Expression of apoptosis regulating proteins p53 and bcl-2 in psoriasis.

BACKGROUND

Dysfunctional apoptosis has an important role in the development of several skin diseases. Psoriatic keratinocytes possess an enhanced ability to resist apoptosis, which might be one of the key pathogenetic mechanisms in psoriasis. P53 and bcl-2 are two proteins which control apoptosis. Several studies have evaluated the expression of these two proteins in the psoriatic skin, but the results are controversial.

METHODS

Fifty-eight cases of psoriatic skin biopsies were studied, and the grade of p53 and bcl-2 immunostaining was correlated with the histopathological indices of severity.

RESULTS

Bcl-2 expression in the epidermis strongly correlated with the expression in the basal cells and lymphocytes (P--0.001 and 0.035). There was no correlation with epidermal hyperplasia or with p53 expression in the three compartments. Bcl-2 expression in the basal layer correlated with the p53 expression in the epidermis (P--0.027), basal layer (P--0.015) and the lymphocytes (P--0.034). There was a strong correlation among the p53 expression in all the compartments. There was also a weak correlation of the p53 expression in the epidermis with the epidermal hyperplasia (P--0.042).

CONCLUSIONS

Bcl-2 does not appear to play an important role in the apoptotic process in psoriasis. In contrast, it is likely that p53 has a far more important role to play. Mutation analysis of the p53 protein is necessary to evaluate if the protein has mutated or if it is of the wild type.