Inhibitory Effect of HCPT on Expression of HIF-1α and Downstream Genes in Hypoxic Human Cervical SiHa Cancer Cells

The hypoxic model to simulate hypoxic microenvironment in solid tumors was established and the effect of hydrocamptothecin （HCPT） on the hypoxia-induced over-expression of HIF-1α and VEGF genes was explored. Human cervical cancer SiHa cells were cultured in vitro under hypoxic conditions （37℃, 5% CO2, 1%O2） and treated with different concentrations of HCPT for 24 h. The mRNA and protein expression levels of HIF-1α, VEGF and Glutl in SiHa cells were detected by semi-quantitative RT-PCR and Western blot respectively. Normoxic control groups were exposed to normoxic conditions for 24 h. Under normoxic conditions, HCPT had no obvious effects on the HIF-1α and VEGF gene expression. Hypoxia induced the up-regulation of HIF-1α protein and downstream VEGF gene, and HCPT showed a dose-dependently inhibitory effect on the hypoxia-induced over-expression of HIF-1α protein and VEGF gene expression in SiHa cells, whereas HCPT had no significant effect on the HIF-1α mRNA expression. No difference in HCPT cytotoxic- ity was observed between hypoxic groups and normoxic control groups. It was suggested that HCPT could inhibite the expression of HIF-1α protein and downstream VEGF gene in hypoxic SiHa cells in a dose-dependent manner, and the inhibitory effect was not related with HCPT cytotoxicity.

Inhibitory effect of HCPT on expression of HIF-1α and downstream genes in hypoxic human cervical SiHa cancer cells

Summary The hypoxic model to simulate hypoxic microenvironment in solid tumors was established and the effect of hydrocamptothecin (HCPT) on the hypoxia-induced over-expression of HIF-1α and VEGF genes was explored. Human cervical cancer SiHa cells were cultured in vitro under hypoxic conditions (37°C, 5% CO₂, 1% O₂) and treated with different concentrations of HCPT for 24 h. The mRNA and protein expression levels of HIF-1α, VEGF and Glut1 in SiHa cells were detected by semi-quantitative RT-PCR and Western blot respectively. Normoxic control groups were exposed to normoxic conditions for 24 h. Under normoxic conditions, HCPT had no obvious effects on the HIF-1α and VEGF gene expression. Hypoxia induced the up-regulation of HIF-1α protein and downstream VEGF gene, and HCPT showed a dose-dependently inhibitory effect on the hypoxia-induced over-expression of HIF-1α protein and VEGF gene expression in SiHa cells, whereas HCPT had no significant effect on the HIF-1α mRNA expression. No difference in HCPT cytotoxicity was observed between hypoxic groups and normoxic control groups. It was suggested that HCPT could inhibite the expression of HIF-1α protein and downstream VEGF gene in hypoxic SiHa cells in a dose-dependent manner, and the inhibitory effect was not related with HCPT cytotoxicity.