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Background/purpose: Topical 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is an effective treatment for Bowen's disease (BD). In order to compare the efficacy of two different light sources, using either an excimer-dye laser (EDL) (630 nm) or a metal-halide lamp (MHL) (600 to 740 nm) a protocol for topical ALA-PDT for treatment of BD of the extremities was established, and responses during 12 months follow-up were assessed., Methods: From 25 patients a total of 26 lesions that had been histopathologically diagnosed as BD from 2005 to 2010 in the Department of Dermatology at the Aichi Medical University Hospital were randomly selected. The light source used for the topical ALA-PDT was EDL in 17 lesions and MHL in 9 lesions. The photosensitizing protoporphyrin IX that is produced within BD lesions 4 h after application of 20% ALA cream was mostly consumed after exposure to 100 J/cm(2) irradiation using 630 nm EDL. Each lesion was irradiated once a week for 3 weeks, for a total dosage of 300 J/cm(2) (100 mW/cm(2)). Patients were followed up clinically every 3 months for 12 months, and at 1 month after the final treatment lesions were evaluated histopathologically., Results: Histologically, the complete response (CR) rate at 1-month follow-up was 82% (14/17 lesions) in the EDL treatment group and 100% (9/9 lesions) in the MHL treatment group (P > 0.05). The recurrence rate at 12 months after PDT was 46% (6/13 lesions, one patient lost to follow-up) in the EDL group and 0% in the MHL group (P < 0.05) (χ(2) test with Fisher's exact test). The average period before recurrence after EDL treatment was 6.5 months., Conclusion: A novel protocol for topical ALA-PDT in Japanese in Asian patients with BD was developed and implemented. The protocol improved the CR rate compared with previous studies. Moreover, the present results indicate that the efficacy of topical ALA-PDT using MHL was superior to that using EDL for BD patients., (© 2012 John Wiley & Sons A/S.)

Background: Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is widely used for treating Bowen's disease (BD), but recurrence and tumour cell persistence after ALA-PDT is sometimes problematic. Radiation therapy (RT) is also effective for BD, but is limited by its side-effects, such as refractory ulcers., Objective: The objective of the study was to observe a synergic effect of combination therapy with ALA-PDT and RT for BD cases that did not respond effectively to prior ALA-PDT., Methods: Subjects were BD patients whose lesion did not show complete remission or showed recurrence after prior ALA-PDT. A total of four cases involving four lesions were studied (three male and one female, mean age 69.5). ALA ointment (20%) was applied to the lesions. After 4 to 6h, subjects received combination therapy consisting of excimer-pumped dye laser radiation at 630nm (50J/cm(2) ) followed by electron-beam radiation (3Gy). The combination therapy was repeated every 2 to 3days for a total of four treatments. The lesions were evaluated clinically or histologically after the final combination therapy session., Results: Following combination therapy, all of the lesions disappeared. Recurrence was not detected during the observations periods, which averaged 14.0months in duration., Conclusion: Our results indicate that the cure rate of BD could be improved by combination therapy with ALA-PDT and RT. Compared with conventional RT, the synergetic effect of this therapy might reduce the dose of radiation required, thereby also reducing skin side-effects such as refractory ulcers., (© 2010 The Authors. Journal of the European Academy of Dermatology and Venereology © 2010 European Academy of Dermatology and Venereology.)

In photodynamic therapy (PDT) for skin cancer, 5-aminolevulinic acid (ALA) is applied topically to the affected area to be absorbed percutaneously through passive diffusion, and typically requires 4-6 h before performing PDT. In this study, we attempted to reduce the absorption period in PDT by ionizing ALA using direct-current pulsed iontophoresis to treat actinic keratosis (AK). Twenty percent ALA solution was applied to AK lesions of five patients using direct-current pulsed iontophoresis. ALA-PDT was repeated three times with a total irradiation of 150 J/cm(2) (50 J/cm(2) per irradiation, weekly). One week after the last PDT, therapeutic results were assessed by skin biopsy. In all subjects, protoporphyrin IX (PpIX) production was confirmed after iontophoresis, and its production levels were comparable to the conventional occlusive dressing technique (ODT). Skin biopsies from the treated lesion showed the disappearance of tumour cells. These results indicated that direct-current pulsed iontophoresis for applying ALA before PDT is useful to treat AK.

