Cell density-dependent regulation of tumor necrosis factor α gene expression in a human hepatoma cell line
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- Published online on: December 1, 2007 https://doi.org/10.3892/ijo.31.6.1485
- Pages: 1485-1490
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Abstract
Human tumor necrosis factor α (TNFα) is a pro-inflammatory cytokine expressed in many cell types. Although the TNFα gene expression in human hepatocytes has been detected previously, its regulation is not well understood yet. In this study, we demonstrated that TNFα gene expression in human hepatoma cell line, huH2-2, was activated as a function of cell density. TNFα mRNA expression was low in the low-density culture, while significantly high expression was detected in the high-density culture. Moreover, stability of TNFα mRNA was not changed by cell density, eliminating a possibility of post-transcriptional regulation. Antibody neutralization against human TNFα had no significant effect on the TNFα mRNA expression. A cellular factor for the TNFα gene expression is suggested to be accumulated in the high-density cells. Data indicate that the level of TNFα gene transcription is elevated by a cellular factor in a cell density-dependent manner without influencing the TNFα secretion under the present cell-culture conditions used.