title: The inhibition of ferrochelatase enhances 5-aminolevulinic acid-based photodynamic action for prostate cancer.
abstract: BACKGROUND
  The aim of this study was to clarify the mechanism of accumulation of 5-aminolevulinic acid (ALA)-dependent protoporphyrin IX (PpIX), ALA-photodynamic therapy (PDT)-induced cell death and enhanced efficiency by a ferrochelatase inhibitor in prostate cancer PC-3 cells.
  
  
  METHODS
  The accumulation of ALA-induced PpIX in PC-3 cells was observed by fluorescence microscopy and measured by flow cytometry analysis. The efficiency of ALA-PDT was analyzed by flow cytometry and assessed by cell death, caspase-3 activity and mitochondrial membrane potential. The ALA-PDT-promoting effects of ferrochelatase inhibitors, such as deferoxamine and NOC-18, were also analyzed. We confirmed the results obtained in vivo with an animal model using nude mice.
  
  
  RESULTS
  ALA-induced PpIX accumulation increased in time- and ALA concentration-dependent manners. ALA-PDT decreased the levels of mitochondrial membrane potential, and induced cell death occurred by both apoptosis and necrosis. Inhibition of ferrochelatase by deferoxamine and NOC-18 led to increase of PpIX accumulation and enhanced effect of ALA-PDT in PC-3 cells. In vivo, the degeneration of tumor tissue by ALA-PDT was observed within a broader range and led to apoptosis and necrosis.
  
  
  CONCLUSIONS
  This study demonstrated ALA-PDT induced PC-3 cell death by the mechanisms of both necrosis and apoptosis through a caspase-independent mitochondrial pathway. Inhibition of ferrochelatase enhanced these effects, suggesting that ferrochelatase played an important role in ALA-PDT. ALA-PDT could be a new modality for focal therapy of prostate cancer.
authors.affiliation: Department of Urology, Kochi Medical School, Nankoku, Kochi 783-8505, Japan. Electronic address: jm-fukuhara@kochi-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Fukuhara
authors.forename: Keiji
authors.initials: K
authors.lastname: Inoue
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kurabayashi
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Furihata
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Fujita
authors.forename: Kozo
authors.initials: K
authors.lastname: Utsumi
authors.forename: Junzo
authors.initials: J
authors.lastname: Sasaki
authors.forename: Taro
authors.initials: T
authors.lastname: Shuin
mesh_terms: D000622:Aminolevulinic Acid / Q000008:administration & dosage*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D002738:Chloroquine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D003676:Deferoxamine / Q000008:administration & dosage*; D004357:Drug Synergism; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D011524:Protoporphyrins / Q000096:biosynthesis*
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; C492468:ferrochloroquine; D002738:Chloroquine; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX; D003676:Deferoxamine
keywords: 1-hydroxy-2-oxo3,3-bis(2-aminoethyl)-1-triazene; 10-nonyl acridine orange; 5-Aminolevulinic acid; 5-aminolevulinic acid; ALA; BSA; DFX; FBS; Ferrochelatase; NAO; NOC-18; PDD; PDT; Photodynamic therapy; PpIX; Prostate cancer; Protoporphyrin IX; bovine serum albumin; deferoxamine; fetal bovine serum; photodynamic diagnosis; photodynamic therapy; protoporphyrin IX