title: [Reversal effect of hyperthemia on multidrug resistant phenomena].
abstract: OBJECTIVE
  The purpose of this study was investigate the effect of hyperthemia on multidrug resistance in K562/ADM cell.
  
  
  METHODS
  The MDR1 (mulitdrug resistance gene) and MRP (multidrug resistant associated gene) gene expressions in Tca8113 and K562/ADM cell lines were analyzed by RT-PCR after treated with different cytotoxic drugs and different temperature (37 degrees C and 41 degrees C). The function and expression of Pgp and MRP were detected by fluorescence photometeric assays.
  
  
  RESULTS
  Inhibition rate of both cells was significantly enhanced by exposure to chemotherapeutic drugs and 41 degrees C temperature; Exposing to 41 degrees C hyperthemia reduced MDR1 and MRP expression and enhanced intracellular drug concentration as well in K562/ADM.
  
  
  CONCLUSIONS
  41 degrees C hyperthemia could effectively enhance the inhibition rate of chemotherapeutic drugs and partially reverse the multidrug resistance. It is suggested that hyperthemia could be used as a method to overcome multidrug resistance.
authors.affiliation: Department of Oral and Maxilloficial Surgery, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Dazhang
authors.initials: D
authors.lastname: Wang
authors.forename: Guangyong
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001761:Bleomycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002945:Cisplatin / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D019450:Genes, MDR / Q000235:genetics*; D006801:Humans; D006979:Hyperthermia, Induced; D020014:K562 Cells; D008727:Methotrexate / Q000494:pharmacology; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis* / Q000235:genetics; D014062:Tongue Neoplasms / Q000235:genetics / Q000473:pathology*
chemical_list: D000970:Antineoplastic Agents; D001761:Bleomycin; D002945:Cisplatin; D008727:Methotrexate; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C021771:zhengguangmycin