Expression Of P57kip2, CyclinE And Ki-67 In Non-Small Cell Lung Cancer And Its Significance

Background and ObjectiveThe abnormality of mammalian cell cycle regulation is closely associated with cell over-proliferation and oncogenesis, therefore evaluation of the biological character of carcinomas requires understanding of cell cycle regulators. Studying proliferative activity of tumor cells is useful way to understand tumor biological behavior. Cyclins, cyclin-dependent kinase (CDK), and CDK inhibitors (CKI) are frequently altered in neoplasms. P57kip2 is a member of the CIP/KIP (CDK-interacting protein / kinase inhibitory protein) family of CKI and known to be one of the universal negative regulators of cell cycle and a potential tumor suppressor gene (TSG). P27cipl is the most extensively studied CIP/KIP family member with respect to the clinical significance of the regulators of cell cycle in human neoplasms. However, the clinical significance of p57kip2 expression in lung carcinoma and other human malignant tumors remains unknown. There were few reports about the relationship between p57kip2 protein and lung cancer. CyclinE is one of the positive regulators of cell cycle and participates in the regulation of G1/S phase transition. Ki-67 is a nuclear antigen related to proliferating cell correlating with cell cycle and is a favorable biological marker to evaluate proliferating activity of tumor cells. The detection of Ki-67 may help...