각질형성세포에서 Ornithine Decarboxylase 유전자 발현에 대한 Retinoic Acid와 자외선이 미치는 영향

Abstract

Ornithine decarboxylase(ODC) catalyses the decarboxylation of ornithine to putrescine, an important step in polyamine biosynthesis. The activity of ODC increases in response to a variety of agents that induce cell growth and proliferation. ODC is highly controlled enzyme that is induced by epidermal growth factor(EGF). Several groups have reported increased ODC levels in the lesions of psoriasis, and shown that these normalize following therapy. Retinoids and ultraviolet irradiation are powerful therapeutic methods that have been used to treat a psoriasis. In this study, retinoic acid and ultraviolet irradiation on the levels of ODC mRNA were examined in EGF-stimulated keratinocytes cultures using Northern blot hybridization and the results were as follows: 1.A dose dependent relationship was observed between the amount of EGF and the amount of ODC mRNA. A 2-fold increase in ODC mRNA was observed in cells treated with EGF at 50ng/ml and a 3.8-fold increase in ODC mRNA was observed in cells treated with EGF at 100ng/ml. 2.All-trans-retinoic acid(10-5M) decreased ODC mRNA in EGF-stimulated cultured human keratinocytes by 72%. 3.UVA(10J/cm2) and UVB(10mJ/cm2) irradiationdecreased ODC mRNA in EGF-stimulated cultured human keratinocytes by 45% and 69%. In conclusion, these data suggest that both all-trans-retinoic acid and ultraviolet may be attributed to the inhibition of ODC gene expression by keratinocytes. However, further investigations are needed to elucidate the way in which human keratinocytes respond to UVA irradiation.