D W Edström1, A Porwit, A M Ros. 1. Department of Dermatology, Karolinska Hospital, Stockholm, Sweden. desiree.edstrom@ks.se
Abstract
BACKGROUND: Ultraviolet radiation (UVR) has a variety of effects on human skin. Best known are the effects of UVB (290-320 nm) and UVA2 (320-340 nm), which cause DNA damage and increased risk of cancer. However, the effects of UVA1 (340-400 nm) have been not completely investigated. METHODS: The effects of repetitive low doses of UVA1 and visible light were studied in 12 healthy individuals. A part of the buttock was exposed to 20 J/cm2 UVA1 and another part of 126 J/cm2 of visible light three times a week for 4 weeks. Repeated punch biopsies were taken during the 4 weeks of treatment and also 2 weeks after the last irradiation. The avidin-biotin-immunoperoxidase technique was used to investigate the expression of p53, p21WAF, bcl-2, Ki67 and cyclin A. RESULTS: By comparison to untreated skin, an increased expression of p53 but not p21WAF in keratinocytes was seen. The bcl-2 protein expression increased slightly after both UVA1 and visible light. An increased staining with Ki67 and cyclin A after UVA1 but not after visible light was observed as a sign of increased proliferation. CONCLUSION: These results suggest that suberythemal doses of UVA1 and even visible light may cause DNA damage.
BACKGROUND: Ultraviolet radiation (UVR) has a variety of effects on human skin. Best known are the effects of UVB (290-320 nm) and UVA2 (320-340 nm), which cause DNA damage and increased risk of cancer. However, the effects of UVA1 (340-400 nm) have been not completely investigated. METHODS: The effects of repetitive low doses of UVA1 and visible light were studied in 12 healthy individuals. A part of the buttock was exposed to 20 J/cm2 UVA1 and another part of 126 J/cm2 of visible light three times a week for 4 weeks. Repeated punch biopsies were taken during the 4 weeks of treatment and also 2 weeks after the last irradiation. The avidin-biotin-immunoperoxidase technique was used to investigate the expression of p53, p21WAF, bcl-2, Ki67 and cyclin A. RESULTS: By comparison to untreated skin, an increased expression of p53 but not p21WAF in keratinocytes was seen. The bcl-2 protein expression increased slightly after both UVA1 and visible light. An increased staining with Ki67 and cyclin A after UVA1 but not after visible light was observed as a sign of increased proliferation. CONCLUSION: These results suggest that suberythemal doses of UVA1 and even visible light may cause DNA damage.
Authors: M Klak; M Gomółka; T Dobrzański; G Tymicki; P Cywoniuk; P Kowalska; K Kosowska; T Bryniarski; A Berman; A Dobrzyń; J Idaszek; W Święszkowski; M Wszoła Journal: PLoS One Date: 2020-06-25 Impact factor: 3.240
Authors: Elizabeth G Berry; Joshua Bezecny; Michael Acton; Taylor P Sulmonetti; David M Anderson; Haskell W Beckham; Rebecca A Durr; Takahiro Chiba; Jennifer Beem; Douglas E Brash; Rajan Kulkarni; Pamela B Cassidy; Sancy A Leachman Journal: Cancers (Basel) Date: 2022-01-21 Impact factor: 6.639