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Updated: May 29, 2026
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Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols
Published on: June 6, 2017
Ethanol metabolism activates cell cycle checkpoint kinase, Chk2
Dahn L Clemens1, Katrina J Mahan Schneider, Robert F Nuss
1Research Service, Veterans Administration Medical Center, 4101 Woolworth Avenue, Omaha, NE 68105, USA. dclemens@unmc.edu
Alcohol (Fayetteville, N.Y.)
|September 20, 2011
Summary
Chronic ethanol abuse impairs liver cell replication by activating a signaling pathway involving ATM and Chk2 kinases. This pathway leads to cell cycle arrest, contributing to alcoholic liver injury.
Area of Science:
- Hepatology
- Cell Biology
- Molecular Biology
Background:
- Chronic ethanol abuse causes liver injury and hinders liver cell regeneration.
- Ethanol metabolism induces cell cycle arrest at G2/M, partly via inhibitory phosphorylation of cyclin-dependent kinase Cdc2.
Purpose of the Study:
- To investigate the role of upstream regulators of Cdc2 activity in ethanol-induced G2/M cell cycle arrest.
- To delineate the mechanisms by which ethanol metabolism impairs hepatocyte replication.
Main Methods:
- VA-13 cells (Hep G2 derivative) were cultured with or without ethanol.
- Immunoblots were used to assess the activation of ATM, Chk2, and Cdc25C.
- The effect of ATM inhibition on cell cycle arrest was evaluated.
Main Results:
- Ethanol metabolism increased the active forms of ATM and Chk2.
- Ethanol increased phosphorylated Cdc25C, a key regulator of Cdc2 activity.
- Inhibition of ATM partially rescued cells from G2/M arrest and reduced inhibitory Cdc2 phosphorylation.
Conclusions:
- Ethanol metabolism activates the ATM/Chk2 signaling pathway.
- This pathway leads to Cdc25C phosphorylation and Cdc2 inactivation, causing G2/M arrest.
- This mechanism contributes to impaired hepatocyte replication in alcoholic liver disease.
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