N-butylidenephthalide (BP), isolated from the
chloroform extract of Angelica sinensis, has been examined for its antitumor effects on
glioblastoma multiforme brain tumors; however, little is known about its antitumor effects on
hepatocellular carcinoma cells. Two
hepatocellular carcinoma cell lines, HepG2 and J5, were treated with either
N-butylidenephthalide or a vehicle, and cell viability and apoptosis were evaluated. Apoptosis-related
mRNA and
proteins expressed, including orphan receptor family Nurr1, NOR-1, and Nur77, were evaluated as well as the effect of
N-butylidenephthalide in an in vivo xenograft model.
N-butylidenephthalide caused growth inhibition of both the cell lines at 25 microg/ml. Furthermore,
N-butylidenephthalide-induced apoptosis seems to be related to Nur77 translocation from nucleus to cytosol, which leads to
cytochrome c release and caspase-3-dependent apoptosis.
N-butylidenephthalide-related
tumor apoptosis was associated with
phosphatidylinositol 3-kinase/
protein kinase B (AKT)/
glycogen synthase kinase-3beta rather than the
mitogen-activated protein kinase or
protein kinase C pathway. Blockade of AKT activation enhanced proliferation inhibition and the induction of phosphor-Bcl-2 and Nur77
proteins. Besides, the increasing apoptosis by BP via transfection wild-type
cAMP-response element-binding protein (CREB) into
tumor cell was suppressed by dominant phosphorylation site mutation of CREB. This finding suggested CREB pathway was also partly involved in
tumor apoptosis caused by BP. Administration of
N-butylidenephthalide showed similar antitumoral effects in both HepG2 and J5 xenograft
tumors.
N-Butylidenephthalide induced apoptosis in
hepatocellular carcinoma cells, both in vitro and in vivo, suggesting a potential clinical use of this compound for improving the prognosis of
hepatocellular carcinoma cells.