title: Hyperthermia in combination with oxidative stress induces autophagic cell death in HT-29 colon cancer cells.
abstract: The purpose of this study was to evaluate the mechanism of ROS-induced hyperthermic cell death in a colon cancer cell line. HT-29 colon cancer cells were exposed to heat (43 degrees C) in the presence of tert-butyl hydroperoxide (t-BOOH). t-BOOH combined with hyperthermia significantly decreased cell viability as compared with t-BOOH or hyperthermia alone. This decrease in cell numbers was associated with retardation in the S phase transit and not through apoptosis. Cell death was noted to be accompanied by specific features characteristic of autophagy: the presence of cytoplasmic autophagic vacuoles; autophagosome membrane association of microtubule-associated protein light chain 3; accumulation of acidic vesicular organelles; and increased incorporation of MDC in the autophagosome. Thermal sensitization through modulation of cellular ROS may represent a novel approach to increase the efficacy of hyperthermia as an anticancer modality.
authors.affiliation: Department of Surgery, Division of Surgical Oncology, UMDNJ - New Jersey Medical School, 185 South Orange Avenue, MSB G524, Newark, NJ 07103, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Wang
authors.forename: Eugene
authors.initials: E
authors.lastname: Kim
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Harrison
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects; D000071186:Beclin-1; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D019073:HT29 Cells; D006358:Hot Temperature; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020122:tert-Butylhydroperoxide / Q000494:pharmacology
chemical_list: D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; D020122:tert-Butylhydroperoxide; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D048670:MAP Kinase Kinase 4