Korean J Physiol Pharmacol.
1997 Feb;1(1):107-115.
Induction of apoptosis by bile acids in HepG2 human hepatocellular
carcinoma cells
- Affiliations
-
- 1Department of Molecular Biology, Pusan National University, Pusan 609-735
South Korea.
- 2Department of Biology, Pusan National University, Pusan 609-735
South Korea.
- 3Department of Physiology, College of Medicine, Kwandong University, Kangnung 210-701, South Korea.
Abstract
-
We studied the effects of bile acids on the induction of apoptosis in
HepG2 human hepatocellular carcinoma cells. Treatment with either
ursodeoxycholic acid (UDCA) or lithocholic acid (LCA) resulted in a
dose- and time-dependent decrease in cell viability assessed by MTT
assay. Both UDCA and LCA also induced genomic DNA fragmentation, a
hallmark of apoptosis, indicating that the mechanism by which these
bile acids induce cell death was through apoptosis. Cycloheximide, a
protein synthesis inhibitor, blocked the apoptosis induced by these
bile acids, implying that new protein synthesis may be required for the
apoptosis. Intracellular Ca2+ release blockers (dantrolene and
3,4,5-trimethoxybenzoic acid-8-(diethylamino)octyl ester) inhibited
decreased cell viability and DNA fragmentation induced by these bile
acids. Treatment of HepG2 cells with calcium ionophore A23187 induced
DNA fragmentation. These results suggest that UDCA and LCA induce
apoptosis in the HepG2 cells and that the activation of intracellular
Ca2+ signals may play an important role in the apoptosis induced by
these bile acids.