对肿瘤组织的靶向性可以提高基因治疗的效果 ,避免对正常组织的损伤 ,并且能降低作为载体的微生物对机体的危害。对于瘤内注射的给药方法 ,靶向性似乎显得不是特别重要 ,但是如果要系统给药 ,靶向性是很关键的一个问题。靶向基因治疗肿瘤可以通过靶向基因导入和靶向基因表达来实现。近年来 ,在靶向基因导入方面的研究有很多进展 ,例如 ,用双亲性的桥连分子协助腺病毒和逆转录病毒靶向转导 ;在各种病毒载体的衣壳蛋白中插入靶向性的小肽或较大的多肽靶向结构域 ;增殖病毒作为一种很有前途的抗肿瘤制剂可有效地靶向杀伤肿瘤细胞。受体介导的DNA或DNA 脂质体复合物的靶向系统和其他一些靶向性的有疗效的载体 ,如细菌 ,也处于研究中。其中的一些载体已经进入临床实验。为了实现基因的靶向可调控表达 ,组织或肿瘤特异性的启动子和人工合成的可调控表达系统被用来调控治疗基因的表达。反义核酸、核酶以及脱氧核酶 (DNAzyme)被用来靶向抑制与肿瘤发生密切相关基因的表达。 Targeting tumor tissue can increase the effectiveness of gene therapy, prevent damage to normal tissues, and reduce the risk of the organism as a carrier. Targeting does not seem to be particularly important for intratumoral injection, but targeting is a key issue if administered systemically. Targeting Gene Therapy Tumors can be achieved by targeted gene introduction and targeted gene expression. In recent years, there have been many advances in the study of targeted gene introduction. For example, amphipathic bridging molecules are used to assist adenovirus and retrovirus-targeted transduction. Targeting of capsid proteins in various viral vectors Of small peptide or larger polypeptide targeting domain; proliferating virus as a promising antitumor agent can effectively target killing tumor cells. Targeted systems for receptor-mediated DNA or DNA liposome complexes and other targeted and therapeutically useful vectors such as bacteria are also under study. Some of these vectors have entered clinical trials. In order to achieve targeted regulation of gene expression, tissue or tumor-specific promoters and synthetic, regulatable expression systems are used to regulate the expression of therapeutic genes. Antisense nucleic acids, ribozymes, and DNAzymes are used to target the inhibition of the expression of genes that are closely related to tumorigenesis.