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

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.

In vivo study of photodynamic therapy using a new photosensitizer, 9-hydroxypheophorbide-a and 670 nm diode laser on HT-3 cervical cancer cell / 대한산부인과학회지

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 vivo using 9-HpbD-a and 670 nm diode laser on a HT-3 cervical cancer cell line. METHODS: PDT effects were observed in xenograft nude mouse model. HT-3 cell line was xenografted into the subcutaneous space of the mouse back. When the tumors grew up to 400~500 mm3, the animals were randomly separated into 4 groups: Group I (n=5), control group; group II (n=10), 9-HpbD-a alone; group III (n=10), laser irradiation alone; and group IV (n=20), PDT in nude mouse group. RESULTS: PDT treated group (9-HpbD-a+laser irradiation) showed complete response (15/20, 75%), recurrence (3/20, 15%) or no response (2/20, 10%). PDT group showed significant remission rate, comparing to laser irradiation alone group, 9-HpbD-a alone group and untreated control group (P<0.05). When PDT using 9-HpbD-a, tumor size was decrease and microscopically finding, antitumor effect was showed inflammation and necrosis of tumor cell. Overexpression of p53 and Ki-67 gene had been detected at the HT-3 cervical cancer cell and 10 days after PDT. And no experssion in normal tissue and tumor after PDT. So, immunohistochemical study of p53 and Ki-67 gene correlated with PDT for anticancer effect. CONCLUSION: These results suggest that 9-HpbD-a is one of the promising photosensitizers for the future and would be needed to use 9-HpbD-a as a photosensitizer in clinical setting. We would further suggest that photodynamic therapy is a more effective method than the conventional treatment for women who want to maintain their anatomical and functional uterine cervix.