[Cross-talk between nuclear factor-kappaB and P53 signal pathway in keratinocytes after ultraviolet B irradiation].
OBJECTIVE
To investigate the cross-talk between nuclear factor kappaB (NF-kappaB) and P53 signal pathways in human epidermal keratinocytes (NHEKs) after ultraviolet B (UVB) irradiation.


METHODS
Normal NHEKs harboring wild p53 gene and immortal human keratinocytes of the line HaCaT harboring mutant p53 gene were cultured at 37 degrees C in an atmosphere containing 5% CO(2) and then underwent irradiation of UVB of the dose of 60 mJ/cm(2). Part of the NHEKs and HaCaT cells were pretreated with BAY11-7082, NF-kappaB inhibitor inhibiting IkB-a phosphorylation, of the final concentration of 5 micromol/L. Western blotting was used to detect the protein expression of NF-kappaB, P53, and P21. The transcriptional activity of NF-kappaB was analyzed by electrophoretic mobility shift assay (EMSA).


RESULTS
UVB irradiation increased the protein expression of NF-kappaB, P53, and P21 and triggered the transcriptional activity of NF-kappaB. BAY11-7082 significantly inhibited the NF-kappaB protein expression induced by UVB irradiation in the NHEKs and HaCaT cells. The P53 protein expression of the NHEKs undergoing pretreatment of BAY11-7082 and UVB irradiation was 0.08 +/- 0.07, significantly lower than that of the NHEKs undergoing only UVB irradiation (0.78 +/- 0.32, P < 0.01). The P21 protein expression of the NHEKs undergoing pretreatment of BAY11-7082 and UVB irradiation was 0.65 +/- 0.22, significantly lower than that of the NHEKs undergoing only UVB irradiation (1.58 +/- 0.77, P < 0.05). However, the P53 and the P21 protein expression of the HaCaT cells undergoing pretreatment of BAY11-7082 and UVB irradiation was not significantly different from that of the HaCaT cells undergoing only UVB irradiation.


CONCLUSIONS
There exists a UVB-induced cross-talk between NF-kappaB and P53 signal pathways in human epidermal keratinocytes. This cross-talk is correlated with P53 functional condition.
Wang
Ping
P
Department of Dermatology, Third Hospital of Hangzhou, Hangzhou 310009, China.
Song
Xiu-Zu
XZ
Bi
Zhi-Gang
ZG
Xu
Ai-E
AE
Cui
Yu-Gui
YG
D015153:Blotting, Western; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D009154:Mutation; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D015398:Signal Transduction / Q000528:radiation effects*; D013450:Sulfones / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014466:Ultraviolet Rays
C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016328:NF-kappa B; D009570:Nitriles; D013450:Sulfones; D016159:Tumor Suppressor Protein p53