Objective To investigate whether hypoxia stress enhances adhesion

invasion and migration of human hepatocellular carcinoma cell HepG2 or not.  Methods HepG2 cells were cultured under hypoxia (5%O

2

5%CO

2

and 90%N

2

) for 4

12

24 h or normoxia. The adhesion of HepG2 cells was studied by cell-matrix adhesion assay. Cell invasion and migration assay was used to determine the changes in invasion and migration of HepG2 cells respectively. The expression of HIF-1α mRNA in HepG2 cells was determined by reverse transcription polymerase chain reaction (RT-PCR). 

Results The adhesion of HepG2 cells was gradually enhanced with the increasing hypoxia time (P0.01). The invasion and migration of HepG2 cells after 24-hour hypoxia was significantly higher than that after 24-hour normoxia (P0.01). The expression of HIF-1α mRNA reached the highest level when the cells were exposed to hypoxia for 4 h

then decreased

but still higher than that in normoxia (P0.01).  Conclusion Hypoxia stress upregulates the expression of HIF-1α mRNA

and enhances the adhesion

invasion and migration of HepG2 cells.