NM23-H1 and NM23-H2 messenger RNA abundance in human hepatocellular carcinoma.

nm23 was originally identified as an antimetastatic gene, the expression of which was inversely correlated with tumor metastatic potential in rodent model systems. Subsequently, two related human nm23 genes, nm23-H1 and nm23-H2, were identified. The relationship between expression of nm23-H1 and nm23-H2 in hepatocellular carcinoma specimens from 30 patients and metastatic potential was investigated with the use of a quantitative reverse transcription-PCR procedure. The abundance of nm23-H1 and nm23-H2 mRNA was compared with serum alpha-fetoprotein concentration, tumor size (maximum diameter), and histopathological parameters such as portal vein tumor thrombus, intrahepatic metastasis, capsular formation, capsular infiltration, differentiation of tumor cells, and TNM stage. The abundance of nm23-H1 mRNA showed a significant inverse correlation with intrahepatic metastasis and TNM stage. Furthermore, we confirmed that reduced expression of nm23-H1 mRNA was in accordance with a reduced amount of NM23-H1 protein using Western blot analysis. No correlation was apparent between nm23-H2 mRNA abundance and intrahepatic metastasis. These data support the conclusion that nm23-H1 may play a more important role than nm23-H2 in intrahepatic metastasis in hepatocellular carcinoma. Furthermore, nm23-H1 mRNA abundance may be a predictor of intrahepatic metastasis, the most important factor correlated with the metastatic potential of hepatocellular carcinoma.