UVB radiation increases EGF-R gene expression in cultured human normal melanocytes
(English)Manuscript (preprint) (Other academic)
Epidermal growth factor (EGF) and its receptor are thought to play important roles in the UV response of mammalian cells. Since UVB radiation has been shown to influence melanocyte growth and development, we sought to determine whether UVB would alter the expression of the gene for EGF-R. Using Northern blot, the present study exanlined the expression of EGF-R mRNA in cultured normal human melanocytes exposed to a single physiologic dose of UVB radiation. Total cellular RNA was extracted from cultured normal human melanocytes at various time-points after irradiation or sham-irradiation. Constitutive expression ofEGF-Rmfu'!A was detected in the melanocytes. After UVB irradiation with a single dose of 6o or 180 mJ/cm2, the EGF-R rnRNA decreased within 12 h to approximately 50 % of the initial value. After 24 h there was a subsequent increase and a peak at 36 h, showing a three-fold increase. After 48 hours a decline was seen, but the expression of EGF-R mRNA was still doubled as compared to control.
Using flow cytometric analysis EGF-R on melanocytes were detected. The median EGF-R immunofluorescence was decreased after UVB-irradiation as compared to non-irradiated cells. The lowest EGF-R immunofluorescence was seen 12 hours after UVB irradiation. Witi1in 48 hours post irradiation we could not detect any increase in EGF-R that we would correlate to the increased EGFR gene expression seen at 36 hours. We conclude ti1at the steady-state levels of EGF-R mRNAis upregulated by single exposure to UVB.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-81075OAI: oai:DiVA.org:liu-81075DiVA: diva2:550202