Advances in liver-directed gene therapy for hepatocellular carcinoma by non-viral delivery systems

Hepatocellular carcinoma (HCC) is a malignancy with a high mortality. Gene therapy provides a promising way for the treatment of HCC. Efficient gene delivery system, suitable gene target and appropriate way of administration together determine the effect of gene therapy for HCC. In recent years, employing non-viral gene delivery systems in gene therapy for HCC has attracted a lot of attention. Compared with viral vectors, non-viral gene delivery systems are nearly non-immunogenic, relatively safer, less expensive to produce and can carry a good many of genetic materials. But the transfection efficiency of these vectors still needs to be improved. And the liver targeting is another problem that needs to be solved. Attaching ligands to the non-viral vectors to enhance the targeting ability to the specific receptor and targeting to molecular targets of HCC are the effective strategies. Adopting suitable ways of administration is also a factor that plays an important role to achieve liver targeting. This review introduced the advances in liver-targeted gene therapy by non-viral vectors including the efforts to overcome the low transfection efficiency and enhance the liver targeting effect.