Expression of Skp2 in non-small cell lung cancer and its relationship with p27~(kip1) and Ki-67 protein expressions

OBJECTIVE:To investigate the expression of Skp2 and its relationship with expressions of p27~ kip1 and Ki-67 proteins in human non-small cell lung cancer(NSCLC). METHODS: Immunohistochemical methods were applied to detect the expressions of Skp2, p27~ kip1 and Ki-67 proteins in 60 surgical specimens from NSCLC patients and 20 normal bronchial epithelium. RESULTS: In NSCLC, the positive rate of Skp2 protein was 48.33%(29/60).Which was obviously higher than that in normal bronchial epithelium, P=0.000. There was no relationship between Skp2 expression and age (P=0.833) or sex (P=0.281),respectively;otherwise, there was closely relationship between Skp2 expression and histological subtype, cellular differentiation, TNM stage, lymph node metastasis, smoking, P=0.038, 0.005, 0.019, 0.010 and 0.002, respectively. Expression of Skp2 was negatively correlated with expression of p27~ kip1,P=0.001; but was positively correlated with expression of Ki-67,P=0.027. CONCLUSIONS: Expression of Skp2 is up-regulated significantly in NSCLC compared with normal bronchial epithelium,and overexpression of Skp2 reduces the protein level of p27~ kip1 through ubiquitin-dependent degradation and causes disruption of cell cycle control and enhancement of the proliferative activity, indicating Skp2 playes an important role in oncogenesis and development of NSCLC.