[Expression of cyclin dependent kinase inhibitors of KIP family in gastric cancer].
OBJECTIVE
The cyclin-dependent kinase inhibitors (CDKI) including p21, p27, and p57 of the kinase inhibitor protein (KIP) family are negative regulators of cell cycle progression and potentially act as tumor suppressor. Tumor behavior and growth are influenced by the extent of tumor cell proliferation. The aim of this study was to evaluate the expression of KIP family CDKI in gastric cancer tissue, and to examine the relationship between these expression and various clinicopathological parameters including tumor cell proliferation.


METHODS
We conducted an immunohistochemical analysis of p21, p27, and p57 expression in 109 gastric cancer tissues. Tumor cell proliferation was assessed by immunohistochemistry with antibody against Ki-67.


RESULTS
Negative expression of p21, p27, and p57 was demonstrated in 45.9%, 65.1%, and 57.8% of cancer tissues, respectively. Negative expression of p21 correlated with larger tumor size, poor differentiation, depth of invasion, lymph node metastasis and advanced TNM stage (p=0.048, 0.041, 0.001, 0.005, and 0.001 respectively). Negative expression of p21 correlated with poor survival (p=0.037). Tumors with negative p21 expression had higher Ki-67 expression than those with positive p21 expression (p=0.024). No significant correlation could be observed between status of p27 and p57 expression and various clinicopathological parameters including survival and tumor cell proliferation.


CONCLUSIONS
These results suggest that negative expression of p21 may play an important role in carcinogenesis by stimulating tumor cell proliferation, and may help in predicting the prognosis of gastric cancer.
Lee
Soo Jung
SJ
Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
Joo
Young Eun
YE
Kim
Hyun Soo
HS
Choi
Sung Kyu
SK
Rew
Jong Sun
JS
Park
Chang Soo
CS
Kim
Sei Jong
SJ
D000328:Adult; D000368:Aged; D002455:Cell Division; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate
D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050761:Cyclin-Dependent Kinase Inhibitor p57; D050760:Cyclin-Dependent Kinase Inhibitor p27