Prognostic implications of cyclin B1, p34cdc2, p27(Kip1) and p53 expression in gastric cancer

Cell cycle progression is regulated by interactions of specific cyclins and cyclin dependent kinases (CDKs) at the G1-S and G2-M checkpoints and cell cycle deregulation plays a major role in carcinogenesis of human cancers.

To investigate the role of cell cycle regulators in the pathogenesis and progression of human gastric cancers, 23 cases of gastric carcinomas were examined for the expression of cyclin B1, p34cdc2, p27(Kip1) and p53 by immunohistochemical methods, and gene expression was correlated with various clinicopathologic findings.

Out of 23 cases studied, cyclin B1 was diffusely expressed in 20 cases (87.0%), p34cdc2 in 14 cases (60.9%) and p53 in 12 cases (52.2%), whereas in normal gastric tissues, cyclin B1 and p34cdc2 were weakly expressed and p53 was not expressed. In contrast, p27(Kip1) was expressed in only 8.7% of gastric carcinomas compared with 78.3% of normal gastric tissues. There was correlation between the expression of cyclin B1 and expression of p34cdc2 (p=0.002), between the expression of cyclin B1 and loss of p27(Kip1) (p=0.025), and between the expression of p34cdc2 and loss of p27(Kip1) (p=0.065). In addition, expression of cyclin B1 was correlated with regional lymph node metastasis (p=0.032).

Our results indicate that cyclin B1 and p34cdc2 are involved in the genesis or progression of gastric cancers. Furthermore, overexpression of cyclin B1 may play an important role in lymph node metastatic potential of gastric cancer. Thus, abnormal expression of cyclin B1 and CDKs, overexpression of p53 and loss of p27(Kip1) expression may play important roles in human gastric carcinogenesis.