title: Efficacy of 5-aminolevulinic acid-mediated photodynamic therapy using             light-emitting diodes in human colon cancer cells.
abstract: 5-Aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) (ALA-PDT)             is a highly selective treatment for malignant cells. ALA-PDT has the potential             to develop into a novel therapeutic strategy for various types of cancer. Recently,             light-emitting diodes (LEDs), which are inexpensive, stable and easier to handle             compared to lasers, have been used in PDT as a light source. However, in colorectal             cancer (CRC), the efficacy of ALA-PDT in combination with LEDs has not been fully             assessed. Therefore, in this study, we evaluated the antitumor effect of ALA-PDT             using various LEDs in colon cancer cells. The HT-29 human colon cancer cell line             was used both in vitro and in vivo. HT-29 cells were seeded in 96-well plates.             Following 5-ALA administration, cells were irradiated using LEDs at different             wavelengths. Three types of LEDs, blue (peak wavelength, 456 nm), white (broad-band)             and red (635 nm) were used. Twenty-four hours after irradiation, the cytotoxic             effects of ALA-PDT were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium             bromide (MTT) assay. In order to evaluate the antitumor effect of ALA-PDT in vivo,             nude mice were inoculated with HT-29 cells. Xenograft mice were injected intraperitoneally             with 5-ALA and irradiated with 3 types of LEDs at a measured fluence rate of 96 mW/cm2             and fluence of 32 J/cm2. Each group comprised 6 mice. ALA-PDT was repeated 3 times             at weekly intervals. Tumor weights were measured. Compared to the controls, ALA-PDT             using LEDs showed significant antitumor effects in vitro and in vivo. The blue             and white LEDs demonstrated greater antitumor effects compared to the red LEDs             in vitro and in vivo. In particular, tumor inhibition rates in the blue and white             LED groups were approximately 88% to those of the control group in the mouse models.             In conclusion, ALA-PDT using LEDs is effective and useful in the treatment of             CRC cells. This method could be a novel treatment modality for CRC.
authors.affiliation: Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural                     University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hatakeyama
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Murayama
authors.forename: Shuhei
authors.initials: S
authors.lastname: Komatsu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shiozaki
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kuriu
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ikoma
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ichikawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Kazuma
authors.initials: K
authors.lastname: Okamoto
authors.forename: Toshiya
authors.initials: T
authors.lastname: Ochiai
authors.forename: Yukihito
authors.initials: Y
authors.lastname: Kokuba
authors.forename: Katsushi
authors.initials: K
authors.lastname: Inoue
authors.forename: Motowo
authors.initials: M
authors.lastname: Nakajima
authors.forename: Eigo
authors.initials: E
authors.lastname: Otsuji
mesh_terms: D000622:Aminolevulinic Acid / Q000008:administration & dosage*; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003110:Colonic Neoplasms / Q000188:drug therapy*; D005260:Female; D019073:HT29 Cells; D006801:Humans; D007274:Injections, Intraperitoneal; D008027:Light; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid