Department of Dermatology, Faculty of Medicine, Cairo University, Cairo, Egypt.
Clin Exp Dermatol. 2010 Oct;35(7):781-5. doi: 10.1111/j.1365-2230.2009.03774.x.
Psoriasis vulgaris (PV) is characterized by keratinocyte hyperproliferation. Altered expression of cell-cycle regulatory genes involved in the cyclin D1 ⁄ p16 INK4-pRb pathway may contribute to this epidermal hyperproliferation.
To assess the expression of cyclin D1 and p16 in psoriasis, and to evaluate the effect of phototherapy on their expression.
The study population comprised 25 patients with PV and 10 healthy controls. Patients were treated with 24 sessions of either narrowband ultraviolet (UV) B or psoralen UVA. Skin biopsies were taken from the affected skin of each patient before and after treatment, and from the healthy controls, to examine cyclin D1 and p16 expression.
Before phototherapy, the mean value of cyclin D1 concentration in patients was significantly greater than that in controls and the mean value of p16 concentration in patients was significantly lower than that in controls. Following treatment, we detected a significant decrease in cyclin D1 and a significant increase in p16.
Cyclin D1 upregulation and p16 downregulation may play a role in the pathogenesis of psoriasis. Normalization of the levels of both parameters may be a mechanism by which phototherapy induces remission in psoriasis.
寻常型银屑病（PV）的特征是角质形成细胞过度增殖。参与细胞周期调控的基因表达异常，如 cyclin D1/p16INK4-pRb 通路，可能导致这种表皮过度增殖。
评估 cyclin D1 和 p16 在银屑病中的表达，并评估光疗对其表达的影响。
研究人群包括 25 例 PV 患者和 10 例健康对照者。患者接受 24 次窄带紫外线（UV）B 或补骨脂素 UVA 治疗。在治疗前后，从每位患者的皮损处和健康对照者处取皮肤活检标本，以检测 cyclin D1 和 p16 的表达。
在光疗前，患者的 cyclin D1 浓度平均值明显高于对照组，而患者的 p16 浓度平均值明显低于对照组。治疗后，我们检测到 cyclin D1 显著下降，p16 显著增加。
cyclin D1 的上调和 p16 的下调可能在银屑病的发病机制中发挥作用。这两个参数水平的正常化可能是光疗诱导银屑病缓解的机制之一。
