TY - JOUR
T1 - Characterization of coordinated immediate responses by p16INK4A and p53 pathways in UVB-irradiated human skin cells.
AU - Abd Elmageed, Zakaria Y.
AU - Gaur, Rajiv L.
AU - Williams, Mandy
AU - Abdraboh, Mohamed E.
AU - Rao, Prakash N.
AU - Raj, Madhwa H.G.
AU - Ismail, Fathi M.
AU - Ouhtit, Allal
N1 - Funding Information:
Dr Allal Ouhtit and Dr Rajiv Gaur are funded by The Louisiana Cancer Research Consortium (LCRC). Abdraboh EM was funded by the Egyptian Ministry of Higher Education. We thank Dr Heidi Davis for the editing of this paper.
PY - 2009/1
Y1 - 2009/1
N2 - While the precise mechanisms of melanoma development are unknown, recent in vivo studies have revealed that the p16(Ink4a)/Rb pathway is disrupted in melanomagenesis. Here, we characterize the role of p16/Rb in coordinating the early events in UVB-irradiated skin. Foreskins and melanoma cell cultures were irradiated with low and high acute UVB doses and examined for cell-cycle- and apoptosis-associated genes. In melanoma cells, low UVB dose upregulated p16, p53, and p21 expression levels in Malme-3M, and high UVB dose accentuated the expression of p53 and p21(Cip1/Waf1), in particular; however, in SkMel-28 cells only p16 expression was upregulated in response to UV irradiation. In HaCaT cells, high UVB dose caused dramatic increase in p53 expression followed by upregulation of p21(Cip1/Waf1) and Bax, and downregulation of Bcl-2 leading to apoptosis. In HaCaT cells, reinstatement of p16 pathway restored cell-cycle arrest in response to low dose. Foreskin organ culture experiments confirmed our in vitro cell results. These data indicate that the p53 and p16 pathways respond independently to UVB insult. The p16 pathway is favored at low doses and results in cell-cycle arrest; the p53 pathway is more responsive to higher doses and induces apoptosis depending on p53 mutation status.
AB - While the precise mechanisms of melanoma development are unknown, recent in vivo studies have revealed that the p16(Ink4a)/Rb pathway is disrupted in melanomagenesis. Here, we characterize the role of p16/Rb in coordinating the early events in UVB-irradiated skin. Foreskins and melanoma cell cultures were irradiated with low and high acute UVB doses and examined for cell-cycle- and apoptosis-associated genes. In melanoma cells, low UVB dose upregulated p16, p53, and p21 expression levels in Malme-3M, and high UVB dose accentuated the expression of p53 and p21(Cip1/Waf1), in particular; however, in SkMel-28 cells only p16 expression was upregulated in response to UV irradiation. In HaCaT cells, high UVB dose caused dramatic increase in p53 expression followed by upregulation of p21(Cip1/Waf1) and Bax, and downregulation of Bcl-2 leading to apoptosis. In HaCaT cells, reinstatement of p16 pathway restored cell-cycle arrest in response to low dose. Foreskin organ culture experiments confirmed our in vitro cell results. These data indicate that the p53 and p16 pathways respond independently to UVB insult. The p16 pathway is favored at low doses and results in cell-cycle arrest; the p53 pathway is more responsive to higher doses and induces apoptosis depending on p53 mutation status.
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U2 - 10.1038/jid.2008.208
DO - 10.1038/jid.2008.208
M3 - Article
C2 - 18719612
AN - SCOPUS:58149332171
SN - 0022-202X
VL - 129
SP - 175
EP - 183
JO - The Journal of investigative dermatology
JF - The Journal of investigative dermatology
IS - 1
ER -