Method for diagnosis of abnormal keratinization

PURPOSE: A method for screening an agent for preventing aberrant keratinocyte differentiation is provided to use a gene as a gene target for developing a therapeutic agent for treating dermatitis and to evaluate the agent. CONSTITUTION: A method for screening an agent for preventing aberrant keratinocyte differentiation comprises: a step of transfection of plasmids to cells; a step of treating the cell to a test compound; and a step of identifying whether the test compound stimulates the reporter gene. The plasmids includes: a plasmid containing Nrf-2 gene and universal promoter; a plasmid contains DNA which binds with a transcription factor and a reporter gene; and a plasmid containing Nkx-2.5, AP-1, MEIS1A/HOXA9, MEIS1B/HOXA9, CREB, ISRE-BP, Hand1/E47, Pax-6, c-Myb, v-Maf, Elk-1, E47, CRE-BP1, IRF-1, IRF-2, c-Rel, c-Ets-1(p54), USF, VBP, Hox-1.3, Brn-2, COMP1-factor, CDP_CR1, CP2 or NF-kB(p50) gene and a universal promoter. The agent is a therapeutic agent for treating psoriasis. [Reference numerals] (AA) Gene pattern in which expression is reduced during differentiation; (BB) Relative expression level(times); (CC) Time(days)