title: Molecular mechanisms of hyperthermia-induced apoptosis enhanced by withaferin A.
abstract: Hyperthermia is a good therapeutic tool for non-invasive cancer therapy; however, its cytotoxic effects are not sufficient. In the present study, withaferin A (WA), a steroidal lactone derived from the plant Withania somnifera Dunal, has been investigated for its possible enhancing effects on hyperthermia-induced apoptosis. In HeLa cells, treatment with 0.5 or 1.0μM WA at 44°C for 30min induced significant apoptosis accompanied by decreased intracellular GSH/GSSG ratio and caspase-3 activation, while heat or WA alone did not induce such changes. The upregulation in apoptosis was significantly inhibited by glutathione monoethyl ester, a cell permeable glutathione precursor. Mitochondrial transmembrane potentials were dramatically decreased by the combined treatment, with increases in pro-apoptotic Bcl-2-family proteins tBid and Noxa, and downregulation of antiapoptotic Bcl-2 and Mcl-1. Combined treatment with hyperthermia and WA induced significant increases in JNK phosphorylation (p-JNK), and decreases in the phosphorylation of ERK (p-ERK) compared with either treatment alone. These results suggest that WA enhances hyperthermia-induced apoptosis via a mitochondria-caspase-dependent pathway; its underlying mechanism involves elevated intracellular oxidative stress, mitochondria dysfunction, and JNK activation.
authors: Department of Public Health, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: sai@med.u-toyama.ac.jp.
authors: Zheng-Guo
authors: ZG
authors: Cui
authors: Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: d1061016@ems.u-toyama.ac.jp.
authors: Jin-Lan
authors: JL
authors: Piao
authors: Department of Dermatology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: rehman.mu84@yahoo.com.
authors: Mati U R
authors: MU
authors: Rehman
authors: Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: ogawa@med.u-toyama.ac.jp.
authors: Ryohei
authors: R
authors: Ogawa
authors: Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: lipeng198511@hotmail.com.
authors: Peng
authors: P
authors: Li
authors: Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: zhao@med.u-toyama.ac.jp.
authors: Qing-Li
authors: QL
authors: Zhao
authors: Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: kondot@med.u-toyama.ac.jp.
authors: Takashi
authors: T
authors: Kondo
authors: Department of Public Health, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: inadera@med.u-toyama.ac.jp.
authors: Hidekuni
authors: H
authors: Inadera
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D006979:Hyperthermia, Induced; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D054358:Withanolides / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D054358:Withanolides; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D005978:Glutathione; C009684:withaferin A
keywords: Apoptosis; Cancer; Hyperthermia; JNK; Withaferin