title: HuCOP1 contributes to the regulation of DNA repair in keratinocytes.
abstract: We have previously demonstrated that the E3 ligase Human Constitutive Photomorphogenic Protein (huCOP1) is expressed in human keratinocytes and negatively regulates p53. The MutS homolog 2 (MSH2) protein plays a central role in DNA MMR mechanism and is implicated in the cellular response to anticancer agents, such as cisplatin. Our aim was to clarify whether huCOP1 plays a role in DNA MMR by affecting MSH2 protein level in human keratinocytes. To define the role of huCOP1 in DNA mismatch repair, we determined whether huCOP1 affects MSH2 abundance. MSH2 protein level was detected by immunocytochemical staining using a keratinocyte cell line in which the expression level of huCOP1 was stably decreased (siCOP1). To investigate whether huCOP1 silencing influences cisplatin-induced cell death, control and siCOP1 keratinocyte cells were treated with increasing concentrations of cisplatin and cell viability was recorded after 48 and 96 h. Stable silencing of huCOP1 in human keratinocytes resulted in a reduced level of MSH2 protein. huCOP1 silencing also sensitized keratinocytes to the interstrand crosslinking inducer cisplatin. Our results indicate that decreased huCOP1 correlates with lower MSH2 levels. These protein level changes lead to increased sensitivity toward cisplatin treatment, implicating that huCOP1 plays a positive role in maintaining genome integrity in human keratinocytes.
authors.affiliation: Department of Dermatology and Allergology, Faculty of Medicine, University of Szeged, Korányi fasor 6, Szeged, 6720, Hungary. barbara.fazekas8@gmail.com.
authors.forename: B
authors.identifier: http://orcid.org/0000-0001-9771-6133
authors.initials: B
authors.lastname: Fazekas
authors.affiliation: Centre for Chromosome Biology, and Biochemistry, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, Ireland.
authors.forename: M P
authors.initials: MP
authors.lastname: Carty
authors.affiliation: Department of Dermatology and Allergology, Faculty of Medicine, University of Szeged, Korányi fasor 6, Szeged, 6720, Hungary.
authors.forename: I
authors.initials: I
authors.lastname: Németh
authors.affiliation: Department of Dermatology and Allergology, Faculty of Medicine, University of Szeged, Korányi fasor 6, Szeged, 6720, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Kemény
authors.affiliation: MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, 6720, Hungary.|Department of Medical Genetics, Faculty of Medicine, University of Szeged, Somogyi Béla st. 4, Szeged, 6720, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Széll
authors.affiliation: Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, 6726, Hungary.
authors.forename: É
authors.initials: É
authors.lastname: Ádám
mesh_terms: D002461:Cell Line, Transformed; D002945:Cisplatin / Q000494:pharmacology; D004260:DNA Repair; D042822:Genomic Instability / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D051718:MutS Homolog 2 Protein / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C471981:COP1 protein, human; D044767:Ubiquitin-Protein Ligases; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein; D002945:Cisplatin
keywords: Cisplatin; Genome stability; Keratinocyte; MSH2; huCOP1