<p><b>OBJECTIVE</b>To investigate the effect of
miRNA silencing HIF-1α
gene on the proliferation of
HepG2 cells.</p><p><b>
METHODS</b>The eukaryotic expression
plasmids of HIF-1α
miRNA and
report gene containing
hypoxia-reponse
element were constructed and transfected into
HepG2 cells. The expressions of HIF-1α
gene and
protein were determined by real
time-
PCR and
Western blotting. The expressions of HIF-1α,
vascular endothelial growth factor (
VEGF) and
angiopoietin-2 (Ang-2) were quantitatively detected by
ELISA. The alterations of
cell cycles and
apoptosis rate were quantitatively measured by
flow cytometry and
Annexin V-
FITC/PI double dyeing assay.</p><p><b>RESULTS</b>72 h after
transfection the down
regulations of HIF-1α
mRNA and
protein were 87% and 56% respectively, and the decrease of target
gene was 46% in the
report gene, 54% in
VEGF and 36% in Ang-2, respectively. The apoptotic ratio of
HepG2 cells was 22.46+/-0.61% (P < 0.01). The
cell cycle changed greatly at the ratio of G1 (61.49+/-1.12%) and S (22.40+/-0.58%, P < 0.01). After being combined with
doxorubicin, the apoptotic ratio increased to 36.99+/-0.88% and the ratios of G1 and
S phases were upregulated to 65.68+/-0.91% and 19.47+/-1.34% respectively.</p><p><b>CONCLUSIONS</b>HIF-1α
miRNA or / and
doxorubicin can regulate the
growth cycles of
HepG2 cells, promote the
cell apoptosis and inhibit the
cell proliferation.</p>