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DCT protects human melanocytic cells from UVR and ROS damage and increases cell viability
Author(s) -
Ainger Stephen A.,
Yong Xuan L.,
Wong Shu S.,
Skalamera Dubravka,
Gabrielli Brian,
Leonard J. Helen,
Sturm Richard A.
Publication year - 2014
Publication title -
experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 96
eISSN - 1600-0625
pISSN - 0906-6705
DOI - 10.1111/exd.12574
Subject(s) - foreskin , gene knockdown , apoptosis , viability assay , cell , melanoma , cell culture , dna damage , microbiology and biotechnology , cell growth , chemistry , cancer research , biology , biochemistry , dna , genetics
Dopachrome tautomerase ( DCT ) is involved in the formation of the photoprotective skin pigment eumelanin and has also been shown to have a role in response to apoptotic stimuli and oxidative stress. The effect of DCT on UVR DNA damage responses and survival pathways in human melanocytic cells was examined by knockdown experiments using melanoma cells, neonatal foreskin melanoblasts ( MB ) in monoculture and in co‐culture with human keratinocytes. MB cell strains genotyped as either MC 1R WT or MC 1R RHC homozygotes, which are known to be deficient in DCT , were transduced with lentivirus vectors for either DCT knockdown or overexpression. We found melanoma cell survival was reduced by DCT depletion and by UVR over time. UVR ‐induced p53 and pp53‐Ser15 levels were reduced with DCT depletion. Knockdown of DCT in MC 1R WT and MC 1R RHC MB cells reduced their survival after UVR exposure, whereas increased DCT protein levels enhanced survival. DCT depletion reduced p53 and pp53‐Ser15 levels in WM 266‐4 melanoma and MC 1R WT MB cells, while MC 1R RHC MB cells displayed variable levels. Both MC 1R WT and RHC genotypes of MB cells were responsive to UVR at 3 h with increases in both p53 and pp53‐Ser15 proteins. MC 1R WT MB cell strains in coculture with keratinocytes have an increased cell survival after UVR exposure when compared to those in monoculture, a protective effect which appears to be conferred by the keratinocytes.