Immunohistochemical Study of p53 and p21Waf1/Cip1 Expression in Several Epithelial Tumors of the Skin

Lee, Sang Hun; Kim, Chul Woo; Kim, Kwang Ho; Kim, Kwang Joong; Park, Hye Rim

Abstract

BACKGROUND
The p53 gene is one of a family of tumor suppressor genes that have been implicated in the genesis of a wide variety of malignant neoplasms including several epithelial tumors of the skin, and its role in oncogenesis and tumor progression is thought to be of importance. p21Waf1/Cip1 is thought to mediate p53 signaling, induced by a DNA-damaged status, to arrest the cell cycle. The mechanism that controls p21Waf1/Cip1 expression has not been clearly elucidated yet. OBJECTIVE: To evaluate the expression pattern of p53 and p21Waf1/Cip1, and their correlations in several epithelial tumors of the skin. METHOD: We investigated the expression of p53 and p21Waf1/Cip1 proteins by a immunohistoc- hemical method on the formalin-fixed, paraffin-embedded tissue specimens of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Bowen's disease, actinic keratosis (AK) and porokeratosis. RESULTS: p21Waf1/Cip1 was expressed in 50% (5/10) of SCC, 10% (1/10) of BCC, 70% (7/10) of Bowen's disease, 80% (8/10) of AK, and 40% (4/10) of porokeratosis. An increased expression of p53 was found 90% (9/10) of SCC, 70% (7/10) of BCC, 60% (6/10) of Bowen's disease, 50% (5/10) of AK, and 40% (4/10) of porokeratosis. The expression level of p53 had a significantly positive correlation with the expression level of p21Waf1/Cip1 in Bowen's disease (p = 0.045). There was no correlation observed between the expression levels of these two markers in the other diseases mentioned above (p >0.05). CONCLUSION: This data suggest that decreased p21Waf1/Cip1 expression may have a role in epithelial tumors of the skin. However, our present study indicates that there are weak interrelationship between p53, p21Waf1/Cip1, and p53-independent pathways of p21Waf1/Cip1 induction in the skin. The mechanism of how they interact to promote tumorigenesis and its prognostic values in epithelial tumors of the skin remain to be elucidated.