Research progress of tumor gene therapy

Gene therapy is one of biological treatment methods that exogenous normal gene is transferred into target cells by gene transfer technology to correct or compensate for genetic defects or abnormality of diseases in order to achieve the treatment purpose.In this paper,research and development status of tumor gene therapy in recent years were reviewed from suicide gene,gene silencing,tumor suppress gene,immune gene and anti-angiogenesis gene.Suicide gene therapy system include:HSV-tkGCV system,H19 RNA,hTERT,etc.HSV-tkGCV system is one of the most studied suicide gene therapy system.TK gene is drug sensitivity gene and tumor cells will be kill by GCV or ACV after transfect with TK gene.RNA interference is a major mode of gene silencing therapy.The growth of tumor was inhibited obviously when silent tumor related genes (IDO2,DUSP6,IGF1R,ORAOV1,etc.).Activation or overexpression of tumor suppress genes can also suppress tumor growth,such as p53 and PTEN gene.Cytokines or costimulatory molecules were used to activate immune functions of body to kill tumor cells in immune gene therapy.Common immunologic effector cells were TIL,CTL,LAK,NK,etc.and target genes were TNFIL,CSF,IFN,CF,etc.Anti-angiogenesis gene by suppressing anti-angiogenesis in tumors for stopping tumor growth and metastasis.VEGF-Trap,PEDF,ES can significantly inhibit tumor growth by transfected with adenovirus.The problems such as specificity,safety and targeting still exist in current cancer gene therapy.