Expression of the Midkine gene in human hepatocellular carcinomas

BACKGROUD/AIMS: Aberrant expression of Midkine (MK) has been found in vario us human carcinomas including hepatocellular carcinoma (HCC). The aim of st udy is to identify the incidence of MK expression in tumor and surrounding non-tumor tissues of the liver, and to find the correlation of MK expressio n with other tumor markers. METHODOLOGY: Liver tissues were obtained from 16 patients with HCC and 4 wi th metastatic liver cancer. Background diseases of the HCC patients include liver cirrhosis and chronic hepatitis of type B or C. RNA was prepared fro m both cancerous and surrounding non-cancerous tissues, and analyzed for th e presence of MK mRNA by RT-PCR, PCR-Southern blot, and Northern blot analy sis. RESULTS: MK expression was detected in 12 (75%) of 16 HCCs by PCR-Southern blot analysis, the most sensitive of the 3 methods. Three of 9 surrounding cirrhotic tissues were weakly positive for MK expression, and none of 7 chr onic hepatitis and 4 normal tissues were negative. No significant differenc e was found in clinical and pathological parameters between MK negative and positive cases. Among metastatic cancers, 1 of gastric origin was positive for MK expression, but 1 each of chorangiocellular, gall bladder, and gast rinoma origin was negative. CONCLUSIONS: These results suggest that MK is expressed in the majority of HCC tissues and rarely in surrounding tissues in chronic liver diseases.