title: Enhancement of hyperthermia-induced apoptosis by 5Z-7-oxozeaenol, a TAK1 inhibitor, in Molt-4 cells.
abstract: OBJECTIVE
  Transforming growth factor-β-activated kinase1 (TAK1) plays an anti-apoptotic role in response to multiple stresses. TAK1 inhibitor, 5Z-7-oxozeaenol (OZ) has been studied for its apoptotic effects. However, the combined effect of OZ with physical stresses remains to be elusive. Therefore, in this study we focussed to determine the combined effects of OZ with hyperthermia (HT) using Molt-4 cell line.
  
  
  METHODS
  Molt-4 cells were pre-treated with OZ for 1 h followed by heat exposure (44 °C, 10 min) and harvested 24 h after incubation at 37 °C, apoptosis was measured by Annexin V-FITC/PI double staining assay using flow cytometry and cell growth was observed by cell counting assay. Further mechanism involved in the combination was investigated by measuring mitochondrial membrane potential (MMP), intracellular ROS generation, expression of apoptosis related protein, intracellular calcium ion level and Fas activity.
  
  
  RESULTS
  Combination of OZ with HT significantly enhances MMP loss and superoxide generation. Furthermore, OZ pre-treatment promotes caspase-8 cleavage, Fas externalisation, caspase 3 activity and intracellular calcium ion levels. OZ pre-treatment decreased the expression of HT-induced Bcl-2 and increased the expression of pro-apoptotic Bax, while markedly suppressed the phosphorylation of JNK and p38. In addition, increased expression of CHOP following combined treatment indicates that ER stress may also involve in the enhancement of HT-induced apoptosis.
  
  
  CONCLUSIONS
  Our data showed for the first time that OZ sensitizes Molt-4 cells to HT-induced apoptosis via extrinsic and intrinsic apoptotic pathways. Furthermore, ROS and ER stress may also play role in the enhancement of HT-induced apoptosis by OZ.
authors.affiliation: a Department of Radiological Sciences , Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan.
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.affiliation: a Department of Radiological Sciences , Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan.
authors.forename: Qing-Li
authors.initials: QL
authors.lastname: Zhao
authors.affiliation: a Department of Radiological Sciences , Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan.
authors.forename: Paras
authors.initials: P
authors.lastname: Jawaid
authors.affiliation: a Department of Radiological Sciences , Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan.
authors.forename: Mati Ur
authors.initials: MU
authors.lastname: Rehman
authors.affiliation: c Department of Basic Medical Sciences , College of Medicine, King Saud Bin Abdulaziz University of Health Sciences , Jeddah , Kingdom of Saudi Arabia.
authors.forename: Kanwal
authors.initials: K
authors.lastname: Ahmed
authors.affiliation: b Department of Cancer Cell Biology , Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: a Department of Radiological Sciences , Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
keywords: 5Z-7-oxozeaenol; TAK1; apoptosis; hyperthermia; oxygen; reactive; species