Alterations of Cell Cycle Regulation and Apoptosis Related Factors in Skin Tumors / 대한피부과학회지

ABSTRACT

BACKGROUND: Tumor growth and progression is dependent on a variety of factors including; increased cell survival, i. e. resistance to undergo apoptosis, increased proliferation, and the inability to undergo growth arrest or differentiation. The cyclins are a growing group of proteins that form the regulatory subunits in complexes with a specific catalytic protein kinase(cyclin-dependent kinase(CDK)) partner. Tumor suppressor gene such as Rb, p53 and cell cycle regulatory proteins such as p16, p27, WAF1(p21, or Cip 1) also act as a regulator of cyclin and CDK. Apoptosis regulatory proteins such as bcl-2, bcl-x act as a blocking protein of apoptosis and Ki-67 is frequently used as a marker for cell proliferation. OBJECTIVE: The purpose of this study was to investigate the alterations of cell cycle regulation and apoptosis in skin tumors. METHODS: We compared expressions for cyclin A, cyclin E, WAF1, Ki-67, p53, p27, Rb, bcl-2 and bcl-x in paraffin embedded samples from 5 normal adult skin tissues, 10 basal cell epithelioma, 10 squamous cell carcinoma, 10 Bowen's disease, 5 keratoacanthoma and 5 solar keratosis by immunohistochemical staining method. RESULTS: The stainings of the tumors showed some differences from normal tissues in expression of antigens according to the differentiation state and nature of tumors. CONCLUSION: These results support an important role for cell cycle and apoptosis regulatory proteins in the regulation of growth and differentiation of malignant keratinocyte in these cutaneous neoplasms. Aberrant expression of such proteins may participate in the multistep process of carcinogenesis.