OBJECTIVETo investigate the expression of two tumor metastasis suppressor genes nm23 and KAI1 in gallbladder adenocarcinoma, and their clinicopathological significance.

METHODSSpecimens and clinical data from 31 gallbladder adenocarcinoma patients were collected. Histopathological grading and the expression of nm23 and KAI1 were detected by HE and immunohistochemical staining, respectively. All cases were followed up for at least three years.

RESULTSImmunohistochemical staining showed that the positive rate of nm23 and KAI1 proteins was 71.0% (22/31) and 61.3% (19/31), respectively. The positive expression rates of nm23 and KAI1 proteins in the early stage carcinomas were significantly higher than those in the moderate and advanced stage ones (P exact = 0.0051 and P exact = 0.0084), and both had an negative correlation with clinicopathologic stage (P trend = 0.0047 and P trend = 0.0058). There was a significant difference in the expression of nm23 and KAI1 proteins among well, moderately and poorly differentiated carcinomas (P exact = 0.0328 and P exact = 0.0020). The expression of nm23 and KAI1 was positively correlated with histopathological grade (P trend = 0.0086 and P trend = 0.0006). There was also a significant difference in the expression of nm23 and KAI1 proteins between 17 survival and 14 dead patients (P exact = 0.0038 and P exact = 0.0001 ). A synergistic effect of nm23 and KAI1 protein on the survival was observed , and seemed to be more important than any individual gene alone (P exact = 0.0005).

CONCLUSIONThe expressions of nm23 and KAI1 proteins are negatively correlated with clinical stage, but positively with histopathological grade in gallbladder adenocarcinoma. These two tumor metastasis suppressor genes may act synergistically to inhibit the tumor metastasis.