engleski

DNA damage response in psoriasis - expression of 53BP1 and gammaH2AX

Since psoriatic epidermis is also characterized by hyperproliferation of keratinocytes, we aimed to investigate the expression of two DDR markers, p53-binding protein 1 (53BP1) foci and phosphorylated histone H2AX (gammaH2AX), in psoriatic lesions. Immunohistochemical and immunofluorescent staining was performed on paraffin-embedded tissue of lesional skin of patients with psoriasis and skin of healthy volunteers. The percentage of keratinocytes positive for Ki-67, 53BP1 and gammaH2AX and the number of foci per nucleus were determined. The number of cells positive for proliferation marker Ki-67, as well as the number of cells positive for gammaH2AX and 53BP1 foci, was significantly higher in psoriasis when compared to normal skin. In addition, the mean number of 53BP1 foci per nucleus, in cells expressing foci, was higher in psoriatic than in normal epidermis. Positive cells were predominantly localized in the basal and suprabasal epidermal layers. These results indicate that psoriasis, similarly to preneoplastic lesions, is characterized by high proliferative index and increased expression of DDR markers. It is possible that potent activation of DDR in psoriasis overcomes the effects of DNA replication stress and represents a part of the barrier to malignant transformation.

psoriasis; DNA damage response; 53BP1; gammaH2Ax

nije evidentirano