The anticancer effect and mechanism of photodynamic therapy using a new photosensitizer and diode laser on cervical cancer cell / 대한산부인과학회지

ABSTRACT

OBJECTIVE: During the last several years, such as Photofrin(R), Photogem(R), HpD, and 5-aminolevulenic acid (ALA) has been used as photosensitizers for a wide range of malignant tumors as well as non-malignant disease. A new photosensitizer, 9-Hydroxypheophorbide-a (9-HpbD-a) was derived from Spirulina platensis. The aim of this study was to evaluate the anticancer effect and mechanism of photodynamic therapy in vitro using 9-HpbD-a and 670 nm diode laser on a HT-3 cervical cancer cell line. METHODS: We studied the cytotoxic effect of 9-HpbD-a and 670 nm diode laser in HT-3 cervical cancer cell line. The cultured HT-3 cells were treated with serial concentrations of 9-HpbD-a followed by various irradiation time (0, 5, 15, 30 min) and by various interval times (0, 3, 6, 9, 12 24 hours) until laser irradiation, then 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyl-tetrazolium bromide (MTT) assay was applied to measure the relative inhibitory effect of PDT. RESULTS: Optimal condition for laser irradiation time was 15 minutes and the cytotoxic effect according to the incubation time after 9-HpbD-a treatment was increased until 6 hours. Under confocal microscopy, to observe intracellular localization of 9-HpbD-a, cells dual-stained with 9-HpbD-a and panel of organelle-specific fluorescence probes (MitoTracker, LysoTracker, ER-Tracker), endoplasmic reticulum (ER) as a major accumulation organelle site in HT-3 cervical cell line for this new photosensitizer. CONCLUSION: The anticancer effect of PDT using 9-HpbD-a is effective in HT-3 cervical cancer cell line. This agent therefore represents a promising photosensitizing prodrug for the treatment of cervical cancer with PDT in clinical setting for the future.