Involvement of hepatoma-derived growth factor in the growth inhibition of hepatocellular carcinoma cells by vitamin K(2)

• Published in: Journal of gastroenterology 2009, Vol.44 (3), p.228
• Main Authors: Yamamoto, Teruhisa, Nakamura, Hideji, Liu, Weidong, Cao, Ke, Yoshikawa, Shohei, Enomoto, Hirayuki, Iwata, Yoshinori, Koh, Noritoshi, Saito, Masaki, Imanishi, Hiroyasu, Shimomura, Soji, Iijima, Hiroko, Hada, Toshikazu, Nishiguchi, Shuhei
• Format: Article
• Language: English
• Subjects: Antineoplastic Agents - administration & dosage; Antineoplastic Agents - pharmacology; Blotting, Western; Carcinoma, Hepatocellular - drug therapy; Carcinoma, Hepatocellular - metabolism; Cell Line, Tumor; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation, Neoplastic - drug effects; Genes, Reporter; Humans; Intercellular Signaling Peptides and Proteins - metabolism; Liver Neoplasms - drug therapy; Liver Neoplasms - metabolism; Luciferases - genetics; Luciferases - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - drug effects; RNA, Messenger - metabolism; Vitamin K 2 - administration & dosage; Vitamin K 2 - pharmacology
• ISSN: 0944-1174
• DOI: 10.1007/s00535-008-2304-4

Vitamin K(2) has been reported to suppress the growth of human hepatocellular carcinoma (HCC) in vitro and hepatocarcinogenesis in hepatitis C virus (HCV)-related cirrhosis in vivo. Hepatoma-derived growth factor (HDGF) is a unique nuclear targeting growth factor that is highly expressed in HCC cells and is a possible prognostic factor for patients with HCC. We investigated the regulation of HDGF expression by vitamin K(2). Three HCC-derived cell lines, HepG2, HuH-7, and SK-Hep-1, were used. Cell number was determined with the MTT assay. The expression levels of HDGF mRNA and protein were measured by the real-time reverse transcriptase-polymerase chain reaction (PCR) method and ELISA and Western blot analysis, respectively. The HDGF promoter activity was measured by a dual luciferase-reporter assay. Vitamin K(2) suppressed the growth of the three HCC cell lines in a dose-dependent manner. Vitamin K(2) significantly suppressed the expression of the HDGF protein and mRNA in three cell lines. By a luciferase assay, vitamin K(2) significantly suppressed the promoter activity of the HDGF protein. Based on some luciferase-reporter plasmids containing truncated promoter regions, the possible responsive site of vitamin K(2) seems to reside in the region -1 to -150 bp of the HDGF gene. These findings suggested that regulation of the HDGF gene expression is one of the crucial mechanisms of vitamin K(2)-induced cell growth suppression for HCC.