[Influence of hypoxia inducible factor-1alpha on cervical cancer cell line HeLa in vitro]

To explore the direct influence of hypoxia inducible factor-1alpha (HIF-1alpha) on the development of invasive cervical cancer and the possible molecular mechanism.

Recombinant antisense targeting HIF-1alpha eukaryotic expression vector was constructed and transfected into cultured human cervical cancer cell line HeLa to reduce the expression of HIF-1alpha and its effect on cell proliferation, apoptosis, invasion and the cascade downstream gene expression of HIF-1alpha, including vascular endothelial growth factor (VEGF), glucose transport 1 (GLUT1) and multidrug resistance 1 (MDR1) genes was observed. The chemical method using CoCl(2) to induce hypoxia environment of growing cell was performed. Cells were divided into six groups, NN (normal non-transfected), NI (normal invalid transfected), NT (normal transfected), HN (hypoxia non-transfected), HI (hypoxia invalid transfected), and HT (hypoxia transfected). Methyl thiazolyl tetrazolium (MTT), flow cytometry, and Transwell methods were performed to evaluate the proliferation, invasion and apoptosis, and RT-PCR method was used to detect the gene expression of HIF-1alpha, VEGF, GLUT1 and MDR1.

After induction of hypoxia by CoCl(2), the change of gene expression of HIF-1alpha in HN (or HI) group compared to that in NN (or NI) group was not obvious (P > 0.05), but expression of VEGF, GLUT1 and MDR1 were all enhanced and overall proliferation was promoted, apoptosis inhibited [(11.46 +/- 0.28)% vs (29.27 +/- 0.18)%, (15.77 +/- 0.49)% vs (31.13 +/- 0.08)%], and transmembrane behavior enhanced [(37 +/- 12)% vs (26 +/- 7)%, (40 +/- 9)% vs (28 +/- 5)%], and the variations were significant (P < 0.05). On the contrary, transfection with pcDNA3.0/HIF-1alpha was companied by declined gene expression of HIF-1alpha (NT: 0.05 +/- 0.12, HT: 0.04 +/- 0.16), and all the variations were significant (P < 0.05).

HIF-1alpha may participate in malignant biological behaviors of cervical cancer such as anti-apoptosis, accelerating proliferation, increasing supply of blood and energy, increased resistance to chemotherapy through upregulation of its downstream genes. Suppression of HIF-1alpha expression in vitro can inhibit cervical cancer cell line.