ABSTRACT
<p><b>OBJECTIVES</b>To construct a hepatoma directed gene delivery system which could transfer preS2 antisense RNA to liver cancer cells specifically, and to explore a new therapeutic strategy for hepatocellular carcinoma by blocking hepatitis B virus (HBV) with antisense RNA targeting hepatocellular carcinoma.</p><p><b>METHODS</b>GE7 and HA20 were synthesized and mixed with pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system named AFP-enhancing 4-element complex. Nude mice bearing hepatocelluar carcinoma cells HepG2.2.15 were injected with AFP-enhancing 4-element complex via a tail vein. Total RNA from tissues was extracted, and reversal transcription-ploymerase chain reaction (RT-PCR) was used to detect the expression of preS2. Different doses of AFP-enhancing 4-element complex was injected into nude mice at different time points, and tumor diameter was measured.</p><p><b>RESULTS</b>AFP-enhancing 4-element complex was constructed successfully. RT-PCR showed preS2 antisense RNA delivered by AFP-enhancing 4-element complex only expressed in liver tumor HepG2.2.15 cells of the mice. After the treatment of AFP-enhancing 4-element complex with dose of 0.2 micro g per mouse (once a week for 4 weeks), the mean tumor diameter of nude mice was significantly shorter than that of the control groups (0.995 +/- 0.35 cm vs 2.125 +/- 0.25 cm, P < 0.01).</p><p><b>CONCLUSIONS</b>An HBV antisense RNA gene delivery system targeting hepatocellular carcinoma, AFP-enhancing 4-element complex, was constructed successfully. PreS2 antisense RNA expressed specifically in hepatocelluar carcinoma cells significantly inhibits tumor growth of mice bearing hepatocarcinoma HepG2.2.15 and may have therapeutic potential in HBV related hepatocarcinoma.</p>