Expressions of cyclin E, cyclin dependent kinase 2 and p57(KIP2) in human gastric cancer.
OBJECTIVE
To investigate the expressions of cyclin E, cyclin dependent kinase 2 (CDK-2) and cyclin-dependent kinase inhibitor p57(KIP2) in human gastric cancer, and to evaluate the relationships between protein levels and clinicopathological parameters.


METHODS
Western blot was used to measure the expressions of cyclin E, CDK-2 and p57(KIP2) proteins in the surgically resected gastric carcinoma, adjacent normal mucosa and metastatic lymph nodes from 36 patients.


RESULTS
Cyclin E and CDK-2 protein levels were higher in gastric cancer tissues in comparison with normal tissues (P < 0.05). Overexpression of cyclin E was correlated with lymph node involvement, poor histological grade and serosa invasion (P < 0.05). Overexpression of CDK-2 was correlated with lymph nodes involvement (P < 0.05). No statistically significant difference between cyclin E and CDK-2 expression was found when samples were stratified according to tumor size (P > 0.05). Expression of cyclin E and CDK-2 showed a positive linear correlation (r = 0.451, P = 0.01). Protein levels of p57(KIP2) were lower in gastric cancer tissues than in the normal mucosa (P < 0.05). Decreased expression of p57(KIP2) was correlated with lymph node involvement (P < 0.05). No statistically significant difference in p57(KIP2) expression was found when sample were stratified according to tumor size, histological grade or serosa invasion (P > 0.05). In metastatic lymph nodes, expression of cyclin E was increased and the expression of p57(KIP2) decreased.


CONCLUSIONS
Overexpressions of cyclin E, CDK-2 and downregulated expression of p57(KIP2) may play important roles in tumorigenesis and metastatic potential of gastric cancer.
Liang
Bin
B
Department of Surgery, Peking University People's Hospital, Beijing 100044, China.
Wang
Shan
S
Yang
Xiaodong
X
Ye
Yingjiang
Y
Yu
Yongxiang
Y
Cui
Zhirong
Z
D015153:Blotting, Western; D042846:CDC2-CDC28 Kinases; D019927:Cyclin E / Q000032:analysis* / Q000502:physiology; D051357:Cyclin-Dependent Kinase 2; D050761:Cyclin-Dependent Kinase Inhibitor p57; D018844:Cyclin-Dependent Kinases / Q000032:analysis* / Q000502:physiology; D006801:Humans; D008207:Lymphatic Metastasis; D009687:Nuclear Proteins / Q000032:analysis* / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000032:analysis* / Q000502:physiology; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000473:pathology
C493964:CDKN1C protein, human; D019927:Cyclin E; D050761:Cyclin-Dependent Kinase Inhibitor p57; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases