- 作者：Hideo Fukuhara ; Keiji Inoue ; Atsushi Kurabayashi ; Mutsuo Furihata ; Hirofumi Fujita ; Kozo Utsumi ; Junzo Sasaki ; Taro Shuin
- 关键词：ALA ; 5-aminolevulinic acid ; PpIX ; protoporphyrin IX ; PDD ; photodynamic diagnosis ; PDT ; photodynamic therapy ; FBS ; fetal bovine serum ; BSA ; bovine serum albumin ; DFX ; deferoxamine ; NOC-18 ; 1-hydroxy-2-oxo3 ; 3-bis(2-aminoethyl)-1-triazene ; NAO ; 10-nonyl acridine orange
- 刊名：Photodiagnosis and Photodynamic Therapy
- 出版年：December, 2013
- 年：2013
- 卷：10
- 期：4
- 页码：399-409
- 全文大小：2457 K
Summary
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.
Conclusion
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.