Effect of 5-Aminolevulinic Acid-Mediated Photodynamic Therapy on MCF-7 and MCF-7/ADR Cells
Journal
Lasers in Surgery and Medicine
Journal Volume
34
Journal Issue
1
Pages
62-72
Date Issued
2004
Author(s)
Abstract
Background and Objectives: Photodynamic therapy (PDT) has been proposed as an alternative approach in overcoming multidrug resistance (MDR) phenotype. To verify whether 5-aminolevulinic acid (ALA)-mediated PDT is effective in MDR cells, we studied the protoporphyrin IX (PpIX) content, intracellular localization, and phototoxicity in human breast cancer cells MCF-7 and derived MDR subline, MCF-7/ADR. Study Design/Materials and Methods: The fluorescence kinetics of ALA-induced PpIX was evaluated by spectrofluorometer. The phototoxicity of MCF-7 and MCF-7/ADR cells was determined by tetrazolium (MTT) assays and clonogenic assay. Furthermore, Annexin V and propidium iodide (PI) binding assays were performed to analyze the characteristics of cell death after ALA-PDT. Results: MCF-7/ADR accumulated a lower level of PpIX as compared to parental MCF-7 cells. Significant phototoxicity was observed in MCF-7 and increased in a fluence-dependent manner with LD50 around 8 J/cm 2. Compared to its parental counterpart, MCF-7/ADR cells were less sensitive to ALA photodynamic treatment and PDT-induced cytotoxicity did not increase in a dose responsive manner as the concentration of ALA increased or the fluence of light increased. ALA-PDT was less effective for MCF-7/ADR cells than MCF-7 cells even under the condition when these two cell lines contained the similar amounts of PpIX. Conclusions: These results indicate that, except for the MDR related characteristics, MCF-7/ADR cells might possess intrinsic mechanisms that render them less sensitive to ALA-PDT induced phototoxicity.
SDGs
Other Subjects
3 (4,5 dimethyl 2 thiazolyl) 2,5 diphenyltetrazolium bromide; aminolevulinic acid; lipocortin 5; propidium iodide; protoporphyrin; article; cell line; cell strain MCF 7; cellular distribution; clonogenic assay; controlled study; cytotoxicity; dose response; fluorescence; human; human cell; light; multidrug resistance; photodynamic therapy; photosensitivity; phototoxicity; priority journal; spectrofluorometry; Aminolevulinic Acid; Cell Death; Cell Line, Tumor; Humans; Mitochondria; Photochemotherapy; Photosensitizing Agents
Type
journal article