Background: Photodynamic therapy (PDT) with 5-aminolaevulinic acid (5-ALA) is a noninvasive and effective treatment for superficial skin cancers. Etretinate, a derivate of vitamin A, with the chemical formula ethyl(2E,4E,6E,8E)-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nona-tetraenoate, has been reported to have antitumour effects and to regulate the proliferation and differentiation of skin cancers., Objective: In order to develop more efficient PDT, we investigated whether etretinate enhanced the cytotoxic action of ALA-based PDT against human squamous cell carcinoma cell line, HSC-5., Method: The in vitro cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptotic cells were detected by double-staining with fluorescent annexin V and propidium iodide. Intracellular protoporphyrin IX (PpIX) converted from exogenous ALA was measured by a fluorescence meter., Results: HSC-5 cells pretreated with a nontoxic concentration of etretinate became more susceptible to the cytotoxic action of ALA-based PDT. Etretinate-pretreated cells underwent apoptosis in response to ALA-based PDT. Etretinate pretreatment resulted in enhanced accumulation of ALA-dependent intracellular PpIX., Conclusions: The results suggest that etretinate enhances the susceptibility of HSC-5 cells to ALA-based PDT via the intracellular increase of ALA-dependent PpIX. Etretinate might be useful for improvement of ALA-based PDT.

Background/purpose: Topical 5-aminolevulinic acid (ALA)-based photodynamic therapy (PDT) is effective for actinic keratosis (AK); few studies have examined Oriental patients. The aim of this study is to assess the efficacy of PDT for the treatment of Japanese AK patients classified by lesion size and histological severity., Methods: Thirty patients with solitary AK lesions were divided into two groups according to diameter: a small lesion group (SL), diameter < or =10 mm and a larger lesion group (LL), diameter >10 mm, and histological severity: Group I (mild and moderate) and Group II (severe). After application of 20% ALA for 4 h, exposure to an excimer-dye laser at 630 nm was performed at a dose of 50 J/cm(2) three times at an interval of 7 days. Therapeutic effects were assessed and followed for 12 months., Results: In all 10 SL patients, atypical cells disappeared after PDT and did not recur for 12 months. However, for the 20 LL patients, recurrence was seen in 2 of the 14 Group I patients, while 4 of 6 Group II patients showed residual tumor cells after the first PDT session., Conclusion: The present study demonstrated that ALA-PDT might be useful for treatment of Japanese AK. The therapeutic outcome might depend on the lesion size and the histopathological severity.

Surgical resection is the first-choice therapy for extramammary Paget's disease, but extensive resection is highly invasive and non-surgical treatments are sometimes preferred. Although photodynamic therapy (PDT) has been used for extramammary Paget's disease for some time, recurrence and residual tumour cells are common. In the present study, five patients with extramammary Paget's disease with a total of eight lesions first underwent carbon dioxide (CO2) laser abrasion, followed by 3 h of occlusive application of aminolaevulinic acid (ALA) and then 100 J/cm2 irradiation with a 630-nm excimer dye laser. This combination treatment regime was repeated every 2 weeks for a total of 3 times. Group 1 comprised two patients (five lesions) who received CO2 laser and ALA-PDT only. Group 2 comprised three patients (three lesions) who received CO2 laser and ALA-PDT for residual tumour cells following surgery. Follow-up examinations showed that seven lesions in five patients had not recurred after 12 months, suggesting the efficacy of the present method.

Background/purpose: 5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT) is widely performed in the clinical setting for superficial skin cancers, giving favorable results, but residual tumor and recurrence occur occasionally. Thioredoxin is a common antioxidant that suppresses apoptosis and facilitates cell growth. We investigated the expression of thioredoxin following ALA-PDT in human skin squamous cell carcinoma cell line, HSC-5., Methods: ALA-PDT was performed in HSC-5 cells using low-dose (5 J/cm(2), 100 mW/cm(2)) or high-dose (30 J/cm(2), 100 mW/cm(2)) irradiation, and the expression of thioredoxin was measured by Western blotting. An MTT assay was used to assess cell growth following a low dose of multiple irradiations. Cell death was examined by Western blotting for caspase-3 and PARP. Immunofluorescence double staining using annexin V and propidium iodine was also performed., Results: Expression of thioredoxin was only observed following low-dose exposure ALA-PDT. Multiple low-dose exposure ALA-PDT significantly proliferated cell growth. With high-dose exposure ALA-PDT, caspase-3 and PARP expression were seen, and cell death due to apoptosis and/or necrosis was observed, but thioredoxin was barely detected., Conclusion: Low-dose exposure ALA-PDT increased the expression of thioredoxin and facilitated the growth of HSC-5 cells.

