Hyperthermia Induced The Apoptosis Of Esophageal Squamous Cell Carcinoma Cells And Affected The Nuclear Translocation Of Nrf2

Objective:Hyperthermia has been accepted as an effective approach for multifarious tumors.It is not well understood that the mechanism of apoptosis induced by hyperthermia.The present study assessed that hyperthermia induced the apoptosis and subcellular localization of Nrf2 in esophageal squamous cell carcinoma.Methods:The cell apoptosis was monitored by flow cytometry,including control group;heat group;t-BHQ(Nrf2 activator)with heat group.The caspase activity assay was used to detect the Caspase-3 and Caspase-9 activity.The expression of anti-apoptosis gene Bcl-2 and pro-apoptosis gene NOXA was determined by RT-PCR and western blotting.The subcellular localization of Nrf2 was evaluated by immunofluorescence staining.Results:1.The apoptosis rate and caspase-3,caspase-9 activity of heat group were significantly higher than those of control group.The Bcl-2 expression was down-regulated in heat group compared to control group,on the contrary,the NOXA expression was up-regulated in heat group compared to control group.2.The t-BHQ could inhibit the cell apoptosis and caspase-3 and caspase-9 activities,up-regulate the expression of Bcl-2 and suppress the expression of NOXA.3.Nrf2 induced by hyperthermia shifted into cytoplasm,which was inhibited by t-BHQ.Conclusions:The present study showed hyperthermia induced the apoptosis of ESCC cell and impacted on the nuclear translocation of Nrf2.However,we do not investigate the definite mechanism of the nuclear translocation of Nrf2 induced by hyperthermia,there needed further researches.Radiation and/or chemotherapy with hyperthermia could be a promising comprehensive therapy of tumor.