Expression Of Keratin17in Proliferative Skin Diseases

Objective:To investigate the expression characteristics of keratin17(K17) and its role in the pathological significance, diagnosis and differential diagnosis of psoriasis (PS), seborrheic keratosis (SK), basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma.Methods:Expression of K17in the skin tissues of normal skin, psoriasis, SK, BCC, SCC and melanoma were determined by Immunohistochemistry or immunofluorescence.Results:17normal cases,14psoriasis,18SK,16BCC,16SCC, and8melanoma patients were included. In normal skin, faint or absent cytoplasmic expression of K17was detected on stratum basal, spinosum and granular layers. However, in psoriatic skin, K17was much stronger than in normal ones and distributed in the whole stratum spinosum, faintly or absent in the basal cells, and absent in the parakeratosis. In the SK skin, K17was expressed in the basal and suprabasal cells, but was absent in the upper prickle cells and cornified layers. In BCC tissues, the cancer tissues did not show positive signals, but the prickle and granular cells in the same section were strongly stained. In SCC tissues, K17was localized in the high differentiated SCC cells, but not in the low differentiated SCC cells. In melanoma epidermis, K17is much stronger than in normal ones and distributed in the whole epidermis. However, K17is absent in melanoma cells and melanocytes.Conclusion:K17may serve as a molecular marker for the diagnosis and differential diagnosis of proliferative skin diseases.