Objective: Photodynamic therapy for prostate cancer has emerged, however the evaluation of its mechanism of action has not yet been clarified. This study aims to explore the mechanism and significance of photodynamic therapy on prostate cancer in vitro.
Methods: Cultured prostate cancer cells were divided into two groups: untreated and photodynamic therapy treatment. The protein of each group was extracted and analyzed by MALDI-TOF/MSMS method. The significantly expressed proteins were identified in the NCBI human protein database. The change of mitochondrial membrane permeability after photodynamic treatment was examined by transmission electron microscopy.
Results: The total protein content and band distribution of photodynamic treatment group were similar to the control group. Two mitochondrial membrane proteins were down-regulated significantly. They are mitochondrial heat shock protein (HSP60) (Entrez Gene ID: 31542947, PI 5.7, MW: 61016.4, Protein Score: 354, Protein Score C.I.%:100), and voltage-dependent anion channel (VDAC) (Entrez Gene ID: 340201, PI 7.49, MW: 31574.6, Protein Score: 178, Protein Score C.I.%:100). Transmission electron microscopy showed the loss of integrity of mitochondrial membranes.
Conclusions: Photodynamic therapy changes mitochondrial membrane permeability, leading to the eventual death of cancer cells. The regulation of proteins related to mitochondrial membrane permeability may become an indicator of the efficacy of photodynamic therapy.
Keywords: Cells; Mitochondrial membrane permeability; Photodynamic therapy; Prostate cancer.
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