[Inhibition of promyelocytic leukemia gene by tazarotene in hyperproliferative epidermis of psoriasis].

Objective: To investigate the mechanism of tazarotene against active psoriasis vulgaris.

Methods: A randomized, controlled trial was conducted in 43 patients with active psoriasis vulgaris, who were divided into tazarotene and control groups. Promyelocytic leukemia (PML) mRNA in active psoriatic lesions before and 14 days after tazarotene treatment was detected by in situ hybridization.

Results: PML mRNA expression was detected not only in the basal layer (86.96%), but also in the suprabasal layers of the epidermis in the manner of focal expression (78.26%). After tazarotene treatment, virtually no PML mRNA expression could be detected in the psoriatic lesions (8.69% in the basal layer and 4.35% in the suprabasal layers). PML mRNA expression in the control group underwent no obvious changes during the observation.

Conclusions: Tazarotene may inhibit abnormal proliferation of keratinocytes through down-regulating PML gene expression in active psoriatic epidermis.