Abstract

BACKGROUND
Aberration of the cell cycle regulatory proteins has been reported to contribute to the development and progression of human malignancy. We studied the expression of G1/S cell cycle regulatory proteins to investigate the carcinogenesis in cutaneous squamous cell lesions. METHODS: We evaluated the expressions of p16, pRb, cyclin D1 and Ki-67 protein by immunonohistochemistry in cases of normal skin (n=15), seborrheic keratosis (SK; n=26), actinic keratosis (AK; n=30), Bowen's disease (BD; n=37), keratoacanthoma (KA; n=23), and squamous cell carcinoma (SCC; n=22). RESULTS: The Ki-67 expression gradually increased from SK, through AK, to BD. The expression of p16 was more increased in BD than that in AK. The decreased expressions of p16 and Rb, and the increased expression of cyclin D1 were observed to a greater degree in SCC than those in BD. The expressions of cyclin D1 and Ki-67 were higher in SCC than those in KA. CONCLUSIONS: The altered expressions of p16, Rb, and cyclin D1 were considered to be related to the carcinogenesis in the cutaneous squamous cell lesions. Therefore, immunohistochemical studies of the cell cycle regulatory proteins and a combined analysis may be helpful as an adjunct to the histomorphology in the diagnosis of cutaneous squamous cell lesions.

• Keywords: Skin;Carcinoma;Squamous cell;Cell cycle