Objective:

2

To evaluate the effects of

Celastrus Orbiculatus

extracts (COE) on metastasis in hypoxiainduced hepatocellular carcinoma cells (HepG2) and to explore the underlying molecular mechanisms.

Methods:

2

The effect of COE (160

200 and 240 μg/mL) on cell viability

scratch-wound

invasion and migration were studied by 3-4

5-dimethyl-2-thiazolyl-2

5-diphenyl-2-H-tetrazolium bromide (MTT)

scratch-wound and transwell assays

respectively. CoCl

2

was used to establish a hypoxia model

in vitro

. Effects of COE on the expressions of E-cadherin

vimentin and N-cadherin were investigated with Western blot and immunofluorescence analysis

respectively.

Results:

2

COE inhibited proliferation and metastasis of hypoxia-induced hepatocellular carcinoma cells in a dose-dependent manner (

P

<

0.01). Furthermore

the expression of epithelial-mesenchymal transition (EMT) related markers were also remarkably suppressed in a dose-dependent manner (

P

<

0.01). In addition

the upstream signaling pathways

including the hypoxia-inducible factor 1α (Hif-1α) and Twist1 were suppressed by COE. Additionally

the Hif-1α inhibitor 3-5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1)

potently suppressed cell invasion and migration as well as expression of EMT in hypoxia-induced HepG2 cells. Similarly

the combined treatment with COE and YC-1 showed a synergistic effect (

P

<

0.01) compared with the treatment with COE or YC-1 alone in hypoxia-induced HepG2 cells.

Conclusions:

2

COE significantly inhibited the tumor metastasis and EMT by suppressing Hif-1α/Twist1 signaling pathway in hypoxia-induced HepG2 cell. Thus

COE might have potential effect to inhibit the progression of HepG2 in the context of tumor hypoxia.