Abstract
Transcatheter arterial embolization (TAE) is a standard treatment for unresectable hepatic malignancies. It blocks the arterial blood supply to the tumor, but blockade of the blood supply can be short-lived as collateral blood vessels develop, leading to the failure of TAE. Here we report that intraportal delivery of adeno-associated viral (AAV) vectors expressing antisense hypoxia-inducible factor-1α (HIF-1α) (AAV-ASHIF) augments TAE to combat hepatocellular carcinoma (HCC). Intraportal delivery of AAV-ASHIF led to long-term localized expression of transgenic ASHIF in rat liver, and suppressed the growth of CBRH7919 HCC tumors established in rat liver by inhibiting the formation of neovessels and tumor cell proliferation. TAE therapy caused the necrosis and shrinkage of liver tumors; however, neovessels quickly formed and the residual tumors underwent rapid expansion. TAE enhanced tumor and liver hypoxia, which in turn upregulated expression of HIF-1α, vascular endothelial growth factor, glucose transporter-1, lactate dehydrogenase A, and proliferating cell nuclear antigen. Intraportal injection of AAV-ASHIF augmented the therapeutic effects of TAE and diminished its undesirable effects, resulting in extensive tumor cell death and suppression of the growth of liver tumors. In conclusion, this study has revealed that HIF-1 impedes the response of liver tumors to TAE. Antisense HIF-1α therapy is warranted as an approach for enhancing the efficacy of TAE to treat unresectable liver cancers.