Dual antiglioma action of metformin: cell cycle arrest and mitochondria-dependent apoptosis

The present study reports for the first time a dual antiglioma effect of the well-known antidiabetic drug metformin. In low-density cultures of the C6 rat glioma cell line, metformin blocked the cell cycle progression in G₀/G₁ phase without inducing significant cell death. In confluent C6 cultures, on the other hand, metformin caused massive induction of caspase-dependent apoptosis associated with c-Jun N-terminal kinase (JNK) activation, mitochondrial depolarization and oxidative stress. Metformin-triggered apoptosis was completely prevented by agents that block mitochondrial permeability transition (cyclosporin A) and oxygen radical production (N-acetylcisteine), while the inhibitors of JNK activation (SP600125) or glycolysis (sodium fluoride, iodoacetate) provided partial protection. The antiglioma effect of metformin was reduced by compound C, an inhibitor of AMP-activated protein kinase (AMPK), and was mimicked by the AMPK agonist AICAR. Similar effects were observed in the human glioma cell line U251, while rat primary astrocytes were completely resistant to the antiproliferative and proapoptotic action of metformin. Received 14 February 2007; received after revision 26 March 2007; accepted 3 April 2007     

线粒体转录终止因子3在甲状腺癌中的表达及预后意义

对线粒体转录终止因子3（MTERF3）在甲状腺癌中的表达水平进行分析并评估其预后价值。从TCGA和GTEx等数据库提取甲状腺癌患者MTERF3的表达数据，探究MTERF3在甲状腺癌和癌旁组织中差异表达，分析差异表达对患者免疫细胞浸润和预后情况的影响，并明确MTERF3的临床意义。MTERF3在甲状腺癌中表达水平显著低于正常甲状腺组织，该基因在甲状腺癌中表达较低提示患者预后不良。MTERF3是甲状腺癌的预后标志物，是甲状腺癌诊断和治疗的潜在分子靶标。