO - 10.3892/mmr.2017.7325 EP - 5914 IS - 5 JO - Mol Med Rep KW - tanshinone IIA apoptosis β‑catenin O6‑methylguanine‑ DNA methyltransferase PY - 2017 SN - 1791-2997 1791-3004 SP - 5908 ST - Tanshinone IIA induces apoptosis via inhibition of Wnt/β‑catenin/MGMT signaling in AtT‑20 cells T2 - Molecular Medicine Reports TI - Tanshinone IIA induces apoptosis via inhibition of Wnt/β‑catenin/MGMT signaling in AtT‑20 cells UR - https://doi.org/10.3892/mmr.2017.7325 VL - 16 ER -