Significance And Expression Of P-gp And P53 In Psoriatic Lesions

Background Uncontrolled proliferation of epidermal cells is the most prominent characteristic of psoriasis. Frequently relapsed patients undergo anti-DNA synthesis agents treatment, which often causes multidrug resistance.Objective To investigate whether the multidrug resistance relates to the expressions of P-glycoprotein (P-gp) and p53 in skin of psoriatic patients.Methods Lesional skin of patients (17 cases of newly diagnosed patients, 23 cases of relapsed patients) and ten normal skin samples were stained immunohistochemically with monoclonal antibodies JSB-1 against P-gp, Do-7 against p53 .Results No or low reactivities of P-gp and p53 were observed in the normal keratinocytes; by contrast, P-gp and p5 3-positive keratinocytes could be found in the majority of psoriatic lesions. P-gp reactivity that presented ineach layer of epidermis except stratum corneum, especially in the upper layers, was significantly stronger in the relapsed patients than in the newly diagnosed patients (P<0.01). Maximum expression of p53 existed in the lower and basal layers of epidermis. The p53-positive reactivity was not significantly stronger in the relapsed group as comparied to the other group. No correlation in expression existed between of p53 and P-gp.Conclusion Increased expression of P-gp might be one of the factors up-regulating drug resistance. There is no enough evidence to consider p53 positivity is associated with drug resistance, though it is very important in the pathogenesis of psoriasis. However, we believe that our results need to be integrated with patients' clinical follow-up to gain more accurate imformation.