title: Photodynamic therapy using a novel photosensitizer, TONS501, is similarly effective to ALA and EC036 photodynamic therapy on DMBA-and TPA-induced mouse skin papilloma.
abstract: BACKGROUND
  Although topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is applied for skin tumors including actinic keratosis, Bowen disease, and squamous cell carcinoma, there are no approved photosensitizers in dermatological field in Japan. TONS501 and TONS504 are novel hydrophobic photosensitizers with anionic and cationic chemical characteristics, respectively.
  
  
  OBJECTIVE
  Using 7, 12-dimethylbenz[a]anthracene (DMBA) and 12-ο-tetradecanoylphorbol-13-acetate (TPA)-induced mouse skin papilloma model, we compared the efficacy of ALA-, TONS501-, and TONS504-PDT on the skin tumor regression.
  
  
  METHODS
  Following application of ALA, TONS501, TONS504 ointment or TONS501 lotion on DMBA- and TPA-induced mouse papillomas, 670 nm laser irradiation by LD670-05 diode laser was performed. Then tumor regression rate was calculated at the indicated time.
  
  
  RESULTS
  The anti-tumor effect of ALA, TONS501, and TONS504 ointment was detected at 24 h and the maximal response was observed at 3 day following the PDT treatment. The maximal response was observed at 150 J/cm(2) irradiation in all 3 photosensitizers. Although both ALA, TONS501 (ointment)-PDT showed more potent anti-tumor effect compared with that of TONS504 ointment or TONS501 lotion, no significant difference was detected between ALA ointment and TONS501 ointment.
  
  
  CONCLUSIONS
  A novel TONS501ointment-PDT shows potent anti-tumor effect on DMBA- and TPA-induced mouse skin papilloma and might be more useful for the clinical applications.
authors.affiliation: Department of Dermatology, Asahikawa Medical University, 2-1-1-1 Midorigaokahigashi, Asahikawa 078-8510, Japan. ht@asahikawa-med.ac.jp
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Susumu
authors.initials: S
authors.lastname: Nakajima
authors.forename: Ryuji
authors.initials: R
authors.lastname: Asano
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nakae
authors.forename: Isao
authors.initials: I
authors.lastname: Sakata
authors.forename: Hajime
authors.initials: H
authors.lastname: Iizuka
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000009:adverse effects; D000287:Administration, Topical; D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D009824:Ointments; D010212:Papilloma / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D011166:Porphyrins / Q000008:administration & dosage / Q000627:therapeutic use*; D012878:Skin Neoplasms / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D013755:Tetradecanoylphorbol Acetate / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: C544479:13,17-bis(1-carboxyethyl)-3-(1,3-dioxan-2-yl)methylidene-8-ethenyl-2-hydroxy-2,7,12,18-tetramethylchlorin dimethyl ester; C576983:13,17-bis(1-carboxypropionyl)carbamoylethyl-3-ethenyl-2-hydroxy-3-hydroxyiminoethlidene-2,7,12,18-tetramethylporphyrin; D009824:Ointments; D017319:Photosensitizing Agents; D011166:Porphyrins; D015127:9,10-Dimethyl-1,2-benzanthracene; D000622:Aminolevulinic Acid; D013755:Tetradecanoylphorbol Acetate