title: Comparison study of the expressions of myristoylated alanine-rich C kinase substrate in hepatocellular carcinoma, liver cirrhosis, chronic hepatitis, and normal liver.
abstract: The myristoylated alanine-rich C kinase substrate (MARCKS) is a prominent substrate for protein kinase C (PKC) in a variety of cells. The aim of this study was not only to evaluate the expression and localization of MARCKS in various pathological liver tissues, including HCC, but also to analyze the difference in MARCKS expression between hepatitis virus-induced HCC and cirrhosis. The level of MARCKS and its phosphorylated proteins, as well as its localization, were determined using Western blot and/or immunohistochemistry in HCC and other pathological liver tissues. We also analyzed the change of MARCKS localization on the influence of MARCKS phosphorylation in the HLF cancer cell line by phosphorylation study. In addition, the relationship between MARCKS expression and proliferative activity was studied in HCC. In the immunohistochemical study, a very small amount of MARCKS protein was found along the contour of the hepatocellular membrane in normal liver and in cases of chronic hepatitis. MARCKS was up-regulated in liver cirrhosis tissue and was localized in the cytoplasm of hepatocytes. The expression of MARCKS was down-regulated in HCC tissues, as compared with non-tumorous liver cirrhosis tissues from the same patients. Furthermore, MARCKS was serine-phosphorylated in liver cirrhosis and HCC, and phosphorylated MARCKS was detected in a cytosolic fraction of these tissues. In a phosphorylation study using the HLF HCC cell line, MARCKS was displaced from the plasma membrane to the cytosol following the activation of protein kinase C (PKC) by phorbol 12-myristrate 13-acetate (PMA). Furthermore, the activity of cyclin D1 and cyclin E kinases was found to be higher in HCCs with low MARCKS expression than in HCCs with high MARCKS expression. These results suggest that up-regulation of MARCKS might be essential in the generation of cirrhotic nodules through chronic hepatitis from normal liver, and that the phosphorylation and/or down-regulation of MARCKS might play an important role in the development and progression of HCC from liver cirrhosis.
authors.affiliation: Third Department of Internal Medicine, Kagawa Medical University, Miki-cho, Kita-gun, Kagawa 761-0793, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Masaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tokuda
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yoshida
authors.forename: Seiji
authors.initials: S
authors.lastname: Nakai
authors.forename: Asahiro
authors.initials: A
authors.lastname: Morishita
authors.forename: Naohito
authors.initials: N
authors.lastname: Uchida
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Funaki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kita
authors.forename: Fumi
authors.initials: F
authors.lastname: Funakoshi
authors.forename: Takako
authors.initials: T
authors.lastname: Nonomura
authors.forename: Takashi
authors.initials: T
authors.lastname: Himoto
authors.forename: Akihiro
authors.initials: A
authors.lastname: Deguchi
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kimura
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Izuishi
authors.forename: Hisao
authors.initials: H
authors.lastname: Wakabayashi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Usuki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yoshiji
authors.forename: Seishiro
authors.initials: S
authors.lastname: Watanabe
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kurokohchi
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kuriyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology*; D015536:Down-Regulation; D005260:Female; D019698:Hepatitis C, Chronic / Q000235:genetics* / Q000473:pathology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008099:Liver / Q000201:enzymology; D008103:Liver Cirrhosis / Q000235:genetics* / Q000473:pathology*; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis*; D008875:Middle Aged; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D011493:Protein Kinase C; D015854:Up-Regulation
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C000619710:MARCKS protein, human; D008565:Membrane Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D011493:Protein Kinase C