RNA interference of hypoxia-inducible factor-1 alpha improves the effects of transcatheter arterial embolization in rat liver tumors

Transcatheter arterial embolization (TAE) and transcatheter arterial chemoembolization are widely used palliative treatments for patients with nonsurgical hepatocellular carcinoma. TAE has been shown to increase levels of hypoxia-inducible factor-1 alpha (HIF-1α) in tumors. In this study, we investigated whether RNA interference (RNAi) of HIF-1α could improve the efficacy of TAE to treat HCC. Four treatment groups were assessed using a rat allograft model of HCC: RNAi of HIF-1α combined with TAE, RNAi of HIF-1α only, TAE only, and a control group. Rats were treated by TAE by retrograde placement of a microcatheter into the gastroduodenal artery. The results demonstrated that the RNAi of HIF-1α visibly reduced the expression of HIF-1α and vascular endothelial growth factor, suppressed tumor angiogenesis, and attenuated metastasis, which were all enhanced by TAE. The RNAi of HIF-1α synergized with TAE to significantly inhibit tumor growth. In conclusion, RNAi of HIF-1α augmented the therapeutic effects of TAE and diminished its undesirable effects.