title: Skin cancer prevention: a possible role of 1,25dihydroxyvitamin D3 and its analogs.
abstract: We previously reported that the natural hormone 1,25dihydroxyvitamin D3 (1,25(OH)(2)D(3)) protects human skin cells from ultraviolet radiation (UVR)-induced apoptosis. UVR-induced pre-mutagenic cyclobutane pyrimidine dimers are diminished in number from 0.5h after cessation of UVR in all skin cell types, by treatment with three different Vitamin D compounds: by 1,25(OH)(2)D(3), by the rapid acting, low calcemic analog, 1alpha,25(OH)(2)lumisterol(3) (JN) and by the low calcemic but transcriptionally active hybrid analog 1alpha-hydroxymethyl-16-ene-24,24-difluoro-25-hydroxy-26,27-bis-homovitamin D3 QW-1624F2-2 (QW), which may explain the enhanced cell survival. The rapid response antagonist analog 1beta,25(OH)(2)D(3) (HL) abolished the photoprotective effects of 1,25(OH)(2)D(3) whilst a genomic antagonist, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647), had no effect. UVR increased p53 expression in human skin cells, whilst concurrent treatment with 1,25(OH)(2)D(3) further enhanced this effect several fold, at 3 and 6h after UVR. Combined with previously reported lower nitrite levels with 1,25(OH)(2)D(3), this increased p53 expression may favor DNA repair over apoptosis. We now report that topical application of 1,25(OH)(2)D(3) or QW also suppressed solar simulated UV (SSUVR-induced pyrimidine dimers in the epidermis of irradiated hairless Skh:HR1 mice, measured 24h after irradiation. Furthermore, UVR-induced immunosuppression in the mice was markedly reduced by topical application of either 1,25(OH)(2)D(3) or QW. These preliminary results show, for the first time, a protective effect of Vitamin D compounds against DNA photodamage in vivo.
authors.affiliation: Department of Physiology and Institute for Biomedical Research, University of Sydney, NSW 2006, Australia.
authors.forename: K M
authors.initials: KM
authors.lastname: Dixon
authors.forename: S S
authors.initials: SS
authors.lastname: Deo
authors.forename: G
authors.initials: G
authors.lastname: Wong
authors.forename: M
authors.initials: M
authors.lastname: Slater
authors.forename: A W
authors.initials: AW
authors.lastname: Norman
authors.forename: J E
authors.initials: JE
authors.lastname: Bishop
authors.forename: G H
authors.initials: GH
authors.lastname: Posner
authors.forename: S
authors.initials: S
authors.lastname: Ishizuka
authors.forename: G M
authors.initials: GM
authors.lastname: Halliday
authors.forename: V E
authors.initials: VE
authors.lastname: Reeve
authors.forename: R S
authors.initials: RS
authors.lastname: Mason
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology* / Q000627:therapeutic use; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy; D008297:Male; D051379:Mice; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D016159:Tumor Suppressor Protein p53; D002117:Calcitriol