Abstract: Mao Xuhua, Luan Chao, Hu Yu, Dong Huiyan, Jiang Mingjun, Chen Min Clinical Laboratory, Yixing People′s Hospital, Yixing 214200, Jiangsu, China （Mao XH）; Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China （Luan C, Hu Y, Jiang MJ, Chen M）; Xuzhou Medical University, Xuzhou 221004, China （Dong HY） Corresponding author: Chen Min, Email: drchenmin@126.com 【Abstract】 Objective To investigate the of DNA methyltransferase 2 （DNMT2） and 3a （DNMT3a） in the epidermis of patients with psoriasis vulgaris. Methods Between March 2009 and December 2010, 46 patients with psoriasis vulgaris were enrolled from the Department of Dermatology, Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, and the Department of Dermatology of Yixing People′s Hospital, and 28 healthy controls were enrolled from the Department of Dermatologic Surgery, Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College. Real-time quantitative PCR was performed to determine the mRNA of DNMT2 and DNMT3a in the epidermis of the lesional and nonlesional skin of patients with psoriasis vulgaris, as well as in the epidermis of normal skin of the healthy controls. Results The mRNA of DNMT2 （expressed as 2-△△Ct） in the lesional skin, non-lesional skin of the patients and normal skin of the healthy controls was 0.62 ± 0.02, 0.36 ± 0.05 and 0.15 ± 0.11, respectively. The mRNA of DNMT2 was significantly higher in the lesional skin than in the non-lesional skin of the patients （t = 6.23, P < 0.01）, and higher in the non-lesional skin of the patients than in the normal skin of the healthy controls （t = 7.33, P < 0.01）. Additionally, the mRNA of DNMT3a was significantly higher in the lesional skin （0.85 ± 0.03） than in the non-lesional skin （0.43 ± 0.04） of the patients （t = 5.66, P < 0.01）, and higher in the non-lesional skin of the patients than in the normal skin of healthy controls （0.18 ± 0.09, t = 8.62, P < 0.01）. Conclusion Both DNMT2 and DNMT3a mRNA were abnormally expressed in the epidermis of patients with psoriasis vulgaris.

Key words: Psoriasis, DNA modification methylases, DNMT2, DNMT3a