Protein phosphatase inhibitor-1 mRNA expression correlates with neoplastic transformation of epithelial liver cells and progression of hepatocellular carcinomas

  • Authors:
    • Eiman Aleem
    • Thomas Flohr
    • Heinz Walter Thielmann
    • Peter Bannasch
    • Doris Mayer
  • View Affiliations

  • Published online on: April 1, 2004     https://doi.org/10.3892/ijo.24.4.869
  • Pages: 869-877
Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

Protein phosphatase inhibitor-1 plays an important role in the regulation of glycogen metabolism through inhibition of protein phosphatase-1 activity, and it has been implicated in the regulation of cell growth. Using real-time quantitative RT-PCR, we studied the mRNA expression of inhibitor-1 in hepatocellular carcinomas induced in rats by oral administration of N-nitrosomorpholine, and in a non-tumorigenic liver cell line (C1I), that stores glycogen in excess during early passages. In late passages, glycogen is gradually lost concomitant with cell transformation. Our in vitro model included a tumorigenic subline of C1I cells that was obtained by chemically-induced neoplastic transformation using N-methyl-N'-nitro-N-nitrosoguanidine (C1Ict), and does not store glycogen, as well as Morris hepatoma 3924A (MH3924A) cells. We found that in hepatocellular carcinomas, in the late glycogen-poor passages (C1Ilate), and in the tumorigenic subline (C1Ict) of C1I cells, and in MH3924A cells the mRNA expression of inhibitor-1 is significantly increased. This increase in expression varied from 15 to 290-fold of that observed in normal liver. In contrast, in the early glycogen-storing passage of C1I cells (C1Iearly) the level of inhibitor-1 mRNA was found to be slightly less than that of normal liver. Inhibitor-1 mRNA levels correlated with the degree of differentiation of HCCs. These results indicate that the expression of inhibitor-1 mRNA is tightly linked to tumor progression and to the process of liver cell transformation in vitro and is inversely correlated with the glycogen content of the cell.

Related Articles

Journal Cover

April 2004
Volume 24 Issue 4

Print ISSN: 1019-6439
Online ISSN:1791-2423

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
x
Spandidos Publications style
Aleem E, Flohr T, Thielmann HW, Bannasch P and Mayer D: Protein phosphatase inhibitor-1 mRNA expression correlates with neoplastic transformation of epithelial liver cells and progression of hepatocellular carcinomas. Int J Oncol 24: 869-877, 2004.
APA
Aleem, E., Flohr, T., Thielmann, H.W., Bannasch, P., & Mayer, D. (2004). Protein phosphatase inhibitor-1 mRNA expression correlates with neoplastic transformation of epithelial liver cells and progression of hepatocellular carcinomas. International Journal of Oncology, 24, 869-877. https://doi.org/10.3892/ijo.24.4.869
MLA
Aleem, E., Flohr, T., Thielmann, H. W., Bannasch, P., Mayer, D."Protein phosphatase inhibitor-1 mRNA expression correlates with neoplastic transformation of epithelial liver cells and progression of hepatocellular carcinomas". International Journal of Oncology 24.4 (2004): 869-877.
Chicago
Aleem, E., Flohr, T., Thielmann, H. W., Bannasch, P., Mayer, D."Protein phosphatase inhibitor-1 mRNA expression correlates with neoplastic transformation of epithelial liver cells and progression of hepatocellular carcinomas". International Journal of Oncology 24, no. 4 (2004): 869-877. https://doi.org/10.3892/ijo.24.4.869