title: Development of an in vitro photosensitization test based on changes of cell-surface thiols and amines as biomarkers: the photo-SH/NH₂ test.
abstract: As a part of our studies to develop a cell-based in vitro photosensitization assay, we examined whether changes of cell-surface thiols and amines on human monocytic cell line THP-1 could be used to predict photosensitizing potential of chemicals. First, we identified a suitable ultraviolet A (UV-A) irradiation dose to be 5.0 J/cm(2) by investigating the effect of UV-A on the levels of cell-surface thiols and amines in ketoprofen (KP; a representative photoallergen)-treated THP-1 cells. Next, we confirmed that phenol red, a known photoirritant used as a pH indicator in the culture medium, did not affect the KP-induced changes of cell-surface thiols and amines. Using the criterion of more than 15% change of cell-surface thiols and/or amines in response to UV-A irradiation, 22 of 26 known photosensitizers (15 of 18 photoallergens, 7 of 8 photoirritants) were judged positive. Seven of 7 known non-phototoxins did not alter cell-surface thiols or amines. The accuracy for predicting photosensitizers was 87.9% (sensitivity/specificity; 84.6%/100%), and the accuracy for predicting photoallergens was 69.7% (sensitivity/specificity; 83.3%/53.3%). Our results suggest that changes of cell-surface thiols and/or amines may be useful biomarkers for predicting photosensitization potential, including photoallergenicity, of compounds. We designate this test as the photo-SH/NH2 test.
authors.affiliation: Shiseido Research Center, Shiseido Co. Ltd.
authors.forename: Shiho
authors.initials: S
authors.lastname: Oeda
authors.forename: Morihiko
authors.initials: M
authors.lastname: Hirota
authors.forename: Hayato
authors.initials: H
authors.lastname: Nishida
authors.forename: Takao
authors.initials: T
authors.lastname: Ashikaga
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sasa
authors.forename: Setsuya
authors.initials: S
authors.lastname: Aiba
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Tokura
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kouzuki
mesh_terms: D000588:Amines / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D010787:Photosensitivity Disorders; D011237:Predictive Value of Tests; D012882:Skin Tests / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000032:analysis; D018675:Toxicity Tests / Q000379:methods*; D014466:Ultraviolet Rays
chemical_list: D000588:Amines; D015415:Biomarkers; D013438:Sulfhydryl Compounds