title: Endogenous survivin modulates survival and proliferation in UVB-treated human keratinocytes.
abstract: Survivin is a bi-functional member of inhibitor of apoptosis protein family, as it is able to both inhibit apoptosis and to regulate cell cycle. We investigated the role of survivin in human keratinocytes under normal conditions and during UVB irradiation. Survivin siRNA decreases proliferation and induces apoptosis in human keratinocytes, in a mode consistent with the mitotic catastrophe. Low doses UVB increase survivin expression at earlier times, while high doses down-regulate survivin level. Low doses UVB induce cell cycle arrest in G2/M, while high doses UVB cause apoptosis. Moreover, overexpression of survivin protects keratinocytes from UVB-induced apoptosis, and silencing of survivin renders keratinocytes more susceptible to UVB-induced cell death. Finally, survivin siRNA increases UVB-induced reduction of cell proliferation. Taken together, these results indicate that survivin plays a critical role in epidermal homeostasis in normal conditions and during UVB exposure, with possible implication in skin carcinogenesis.
authors.affiliation: Institute of Dermatology, School of Biosciences and Biotechnologies, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Katiuscia
authors.initials: K
authors.lastname: Dallaglio
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Palazzo
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marconi
authors.forename: Marc
authors.initials: M
authors.lastname: Dumas
authors.forename: Francesca
authors.initials: F
authors.lastname: Truzzi
authors.forename: Roberta
authors.initials: R
authors.lastname: Lotti
authors.forename: Frederic
authors.initials: F
authors.lastname: Bontè
authors.forename: Carlo
authors.initials: C
authors.lastname: Pincelli