Although actinic cheilitis is a common disease, it should be treated carefully because it can undergo malignant transformation. We report a case of actinic cheilitis treated with photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA), with satisfactory outcome in both clinical and pathological aspects. Actinic cheilitis is a pathologic condition affecting mainly the lower lip caused by long-term exposure of the lips to the UV radiation in sunlight. Analogous to actinic keratosis of the skin, actinic cheilitis is considered as a precancerous lesion and it may develop into squamous cell carcinoma. We report a case of actinic cheilitis treated with PDT using ALA, with satisfactory outcome in both clinical and pathological aspects.

Background: Anti-cancer effects of cyclooxygenase (COX)-2 inhibitors have been reported, but not fully investigated in skin and oral diseases. 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) for treating those patients with skin and oral lesions is a highly sophisticated procedure, but the incidence of disease recurrence after treatment is rather significant., Objective: To confirm that COX-2 could be a molecular target in adjunctive therapy to ALA-based PDT, we investigated (i) COX-2 expression in various skin and oral diseases, and (ii) the inhibitory effects on cellular growth of COX-2 selective inhibitor (nimesulide), ALA-based PDT and their combination on human oral squamous cell carcinoma (SCC) cell lines., Methods: A total of 129 biopsy samples from the skin and oral mucosal lesions were tested immunohistochemically for COX-2 expression. Then the in vitro effects of nimesulide, ALA-based PDT, and their combination were determined on two SCC cell lines, HSC-2 and HSC-4. Three different methods (MTT assay, double-staining for annexin V and propidium iodide, caspase-3/CPP32 fluorometric protease assay) were applied for evaluation of their inhibitory effects on these two cell lines., Results: Among the skin diseases, a considerable number of COX-2 high expressers were found in actinic keratosis (15 of 25, 60%), Bowen's disease (13 of 17, 76%) and extramammary Paget's disease (15 of 15, 100%). In contrast, only one of 33 (3%) basal cell carcinoma tumours was a COX-2 high expresser. Among the oral mucosal biopsies, the proportion of COX-2 high expressers increased gradually from hyperplasia (one of six, 17%) through mild dysplasia (five of eight, 63%) and moderate dysplasia (20 of 23, 87%) to severe dysplasia (two of two, 100%). Nimesulide had an inhibitory effect in vitro on HSC-2 (proven to be a COX-2 high expresser), but not on HSC-4 (a COX-2 non-expresser). While ALA-based PDT showed an inhibitory effect on both HSC-2 and HSC-4, most importantly the combination of nimesulide and ALA-based PDT demonstrated a significant synergistic effect on the cellular growth inhibition of only HSC-2, but not of HSC-4., Conclusions: Our study strongly suggests that COX-2 can be one of the molecular targets in treating various skin and oral diseases. The results from our in vitro experiments also prompt us to develop a new protocol with a combination of COX-2 selective inhibitor and ALA-based PDT for more effective treatment of those diseases.

Background: Photodynamic therapy (PDT), which employs a combination of a tumour-localizing photosensitizer and visible light, has been used to treat superficial malignancies in the epidermis., Objectives: To examine histological changes and the role of apoptosis in lesions of actinic keratosis (AK) after PDT using 5-aminolaevulinic acid (ALA) and excimer dye laser., Methods: After topical ALA-PDT, biopsy specimens were collected from 18 skin lesions in 15 patients with AK. Paraffin-embedded sections of the skin specimens were stained with haematoxylin and eosin. The detection of apoptosis was performed using a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) method, antiactivated caspase-3 antibody and anti-Fas antibody., Results: One hour after PDT, cells with eosinophilic cytoplasm and markedly stained nuclei were found, and vacuolation of some tumour cells was noted in the lower layer of the epidermis. An infiltrate of lymphocytes and neutrophils was observed in the upper layer of the dermis. One day after PDT, all layers of the epidermis exhibited slightly degenerative necrosis, with shadow cell formation and chromatin condensation around the nuclear membrane in the lower layer of the epidermis. Necrosis in all layers of the epidermis and lymphocyte infiltration in the dermis were found 3 days after PDT. Tumour cells had disappeared and regenerative thickening of the epidermis was observed 7 days after PDT. TUNEL staining revealed apoptosis-positive cells in the epidermis in 8 of 11 specimens obtained 1 day after PDT. Activated caspase-3 expression was noted in the lower layer of the epidermis in four of these eight TUNEL-positive specimens., Conclusions: Results suggested that apoptosis is involved in tumour cell death after PDT in patients with AK, and that it occurs within 1 day after PDT.