Expression Of P27～(kip1) And Cyclin E In Bowen's Disease And Squamous Cell Carcinoma

Objective This study examined the expression of p27kip1, a newly identified tumor suppressor protein, and cyclin E in Bowen's disease and squamous cell carcinoma, to evaluate whether the expression of p27kip1 and cyclin E is related to the malignancy of Bowen's disease and whether their expressions, alone and in combination, are associated with progression of Bowen's disease and squamous cell carcinoma.Methods Using immunohistochemical technique, we detected the expression of p27kip1 and cyclin E in 16 cases of Bowen's disease, 27 cases of squamous cell carcinoma and 25 cases of normal skin. Of the 27 cases of squamous cell carcinomas , 14 cases were classified as grade I , 10 cases as grade II and 3 cases as grade III, according to modified Border's standard. Grade I and grade II were regarded as highly differentiated squamous cell carcinoma, and grade III was regarded as pooly differentiated squamous cell carcinoma. Breast carcinoma specimens served as the positive control. Substitution of PBS for the primary antibody served as a negative control.Result The positive expression rate of p27kip1 in normal skin, Bowen's disease, and squamous cell carcinoma was 100%, 75% and 37% respectively .The positive expression rate of p27kip1 was lower in Bowen's disease and squamous cell carcinoma than in normal skin (p<0.05 and p<0.001 respectively). The positive expression rate of p27kip1 was lower in squamous cell carcinoma than in Bowen's disease (p<0.05). The positive expression rate of p27kip1 was decreased from Bowen's disease, highly differentiatedsquamous cell carcinoma to poorly differentiated squamous cell carcinoma ( t =0.215, p<0.01). The positive expression rate of cyclin E in normal skin, Bowen's disease, and squamous cell carcinoma was 8%, 43.8% and 63% respectively. The positive expression rate of cyclin E was higher in Bowen's disease and squamous cell carcinoma than in normal skin (p<0.05 and p<0.001 respectively). But there was no significant difference of cyclin E expression between Bowen's disease and squamous cell carcinoma (p>0.05). Among all the 43 cases of Bowen's diseases and squamous cell carcinomas, p27kip1 and cyclin E were all expressed in 5 cases, and were all negative in 2 cases .The expression of p27kip1 was inversely correlated with that of cyclin E ( t =-0.347, P<0.001).Conclusion p27kip1 was down regulated in Bowen's disease and squamous cell carcinoma, and its expression level was correlated with the degree of differentiation. Cyclin E was up regulated in Bowen's disease and squamous cell carcinoma. The expression of p27kip1 was inversely correlated with that of cyclin E in Bowen's disease and squamous cell carcinoma. This result suggests that the abnormal expression of p27kip1 and cyclin E may contribute to the oncogenesis of Bowen's disease and squamous cell carcinoma. The level of p27kip1 may be a prognostic marker for Bowen's disease and squamous cell carcinoma.