title: Heat-induced cellular damage and tolerance in combination with adriamycin for the PC-3 prostate cancer cell line: relationships with cytotoxicity, reactive oxygen species and heat shock protein 70 expression.
abstract: OBJECTIVE
  To analyze the relationships among the antitumor effect of chemothermotherapy, generation of reactive oxygen species (ROS), and expression of heat shock protein 70 (HSP-70) in the PC-3 prostate cancer cell line.
  
  
  METHODS
  Changes in cell proliferation, cell cycle fractions, intracellular ROS accumulation and HSP-70 expression were examined after thermotherapy of PC-3 cells at 41, 42, 43 and 44 degrees C and/or simultaneous treatment with Adriamycin for 1 h, using the trypan blue dye exclusion method, flow cytometry, fluorescent 2', 7'-dichlorofluorescein (DCF) assay, and Western blot analysis.
  
  
  RESULTS
  A significant decrease in the number of viable cells was observed with chemothermotherapy compared with thermotherapy at 42, 43, or 44 degrees C (p<0.05). DNA distribution histograms revealed cell accumulation in the S-G(2)/M phase after thermotherapy at 43 degrees C and after chemothermotherapy at 37, 41, 42 and 43 degrees C. After thermotherapy and chemothermotherapy at 44 degrees C, DNA histograms revealed no accumulation of cells with S-G(2)/M DNA content and cells exhibited a marked loss of viability. A significant increase in DCF production was observed with chemothermotherapy compared with thermotherapy at 42, 43 or 44 degrees C (p<0.05, p<0.01 and p<0.01, respectively). HSP-70 levels increased linearly with increasing temperature. HSP-70 levels after thermotherapy and chemothermotherapy increased with time and reached plateaus at 30 min, whereas the level after thermotherapy at 44 degrees C decreased at 60 min.
  
  
  CONCLUSIONS
  In conclusion, one possible synergism in cytotoxic effects of chemothermotherapy and Adriamycin could be evaluated by the relationship between ROS accumulation and HSP-70 expression in the PC-3 prostate cancer cell line.
authors.affiliation: Department of Urology, Shimane Medical University, Izumo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Moriyama-Gonda
authors.forename: M
authors.initials: M
authors.lastname: Igawa
authors.forename: H
authors.initials: H
authors.lastname: Shiina
authors.forename: S
authors.initials: S
authors.lastname: Urakami
authors.forename: Y
authors.initials: Y
authors.lastname: Wada
authors.forename: M
authors.initials: M
authors.lastname: Terashima
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D018840:HSP70 Heat-Shock Proteins; D017382:Reactive Oxygen Species; D004317:Doxorubicin