Expression And Significance Of Cell Cycle Regulators Cyclin D1, CDK4 And P27 In Skin Cancer

Objective: Basal cell carcinoma(BCC), squamous cell carcinoma (SCC), Bowen's disease(BOD),actinic keratosis(AK)and seborrheic keratosis (SK)are the commonest non-melanoma skin cancers (NMSC ). BCC and SCC comprise the majority of NMSC. In the recent years, the incidence of BCC and SCC continue to rise. Skin cancer receives a disproportionate share of attention because mortality is relatively low. However, the impact on public health is striking. The cause and pathogenesis of these skin cancers are unknown, yet. The current study shows that oncogene mutant has been associated with the pathogenesis of skin cancers except for exposure to sunlight and HPV infection. Recently, more evidence reveal that cell cycle and cell carcinogenesis are not independent events. Regulators of the cell cycle are abnormal more or less in every stage of the cycle in human cancers. They play a very important role as proto-oncogene or anti-oncogene in the cycle. However, regulators of the cell cycle in the pathogenesis of skin cancers have almost not been reported. Moreover, there are different views on this problem at home and abroad. So this study was designed to explore regulators of the cell cycle cyclin D1, CDK4 and p27 in the pathogenesis of skin cancers and to offer elementary theory for the clinical treatment of skin cancers. Methods: Skin cancer patients, diagnosed by clinic and histopathology, were derived from the dermatology deparment of the Fourth Affiliated Hospital of Hebei Medical University from June, 1999 to September, 2004. 85 patients, being 22 with BCC, 20 with SCC, 12 with BOD, 11 with AK and 20 with SK were investigated with routine histopathological methods. The levels of cyclin D1, CDK4 and p27 expressions in these patients were detected by immunohistochemical method. 15 healthy skin specimens from department of surgery were taken as controls. There were no significant difference in sexes, ages and locus of biopsy between controls and patients. Apply SPSS11.0 statistical software handling data. Paraffin section was used by HE staining in histopathology and by histostain-SP method in immunohistochemistry. Results: ⑴Cyclin D1 and CDK4 showed negative staining or low expression in normal skin while overexpression in skin cancer(p<0.05). The levels of cyclin D1 and CDK4 expression in BCC and SCC were significantly higher than those in BOD, AK and SK (p<0.05). In normal skin, cells showed strongly positive, while in skin cancer exhibited p27 low or negtive expression. The levels of p27 expression in BCC and SCC were markedly lower than those in BOD, AK and SK (p<0.05). ⑵Between overexpression of cyclin D1 and CDK4 showed a significantly correlation(r=0.373, p<0.05). In...