Transarterial embolization combined with RNA interference targeting hypoxia-inducible factor-1α for hepatocellular carcinoma: a preliminary study of rat model

To study whether transarterial embolization (TAE) with RNA interference (RNAi) targeting hypoxia-inducible factor-1 alpha (HIF-1 alpha) can improve efficacy of TAE in treating hepatocellular carcinoma (HCC). CBRH-7919 rat hepatoma cell line was used and HCC models of rats were constructed. The siRNA transfection compound was made by mixing specific siRNA and Lipofectamine 2000 (TM). Delivery and transfection of siRNA were administered by injecting iodized oil emulsion (diluted lipiodol and siRNA) via hepatic artery. The expression levels of mRNA and protein were detected using the real-time reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry and western blotting assays, respectively. In vitro experiment, the specific HIF-1 alpha-siRNA was proved to inhibit expression levels of HIF-1 alpha and vascular endothelial growth factor (VEGF) effectively. In animal study, real-time RT-PCR assay showed the average relative mRNA expressions of HIF-1 alpha were 0.31 +/- 0.01, 0.65 +/- 0.03, 0.46 +/- 0.005, and 1.00 +/- 0.00 in TAE + siRNA, siRNA, TAE, and control groups, respectively. Western blotting assay showed the average relative protein expressions of HIF-1 alpha were 0.13 +/- 0.02, 0.87 +/- 0.02, 0.39 +/- 0.02, and 1.02 +/- 0.01 in TAE + siRNA, siRNA, TAE, and control groups, respectively. Compared with control, TAE, and siRNA groups, TAE + siRNA can significantly inhibit protein expressions of HIF-1 alpha and VEGF (P (HIF-1 alpha) < 0.001; P (VEGF) < 0.001). Overall survival of rats underwent TAE + siRNA was significantly longer than that of rats treated with TAE monotherapy (P = 0.001). This animal study showed TAE combined with HIF-1 alpha-RNAi could significantly improve efficacy of TAE in treating HCC by inhibiting expressions of HIF-1 alpha and VEGF after TAE treatment.