Significance of nm23 mRNA expression in human hepatocellular carcinoma

It has been proposed that nm23-H1, a candidate suppressor gene for metastasis, plays an important role in the metastasis of human tumors. In order to investigate its role in the human hepatocellular carcinoma (HCC), 18 matched pairs of tumorous and adjacent nontumorous liver tissues of hepatectomy from patients with HCC were studied by quantitative reverse transcription-PCR. Further analyses of the nm23-H1 gene were also done. The results of these molecular studies were correlated with the clinicopathologic features of the patients. Nm23-H1 transcript was expressed in all neoplastic and adjacent nontumorous liver tissue. The level of expression, however, did not correlate well with the extension or metastatic potential of the tumors. Instead, in 15 (83.3%) of 18 HCC, nm23-H1 expression was higher in the tumorous tissues, compared with the adjacent nontumorous tissues; and significantly higher levels of nm23-H1 mRNA expression was detected in HCC with poor differentiation (Edmonson classification, III and IV) than those with moderate differentiation (I and II). Southern blot analysis of nm23-H1 gene revealed neither amplification nor loss of heterozygosity of all HCC tissues examined. Direct sequencing of the nm23-H1 gene in all HCC tissues detected no mutations. Our findings suggested that increased nm23-H1 mRNA expression is correlated with HCC tumor progression.